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The relationship between community prevalence of Plasmodium falciparum and the burden of severe, life-threatening disease remains poorly defined. To examine the three most common severe malaria phenotypes from catchment populations across East Africa, we assembled a dataset of 6506 hospital admissions for malaria in children aged 3 months to 9 years from 2006 to 2020. Admissions were paired with data from community parasite infection surveys. A Bayesian procedure was used to calibrate uncertainties in exposure (parasite prevalence) and outcomes (severe malaria phenotypes). Each 25% increase in prevalence conferred a doubling of severe malaria admission rates. Severe malaria remains a burden predominantly among young children (3 to 59 months) across a wide range of community prevalence typical of East Africa. This study offers a quantitative framework for linking malaria parasite prevalence and severe disease outcomes in children.

Background Understanding the age patterns of disease is necessary to target interventions to maximise cost-effective impact. New malaria chemoprevention and vaccine initiatives target young children attending routine immunisation services. Here we explore the relationships between age and severity of malaria hospitalisation versus malaria transmission intensity. Methods Clinical data from 21 surveillance hospitals in East Africa were reviewed. Malaria admissions aged 1 month to 14 years from discrete administrative areas since 2006 were identified. Each site-time period was matched to a model estimated community-based age-corrected parasite prevalence to provide predictions of prevalence in childhood (PfPR2–10). Admission with all-cause malaria, severe malaria anaemia (SMA), respiratory distress (RD) and cerebral malaria (CM) were analysed as means and predicted probabilities from Bayesian generalised mixed models. Results 52,684 malaria admissions aged 1 month to 14 years were described at 21 hospitals from 49 site-time locations where PfPR2–10 varied from PfPR2–10 < 5%), five low-moderate transmission (PfPR2–10 5–9%), 20 moderate transmission (PfPR2–10 10–29%) and 12 high transmission (PfPR2–10 ≥ 30%). The majority of malaria admissions were below 5 years of age (69–85%) and rare among children aged 10–14 years (0.7–5.4%) across all transmission settings. The mean age of all-cause malaria hospitalisation was 49.5 months (95% CI 45.1, 55.4) under low transmission compared with 34.1 months (95% CI 30.4, 38.3) at high transmission, with similar trends for each severe malaria phenotype. CM presented among older children at a mean of 48.7 months compared with 39.0 months and 33.7 months for SMA and RD, respectively. In moderate and high transmission settings, 34% and 42% of the children were aged between 2 and 23 months and so within the age range targeted by chemoprevention or vaccines. Conclusions Targeting chemoprevention or vaccination programmes to areas where community-based parasite prevalence is ≥10% is likely to match the age ranges covered by interventions (e.g. intermittent presumptive treatment in infancy to children aged 2–23 months and current vaccine age eligibility and duration of efficacy) and the age ranges of highest disease burden.

Background Pneumonia is among the leading causes of avoidable deaths for young children globally. The main burden of mortality falls on children from poor and rural families who are less likely to obtain the treatment they need, highlighting inequities in access to effective care and treatment. Caretakers’ illness perceptions and care-seeking practices are of major importance for children with pneumonia to receive adequate care. This study qualitatively explores the caretaker concepts of childhood pneumonia in relation to treatment seeking behaviour and health worker management in Moshi urban district, Tanzania. Methods In May - July 2013 data was gathered through different qualitative data collection techniques including five focus group discussions (FGDs) with mothers of children under-five years of age. The FGDs involved free listing of pneumonia symptoms and video presentations of children with respiratory symptoms done, these were triangulated with ten case narratives with mothers of children admitted with pneumonia and eleven in-depth interviews with hospital health workers. Transcripts were coded and analysed using qualitative content analysis. Results Mothers demonstrated good awareness of common childhood illnesses including pneumonia, which was often associated with symptoms such as cough, flu, chest tightness, fever, and difficulty in breathing. Mothers had mixed views on causative factors and treatments options but generally preferred modern medicine for persisting and severe symptoms. However, all respondent reported access to health facilities as a barrier to care, associated with transport, personal safety and economic constraints. Conclusion Local illness concepts and traditional treatment options did not constitute barriers to care for pneumonia symptoms. Poor access to health facilities was the main barrier. Decentralisation of care through community health workers may improve access to care but needs to be combined with strengthened referral systems and accessible hospital care for those in need.

Background The availability of reliable point-of-care tests for malaria has heralded a paradigm shift in the management of febrile illnesses away from presumptive antimalarial therapy. In the absence of a definitive diagnosis, health care providers are more likely to prescribe empirical antimicrobials to those who test negative for malaria. To improve management and guide further test development, better understanding is needed of the true causative agents and their geographic variability. Methods A systematic review of published literature was undertaken to characterise the spectrum of pathogens causing non-malaria febrile illness in Africa (1980–2015). Literature searches were conducted in English and French languages in six databases: MEDLINE, EMBASE, Global Health (CABI), WHO Global Health Library, PASCAL, and Bulletin de la Société Française de Parasitologie (BDSP). Selection criteria included reporting on an infection or infections with a confirmed diagnosis, defined as pathogens detected in or cultured from samples from normally sterile sites, or serological evidence of current or past infection. A number of published articles (rather than incidence or prevalence) reporting a given pathogen were presented. Results A total of 16,523 records from 48 African countries were screened, of which 1065 (6.4%) met selection criteria. Bacterial infections were reported in 564 (53.0%) records, viral infections in 374 (35.1%), parasitic infections in 47 (4.4%), fungal infections in nine (0.8%), and 71 (6.7%) publications reported more than one pathogen group. Age range of the study population was not specified in 233 (21.9%) publications. Staphylococcus aureus (18.2%), non-typhoidal Salmonella (17.3%), and Escherichia coli (15.4%) were the commonly reported bacterial infections whereas Rift Valley fever virus (7.4%), yellow fever virus (7.0%), and Ebola virus (6.7%) were the most commonly reported viral infections. Dengue virus infection, previously not thought to be widespread in Africa, was reported in 54 (5.1%) of articles. Conclusions This review summarises the published reports of non-malaria pathogens that may cause febrile illness in Africa. As the threat of antimicrobial resistance looms, knowledge of the distribution of infectious agents causing fever should facilitate priority setting in the development of new diagnostic tools and improved antimicrobial stewardship. Trial registration PROSPERO, CRD42016049281

The roles that rapid, point-of-care tests will play in healthcare in low-income settings are likely to expand over the coming years. Yet, very little is known about how they are incorporated into practice, and what it means to use and rely upon them. This paper focuses on the rapid diagnostic test for malaria (mRDT), examining its introduction into low-level public health facilities in Tanzania within an intervention to improve the targeting of costly malaria medication. We interviewed 26 health workers to explore how a participatory training programme, mobile phone messages, posters and leaflets shaped the use and interpretation of the test. Drawing on notions of biopolitics, this paper examines how technologies of the self and mechanisms of surveillance bolstered the role mRDT in clinical decision-making. It shows how the significance of the test interacted with local knowledge, the availability of other medication, and local understandings of good clinical practice. Our findings suggest that in a context in which care is reduced to the provision of medicines, strict adherence to mRDT results may be underpinned by increasing the use of other pharmaceuticals or may leave health workers with patients for whom they are unable to provide care.

