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The rapid diagnosis of coronavirus disease 2019 (COVID-19) is critical for comprehensive public health response strategies, and self-testing with antigen rapid diagnostic tests (Ag-RDTs) presents opportunities to test in hard-to-reach communities. Therefore, we evaluated the acceptability, feasibility, and uptake of Ag-RDT self-testing at the community level in Tanzania. From June to October 2022, symptomatic individuals or those with recent contact with a known or suspected COVID-19 patient were offered assisted testing and self-testing within mining communities and at transport hubs. This study included a cross-sectional survey before and after implementation. Participants were assessed for their acceptability and uptake of the nasal Ag-RDT self-test and their preference for nasal Ag-RDT self-testing. The survey data were collected in Open Data Kit, whereas the Ag-RDT results in the community were recorded by using the COVISUSPECT Mobile Application. Data analysis was performed by using STATA and R Statistical Software. A total of 538 individuals were screened, and 454 (84.4%) consented to be tested. The preference for self-testing was relatively low (33%), and the majority of participants (67%) opted to be assisted by a healthcare professional. Of the participants who opted for testing, 149 (32.8%) were able to self-test. Generally, there was no major difference in the various assessed parameters between the baseline and end-line surveys. The results from fitting multiple logistic regression indicated that after controlling for age, participants living in Dodoma were significantly less likely to opt for self-testing (odds ratio = 0.54; P-value = 0.023) compared with those living in Dar es Salaam. There was no significant difference in self-testing between participants living in Mara and those living in Dar es Salaam (odds ratio = 0.7; P-value = 0.179). After controlling for region, older (≥40 years) participants were significantly less likely to self-test compared with participants aged 18 to <40 years (odds ratio = 0.47; P-value = 0.002). The intervention was well-accepted in all areas in which Ag-RDTs were deployed. Our findings can therefore support the Ministry of Health by increasing accessibility to severe acute respiratory syndrome coronavirus 2 testing in the hard-to-reach communities in response to the next COVID-19 wave.

Cough is a common and commonly ignored symptom of lung disease. Cough is often perceived as difficult to quantify, frequently self-limiting, and non-specific. However, cough has a central role in the clinical detection of many lung diseases including tuberculosis (TB), which remains the leading infectious disease killer worldwide. TB screening currently relies on self-reported cough which fails to meet the World Health Organization (WHO) accuracy targets for a TB triage test. Artificial intelligence (AI) models based on cough sound have been developed for several respiratory conditions, with limited work being done in TB. To support the development of an accurate, point-of-care cough-based triage tool for TB, we have compiled a large multi-country database of cough sounds from individuals being evaluated for TB. The dataset includes more than 700,000 cough sounds from 2,143 individuals with detailed demographic, clinical and microbiologic diagnostic information. We aim to empower researchers in the development of cough sound analysis models to improve TB diagnosis, where innovative approaches are critically needed to end this long-standing pandemic., (© 2024. The Author(s).)

