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In large experimental trials throughout Africa, insecticide-treated bednets and curtains have reduced child mortality in malaria-endemic communities by 15%-30%. While few questions remain about the efficacy of this intervention, operational issues around how to implement and sustain insecticide-treated materials (ITM) projects need attention. We revisited the site of a small-scale ITM intervention trial, 3 years after the project ended, to assess how local attitudes and practices had changed. Qualitative and quantitative methods, including 16 focus group discussions and a household survey (n = 60), were employed to assess use, maintenance, retreatment and perceptions of ITM and the insecticide in former study communities. Families that had been issued bednets were more likely to have kept and maintained them and valued bednets more highly than those who had been issued curtains. While most households retained their original bednets, none had treated them with insecticide since the intervention trial was completed 3 years earlier. Most of those who had been issued bednets repaired them, but none acquired new or replacement nets. In contrast, households that had been issued insecticide-treated curtains often removed them. Three (15%) of the households issued curtains had purchased one or more bednets since the study ended. In households where bednets had been issued, children 10 years of age and younger were a third as likely to sleep under a net as were adults (relative risk (RR) = 0. 32; 95% confidence interval (95%CI) = 0.19, 0.53). Understanding how and why optimal ITM use declined following this small-scale intervention trial can suggest measures that may improve the sustainability of current and future ITM efforts. [ABSTRACT FROM AUTHOR]

Abstract Background Artemisinin-based combination therapy (ACT) is recommended as a means of prolonging the effectiveness of first-line malaria treatment regimens. Different brands of mefloquine (MQ) have been reported to be non-bioequivalent; this could result in sub-therapeutic levels of mefloquine with decreased efficacy. In 2002, mefloquine-artesunate (MQ-AS) combination therapy was adopted as the first-line treatment for uncomplicated Plasmodium falciparum malaria in the Amazon region of Peru. Although MQ resistance has yet to be reported from the Peruvian Amazon, it has been reported from other countries in the Amazon Region. Therefore, continuous monitoring is warranted to ensure that the first-line therapy remains efficacious. This study examines the in vivo efficacy and pharmacokinetic parameters through Day 56 of three commercial formulations of MQ (Lariam®, Mephaquin®, and Mefloquina-AC® Farma) given in combination with artesunate. Methods Thirty-nine non-pregnant adults with P. falciparum mono-infection were randomly assigned to receive artesunate in combination with either (1) Lariam, (2) Mephaquin, or (3) Mefloquina AC. Patients were assessed on Day 0 (with blood samples for pharmacokinetics at 0, 2, 4, and 8 hours), 1, 2, 3, 7, and then weekly until day 56. Clinical and parasitological outcomes were based on the standardized WHO protocol. Whole blood mefloquine concentrations were determined by high-performance liquid chromatography and pharmacokinetic parameters were determined using non-compartmental analysis of concentration versus time data. Results By day 3, all patients had cleared parasitaemia except for one patient in the AC Farma arm; this patient cleared by day 4. No recurrences of parasitaemia were seen in any of the 34 patients. All three MQ formulations had a terminal half-life of 14–15 days and time to maximum plasma concentration of 45–52 hours. The maximal concentration (Cmax) and interquartile range was 2,820 ng/ml (2,614–3,108) for Lariam, 2,500 ng/ml (2,363–2,713) for Mephaquin, and 2,750 ng/ml (2,550–3,000) for Mefloquina AC Farma. The pharmacokinetics of the three formulations were generally similar, with the exception of the Cmax of Mephaquin which was significantly different to that of Lariam (p = 0.04). Conclusion All three formulations had similar pharmacokinetics; in addition, the pharmacokinetics seen in this Peruvian population were similar to reports from other ethnic groups. All patients rapidly cleared their parasitaemia with no evidence of recrudescence by Day 56. Continued surveillance is needed to ensure that patients continue to receive optimal therapy.