Summary Objective Cough or difficult breathing and an increased respiratory rate for their age are the commonest indications for outpatient antibiotic treatment in African children. We aimed to determine whether respiratory rate was likely to be transiently raised by a number of contextual factors in a busy clinic leading to inaccurate diagnosis. Methods Respiratory rates were recorded in children aged 2–59 months presenting with cough or difficulty breathing to one of the two busy outpatient clinics and then repeated at 10‐min intervals over 1 h in a quiet setting. Results One hundred and sixty‐seven children were enrolled with a mean age of 7.1 (SD ± 2.9) months in infants and 27.6 (SD ± 12.8) months in children aged 12–59 months. The mean respiratory rate declined from 42.3 and 33.6 breaths per minute (bpm) in the clinic to 39.1 and 32.6 bpm after 10 min in a quiet room and to 39.2 and 30.7 bpm (P

Significant selection pressure has been exerted on the genomes of human populations exposed to Plasmodium falciparum infection, resulting in the acquisition of mechanisms of resistance against severe malarial disease. Many host genetic factors, including sickle cell trait, have been associated with reduced risk of developing severe malaria, but do not account for all of the observed phenotypic variation. Identification of novel inherited risk factors relies upon high-resolution genome-wide association studies (GWAS). We present findings of a GWAS of severe malaria performed in a Tanzanian population (n = 914, 15.2 million SNPs). Beyond the expected association with the sickle cell HbS variant, we identify protective associations within two interleukin receptors (IL-23R and IL-12RBR2) and the kelch-like protein KLHL3 (all P0.3). Our approach demonstrates the potential of a joint genotyping-sequencing strategy to identify as-yet unknown susceptibility loci in an African population with well-characterised malaria phenotypes. The regions encompassing these loci are potential targets for the design of much needed interventions for preventing or treating malarial disease., Author summary Malaria, caused by Plasmodium falciparum parasites, is a major cause of mortality and morbidity in endemic countries of sub-Saharan Africa, including Tanzania. Some gene mutations in the human genome, including sickle cell trait, have been associated with reduced risk of developing severe malaria, and have increased in frequency through natural selection over generations. However, new genetic mutations remain to be discovered, and recent advances in human genome research technologies such as genome-wide association studies (GWAS) and fine-scale molecular genotyping tools, are facilitating their identification. Here, we present findings of a GWAS of severe malaria performed in a well characterised Tanzanian population (n = 914). We confirm the expected association with the sickle cell trait, but also identify new gene targets in immunological pathways, some under natural selection. Our approach demonstrates the potential of using GWAS to identify as-yet unknown susceptibility genes in endemic populations with well-characterised malaria phenotypes. The genetic mutations are likely to form potential targets for the design of much needed interventions for preventing or treating malarial disease.

Objectives\ud To examine the impact of use of rapid diagnostic tests for malaria on prescribing of antimicrobials, specifically antibiotics, for acute febrile illness in Africa and Asia. \ud Design\ud Analysisof nine preselected linked and codesigned observational and randomised studies (eight cluster or individually randomised trials and one observational study).\ud Setting\ud Public and private healthcare settings, 2007-13, in Afghanistan, Cameroon, Ghana, Nigeria, Tanzania, and Uganda.\ud Participants\ud 522 480 children and adults with acute febrile illness.\ud Interventions\ud Rapid diagnostic tests for malaria.\ud Main outcome measures\ud Proportions of patients for whom an antibiotic was prescribed in trial groups who had undergone rapid diagnostic testing compared with controls and in patients with negative test results compared with patients with positive results. A secondary aim compared classes of antibiotics prescribed in different settings.\ud Results\ud Antibiotics were prescribed to 127 052/238 797 (53%) patients in control groups and 167 714/283 683 (59%) patients in intervention groups. Antibiotics were prescribed to 40% (35 505/89 719) of patients with a positive test result for malaria and to 69% (39 400/57 080) of those with a negative result. All but one study showed a trend toward more antibiotic prescribing in groups who underwent rapid diagnostic tests. Random effects meta-analysis of the trials showed that the overall risk of antibiotic prescription was 21% higher (95% confidence interval 7% to 36%) in intervention settings. In most intervention settings, patients with negative test results received more antibiotic prescriptions than patients with positive results for all the most commonly used classes: penicillins, trimethoprim-sulfamethoxazole (one exception), tetracyclines, and metronidazole.Conclusions Introduction of rapid diagnostic tests for malaria to reduce unnecessary use of antimalarials-a beneficial public health outcome-could drive up untargeted use of antibiotics. That 69% of patients were prescribed antibiotics when test results were negative probably represents overprescription.This included antibiotics from several classes, including those like metronidazole that are seldom appropriate for febrile illness, across varied clinical, health system, and epidemiological settings. It is often assumed that better disease specific diagnostics will reduce antimicrobial overuse, but they might simply shift it from one antimicrobial class to another. Current global implementation of malaria testing might increase untargeted antibiotic use and must be examined. [Abstract copyright: Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.]

Many human genetic associations with resistance to malaria have been reported, but few have been reliably replicated. We collected data on 11,890 cases of severe malaria due to Plasmodium falciparum and 17,441 controls from 12 locations in Africa, Asia and Oceania. We tested 55 SNPs in 27 loci previously reported to associate with severe malaria. There was evidence of association at P < 1 × 10(-4) with the HBB, ABO, ATP2B4, G6PD and CD40LG loci, but previously reported associations at 22 other loci did not replicate in the multicenter analysis. The large sample size made it possible to identify authentic genetic effects that are heterogeneous across populations or phenotypes, with a striking example being the main African form of G6PD deficiency, which reduced the risk of cerebral malaria but increased the risk of severe malarial anemia. The finding that G6PD deficiency has opposing effects on different fatal complications of P. falciparum infection indicates that the evolutionary origins of this common human genetic disorder are more complex than previously supposed.

Objective To assess the role of point‐of‐care (PoC) assessment of C‐reactive protein (CRP) and white blood cell (WBC) count to identify bacterial illness in Tanzanian children with non‐severe non‐malarial fever. Methods From the outpatient department of a district hospital in Tanzania, 428 patients between 3 months and 5 years of age who presented with fever and a negative malaria test were enrolled. All had a physical examination and bacterial cultures from blood and urine. Haemoglobin, CRP and WBC were measured by PoC devices. Results Positive blood cultures were detected in 6/428 (1.4%) children and urine cultures were positive in 24/401 (6.0%). Mean WBC was similar in children with or without bacterial illness (14.0 × 109, 95% CI 12.0–16.0 × 109 vs. 12.0 × 109, 95% CI 11.4–12.7 × 109), while mean CRP was higher in children with bacterial illness (41.0 mg/l, 95% CI 28.3–53.6 vs. 23.8 mg/l, 95% CI 17.8–27.8). In ROC analysis, the optimum cut‐off value for CRP to identify bacterial illness was 19 mg/l but with an area under the curve of only 0.62. Negative predictive values exceeded 80%, while positive predictive values were under 40%. Conclusion WBC and CRP levels had limited value in identifying children with bacterial infections. The positive predictive values for both tests were too low to be used as single tools for treatment decisions.

Background. The epidemiology of Salmonella Typhi and invasive nontyphoidal Salmonella (NTS) differs, and prevalence of these pathogens among children in sub-Saharan Africa may vary in relation to malaria transmission intensity. Methods. We compared the prevalence of bacteremia among febrile pediatric inpatients aged 2 months to 13 years recruited at sites of high and low malaria endemicity in Tanzania. Enrollment at Teule Hospital, the high malaria transmission site, was from June 2006 through May 2007, and at Kilimanjaro Christian Medical Centre (KCMC), the low malaria transmission site, from September 2007 through August 2008. Automated blood culture, malaria microscopy with Giemsa-stained blood films, and human immunodeficiency virus testing were performed. Results. At Teule, 3639 children were enrolled compared to 467 at KCMC. Smear-positive malaria was detected in 2195 of 3639 (60.3%) children at Teule and 11 of 460 (2.4%) at KCMC (P < .001). Bacteremia was present in 336 of 3639 (9.2%) children at Teule and 20 of 463 (4.3%) at KCMC (P < .001). NTS was isolated in 162 of 3639 (4.5%) children at Teule and 1 of 463 (0.2%) at KCMC (P < .001). Salmonella Typhi was isolated from 11 (0.3%) children at Teule and 6 (1.3%) at KCMC (P = .008). With NTS excluded, the prevalence of bacteremia at Teule was 5.0% and at KCMC 4.1% (P = .391). Conclusions. Where malaria transmission was intense, invasive NTS was common and Salmonella Typhi was uncommon, whereas the inverse was observed at a low malaria transmission site. The relationship between these pathogens, the environment, and the host is a compelling area for further research.