Background: Parasitic infectious agents rarely occur in isolation. Epidemiological evidence is mostly lacking, and little is known on how the two common parasites Plasmodium and soil transmitted helminths (STH) interact. There are contradictory findings in different studies. Synergism, antagonism and neutral effect have been documented between Plasmodium and STH. This study investigated the impact of STH on clinical malaria presentation and treatment outcome., Methods: A matched case control study with a semi longitudinal follow up according to World Health Organization (WHO) antimalarial surveillance guideline was done among children aged 2 months to 9 years inclusively living in western rural areas of Bagamoyo, coastal region of Tanzania. Cases were children with uncomplicated and severe malaria enrolled from the health facilities while controls were children with asymptomatic Plasmodium parasitemia enrolled from the same community., Results: In simple conditional regression analysis there was a tendency for a protective effect of STH on the development of clinical malaria [OR = 0.6, 95% CI of 0.3-1.3] which was more marked for Enterobius vermicularis species [OR = 0.2, 95% CI of 0.0-0.9]. On the contrary, hookworm species tended to be associated with increased risk of clinical malaria [OR = 3.0, 95% CI of 0.9-9.5]. In multiple conditional regression analysis, the overall protective effect was lower for all helminth infection [OR = 0.8, 95% CI of 0.3-1.9] but remained significantly protective for E. vermicularis species [OR = 0.1, 95% CI of 0.0-1.0] and borderline significant for hookworm species [OR = 3.6, 95% CI of 0.9-14.3]. Using ordinal logistic regression which better reflects the progression of asymptomatic Plasmodium parasitemia to severe malaria, there was a 50% significant protective effect with overall helminths [OR = 0.5, 95% CI of 0.3-0.9]. On the contrary, hookworm species was highly predictive of uncomplicated and severe malaria [OR = 7.8, 95% (CI of 1.8-33.9) and 49.7 (95% CI of 1.9-1298.9) respectively]. Generally, children infected with STH had higher geometric mean time to first clearance of parasitemia., Conclusion: The findings of a protective effect of E. vermicularis and an enhancing effect of hookworms may explain the contradictory results found in the literature about impact of helminths on clinical malaria. More insight should be gained on possible mechanisms for these opposite effects. These results should not deter at this stage deworming programs but rather foster implementation of integrated control program for these two common parasites., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Salim Masoud et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Broadly neutralizing antibodies (bNAbs) are promising candidates for the treatment and prevention of HIV-1 infections. Despite their critical importance, automatic detection of HIV-1 bNAbs from immune repertoires is still lacking. Here, we develop a straightforward computational method for the Rapid Automatic Identification of bNAbs (RAIN) based on machine learning methods. In contrast to other approaches, which use one-hot encoding amino acid sequences or structural alignment for prediction, RAIN uses a combination of selected sequence-based features for the accurate prediction of HIV-1 bNAbs. We demonstrate the performance of our approach on non-biased, experimentally obtained and sequenced BCR repertoires from HIV-1 immune donors. RAIN processing leads to the successful identification of distinct HIV-1 bNAbs targeting the CD4-binding site of the envelope glycoprotein. In addition, we validate the identified bNAbs using an in vitro neutralization assay and we solve the structure of one of them in complex with the soluble native-like heterotrimeric envelope glycoprotein by single-particle cryo-electron microscopy (cryo-EM). Overall, we propose a method to facilitate and accelerate HIV-1 bNAbs discovery from non-selected immune repertoires., (© 2024. The Author(s).)

A pilot implementation of the rapid diagnostic test program was performed to collect evidence of the feasibility, acceptability, and uptake of the COVID-19 AgRDT in Tanzania. We conducted a prospective cross-sectional study in the community to provide quantitative details of the pilot implementation of the antigen rapid diagnostic test (AgRDT) in Tanzania. This study was undertaken between March 2022 and September 2022. The pilot was implemented by distributing and offering test kits to people suspected of having COVID-19 in Dar es Salaam through community health workers. A total of 1039 participants consented to participate in the survey. All the participants reported having heard about the disease. The radio was the main source (93.2%) of information on COVID-19. With regard to prevention measures, approximately 930 (89.5%) of the respondents thought that COVID-19 could be prevented. Approximately 1035 (99.6%) participants reported that they were willing to have a COVID-19 AgRDT test and wait for 20 min for the results. With regard to the participants' opinions on the AgRDT device, the majority 907 (87.3%) felt comfortable with the test, and 1,029 (99.0%) were very likely to recommend the AgRDT test to their friends. The majority of participants 848 (83.1%) mentioned that they would be willing to pay for the test if it was not available for free. The results suggest overall good acceptance of the COVID-19 AgRDT test. It is evident that the use of trained community healthcare workers allows easy screening of all possible suspects and helps them receive early treatment., (© 2024. The Author(s).)

Cough is a common and commonly ignored symptom of lung disease. Cough is often perceived as difficult to quantify, frequently self-limiting, and non-specific. However, cough has a central role in the clinical detection of many lung diseases including tuberculosis (TB), which remains the leading infectious disease killer worldwide. TB screening currently relies on self-reported cough which fails to meet the World Health Organization (WHO) accuracy targets for a TB triage test. Artificial intelligence (AI) models based on cough sound have been developed for several respiratory conditions, with limited work being done in TB. To support the development of an accurate, point-of-care cough-based triage tool for TB, we have compiled a large multi-country database of cough sounds from individuals being evaluated for TB. The dataset includes more than 700,000 cough sounds from 2,143 individuals with detailed demographic, clinical and microbiologic diagnostic information. We aim to empower researchers in the development of cough sound analysis models to improve TB diagnosis, where innovative approaches are critically needed to end this long-standing pandemic., Competing Interests: COMPETING INTERESTS The authors declare no competing interest.