Background: Despite considerable reductions in malaria achieved by scaling-up long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), maintaining sustained community protection remains operationally challenging. Increasing insecticide resistance also threatens to jeopardize the future of both strategies. Non-pyrethroid insecticide-treated wall lining (ITWL) may represent an alternate or complementary control method and a potential tool to manage insecticide resistance. To date no study has demonstrated whether ITWL can reduce malaria transmission nor provide additional protection beyond the current best practice of universal coverage (UC) of LLINs and prompt case management., Methods/design: A two-arm cluster randomized controlled trial will be conducted in rural Tanzania to assess whether non-pyrethroid ITWL and UC of LLINs provide added protection against malaria infection in children, compared to UC of LLINs alone. Stratified randomization based on malaria prevalence will be used to select 22 village clusters per arm. All 44 clusters will receive LLINs and half will also have ITWL installed on interior house walls. Study children, aged 6 months to 11 years old, will be enrolled from each cluster and followed monthly to estimate cumulative incidence of malaria parasitaemia (primary endpoint), time to first malaria episode and prevalence of anaemia before and after intervention. Entomological inoculation rate will be estimated using indoor CDC light traps and outdoor tent traps followed by detection of Anopheles gambiae species, sporozoite infection, insecticide resistance and blood meal source. ITWL bioefficacy and durability will be monitored using WHO cone bioassays and household surveys, respectively. Social and cultural factors influencing community and household ITWL acceptability will be explored through focus-group discussions and in-depth interviews. Cost-effectiveness, compared between study arms, will be estimated per malaria case averted., Discussion: This protocol describes the large-scale evaluation of a novel vector control product, designed to overcome some of the known limitations of existing methods. If ITWL is proven to be effective and durable under field conditions, it may warrant consideration for programmatic implementation, particularly in areas with long transmission seasons and where pyrethroid-resistant vectors predominate. Trial findings will provide crucial information for policy makers in Tanzania and other malaria-endemic countries to guide resource allocations for future control efforts., Trial Registration: NCT02533336 registered on 13 July 2014.