Parenteral artesunate (ARS) is the drug of choice for the treatment of severe malaria. Pharmacokinetics data on intramuscular ARS are limited with respect to the main treatment group that carries the highest mortality, namely, critically ill children with severe malaria. A population pharmacokinetic study of ARS and dihydroartemisinin (DHA) was conducted from sparse sampling in 70 Tanzanian children of ages 6 months to 11 years. All the children had been admitted with severe falciparum malaria and were treated with intramuscular ARS (2.4 mg/kg at 0, 12, and 24 h). Venous plasma concentration-time profiles were characterized using nonlinear mixed-effects modeling (NONMEM). A one-compartment disposition model accurately described first-dose population pharmacokinetics of ARS and DHA. Body weight significantly affected clearance and apparent volume of distribution (P < 0.001), resulting in lower ARS and DHA exposure levels in smaller children. An adapted dosing regimen including a practical dosing table per weight band is proposed for young children based on the pharmacokinetic model. © 2013 American Society for Clinical Pharmacology and Therapeutics.

Objective Measurement of respiratory rate is an important clinical sign in the diagnosis of pneumonia but suffers from interobserver variation. Here, we assess the use of video recordings as a quality assurance tool that could be useful both in research and in training of staff. Methods Respiratory rates (RR) were recorded in children aged 2–59 months presenting with cough or difficulty breathing at two busy outpatient clinics in Tanzania. Measurements were repeated at 10‐min intervals in a quiet environment with simultaneous video recordings that were independently reviewed by two paediatricians. Results Eight hundred and fifty‐nine videos were sent to two paediatricians; 148 (17.2%) were considered unreadable by one or both. For the 711 (82.8%) videos that were readable by both paediatricians, there was perfect agreement for the presence of raised RR with a kappa value (κ) of 0.85 (P < 0.001); and in 476 (66.9%) cases, both paediatricians agreed on the RR within 2 breaths per minute (±2 bpm). A reported illness of 5 days or more was associated with unreadable video recordings (OR = 3.44, CI: 1.5–6.08; P < 0.001). The multilevel model showed that differences between observers accounted for only 13% of the variability in RR. Conclusion Video recordings are reliable tools for quality assurance of RR measurements in children with suspected pneumonia. Videos with a clear view of respiratory movements may also be useful in training primary healthcare staff.

INTRODUCTION Malaria parasites cause human disease by invading and replicating inside red blood cells. In the case of Plasmodium falciparum , this can lead to severe forms of malaria that are a major cause of childhood mortality in Africa. This species of parasite enters the red blood cell through interactions with surface proteins including the glycophorins GYPA and GYPB, which determine the polymorphic MNS blood group system. In a recent genome-wide association study, we identified alleles associated with protection against severe malaria near the cluster of genes encoding these invasion receptors. RATIONALE Investigation of genetic variants at this locus and their relation to severe malaria is challenging because of the high sequence similarity between the neighboring glycophorin genes and the relative lack of available sequence data capturing the genetic diversity of sub-Saharan Africa. To better assess whether variation in the glycophorin genes could explain the signal of association, we generated additional sequence data from sub-Saharan African populations and developed an analytical approach to characterize structural variation at this complex locus. RESULTS Using 765 newly sequenced human genomes from 10 African ethnic groups along with data from the 1000 Genomes Project, we generated a reference panel of haplotypes across the glycophorin region. In addition to single-nucleotide polymorphisms and short indels, we assayed large copy number variants (CNVs) using sequencing read depth and uncovered extensive structural diversity. By imputing from this reference panel into 4579 severe malaria cases and 5310 controls from three African populations, we found that a complex CNV, here called DUP4, is associated with resistance to severe malaria and fully explains the previously reported signal of association. In our sample, DUP4 is present only in east Africa, and this localization, as well as the extent of similarity between DUP4 haplotypes, suggests that it has recently increased in frequency, presumably under natural selection due to malaria. To evaluate the potential functional consequences of this structural variant, we analyzed high-coverage sequence-read data from multiple individuals to generate a model of the DUP4 chromosome structure. The DUP4 haplotype contains five glycophorin genes, including two hybrid genes that juxtapose the extracellular domain of GYPB with the transmembrane and intracellular domains of GYPA. Noting that these predicted hybrids are characteristic of the Dantu antigen in the MNS blood group system, we sequenced a Dantu positive individual and confirmed that DUP4 is the molecular basis of the Dantu NE blood group variant. CONCLUSION Although a role for GYPA and GYPB in parasite invasion is well known, a direct link between glycophorin polymorphisms and clinical susceptibility to malaria has been elusive. Here we have provided a systematic catalog of CNVs, describing structural diversity that may have functional importance at this locus. Our results identify a specific variant that encodes hybrid glycophorin proteins and is associated with protection against severe malaria. This discovery calls for further work to determine how this particular molecular rearrangement affects parasite invasion and the red blood cell response and may lead us toward new parasite vulnerabilities that can be utilized in future interventions against this deadly disease.

This comparative study in 1898 children in 2 different African population shows that a pfHRP2-based rapid diagnostic test is a reliable diagnostic for diagnosing severe falciparum malaria in these settings and performs better than routine microscopy or a pLDH based test., Background. Rapid diagnostic tests (RDTs) now play an important role in the diagnosis of falciparum malaria in many countries where the disease is endemic. Although these tests have been extensively evaluated in uncomplicated falciparum malaria, reliable data on their performance for diagnosing potentially lethal severe malaria is lacking. Methods. We compared a Plasmodium falciparum histidine-rich-protein2 (PfHRP2)–based RDT and a Plasmodium lactate dehydrogenase (pLDH)–based RDT with routine microscopy of a peripheral blood slide and expert microscopy as a reference standard for the diagnosis of severe malaria in 1898 children who presented with severe febrile illness at 2 centers in Mozambique and Tanzania. Results. The overall sensitivity, specificity, positive predictive value, and negative predictive values of the PfHRP2-based test were 94.0%, 70.9%, 85.4%, and 86.8%, respectively, and for the pLDH-based test, the values were 88.0%, 88.3%, 93.2%, and 80.3%, respectively. At parasite counts

Background to the debate: Current guidelines recommend that all fever episodes in African children be treated presumptively with antimalarial drugs. But declining malarial transmission in parts of sub-Saharan Africa, declining proportions of fevers due to malaria, and the availability of rapid diagnostic tests mean it may be time for this policy to change. This debate examines whether enough evidence exists to support abandoning presumptive treatment and whether African health systems have the capacity to support a shift toward laboratory-confirmed rather than presumptive diagnosis and treatment of malaria in children under five., Blaise Genton and colleagues argue that we should abandon presumptive antimalarial treatment in children with fever in sub-Saharan Africa, while in a related paper Mike English and colleagues disagree that we have sufficient evidence and health system capacity to do so.

The WHO recommendation for parasitological diagnosis of malaria wherever possible is challenged by evidence of poor-quality microscopy in African hospitals but the reasons are not clear.All 12 of the busier district hospital laboratories from three regions of Tanzania were assessed for quality of the working environment and slide readers read 10 reference slides under exam conditions. Slides that had been routinely read were removed for expert reading.Of 44 slide readers in the study, 39 (88.6%) correctly read90% of the reference slides. Of 206 slides that had been routinely read, 33 (16%) were judged to be unreadable, 104 (51%) were readable with difficulty, and 69 (34%) were easily readable. Compared to expert reading of the same slide, the sensitivity of routine slide results of easily readable slides was 85.7% (95% confidence interval: 77.4-94.0), falling to 44.4% (95% confidence interval: 34.5-54.4) for slides that were 'readable with difficulty'.The commonest cause of inaccurate results was the quality of the slide itself, correction of which is likely to be achievable within existing resources. A minority of slide readers were unable to read slides even under ideal conditions, suggesting the need for a 'slide reading licence' scheme.