Background: RH5 is a leading blood-stage candidate antigen for a Plasmodium falciparum vaccine; however, its safety and immunogenicity in malaria-endemic populations are unknown., Methods: A phase 1b, single-center, dose-escalation, age-de-escalation, double-blind, randomized, controlled trial was conducted in Bagamoyo, Tanzania (NCT03435874). Between 12 th April and 25 th October 2018, 63 healthy adults (18-35 years), young children (1-6 years), and infants (6-11 months) received a priming dose of viral-vectored ChAd63 RH5 or rabies control vaccine. Sixty participants were boosted with modified vaccinia virus Ankara (MVA) RH5 or rabies control vaccine 8 weeks later and completed 6 months of follow-up post priming. Primary outcomes were the number of solicited and unsolicited adverse events post vaccination and the number of serious adverse events over the study period. Secondary outcomes included measures of the anti-RH5 immune response., Findings: Vaccinations were well tolerated, with profiles comparable across groups. No serious adverse events were reported. Vaccination induced RH5-specific cellular and humoral responses. Higher anti-RH5 serum immunoglobulin G (IgG) responses were observed post boost in young children and infants compared to adults. Vaccine-induced antibodies showed growth inhibition activity (GIA) in vitro against P. falciparum blood-stage parasites; their highest levels were observed in infants., Conclusions: The ChAd63-MVA RH5 vaccine shows acceptable safety and reactogenicity and encouraging immunogenicity in children and infants residing in a malaria-endemic area. The levels of functional GIA observed in RH5-vaccinated infants are the highest reported to date following human vaccination. These data support onward clinical development of RH5-based blood-stage vaccines to protect against clinical malaria in young African infants., Funding: Medical Research Council, London, UK., Competing Interests: Declaration of interests S.J.D. is a named inventor on patent applications relating to RH5 malaria vaccines and adenovirus-based vaccines, is an inventor on intellectual property licensed by Oxford University Innovation to AstraZeneca, and has been a consultant to GSK on malaria vaccines. A.M.M. has been a consultant to GSK on malaria vaccines, has an immediate family member who is an inventor on patent applications relating to RH5 malaria vaccines and adenovirus-based vaccines, and is an inventor on intellectual property licensed by Oxford University Innovation to AstraZeneca., (Copyright © 2023. Published by Elsevier Inc.)

Background: Though Maytenus senegalensis is one of the medicinal plants widely used in traditional medicine to treat infectious and inflammatory diseases in Africa, there is a lack of safety data regarding its use. Therefore, the study aimed to asselss the safety and tolerability of the antimalarial herbal remedy M. senegalensis ., Material and Methods: The study design was an open-label, single-arm, dose-escalation. Twelve eligible male healthy Tanzanians aged 18 to 45 years were enrolled in four study dose groups. Volunteers' safety and tolerability post-investigational-product administration were monitored on days 0 to 7,14, and 56., Results: There were no deaths or serious adverse events in any of the study groups, nor any adverse events that resulted in premature discontinuation. The significant mean changes observed in WBC ( p = 0.003), Neutrophils ( p = 0.02), Lymphocytes ( p = 0.001), Eosinophils ( p = 0.009), Alanine aminotransferase ( p = 0.002), Creatinine ( p = 0.03) and Total bilirubin ( p = 0.004) laboratory parameters were not associated with any signs of toxicity or clinical symptoms., Conclusions: M. senegalensis was demonstrated to be safe and tolerable when administered at a dose of 800 mg every eight hours a day for four days. This study design may be adapted to evaluate other herbal remedies.