Problem/condition: Malaria is caused by four species of Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, or P. malariae), which are transmitted by the bite of an infective female Anopheles sp. mosquito. Most malaria infections in the United States occur among persons who have traveled to areas with ongoing transmission. Occasionally, cases occur in the United States through exposure to infected blood products, by congenital transmission, or by local mosquito-borne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to guide prevention recommendations for travelers., Reporting Period: Cases with onset of illness during 1995., Description of System: Malaria cases confirmed by blood smears are reported to local and/or state health departments by health-care providers and/or laboratory staff. Case investigations are conducted by local and/or state health departments, and reports are transmitted to CDC through the National Malaria Surveillance System (NMSS). Data from NMSS serve as the basis for this report., Results: CDC received reports of 1,167 cases of malaria with onset of symptoms during 1995 among persons in the United States or one of its territories. This number represents an increase of 15% from the 1,014 cases reported for 1994. P. vivax, P. falciparum, P. malariae, and P. ovale were identified in 48.2%, 38.6%, 3.9%, and 2.2% of cases, respectively. More than one species was present in three patients (0.3% of total). The infecting species was not determined in 80 (6.9%) cases. The number of reported malaria cases acquired in Africa (n=519) remained approximately the same as in 1994 (n=517); cases acquired in Asia increased by 32.4% (n=335); and cases acquired in the Americas increased by 37.4 % (n=246). Of 591 U.S. civilians who acquired malaria abroad, 15.6% had followed a chemoprophylactic drug regimen recommended by CDC for the area where they had traveled. Nine patients became infected in the United States. Of these nine cases, five were congenitally acquired; one was acquired by organ transplantation; and one was acquired by a blood transfusion. For two of the nine cases, the source of infection was unknown. Six deaths were attributed to malaria., Interpretation: The 15% increase in malaria cases in 1995 compared with 1994 resulted primarily from increases in cases acquired in Asia and the Americas, most notably a 100% increase in the number of cases reported from South America. This change could have resulted from local changes in disease transmission, travel patterns, reporting errors, or a decreased use of effective antimalarial chemoprophylaxis. In most reported cases, U.S. civilians who acquired infection abroad were not on an appropriate chemoprophylaxis regimen for the country where they acquired malaria., Actions Taken: Additional information was obtained concerning the six fatal cases and the nine infections acquired in the United States. Malaria prevention guidelines were updated and distributed to health-care providers. Persons traveling to a malarious area should take the recommended chemoprophylaxis regimen and use personal protection measures to prevent mosquito bites. Any person who has been to a malarious area and who subsequently develops a fever or influenza-like symptoms should seek medical care; investigation should include a blood smear for malaria. Malaria infections can be fatal if not diagnosed and treated promptly. Recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Despite the spread of chloroquine-resistant Plasmodium falciparum throughout sub-Saharan Africa, chloroquine (CQ) remains the first-line treatment for uncomplicated infection in most countries. To assess the efficacy of CQ and sulphadoxine-pyrimethamine (SP) in Zambia, studies using a standardized 14-day in vivo test were conducted at 6 geographically representative sites. Febrile children < or = 5 years of age were treated with standard doses of CQ or SP and monitored for parasitological failure (using modified WHO criteria) and clinical failure (fever with parasitaemia after completion of therapy). RII/RIII (high to moderate level) parasitological failures were identified in 34% to 70% of CQ-treated children (total N = 300) at the 6 sites and clinical failures in 31% to 48%. SP testing at 2 sites identified RII/RIII failures in 3% and 17% of children and only 1 clinical failure at each site. Because of the high levels of CQ resistance identified in these trials, the Ministry of Health of Zambia convened a national consensus meeting which recommended that Zambia's national malaria treatment policy be modified to make SP available at all health facilities for use in persons who fail initial therapy with CQ. In addition, selected sites, staff, and the methodology from these studies were used to implement a sentinel surveillance system for antimalarial drug efficacy. This systematic approach to antimalarial drug efficacy testing could be easily replicated in other countries seeking to reassess their malaria treatment policies.

In October 1995 the Ministry of Public Health and Population in Haiti surveyed 42 health facilities for the prevalence and distribution of malaria infection. They examined 1,803 peripheral blood smears from patients with suspected malaria; the overall slide positivity rate was 4.0% (range, 0.0% to 14.3%). The rate was lowest among 1- to 4-year-old children (1.6%) and highest among persons aged 15 and older (5.5%). Clinical and microscopic diagnoses of malaria were unreliable; the overall sensitivity of microscopic diagnosis was 83.6%, specificity was 88.6%, and the predictive value of a positive slide was 22.2%. Microscopic diagnoses need to be improved, and adequate surveillance must be reestablished to identify areas where transmission is most intense. The generally low level of malaria is encouraging and suggests that intensified control efforts targeted to the areas of highest prevalence could further diminish the effect of malaria in Haiti.