Four predictors were independently associated with an increased risk of death: acidosis, cerebral manifestations of malaria, elevated blood urea nitrogen, or signs of chronic illness. The standard base deficit was found to be the single most relevant predictor of death., Background. Data from the largest randomized, controlled trial for the treatment of children hospitalized with severe malaria were used to identify such predictors of a poor outcome from severe malaria. Methods. African children (

(See the editorial commentary by Levine and Farag, on pages 349-351.) Background. Few studies describe patterns of human immunodeficiency virus (HIV) co-infections in African hospitals in the antiretroviral therapy (ART) era. Methods. We enrolled consecutive admitted patients aged ≥13 years with oral temperature of ≥38.0°C during 1 year in Moshi, Tanzania. A standardized clinical history and physical examination was done and hospital outcome recorded. HIV antibody testing, aerobic and mycobacterial blood cultures, and malaria film were performed. HIV-infected patients also received serum cryptococcal antigen testing and CD4+ T lymphocyte count (CD4 cell count). Results. Of 403 patients enrolled, the median age was 38 years (range, 14–96 years), 217 (53.8%) were female, and 157 (39.0%) were HIV-infected. Of HIV-infected patients, the median CD4 cell count was 98 cells/μL (range, 1–1,105 cells/ μL), 20 (12.7%) were receiving ART, and 29 (18.5%) were receiving trimethoprim-sulfamethoxazole prophylaxis. There were 112 (27.7%) patients who had evidence of invasive disease, including 26 (23.2%) with Salmonella serotype Typhi infection, 24 (21.4%) with Streptococcus pneumoniae infection, 17 (15.2%) with Cryptococcus neoformans infection, 12 (10.7%) with Mycobacterium tuberculosis complex infection, 8 (7.1%) with Plasmodium falciparum infection, and 7 (6.3%) with Escherichia coli infection. HIV infection was associated with M. tuberculosis and C. neoformans bloodstream infection but not with E. coli, S. pneumoniae, or P. falciparum infection. HIV infection appeared to be protective against Salmonella. Typhi bloodstream infection (odds ratio, .12; P = .001). Conclusions. While Salmonella Typhi and S. pneumoniae were the most common causes of invasive infection overall, M. tuberculosis and C. neoformans were the leading causes of bloodstream infection among HIV-infected inpatients in Tanzania in the ART era. We demonstrate a protective effect of HIV against Salmonella. Typhi bloodstream infection in this setting. HIV co-infections continue to account for a large proportion of febrile admissions in Tanzania.

Participation rates in epidemiologic studies in African communities are historically high. We recently performed a pilot prevalence study for neurologic morbidity in Mungushi, Tanzania, where the participation rate was 645/657 subjects (98.2%).1 We questioned whether this high rate was due to a sincere motivation to participate or a fear of refusal of participation. As Western investigators are increasingly performing neuroepidemiologic work in Africa, it is imperative to distinguish between the 2 explanations. Investigators need to tailor the consent process to the local community's needs, and be sensitive to the motivation of the participants whose culture may differ from their own.

We report a genome-wide association (GWA) study of severe malaria in The Gambia. The initial GWA scan included 2,500 children genotyped on the Affymetrix 500K GeneChip, and a replication study included 3,400 children. We used this to examine the performance of GWA methods in Africa. We found considerable population stratification, and also that signals of association at known malaria resistance loci were greatly attenuated owing to weak linkage disequilibrium (LD). To investigate possible solutions to the problem of low LD, we focused on the HbS locus, sequencing this region of the genome in 62 Gambian individuals and then using these data to conduct multipoint imputation in the GWA samples. This increased the signal of association, from P = 4 × 10(-7) to P = 4 × 10(-14), with the peak of the signal located precisely at the HbS causal variant. Our findings provide proof of principle that fine-resolution multipoint imputation, based on population-specific sequencing data, can substantially boost authentic GWA signals and enable fine mapping of causal variants in African populations.

Respiratory infections cause significant mortality in developing countries but are frequently undiagnosed. Reasons for this are unclear. We observed 1,081 outpatient consultations with patients less than five years of age in Tanzania. In 554 patients with cough or difficulty breathing, the absolute percentages examined were 5% for respiratory rate counted, 14% chest exposed, and 25% stethoscope used. Decisions to conduct particular examinations did appear to follow clinical logic, with odds ratios of 4.28 for counting respiratory rate (95% confidence interval [CI] = 1.75-10.47), 2.57 for exposing the chest (95% CI = 1.67-3.95), and 18.91 for using a stethoscope (95% CI = 9.52-37.57) in patients with cough or difficulty breathing. Non-clinical variables, including salary level, were also associated with examinations, and history taking was more common among clinicians originating outside the hospital area. Although respiratory examinations are relatively more common in those with cough or difficulty breathing, the absolute rates are low and related to non-clinical and clinical factors. Copyright © 2008 by The American Society of Tropical Medicine and Hygiene.

BACKGROUND AND OBJECTIVE Children are often admitted to district hospitals in Africa without an adequate record of clinical examination, a problem that could be reduced by greater involvement of nurses in their assessment. We aimed to ascertain whether hospital nurses in a district hospital could conduct paediatric examinations as reliably as clinical staff, when provided with a short structured training session. METHODS Hospital nurses (HN), hospital clinical officers (HCO) and research clinical officers (RCO) repeated examinations on children admitted to the paediatric ward shortly after the first examination by an RCO. Kappa scores were used to compare the agreement on the presence or absence of basic clinical signs by different categories of staff. RESULTS Among 439 paired examinations the agreement between RCOs on clinical signs was slightly higher than for HCOs or HNs; the mean (median) Kappa scores for all signs examined were 0.54 (0.57) for RCO-RCO, 0.49 (0.49) for RCO-HCO and 0.50 (0.49) for RCO-HN. Levels of agreement were lower if children were under the age of 18 months or if they cried during the examination. CONCLUSIONS Nurses with basic training appear to perform as well as clinically trained staff in eliciting essential signs in acutely ill children. Their role in the initial and ongoing assessment of these children should be reviewed in light of the critical shortages in clinically trained staff in African hospitals.

OBJECTIVE In Africa antimalarials are often prescribed when malaria is unlikely, a problem that is becoming critical as more expensive antimalarials replace established drugs. However, little is known about what drives the overuse of antimalarials. We conducted this study to explore to what extent current prescribing behaviour in hospitals is driven by patient demand. METHODS Consultations were observed followed by exit interviews with patients or caretakers. Five district hospitals where microscopy was routinely available were selected in areas of low (n = 3) and high (n = 2) malaria transmission in north-eastern Tanzania. All outpatient consultations during the study period were observed (n = 669). Those sent for a malaria blood slide or treated with antimalarials presumptively were interviewed (n = 326). At the end of the study, clinicians were interviewed for their opinions on the use of antimalarials. Findings Patients were not observed to demand antimalarials from clinicians, but occasionally asked for a malaria slide. Patient satisfaction on exit was similar between those prescribed antimalarials and those not prescribed antimalarials, but more patients or carers expressed satisfaction when the patient had been tested than when not. Clinicians rarely reported perceiving patient demand for antimalarials and asserted that such demand for medication would not affect their prescribing behaviour. CONCLUSIONS Patient demand was not found to be driving the over-prescription of antimalarials found in the hospitals in our setting. To the contrary, the involvement of patients may provide an opportunity to improve prescribing practice if their expectations for testing and treatment in line with test results can be effectively communicated to clinicians.

Background Hypertension is a major contributor to ill health in sub-Saharan Africa. Developing countries need to increase access for screening. This study assesses the feasibility and acceptability of using private sector drug retail outlets to screen for hypertension in Mwanza region, Tanzania. Methods A pilot study took place in eight drug retail outlets from August 2013 to February 2014. Customers ≥18 years were invited for screening. Socio-demographic characteristics, hypertension knowledge, hypertension screening and treatment history were collected. Subjects with systolic blood pressure over 140 mmHg were referred for follow up. Referral slips captured attendance. Mystery client visits and follow up phone calls were conducted to assess service quality. Results A total of 971 customers were screened, one person refused; 109 (11.2%) had blood pressure over 140/90 mmHg and were referred for ongoing assessment; 85/109 (78.0%) were newly diagnosed. Customers reported that the service was acceptable. Service providers were able to follow the protocol. Only 18/85 (21%) newly diagnosed participants visited the referral clinic within two weeks. Conclusions Blood pressure screening was feasible and acceptable to customers of private drug retail outlets. However many who were referred failed to attend at a referral centre and further research is needed in this area.