Background: The success of any randomized clinical trial relies on the willingness of people to be recruited in the trial. However, 90% of all clinical trials worldwide have been reported to have failed to recruit the required number of trial participants within the scheduled time. This study aimed to qualitatively explore the motivations and barriers for healthy participants to participate in herbal remedy clinical trials in Tanzania., Materials and Methods: This study used a qualitative descriptive research design based on the theory of planned behaviour. A total of five Focus Group Discussions (FGD) were conducted at Bagamoyo Clinical Trial Facility from 29 to 30 May 2021. Each group consisted of 5 to 10 participants. The participants of the study were 30 healthy males aged 18 to 45 male who participated in the clinical trial that evaluated the safety, tolerability, and efficacy of Maytenus Senegalensis. The focus group discussions were recorded audio-recorded. Verbatim transcription and thematic analysis were performed on the data., Results: The prominent motivations mentioned were the opportunity for self-development, altruism, flexible study visit schedule, and financial compensation. Furthermore, the Participants' mothers and friends were reported as those most likely to approve of participation in an herbal remedy. The most mentioned barriers were inconvenience related to time commitment requirements, possible side effects, inflexible study visit schedule, and having other commitments. Moreover, the participants' father was reported to be more likely to disapprove of participation in a clinical trial of herbal remedy clinical trial., Conclusions: The results of this study showed that the motivations and barriers of healthy participants to participate in clinical trials of herbal remedies are varied and that participants are motivated by more than financial gains. The identified motivations and barriers can be used as a guideline to improve the design of recruitment and retention strategies for herbal remedy clinical trials., Competing Interests: The authors have declared that no competing interests exist.

Background: Despite several interventions, the prevalence of anemia and related complications remains high among infants in Tanzania., Objective: We sought to determine the predictors of iron-deficiency anemia (IDA) among infants of HIV-negative women in Dar es Salaam, Tanzania., Methods: Cross-sectional analysis of 2826 mother-infant pairs who participated in a trial of vitamins and perinatal outcomes in Dar es Salaam, Tanzania. Hemoglobin and mean corpuscular volume were used to determine the prevalence of anemia among infants at 6 and 12 months. Multiple logistic regression was used to determine the maternal and infant risk factors for anemia during infancy., Results: We found high prevalence of anemia (90%) and IDA (44.2%) among infants. Higher maternal education (odds ratio [OR] = 0.52), maternal normal hemoglobin at enrollment (OR = 0.68) and during the early postpartum period reduced the odds of IDA at 6 months (OR = 0.56). The odds of IDA at 6 months were higher among males (OR = 1.65), wealth score below median (OR = 1.35), low birth weight (LBW; OR = 1.75), and small for gestational age (SGA) infants below the third centile (OR = 1.95) or third to less than fifth centile (OR = 2.29). Higher maternal education lowered the odds of IDA at 12 months (OR = 0.25). Wealth score below median (OR = 1.44), preterm delivery (OR = 1.94), SGA (less than third centile; OR = 2.40), and LBW (OR = 2.89) increased the odds of IDA during infancy in the study population. Dietary diversity was low for infants and women in the study sample., Conclusion: Interventions to reduce the risk of infant IDA should address women's education, improvement of wealth status, and optimal care for premature, SGA, and LBW infants.