Problem/condition: Malaria is caused by infection with one of four species of Plasmodium (i.e., P. falciparum, P. vivax, P. ovale, and P. malariae ), which are transmitted by the bite of an infective female Anopheles sp. mosquito. Most malarial infections in the United States occur in persons who have traveled to areas (i.e., other countries) in which disease transmission is ongoing. However, cases are transmitted occasionally through exposure to infected blood products, by congenital transmission, or by local mosquitoborne transmission. Malaria surveillance is conducted to identify episodes of local transmission and to adapt prevention recommendations., Reporting Period Covered: Cases with onset of symptoms during 1994., Description of System: Malaria cases confirmed by blood smear are reported to local and/or state health departments by health-care providers and/or laboratories. Case investigations are conducted by local and/or state health departments, and the reports are transmitted to CDC through the National Malaria Surveillance System (NMSS), which was the source of data for this report. Numbers of cases reported through NMSS may differ from those reported through other passive surveillance systems because of differences in the collection and transmission of data., Results: CDC received reports of 1,014 cases of malaria with onset of symptoms during 1994 among persons in the United States or one of its territories. This number represented a 20% decrease from the 1,275 cases reported for 1993. P. vivax, P. falciparum, P. malariae, and P. ovale accounted for 44%, 44%, 4%, and 3% of cases, respectively. More than one species was present in five persons (<1% of the total number of patients). The infecting species was not determined in 50 (5%) cases. The number of reported malaria cases in U.S. military personnel decreased by 86% (i.e., from 278 cases in 1993 to 38 cases in 1994). Of the U.S. civilians who acquired malaria during travel to foreign countries, 18% had followed a chemoprophylactic drug regimen recommended by CDC for the area to which they had traveled. Five persons became infected while in the United States; the infection was transmitted to two of these persons through transfusion of infected blood products. The remaining three cases, which occurred in Houston, Texas, were probably locally acquired mosquitoborne infections. Four deaths were attributed to malaria., Interpretation: The 20% decrease in the number of malaria cases from 1993 to 1994 resulted primarily from an 86% decrease in cases among U.S. military personnel after withdrawal from Somalia. Because most malaria cases acquired in Somalia during 1993 resulted from infection with P. vivax, there was a proportionately greater decrease during 1994 in the number of cases caused by P. vivax relative to those caused by P. falciparum., Actions Taken: Additional information was obtained concerning the four fatal cases and the five cases acquired in the United States. Malaria prevention guidelines were updated and distributed to health-care providers. Persons traveling to a geographic area in which malaria is endemic should take the recommended chemoprophylactic regimen and should use protective measures to prevent mosquito bites. Persons who have a fever or influenza-like illness after returning from a malarious area should seek medical care; medical evaluation should include a blood smear examination for malaria. Malarial infections can be fatal if not promptly diagnosed and treated. Recommendations concerning prevention and treatment of malaria can be obtained from CDC.

Objective: To determine the effect of transfusion on hematologic recovery and mortality among severely anemic children during and after hospitalization in rural Kenya., Design: Prospective cohort., Methods: We collected clinical and laboratory information on all severely anemic children (hemoglobin < 5.0 g/dl) and a 33% sample of children with hemoglobin < or = 5.0 g/dl who were admitted to the pediatric ward of a rural Kenyan hospital during a 6 month study period. Children were followed during hospitalization and at 4 and 8 weeks after admission., Results: Overall, 303 (25%) of the 1223 hospitalized children had hemoglobin < 5.0 g/dl, 30% of whom died during the study period. Severely anemic children who were transfused had a higher mean hemoglobin level at discharge (9.0 g/dl) than non-transfused children (5.8 g/dl, P < 0.001) and maintained a higher mean hemoglobin during the 8-week follow-up period. However, the presence of malaria parasitemia on follow-up negated the benefit of transfusion on hematologic recovery at both 4- and 8-week visits (longitudinal linear model, least square means, P > 0.05). Transfusion was associated with improved survival among children with respiratory distress who received transfusions within the first 2 days of hospitalization., Conclusions: The use of transfusion can be improved by targeting use of blood to severely anemic children with cardiorespiratory compromise, improving immediate availability of blood, and treating severely anemic children with effective antimalarial therapy.