Salmonella enterica serovar Typhi expresses a capsule of Vi polysaccharide, while most Salmonella serovars, including S. Enteritidis and S. Typhimurium, do not. Both S. Typhi and S. Enteritidis express the lipopolysaccharide O:9 antigen, yet there is little evidence of cross-protection from anti-O:9 antibodies. Vaccines based on Vi polysaccharide have efficacy against typhoid fever, indicating that antibodies against Vi confer protection. Here we investigate the role of Vi capsule and antibodies against Vi and O:9 in antibody-dependent complement- and phagocyte-mediated killing of Salmonella. Using isogenic Vi-expressing and non-Vi-expressing derivatives of S. Typhi and S. Typhimurium, we show that S. Typhi is inherently more sensitive to serum and blood than S. Typhimurium. Vi expression confers increased resistance to both complement- and phagocyte-mediated modalities of antibody-dependent killing in human blood. The Vi capsule is associated with reduced C3 and C5b-9 deposition, and decreased overall antibody binding to S. Typhi. However, purified human anti-Vi antibodies in the presence of complement are able to kill Vi-expressing Salmonella, while killing by anti-O:9 antibodies is inversely related to Vi expression. Human serum depleted of antibodies to antigens other than Vi retains the ability to kill Vi-expressing bacteria. Our findings support a protective role for Vi capsule in preventing complement and phagocyte killing of Salmonella that can be overcome by specific anti-Vi antibodies, but only to a limited extent by anti-O:9 antibodies.

Populations exposed to Plasmodium falciparum infection develop genetic mechanisms of protection against severe malarial disease. Despite decades of genetic epidemiological research, the sickle cell trait (HbAS) sickle cell polymorphism, ABO blood group, and other hemoglobinopathies remain the few major determinants in severe malaria to be replicated across different African populations and study designs. Within a case-control study in a region of high transmission in Tanzania (n = 983), we investigated the role of 40 new loci identified in recent genome-wide studies. In 32 loci passing quality control procedures, we found polymorphisms in USP38, FREM3, SDC1, DDC, and LOC727982 genes to be putatively associated with differential susceptibility to severe malaria. Established candidates explained 7.4% of variation in severe malaria risk (HbAS polymorphism, 6.3%; alpha-thalassemia, 0.3%; ABO group, 0.3%; and glucose-6-phosphate dehydrogenase deficiency, 0.5%) and the new polymorphisms, another 4.3%. The regions encompassing the loci identified are promising targets for the design of future treatment and control interventions.

Severe anaemia in children is a leading cause of hospital admission and a major cause of mortality in sub-Saharan Africa, yet there are limited published data on blood transfusion in this vulnerable group. We present data from a large controlled trial of fluid resuscitation (Fluid Expansion As Supportive Therapy (FEAST) trial) on the prevalence, clinical features, and transfusion management of anaemia in children presenting to hospitals in three East African countries with serious febrile illness (predominantly malaria and/or sepsis) and impaired peripheral perfusion. Of 3,170 children in the FEAST trial, 3,082 (97%) had baseline haemoglobin (Hb) measurement, 2,346/3,082 (76%) were anaemic (Hb

X-linked Glucose-6-phosphate dehydrogenase (G6PD) A- deficiency is prevalent in sub-Saharan Africa populations, and has been associated with protection from severe malaria. Whether females and/or males are protected by G6PD deficiency is uncertain, due in part to G6PD and malaria phenotypic complexity and misclassification. Almost all large association studies have genotyped a limited number of G6PD SNPs (e.g. G6PD202 / G6PD376), and this approach has been too blunt to capture the complete epidemiological picture. Here we have identified 68 G6PD polymorphisms and analysed 29 of these (i.e. those with a minor allele frequency greater than 1%) in 983 severe malaria cases and controls in Tanzania. We establish, across a number of SNPs including G6PD376, that only female heterozygotes are protected from severe malaria. Haplotype analysis reveals the G6PD locus to be under balancing selection, suggesting a mechanism of protection relying on alleles at modest frequency and avoiding fixation, where protection provided by G6PD deficiency against severe malaria is offset by increased risk of life-threatening complications. Our study also demonstrates that the much-needed large-scale studies of severe malaria and G6PD enzymatic function across African populations require the identification and analysis of the full repertoire of G6PD genetic markers., Author Summary Glucose-6-phosphate dehydrogenase (G6PD) is an essential enzyme that protects red blood cells from oxidative damage. Numerous genetic variants of G6PD, residing in the X chromosome, are found among African populations: mutations causing A- deficiency can lead to serious clinical outcomes (including hemolytic anemia) but also confer protection against severe malaria. Epidemiological studies have used some of the genetic markers that cause A- deficiency to establish who is protected from severe malaria, with differing results. Whether females, with one or two copies of mutant genes, males with one copy, or both genders are protected is uncertain. This uncertainty is due to G6PD and malaria phenotypic complexity and misclassification, and to genetic differences between populations and the limited numbers of genetic markers (usually 2) considered. In this study we analysed more than 30 G6PD genetic markers in 506 Tanzanian children with severe malaria and 477 without malaria. We found that only females with one normal and one mutant copy of the gene (heterozygotes) were protected from severe malaria. Further, we established that the G6PD gene is under evolutionary pressure with the likely mechanism being selection by malaria. Our work demonstrates that studies of severe malaria and G6PD enzymatic function across African populations require, in addition to complete and accurate G6PD phenotypic classification, the identification and analysis of the full repertoire of G6PD genetic markers.

Previous analyses have suggested that immunity to non-cerebral severe malaria due to Plasmodium falciparum is acquired after only a few infections, whereas longitudinal studies show that some children experience multiple episodes of severe disease, suggesting that immunity may not be acquired so quickly. We fitted a mathematical model for the acquisition and loss of immunity to severe disease to the age distribution of severe malaria cases stratified by symptoms from a range of transmission settings in Tanzania, combined with data from several African countries on the age distribution and overall incidence of severe malaria. We found that immunity to severe disease was acquired more gradually with exposure than previously thought. The model also suggests that physiological changes, rather than exposure, may alter the symptoms of disease with increasing age, suggesting that a later age at infection would be associated with a higher proportion of cases presenting with cerebral malaria regardless of exposure. This has consequences for the expected pattern of severe disease as transmission changes. Careful monitoring of the decline in immunity associated with reduced transmission will therefore be needed to ensure rebound epidemics of severe and fatal malaria are avoided.

Malaria clinical trials need precise endpoints to measure efficacy. In endemic areas where asymptomatic parasitaemia is common, 'fever plus parasitaemia' may not differentiate between malaria cases and non-cases. Case definitions based on parasite cut-off densities may be more appropriate but may vary with age and transmission intensity. This study examines appropriate case definitions from parasitological surveys conducted over a broad range of transmission intensities, using altitude as a proxy for transmission intensity.Cross-sectional data collected from 24 villages at different altitudes in an endemic area of northeastern Tanzania were used to calculate malaria-attributable fractions using a modified Poisson regression method. We modelled fever as a function of parasite density and determined the optimum cut-off densities of parasites to cause fever using sensitivity and specificity analyses.The optimum cut-off density varied by altitude in children aged under 5 years: a case definition of 4,000 parasites per mul at altitudes600 m (high transmission intensity) was most appropriate, compared with 1,000 parasites per mul at altitudes600 m (low transmission intensity). In children aged over 5 years and adults, there was little variation by altitude and a case definition of any parasites plus fever was the most appropriate.Locally appropriate case definitions of malaria should be used for research purposes. In our setting, these varied independently with age and transmission intensity.

The isotype/subclass of immunoglobulin determines antibody function, but rather little is known about factors that direct class switching in vivo. To evaluate factors that might influence the maturation of the antibody response during infection, we conducted a seroepidemiological study of the immunoglobulin G (IgG) subclass response to four merozoite-associated antigens ofPlasmodium falciparumin a mountainous region of northeastern Tanzania, where malaria endemicity declines with increasing altitudes. We found that IgG1/IgG3 class switching is independently affected by the nature of the antigen, cumulative exposure to the antigen, and the maturity of the immune system (i.e., the age of the individual). These observations provide insights into the effects of immune system maturity, the duration and intensity of antigen exposure, and inherent characteristics of individual antigens on the process of class switching in human B cells. Our data also throw light on the consequences of class switch decisions on the gradual acquisition of antimalarial immunity.