Background: Iron deficiency anaemia is of major concern in low-income settings, especially for women of childbearing age. Oral iron substitution efficacy is limited by poor compliance and iron depletion severity. We aimed to assess the efficacy and safety of intravenous ferric carboxymaltose versus oral iron substitution following childbirth in women with iron deficiency anaemia in Tanzania., Methods: This parallel-group, open-label, randomised controlled phase 3 trial was done at Bagamoyo District Hospital and Mwananyamala Hospital, Tanzania. Eligible participants were close to delivery and had iron deficiency anaemia defined as a haemoglobin concentration of less than 110 g/L and a ferritin concentration of less than 50 μg/L measured within 14 days before childbirth. Participants were randomly assigned 1:1 to receive intravenous ferric carboxymaltose or oral iron, stratified by haemoglobin concentration and site. Intravenous ferric carboxymaltose was administered at a dose determined by the haemoglobin concentration and bodyweight (bodyweight 35 kg to <70 kg and haemoglobin ≥100 g/L: 1000 mg in one dose; bodyweight 35 kg to <70 kg and haemoglobin <100 g/L, or bodyweight ≥70 kg and haemoglobin ≥100 g/L: 1500 mg in two doses at least 7 days apart; bodyweight ≥70 kg and haemoglobin <100 g/L: 2000 mg in two doses at least 7 days apart). Oral iron treatment consisted of three dried ferrous sulphate tablets of 200 mg containing 60 mg of elementary iron and 5 mg of folic acid every morning. Oral treatment was to be taken for 3 months after haemoglobin normalisation. The primary outcome was haemoglobin normalisation (>115 g/L) at 6 weeks. Follow-up visits were at 6 weeks, and 3, 6, and 12 months. Analyses were done in the modified intention-to-treat population of participants who had a 6-week haemoglobin concentration result, using logistic and linear regression models for binary and continuous outcomes, adjusted for baseline haemoglobin concentration and site. This trial is registered with ClinicalTrials.gov, NCT02541708., Findings: Between Oct 8, 2015, and March 14, 2017, 533 individuals were screened and 230 were enrolled and randomly assigned to a study group (114 to intravenous iron, 116 to oral iron). At 6 weeks, 94 (82%) participants in the intravenous iron group and 92 (79%) in the oral iron group were assessed for the primary outcome. 75 (80%) participants in the intravenous iron group and 47 (51%) in the oral iron group had normalised haemoglobin (odds ratio 4·65, 95% CI 2·33-9·27). There were two mild to moderate infusion-related adverse events; and five serious adverse events (three in the intravenous iron group, two in the oral iron group), unrelated to the study medication., Interpretation: Intravenous iron substitution with ferric carboxymaltose was safe and yielded a better haemoglobin response than oral iron. To our knowledge, this is the first study to provide evidence of the benefits and safety of intravenous iron substitution in a low-income setting., Funding: Vifor Pharma, R Geigy-Stiftung, Freiwillige Akademische Gesellschaft, and Swiss Tropical and Public Health Institute., (Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Human immunodeficiency virus (HIV) infection is the major risk factor predisposing for Mycobacterium tuberculosis progression from latent tuberculosis infection (LTBI) to tuberculosis disease (TB). Since long-term-treated aviremic HIV-infected individuals remained at higher risk of developing TB than HIV-uninfected individuals, we hypothesized that progression from LTBI to pulmonary TB (PTB) might be due not only to CD4 T-cell depletion but also to M. tuberculosis -specific CD4 T-cell functional impairment. To test this hypothesis, M. tuberculosis -specific T-cell frequencies and cytokine profiles were investigated in untreated Tanzanian individuals suffering from LTBI ( n = 20) or PTB ( n = 67) and compared to those of untreated M. tuberculosis /HIV-coinfected individuals suffering from LTBI ( n = 15) or PTB ( n = 10). We showed that HIV infection significantly reduced the proportion of Th2 (interleukin 4 [IL-4]/IL-5/IL-13) producing M. tuberculosis -specific CD4 T cells and IL-2-producing M. tuberculosis -specific CD4 and CD8 T cells in individuals with LTBI or PTB ( P <  0.05). Interestingly, the loss of IL-2 production was associated with a significant increase of PD-1 expression on M. tuberculosis -specific CD4 and CD8 T cells ( P <  0.05), while the loss of Th2 cytokine production was associated with a significant reduction of Gata-3 expression in memory CD4 T cells ( P <  0.05). Finally, we showed that the serum levels of IL-1α, IL-6, C-reactive protein (CRP), IL-23, and IP-10 were significantly reduced in M. tuberculosis /HIV-coinfected individuals with PTB compared to those in HIV-negative individuals with PTB ( P <  0.05), suggesting that HIV infection significantly suppresses M. tuberculosis -induced systemic proinflammatory cytokine responses. Taken together, this study suggests that in addition to depleting M. tuberculosis -specific CD4 T cells, HIV infection significantly impairs functionally favorable M. tuberculosis -specific CD4 T-cell responses in Tanzanian individuals with LTBI or PTB. IMPORTANCE Mycobacterium tuberculosis and human immunodeficiency virus (HIV) infections are coendemic in several regions of the world, and M. tuberculosis /HIV-coinfected individuals are more susceptible to progression to tuberculosis disease. We therefore hypothesized that HIV infection would potentially impair M. tuberculosis -specific protective immunity in individuals suffering from latent tuberculosis infection (LTBI) or active pulmonary tuberculosis (PTB). In this study, we demonstrated that M. tuberculosis /HIV-coinfected individuals have fewer circulating M. tuberculosis -specific CD4 T cells and that those that remained were functionally impaired in both LTBI and PTB settings. In addition, we showed that HIV infection significantly interferes with M. tuberculosis -induced systemic proinflammatory cytokine/chemokine responses. Taken together, these data suggest that HIV infection impairs functionally favorable M. tuberculosis -specific immunity., (Copyright © 2019 Amelio et al.)