The idea of a global campaign to eradicate dracunculiasis was first proposed by the Centers for Disease Control and Prevention in 1980, during the advent of the International Drinking Water Supply and Sanitation Decade (IDWSSD) (1981-1990). In 1981, the Steering Committee of the IDWSSD adopted eradication of dracunculiasis as a subgoal of their efforts to provide safe drinking water to unserved populations. In 1988, African ministers of health voted to eradicate dracunculiasis by the end of 1995, a target date that was endorsed by UNICEF in 1989 and the World Health Assembly in 1991. Although nine of 18 endemic countries, India (1980), Pakistan (1987), Nigeria and Cameroon (1988), Ghana (1989), and Mauritania, Benin, Burkina Faso, and Togo (1990) completed national searches for cases of the disease, only four countries, India (1983), Pakistan (1988), Ghana (1989), and Nigeria (1989), actually started eradication programs during the 1980s. The remaining 14 endemic countries began their eradication programs between 1991 and 1995. At the end of 1996, dracunculiasis had not been entirely eradicated, but its incidence had been reduced by 95%, from an estimated 3.2 million cases in 1986 to 152,805 cases in 1996. Sudan reported a total of 118,578 (78%) of the 152,805 cases of dracunculiasis reported during 1996. Insufficient funding and the civil war in Sudan continue to be the major obstacles to overcome. A primary aim of the eradication program in 1997 is to seek to ensure that all cases of dracunculiasis outside of Sudan are contained. In Sudan the challenge is to pursue all appropriate control measures in all accessible areas as vigorously as possible until political circumstances allow access to all of the remaining affected areas.

Plasmodium falciparum infection is an important cause of the high childhood mortality rates in sub-Saharan Africa. Increasingly, the contribution of P. falciparum-associated severe anemia to pediatric mortality is being recognized while the impact of chloroquine resistance on mortality has not been evaluated. To address the issues of pediatric mortality, causes of death among hospitalized children less than five years of age in western Kenya were identified using standardized clinical examinations and laboratory evaluations. Follow-up examinations were conducted to determine the child's clinical status posthospitalization. Of the 1,223 children admitted to Siaya District Hospital from March to September 1991, 293 (24%) were severely anemic (hemoglobin level < 5.0 g/dL). There were 265 (22%) deaths; 121 (10%) occurred in-hospital and 144 (13%) occurred out-of-hospital within eight weeks after admission; 32% of all deaths were associated with malaria. Treatment for malaria with chloroquine was associated with a 33% case fatality rate compared with 11% for children treated with more effective regimens (pyrimethamine/sulfa, quinine, or trimethoprim/sulfamethoxazole for five days). The risk of dying was associated with younger age (P < 0.0001) and severe anemia (relative risk [RR] = 1.52, 95% confidence interval [CI] = 1.22, 1.90), and was decreased by treatment with an effective antimalarial drug (RR = 0.33, 95% CI = 0.19, 0.65). Effective drug therapy for P. falciparum with regimens that are parasitocidal in areas with a high prevalence of severe anemia and chloroquine resistance can significantly improve the survival of children in Africa.

As part of an effort to involve community members in malaria control activities, we studied knowledge, beliefs, and practices of residents of both the Pacific coastal plain and northeastern Guatemala related to malaria transmission and Anopheles albimanus control. Most residents recognized the role of mosquitoes in malaria transmission, but few knew how mosquitoes acquired their infections or understood the risk of having an untreated person in their midst. If this were more widely known, residents might put greater pressure on infected patients to seek timely and appropriate antimalarial treatment. Seventy-three percent of families owned one or more bed nets; however, even though most informants believed that bed nets help protect against malaria, the major reason for using them was to prevent nuisance mosquito bites. It is concluded that efforts should be made to promote bed net use by seeking ways to make them more affordable and by emphasizing their effectiveness as a barrier to nuisance mosquitoes. Although residents have a very positive opinion of the National Malaria Service spray teams, it is proposed that cooperation might be improved if malaria workers would emphasize the fact that house spraying reduces the numbers of nuisance mosquitoes and other pest insects, rather than focusing solely on malaria prevention, which most informants believed was less important. This study emphasizes the importance of understanding community beliefs and practices when planning or evaluating vector control activities.