In developed countries much progress has been made in reducing vertical transmission of HIV using antiretroviral therapies. To achieve similar gains in Africa the acceptability of routine HIV testing of pregnant women is becoming increasingly important. Evidence of reluctance of pregnant women to undergo HIV testing has led to suggestions to offer antiretroviral therapy to pregnant women without prior HIV testing. In this study we set out to identify risk factors for preferring to avoid HIV testing among women attending an antenatal clinic in northern Tanzania in the context of a hypothetical offer of Nevirapine and to explore the issues raised in more detail in focus group discussions. Two hundred and fifty women attending an antenatal clinic in late pregnancy were interviewed. Almost half of the women preferred to be offered Nevirapine without HIV testing. In a multiple logistic model having a partner with a history of a sexually transmitted disease (OR 2.72, 95% CI 1.14-6.47, p = 0.02) and having a partner who had another sexual partner in the last year (OR 1.89, 95% CI 1.04-3.45, p = 0.04) were positively associated with a preference to avoid HIV testing; while the presence of a partner living at home or feeling able to ask their partner to go for an HIV test were negatively associated with a preference to avoid HIV testing (OR 0.46, 95% CI 0.24-0.89, p = 0.02 and OR 0.56, 95% CI 0.3-1.05, p = 0.07 respectively). FGDs (focus group discussions) suggested that the major concern of women was for the reaction of their male partners to the possibility of a positive HIV test and low confidence in the confidentiality of HIV testing. This fear may lead to low uptake of antiretroviral programmes and treatment without prior testing should be considered.

The implementation and evaluation of malaria control programs would be greatly facilitated by new tools for the rapid assessment of malaria transmission intensity. Because acquisition and maintenance of antimalarial antibodies depend on exposure to malaria infection, such antibodies might be used as proxy measures of transmission intensity. We have compared the prevalence of IgG antibodies with threePlasmodium falciparumasexual stage antigens in individuals of all ages living at varying altitudes encompassing a range of transmission intensities from hyper- to hypoendemic in northeastern Tanzania, with alternative measures of transmission intensity. The prevalence of antibodies to merozoite surface protein-119was significantly more closely correlated with altitude than either point-prevalence malaria parasitemia or single measures of hemoglobin concentration. Analysis of age-specific seroprevalence rates enabled differentiation of recent (seasonal) changes in transmission intensity from longer-term transmission trends and, using a mathematical model of the annual rate of seroconversion, estimation of the longevity of the antibody response. Thus, serological tools allow us to detect variations in malaria transmission over time. Such tools will be invaluable for monitoring trends in malaria endemicity and the effectiveness of malaria control programs.

Hospital-acquired infections (HAI) are a major and largely preventable cause of morbidity and morbidity worldwide. Very few reports on the prevalence of HAI in sub-Saharan Africa have been published and most of those that have appeared in the press have focused on surgical-wound infection. In the present, questionnaire-based, point-prevalence study, in which the doctor on the ward round was used as the primary informant, the prevalences of all HAI among all the inpatients at a tertiary referral hospital in northern Tanzania were estimated. On the day of the study, there were 412 inpatients (in 15 ward areas) and 61 cases of HAI were identified, giving an overall HAI prevalence of 14.8%. The prevalences of HAI were particularly high in the medical intensive-care unit (40%), the surgical (orthopaedic and general surgery) wards (36.7%), and one of the general medical wards (22.2%). Factors associated with a patient having a HAI were hospitalization for >30 days [odds ratio (OR) = 4.07; 95% confidence interval (CI) = 2.07-7.99]; being a patient on the orthopaedic and general surgical ward known as 'Surgical 2' (OR = 2.14; CI = 1.02-4.46); and being referred from another health facility (OR = 1.90; CI = 1.02-3.42). The most commonly identified HAI in the hospital were urinary-tract infections (14 cases), followed by surgical-wound infections (10 cases) and then lower respiratory-tract infections (six cases). Twenty HAI were 'unspecified'. The study was rapid and cheap to carry out. The results not only gave a baseline estimate of HAI in the study setting but also identified key areas for interventions to reduce HAI.

Background: There is increasing recognition among trialists of the challenges in understanding how particular 'real-life' contexts influence the delivery and receipt of complex health interventions. Evaluations of interventions to change health worker and/or patient behaviours in health service settings exemplify these challenges. When interpreting evaluation data, deviation from intended intervention implementation is accounted for through process evaluations of fidelity, reach, and intensity. However, no such systematic approach has been proposed to account for the way evaluation activities may deviate in practice from assumptions made when data are interpreted.Methods: A collective case study was conducted to explore experiences of undertaking evaluation activities in the real-life contexts of nine complex intervention trials seeking to improve appropriate diagnosis and treatment of malaria in varied health service settings. Multiple sources of data were used, including in-depth interviews with investigators, participant-observation of studies, and rounds of discussion and reflection.Results and discussion: From our experiences of the realities of conducting these evaluations, we identified six key 'lessons learned' about ways to become aware of and manage aspects of the fabric of trials involving the interface of researchers, fieldworkers, participants and data collection tools that may affect the intended production of data and interpretation of findings. These lessons included: foster a shared understanding across the study team of how individual practices contribute to the study goals; promote and facilitate within-team communications for ongoing reflection on the progress of the evaluation; establish processes for ongoing collaboration and dialogue between sub-study teams; the importance of a field research coordinator bridging everyday project management with scientific oversight; collect and review reflective field notes on the progress of the evaluation to aid interpretation of outcomes; and these approaches should help the identification of and reflection on possible overlaps between the evaluation and intervention.Conclusion: The lessons we have drawn point to the principle of reflexivity that, we argue, needs to become part of standard practice in the conduct of evaluations of complex interventions to promote more meaningful interpretations of the effects of an intervention and to better inform future implementation and decision-making. © 2014 Reynolds et al.; licensee BioMed Central Ltd.

Background In 2006, the first-line anti-malarial drug treatment in Tanzania was changed from sulphadoxine-pyrimethamine (SP) to artemether-lumefantrine (ALu), an artemisinin-based combination (ACT), since when the use of SP has been restricted for intermittent preventive treatment in pregnancy (IPTp). A number of Plasmodium falciparum mutations are known to be associated with resistance to SP, but it is not known if the prevalence of these mutations is increasing or decreasing under the conditions of reduced levels of SP use. This study reports on the current SP resistant quintuple Pfdhfr-Pfdhps mutations in six regions of Tanzania. Methods Finger-prick blood on filter paper and rapid diagnostic test strips from P. falciparum-positive individuals of all age groups attending health facilities in six regions of Tanzania between June 2010 and August 2011 were obtained. Using chelex-100 extracted DNA, genotyping was done for mutations on codons 51, 59 and 108 of Pfdhfr and 437 and 540 of Pfdhps genes using PCR-RFLP technique. Results A total of 802 malaria-positive samples were screened and genotyped. The prevalence of Pfdhfr 51I, Pfdhps 437G and 540E varied between the regions (p

Southall made several points about our recent article.1 2 He suggests that “lethal hyperchloraemia” secondary to use of normal saline in FEAST (for boluses or maintenance) resulted in excess mortality. However, he did not comment on the key finding of the trial—that the increased 48 hour mortality was identical in both normal saline bolus (10.6%) and albumin bolus (10.6%) arms compared with the no bolus control group (7.3%).3 Harm was shown for every age group, in every condition, at each …

Cutaneous leishmaniasis (CL) due to Leishmania tropica appears to be an emerging disease in parts of north-east Afghanistan and north-west Pakistan. Timargara, an Afghan refugee camp of 17 years' standing, in the district of Dir, North West Frontier Province of Pakistan, experienced a major outbreak of CL in 1997 for the first time. As part of the investigation, each section of the camp was surveyed for CL. Around 38% of the 9200 inhabitants bore active lesions and a further 13% had scars from earlier attacks. According to interview statements, 99% of earlier infections had healed within the previous 2 years. To confirm the diagnosis, a sample of current CL lesions was examined parasitologically. Amastigotes were detectable by microscopy in only 36% of lesions. However, 48% of slide-negative cases produced positive cultures and some cases negative to both microscopy and culture were positive by PCR. Overall detection rate was about 80%. The sandfly Phlebotomus sergenti, a known vector of L. tropica, was captured within the camp, indicating local transmission. CL has not been reported from this area of Pakistan before. Although the majority of refugees left Afghanistan 2 decades ago, cross-border movement of men is common. The Afghanistan capital, Kabul, is currently experiencing a major epidemic of CL; infected migrant carriers from Kabul are probably the source of the outbreak in Timargara.