Background: Plasmodium and soil transmitted helminth infections (STH) are a major public health problem, particularly among children. There are conflicting findings on potential association between these two parasites. This study investigated the Plasmodium and helminth co-infections among children aged 2 months to 9 years living in Bagamoyo district, coastal region of Tanzania., Methods: A community-based cross-sectional survey was conducted among 1033 children. Stool, urine and blood samples were examined using a broad set of quality controlled diagnostic methods for common STH (Ascaris lumbricoides, hookworm, Strongyloides stercoralis, Enterobius vermicularis, Trichuris trichura), schistosoma species and Wuchereria bancrofti. Blood slides and malaria rapid diagnostic tests (mRDTs) were utilized for Plasmodium diagnosis., Results: Out of 992 children analyzed, the prevalence of Plasmodium infection was 13% (130/992), helminth 28.5% (283/992); 5% (50/992) had co-infection with Plasmodium and helminth. The prevalence rate of Plasmodium, specific STH and co-infections increased significantly with age (p < 0.001), with older children mostly affected except for S. stercoralis monoinfection and co-infections. Spatial variations of co-infection prevalence were observed between and within villages. There was a trend for STH infections to be associated with Plasmodium infection [OR adjusted for age group 1.4, 95% CI (1.0-2.1)], which was more marked for S. stercoralis (OR = 2.2, 95% CI (1.1-4.3). Age and not schooling were risk factors for Plasmodium and STH co-infection., Conclusion: The findings suggest that STH and Plasmodium infections tend to occur in the same children, with increasing prevalence of co-infection with age. This calls for an integrated approach such as using mass chemotherapy with dual effect (e.g., ivermectin) coupled with improved housing, sanitation and hygiene for the control of both parasitic infections.

Hemoglobinopathies, disorders of hemoglobin structure and production, are one of the most common monogenic disorders in humans. Glucose 6 phosphate dehydrogenase deficiency (G6PD) is an inherited enzymopathy resulting in increased oxygen stress susceptibility of red blood cells. The distributions of these genetic traits in populations living in tropical and subtropical regions where malaria has been or is still present are thought to result from survival advantage against severe life threatening malaria disease. 384 male Tanzanian volunteers residing in Dar es Salaam were typed for G6PD, sickle cell disease and α-thalassemia. The most prominent red blood cell polymorphism was heterozygous α(+)-thalassemia (37.8%), followed by the G6PD(A) deficiency (16.4%), heterozygous sickle cell trait (15.9%), G6PD(A-) deficiency (13.5%) and homozygous α(+)-thalassemia (5.2%). 35%, 45%, 17% and 3% of these volunteers were carriers of wild type gene loci, one, two or three of these hemoglobinopathies, respectively. We find that using a cut off value of 28.6 pg. for mean corpuscular hemoglobin (MCH), heterozygous α(+)-thalassemia can be predicted with a sensitivity of 84% and specificity of 72% in this male population. All subjects carrying homozygous α(+)-thalassemia were identified based on their MCH value < 28.6 pg.