Reported are the results of a study of residents' knowledge about malaria and antimalarial drugs and of their treatment-seeking behaviour in a rural area of western Kenya. The study subjects were generally well-informed about the symptoms of the disease. Malaria was perceived as a relatively mild illness, much less severe than acquired immunodeficiency syndrome (AIDS), measles, difficulty in breathing, and diarrhoea. Self-treatment was extremely common: of 138 episodes of febrile illness, 60% were treated at home with herbal remedies or medicines purchased at local shops, and only 18% received treatment at a health centre or hospital; no treatment was sought by the remainder. Commercially available chloroquine preparations were perceived as more effective than either antipyretics or herbal remedies for the treatment of malaria, and injections were regarded as more effective than oral medications. 4-Amino-quinolines were used to treat 58% of febrile illnesses but in only 12% of the cases was a curative dose of > or = 25 mg/kg body weight employed. Even attendance at a health centre did not ensure adequate treatment because of the common practice of sharing medication among family members. Greatly increased attention should be paid to the role of home treatment of malaria when policies are being developed for the management of febrile illnesses in sub-Saharan Africa.

Substantial progress has been realized in the global campaign to eradicate dracunculiasis by the end of 1995 since a previous review of the subject was published in this journal a year ago. All known endemic countries are now engaged in the eradication effort, and one or more control measures are now in place in 93% of endemic villages. Despite improved surveillance for the disease, the number of reported cases of the disease has been reduced by 41% (to about 221,000), and the number of known endemic villages has been reduced by 28% (to about 16,500) in the past year. Priorities for national eradication programs in 1994 include increasing the use of vector control and intensifying the case containment strategy in endemic villages. It is still possible to achieve the eradication target of December 1995, but greatly intensified efforts this year will be required to do so.

Since the late 1950s, most malaria surveillance and treatment in rural areas of Latin America has been carried out by networks of unpaid community malaria workers, known as Volunteer Collaborators, who are selected and supervised by staff of the national malaria services (NMSs) in each country. In spite of the free and readily accessible antimalarial treatment available at these Volunteer Collaborator posts, many residents continue to seek treatment elsewhere and in most cases take doses of antimalarials that are insufficient to cure their infections. To identify ways in which the Volunteer Collaborator Network could be made more attractive to residents and to improve the process of selection of new workers, we asked community residents and Guatemalan NMS workers to rank order, according to their importance, 11 qualities or characteristics of an 'ideal' volunteer malaria worker. Community residents preferred someone who is available to take care of patients at all times of the day, is a responsible person, and has a general knowledge of medicine. No significant differences were noted in the rank orders of male and female residents or literate and illiterate residents. National Malaria Service workers also preferred someone who takes care of patients at all times of the day, even when busy. In addition, they wanted individuals who recognize the importance of their work as a Volunteer Collaborator, but choosing volunteers who had a general knowledge of medicine was not important. By modifying the procedures used to select Volunteer Collaborators so as to identify candidates with the qualities preferred by residents, it should be possible to increase acceptance and improve the performance of these volunteer workers.

Severe anaemia among women in sub-Saharan Africa is frequently treated with blood transfusions. The risk of transmission of human immunodeficiency virus (HIV) through blood products has led to a re-evaluation of the indications for transfusions. Prospective surveillance of women admitted to a district hospital in western Kenya was conducted from 1 December 1990 to 31 July 1991, for haemoglobin (Hb) transfusion status, and outcome. Of the 2986 enrolled women (mean Hb 10.4 g/dL, SD +/- 2.6, median age 24.4 years), 6% were severely anaemic (Hb < 6.0 g/dL). Severe anaemia was associated with a higher mortality rate (10.7% vs. 1.4%, odds ratio (OR) = 8.2, 95% confidence interval (CI) 2.6, 34.2) compared with women with Hb > or = 6.0 g/dL. Decreased mortality rates in hospital were observed with increasing Hb values (OR = 0.43, 95% CI 0.19, 0.98), but blood transfusions did not improve survival in hospital (OR = 1.56, 95% CI 0.22, 11.03). The attributable mortality due to HIV infection and severe anaemia was 75% and 31%, respectively. Maternal/child health care services must include prevention strategies for HIV transmission and the prevention, recognition, and treatment of severe anaemia.