Background Plasmodium falciparum resistance to anti-malarial drugs remains a major obstacle to the control of malaria. In 2001 Tanzania replaced chloroquine (CQ) with sulphadoxine-pyrimethamine (SP) as first-line drug, which in turn was replaced by artemisinin combination therapy in 2006. SP has however, continued to be used in intermittent preventive treatment of malaria in pregnancy (IPTp) despite reports of high levels of resistance to SP due to the lack of alternatives to SP for IPTp. Recent reports have indicated recovery of CQ-susceptibility in Malawi, Kenya, Mozambique, and Tanzania based on the prevalence of wild types at codon 76 of the Pfcrt gene in indigenous P. falciparum populations. The current prevalence of this Pfcrt- 76 CQ resistance marker from six regions of Tanzania mainland is hereby reported. Methods DNA extracted from filter-paper dried blood spots and rapid diagnostics kit strips collected from finger-prick blood were used to genotype the Pfcrt-76 resistance marker using PCR-RFLP. Data from previously published studies were used to generate CQ susceptibility recovery trends using logistic regression model. Results Seven hundred and forty one (741) samples were genotyped. The current frequency of the CQ-susceptible Pfcrt-K76 was above 92% and did not differ between regions in Tanzania (χ 2 = 2.37; p = 0.795). The K76 allelic prevalence was between 85.7 and 93% in regions (χ 2 = 7.88, p = 0.163). The CQ resistance recovery trends showed regional variability that may be caused by differences in malaria transmission intensity, but overall the trends converge as the susceptibility levels in all regions approach >90%. Conclusions CQ withdrawal in Tanzania has resulted into >90% recovery of susceptibility in ten years of withdrawal. These findings are in support of the search for CQ-based combination drugs as a possible future alternative to SP for IPTp in places where full recovery of CQ-susceptibility will be evident.

Although artesunate is clearly superior, parenteral quinine is still used widely for the treatment of severe malaria. A loading-dose regimen has been recommended for 30 years but is still often not used. A population pharmacokinetic study was conducted with 75 Tanzanian children aged 4 months to 8 years with severe malaria who received quinine intramuscularly; 69 patients received a loading dose of 20 mg quinine dihydrochloride (salt)/kg of body weight. Twenty-one patients had plasma quinine concentrations detectable at baseline. A zero-order absorption model with one-compartment disposition pharmacokinetics described the data adequately. Body weight was the only significant covariate and was implemented as an allometric function on clearance and volume parameters. Population pharmacokinetic parameter estimates (and percent relative standard errors [%RSE]) of elimination clearance, central volume of distribution, and duration of zero-order absorption were 0.977 liters/h (6.50%), 16.7 liters (6.39%), and 1.42 h (21.5%), respectively, for a typical patient weighing 11 kg. Quinine exposure was reduced at lower body weights after standard weight-based dosing; there was 18% less exposure over 24 h in patients weighing 5 kg than in those weighing 25 kg. Maximum plasma concentrations after the loading dose were unaffected by body weight. There was no evidence of dose-related drug toxicity with the loading dosing regimen. Intramuscular quinine is rapidly and reliably absorbed in children with severe falciparum malaria. Based on these pharmacokinetic data, a loading dose of 20 mg salt/kg is recommended, provided that no loading dose was administered within 24 h and no routine dose was administered within 12 h of admission. (This study has been registered with Current Controlled Trials under registration number ISRCTN 50258054.)

Data from a prospective study of 3,319 children ages 2 months to 5 years admitted with febrile illness to a Tanzanian district hospital were analyzed to determine the relationship of blood glucose and mortality. Hypoglycemia (blood sugar < 2.5 mmol/L and < 45 mg/dL) was found in 105 of 3,319 (3.2%) children at admission, and low-normal blood glucose (2.5-5 mmol/L and 45-90 mg/dL) was found in 773 of 3,319 (23.3%) children. Mortality was inversely related to admission blood sugar; compared with children with an admission blood glucose of > 5 mmol/L, the adjusted odds of dying were 3.3 (95% confidence interval = 2.1-5.2) and 9.8 (95% confidence interval = 5.1-19.0) among children with admission blood glucose 2.5-5 and < 2.5 mmol/L, respectively. Receiver operating characteristic (ROC) analysis suggested an optimal cutoff for admission blood sugar of < 5 mmol/L in predicting mortality (sensitivity = 57.7%, specificity = 75.2%). A cutoff for admission blood glucose of < 5 mmol/L represents a simple and clinically useful predictor of mortality in children admitted with severe febrile illness to hospital in resource-poor settings.

Background: In malaria-endemic settings, asymptomatic parasitemia complicates the diagnosis of malaria. Histidine-rich protein 2 (HRP2) is produced by Plasmodium falciparum, and its plasma concentration reflects the total body parasite burden. We aimed to define the malaria-attributable fraction of severe febrile illness, using the distributions of plasma P. falciparum HRP2 (PfHRP2) concentrations from parasitemic children with different clinical presentations. Methods: Plasma samples were collected from and peripheral blood slides prepared for 1435 children aged 6−60 months in communities and a nearby hospital in northeastern Tanzania. The study population included children with severe or uncomplicated malaria, asymptomatic carriers, and healthy control subjects who had negative results of rapid diagnostic tests. The distributions of plasma PfHRP2 concentrations among the different groups were used to model severe malaria-attributable disease. Results:The plasma PfHRP2 concentration showed a close correlation with the severity of infection. PfHRP2 concentrations of >1000 ng/mL denoted a malaria-attributable fraction of severe disease of 99% (95% credible interval [CI], 96%–100%), with a sensitivity of 74% (95% CI, 72%–77%), whereas a concentration of 10% (95% CI, 3%–27%) of patients. Bacteremia was more common among patients in the lowest and highest PfHRP2 concentration quintiles. Conclusions: The plasma PfHRP2 concentration defines malaria-attributable disease and distinguishes severe malaria from coincidental parasitemia in African children in a moderate-to-high transmission setting.

Human genetic background strongly influences susceptibility to malaria infection and progression to severe disease and death. Classical genetic studies identified haemoglobinopathies and erythrocyte-associated polymorphisms, as protective against severe disease. High throughput genotyping by mass spectrometry allows multiple single nucleotide polymorphisms (SNPs) to be examined simultaneously. We compared the prevalence of 65 human SNP's, previously associated with altered risk of malaria, between Tanzanian children with and without severe malaria. Five hundred children, aged 1-10 years, with severe malaria were recruited from those admitted to hospital in Muheza, Tanzania and compared with matched controls. Genotyping was performed by Sequenom MassArray, and conventional PCR was used to detect deletions in the alpha-thalassaemia gene. SNPs in two X-linked genes were associated with altered risk of severe malaria in females but not in males: heterozygosity for one or other of two SNPs in the G6PD gene was associated with protection from all forms of severe disease whilst two SNPs in the gene encoding CD40L were associated with respiratory distress. A SNP in the adenyl cyclase 9 (ADCY9) gene was associated with protection from acidosis whilst a polymorphism in the IL-1α gene (IL1A) was associated with an increased risk of acidosis. SNPs in the genes encoding IL-13 and reticulon-3 (RTN3) were associated with increased risk of cerebral malaria. This study confirms previously known genetic associations with protection from severe malaria (HbS, G6PD). It identifies two X-linked genes associated with altered risk of severe malaria in females, identifies mutations in ADCY9, IL1A and CD40L as being associated with altered risk of severe respiratory distress and acidosis, both of which are characterised by high serum lactate levels, and also identifies novel genetic associations with severe malaria (TRIM5) and cerebral malaria(IL-13 and RTN3). Further studies are required to test the generality of these associations and to understand their functional consequences.