Background: There is a paucity of data pertaining to the epidemiology and public health impact of Enterobius vermicularis and Strongyloides stercoralis infections. We aimed to determine the extent of enterobiasis, strongyloidiasis, and other helminth infections and their association with asymptomatic Plasmodium parasitaemia, anaemia, nutritional status, and blood cell counts in infants, preschool-aged (PSAC), and school-aged children (SAC) from rural coastal Tanzania., Methods: A total of 1,033 children were included in a cross-sectional study implemented in the Bagamoyo district in 2011/2012. Faecal samples were examined for intestinal helminth infections using a broad set of quality controlled methods. Finger-prick blood samples were subjected to filariasis and Plasmodium parasitaemia testing and full blood cell count examination. Weight, length/height, and/or mid-upper arm circumference were measured and the nutritional status determined in accordance with age., Results: E. vermicularis infections were found in 4.2% of infants, 16.7%, of PSAC, and 26.3% of SAC. S. stercoralis infections were detected in 5.8%, 7.5%, and 7.1% of infants, PSAC, and SAC, respectively. Multivariable regression analyses revealed higher odds of enterobiasis in children of all age-groups with a reported anthelminthic treatment history over the past six months (odds ratio (OR): 2.15; 95% confidence interval (CI): 1.22 - 3.79) and in SAC with a higher temperature (OR: 2.21; CI: 1.13 - 4.33). Strongyloidiasis was associated with eosinophilia (OR: 2.04; CI: 1.20-3.48) and with Trichuris trichiura infections (OR: 4.13; CI: 1.04-16.52) in children of all age-groups, and with asymptomatic Plasmodium parasitaemia (OR: 13.03; CI: 1.34 - 127.23) in infants. None of the investigated helminthiases impacted significantly on the nutritional status and anaemia, but moderate asymptomatic Plasmodium parasitaemia was a strong predictor for anaemia in children aged older than two years (OR: 2.69; 95% CI: 1.23 - 5.86)., Conclusions: E. vermicularis and S. stercoralis infections were moderately prevalent in children from rural coastal Tanzania. Our data can contribute to inform yet missing global burden of disease and prevalence estimates for strongyloidiasis and enterobiasis. The association between S stercoralis and asymptomatic Plasmodium parasitaemia found here warrants further comprehensive investigations.

Controlled human malaria infection (CHMI) by mosquito bite has been used to assess anti-malaria interventions in > 1,500 volunteers since development of methods for infecting mosquitoes by feeding on Plasmodium falciparum (Pf) gametocyte cultures. Such CHMIs have never been used in Africa. Aseptic, purified, cryopreserved Pf sporozoites, PfSPZ Challenge, were used to infect Dutch volunteers by intradermal injection. We conducted a double-blind, placebo-controlled trial to assess safety and infectivity of PfSPZ Challenge in adult male Tanzanians. Volunteers were injected intradermally with 10,000 (N = 12) or 25,000 (N = 12) PfSPZ or normal saline (N = 6). PfSPZ Challenge was well tolerated and safe. Eleven of 12 and 10 of 11 subjects, who received 10,000 and 25,000 PfSPZ respectively, developed parasitemia. In 10,000 versus 25,000 PfSPZ groups geometric mean days from injection to Pf positivity by thick blood film was 15.4 versus 13.5 (P = 0.023). Alpha-thalassemia heterozygosity had no apparent effect on infectivity. PfSPZ Challenge was safe, well tolerated, and infectious., (© The American Society of Tropical Medicine and Hygiene.)

Sensitive diagnostic tools are crucial for an accurate assessment of helminth infections in low-endemicity areas. We examined stool samples from Tanzanian individuals and compared the diagnostic accuracy of a real-time polymerase chain reaction (PCR) with the FLOTAC technique and the Kato-Katz method for hookworm and the Baermann method for Strongyloides stercoralis detection. Only FLOTAC had a higher sensitivity than the Kato-Katz method for hookworm diagnosis; the sensitivities of PCR and the Kato-Katz method were equal. PCR had a very low sensitivity for S. stercoralis detection. The cycle threshold values of the PCR were negatively correlated with the logarithm of hookworm egg and S. stercoralis larvae counts. The median larvae count was significantly lower in PCR false negatives than true positives. All methods failed to detect very low-intensity infections. New diagnostic approaches are needed for monitoring of progressing helminth control programs, confirmation of elimination, or surveillance of disease recrudescence.