In most rural areas of Latin America, malaria surveillance and treatment is carried out by a network of unpaid village malaria workers, known as Volunteer Collaborators, who are trained and supervised by the National Malaria Service. To identify ways in which the performance of these volunteer workers could be improved and to test changes that would make the Volunteer Collaborator Networks (VCNs) a more attractive model for community participation in malaria case detection and treatment in other regions, we tested a series of modifications in the VCN of Guatemala. These modifications included improved methods for selecting, supervising, and evaluating the volunteer workers and for collecting blood smears and reporting results, and the use of volunteer workers, known as Volunteer Medicators, who administered presumptive antimalarial therapy without taking a blood smear. A cost-effectiveness analysis of the modified VCN was also carried out. Two years after the modifications were introduced, Volunteer Collaborators identified nearly twice as high a percentage (33% versus 17%) of patients with suspected malaria in their villages. Delays in examining blood smears were reduced from 23 days to 11 days and delays from blood smear examination to curative treatment were reduced from 21 days to 7 days. The Volunteer Medicators identified and treated only a slightly higher percentage of patients than the Volunteer Collaborators (36% versus 33%). However, the cost of maintaining a network of Volunteer Medicators ($0.61 per patient treated) was much lower than the traditional VCN ($2.45) or the modified VCN ($1.85). Thus, with a few, simple and relatively inexpensive modifications, the efficiency and cost-effectiveness of Volunteer Collaborators can be markedly improved. Additionally, the VCN can be modified to make it a more suitable model for community-based malaria control and surveillance networks in other malarious areas of the world, which differ in terms of their level of endemicity, the goals of the malaria program, or the available health care infrastructure.

The effectiveness of village-wide use of permethrin-impregnated bed nets or eave, window, and door curtains as control measures for Plasmodium falciparum malaria was evaluated during two successive high-transmission seasons in western Kenya. Pairs of villages were assigned to one of three study groups: bed net, curtain, or control. Clinical, parasitologic, and entomologic measures were made from March to July 1990 and again 12 months later. When compared with the controls in 1990 and 1991, we observed a marked reduction in the incidence of P. falciparum infections in children less than six years old in the bed net villages (reduced by 40% and 48%) and a smaller but still significant reduction in the curtain villages (10% and 33%). Significant reductions were also seen in the incidence of P. falciparum parasitemias greater than 2,500/mm3 in the bed net group (reduced by 44% and 49%) and curtain group (16% and 32%). Additionally, we observed significant reductions in the incidence of documented fevers in association with P. falciparum parasitemia in bed net (reduced by 63%) and curtain villages (53%) when compared with controls. Entomologic inoculation rates in both bed net and control villages decreased by more than 50% below control values during both high transmission seasons. The results of this study, together with a 1988 study in the same area during the low transmission season, show that bed nets offer greater year-round of protection against P. falciparum infection than curtains. However, during the high transmission season, this technique reduces the frequency of P. falciparum infection rather than preventing it entirely.

Objectives: To identify ways to improve the operation of blood-screening programs and to decrease the inappropriate use of blood by evaluating blood-transfusion practices and blood-banking services in a Kenyan hospital., Design: Prospective cohort., Setting: The study was conducted in a rural district hospital in western Kenya between September 1990 and July 1991., Methods: We collected data on all transfusion requests (blood donation, grouping, HIV screening) and blood recipients (age, sex, diagnosis, and for a 3-month period on the pediatric, maternity, and female wards, admission hemoglobin and outcome)., Results: During the 11-month study period, 799 patients received 927 transfusions: 67% were children < 15 years of age, 27% were adult women and 6% were adult men. Transfusions were often delayed due to reliance on patient-recruited donors. Patients who received blood donated on or after the date of request waited longer for transfusion (median, 3 days) than patients who received blood that had been banked and screened before the request (median, 1 day). Patient-recruited donors had a higher HIV-seropositivity rate than volunteer donors (13.4 and 4.6%, respectively; chi 2 test, P < 0.001). Overall, 47% of pediatric transfusions were classified as inappropriate: 23% did not meet the criteria of having hemoglobin < 5.0 g/dl and clinical evidence of respiratory distress, and 27% were transfused 2 or more days after requested. Among adults, 68% received one unit of blood or less., Conclusions: Improved laboratory services, reduction of unnecessary transfusions, and increased recruitment of volunteer donors are critical for improving the appropriate and timely use of blood and reducing transfusion-associated HIV transmission.