Excluding HIV infection among infants and young children in resource-poor settings where nucleic acid amplification tests (NAAT) are not routinely available remains a considerable challenge.To assess the performance of two rapid HIV antibody tests (RT) used alone and in parallel for excluding HIV infection among acutely ill infants and children18 months in comparison to NAAT in a region where maternal HIV prevalence was approximately 7%.Infants and children ≥218 months admitted to hospital with an acute febrile illness had two rapid antibody tests in parallel, with single and parallel results subsequently compared against NAAT.HIV prevalence among 1602 enrolled infants was 3.4%. All 1526 infants with 2 negative RT were HIV negative by NAAT. All 46 infants with 2 positive RT were HIV positive by NAAT. The overall specificity of two rapid tests for excluding HIV infection was 99.5%. Sensitivity and specificity were ≥99% and98%, respectively, across all age brackets ≥218 months. Overall sensitivity and specificity for a single RT was 98.2% and 99%, respectively, for Determine, and 85.5% and 99.6%, respectively, for Capillus.In a setting with a maternal HIV prevalence rate of10%, a single negative RT had excellent specificity and two negative RT performed in parallel had a perfect negative predictive value for HIV infection among acutely ill patients18 months of age. In this and similar settings, RT could assist with excluding HIV infection with much lower complexity and cost than NAAT.

Background While child mortality is declining in Africa there has been no evidence of a comparable reduction in neonatal mortality. The quality of inpatient neonatal care is likely a contributing factor but data from resource limited settings are few. The objective of this study was to assess the quality of neonatal care in the district hospitals of the Kilimanjaro region of Tanzania. Methods Clinical records were reviewed for ill or premature neonates admitted to 13 inpatient health facilities in the Kilimanjaro region; staffing and equipment levels were also assessed. Results Among the 82 neonates reviewed, key health information was missing from a substantial proportion of records: on maternal antenatal cards, blood group was recorded for 52 (63.4%) mothers, Rhesus (Rh) factor for 39 (47.6%), VDRL for 59 (71.9%) and HIV status for 77 (93.1%). From neonatal clinical records, heart rate was recorded for3 (3.7%) neonates, respiratory rate in 14, (17.1%) and temperature in 33 (40.2%). None of 13 facilities had a functioning premature unit despite calculated gestational age Conclusion Key aspects of neonatal care were found to be poorly documented or incorrectly implemented in this appraisal of neonatal care in Kilimanjaro. Efforts towards quality assurance and enhanced motivation of staff may improve outcomes for this vulnerable group.

The distribution of T cells using the V beta 2 gene was studied in a group of 99 humans. The distribution of V beta 2+CD4+ levels was bimodal. Twelve individuals had levels of V beta 2+CD4+ less than 2% and 86 others had values greater than 5%. Only one individual had a value between 2% and 5%. The V beta 2 low (mean 1.3 +/- 0.49) and V beta 2 high (mean 8.2 +/- 1.65) phenotypes were stable. The V beta 2 low phenotype is inherited and not limited to HLA or T cell receptor V beta gene complexes. The CD8V beta 2 levels of CD4V beta 2 low individuals are also low. The residual V beta 2+ T cells in V beta 2 low individuals were not anergic to V beta 2-specific stimulation. These data are compatible with the effects of an endogenous superantigen.

Background In malaria endemic areas, individuals are frequently asymptomatic and may be undetected by conventional microscopy or newer, rapid diagnostic tests. Molecular techniques allow a more accurate assessment of this asymptomatic parasite burden, the extent of which is important for malaria control. This study examines the relative prevalence of sub-microscopic level parasite carriage and clonal complexity of infections (multiplicity of infection) over a range of endemicities in a region of north-eastern Tanzania where altitude is an established proxy of malaria transmission. The PCR prevalence was then compared against other measures of transmission intensity collected in the same area. Methods This study used 1,121 blood samples collected from a previously conducted cross-sectional malario-metric survey during the short rainy season in 2001 from 13 villages (three at < 600 m, four at 600-1,200 m and six at > 1,200 m in altitude above sea level). Samples were analysed by PCR for carriage of parasites and multiplicity of infection. These data were compared with other measures of transmission intensity collected from the same area. Results Parasite prevalence was 34.7% by PCR and 13.6% by microscopy; a 2.5-fold difference in line with other recent observations. This fold difference was relatively consistent at the different altitude bands despite a marked decrease in parasite prevalence with altitude: < 600 m 70.9 vs 28.6, 600-1,200 m 35.5 vs 9.9, > 1,200 m 15.8 vs 5.9. The difference between parasite prevalence by PCR was 3.2 in individuals aged between 15 and 45 years (34.5 vs 10.9) compared with 2.5 in those aged 1-5 (34.0 vs 13.5) though this was not statistically significant. Multiplicity of infection (MOI) ranged from 1.2 to 3.7 and was positively associated with parasite prevalence assessed by both PCR and microscopy. There was no association of MOI and age. Village level PCR parasite prevalence was strongly correlated with altitude, sero-conversion rate and predicted entomological inoculation rate. Conclusions Asymptomatic, low density, multi-clone malaria infection was common in this study area. These infections are important as potential contributors to the infectious reservoir of parasites and need to be identified by control programmes especially in this era where malaria elimination is a focus. High throughput standardized PCR approaches are needed to identify individuals who are malaria carriers.

Severe febrile illness is a major cause of adult hospital admission in Africa. Studies of non-malarial fever come largely from children or from high HIV prevalence settings. This prospective study of adult admissions with severe febrile illness in a malaria-endemic area with moderate/low HIV prevalence investigated admission diagnosis as well as final diagnosis based on results of investigations. Severe malaria was the admission diagnosis in 148/198 (74.7%) cases. Plasmodium falciparum was identified in 38/188 (20.2%) admissions and 26/198 (13.1%) were bacteraemic, with 13/25 (52%) prescribed empirical antibiotics. HIV was equally common among those with (16/37; 43.2%) and without P. falciparum (50/138; 36.2%) (p=0.44). In 6/22 (27.3%) deaths, blood cultures were positive for a pathogen, with Streptococcus pneumoniae, Escherichia coli and non-Typhi Salmonella predominating. Chest radiography was suspicious for bacterial/mycobacterial disease in 5/22 additional deaths. Systemic inflammatory response syndrome criteria were more sensitive but less specific than WHO severe malaria criteria for predicting mortality. Malaria is overdiagnosed in adults with severe febrile illness and was not associated with mortality in the absence of co-infection in this high-incidence setting. Adults with severe febrile illness should be tested for malaria and HIV using rapid, sensitive tests. Early antibiotic use should be promoted. Improved diagnostics for invasive bacterial disease are needed.

Background The annual incidence and temporal trend of severe malaria and community-acquired bacteraemia during a four-year period in Muheza, Tanzania was assessed. Methods Data on severely ill febrile children aged 2 months to 14 years from three prospective studies conducted at Muheza District Hospital from 2006 to 2010 was pooled and analysed. On admission, each enrolled child had a thin and thick blood film and at least one rapid diagnostic test for falciparum malaria, as well as a blood culture. The annual incidence of bacteraemia and severe malaria among children coming from Muheza was calculated and their temporal trend was assessed. Results Overall, 1, 898 severe falciparum malaria and 684 bacteraemia cases were included. Of these, 1, 356 (71%) and 482 (71%), respectively, were from the referral population of Muheza. The incidence of falciparum malaria and all-cause bacteraemia in Muheza decreased five-fold and three-fold, respectively, from the first to the fourth year of surveillance (p < 0.0001). During this period, the median ages of children from Muheza admitted with severe malaria increased from 1.7 to 2.5 years (p < 0.0001). The reduction in all-cause bacteraemia was mainly driven by the 11-fold decline in the incidence of non-typhoidal salmonellosis. The annual incidences of Haemophilus influenzae and pneumococcal invasive bacterial infections decreased as well but were much fewer in number. Conclusions These results add to the growing evidence of the decline in malaria associated with a decrease in non-typhoidal salmonellosis and possibly other bacteraemias. Malarial prevention and control strategies may provide a greater benefit than the mere reduction of malaria alone.