In Africa, blood transfusions are frequently given to treat severe paediatric anaemia. Because of the risk of HIV transmission, identification of when transfusion will reduce the risk of death for severely anaemic children has become increasingly important. For all children admitted to a Kenyan hospital from October, 1989, to October, 1990, we collected data on clinical presentation, haemoglobin (Hb), receipt of transfusion, and in-hospital survival. Of 2433 admissions, 29% (684) had severe anaemia (Hb less than 5.0 g/dl), and 20% (483) received blood transfusions. Based on laboratory criteria only, children with Hb less than 3.9 g/dl who were transfused had lower mortality than those with Hb less than 3.9 g/dl who were not transfused, but this finding applied only to children transfused on the day of admission (odds ratio [OR] 0.30; 95% Cl 0.14, 0.61) or the day after admission (OR 0.37; 95% Cl 0.14, 1.00). Based on a combination of laboratory and clinical criteria, children with clinical signs of respiratory distress and Hb less than 4.7 g/dl who were transfused had lower morality than those who were not (OR 0.19; 95% Cl 0.09, 0.41). Among children without respiratory distress, there was no association between receipt of transfusion and mortality, irrespective of admission Hb. The frequency of blood transfusion can be reduced and survival enhanced by targeting blood to those children with severe anaemia and clinical signs of respiratory distress, and by using transfusion early in the course of hospitalisation.

We tested the ability of a recombinant DNA-encoded fragment (C7Ag) of a Plasmodium falciparum merozoite protein (p75) and of two carrier-free peptide models (28-mer and 76-mer) to stimulate boostable antibody responses in Aotus nancymai monkeys. In addition, we evaluated protection against challenge with the Uganda Palo Alto (FUP) strain of this parasite. The data indicate that C7Ag elicited a strong and boostable IgG antibody response in all the monkeys immunized. However, studies with the peptide models demonstrated that various animals produce antibodies to different portions of this structure. When the post-boost sera from monkeys immunized with C7Ag were analyzed for reactivity against two major portions of C7Ag, most of the antibody response was observed against the disulfide-bonded 76-residue region that forms a conformational immunogenic epitope. In the same sera, antibody levels against the charged helical region modeled with a 28-mer were generally low. Immunization with synthetic peptides revealed that the 76-mer stimulated an antibody response almost as strong as C7Ag, with substantial cross-reactivity against the parasite antigen. The 28-mer evoked a response that was not efficient or uniform, and showed little reactivity with the authentic parasite antigen. Aotus nancymai was shown to be susceptible to infection with the Uganda Palo Alto strain of P. falciparum; however, maximum parasitemia varied markedly in both immunized and control monkeys. Statistical analysis failed to recognize differences in maximum parasitemia between the vaccine and control groups. The variation in maximum parasitemia suggests that the FUP strain in this species of Aotus is a poor model for the detection of differences in efficacy based on maximum parasitemia. This initial study with structures based on parts of the 75-kD merozoite surface antigen of P. falciparum indicated that both the recombinant-produced protein C7 and the 76-mer synthetic peptide, when combined with a Syntex adjuvant formulation, were safe and immunogenic in A. nancymai monkeys. However, the data emphasize the problems of using animal models to evaluate the potential effects of immunogens in humans.