The Tingathe Surge: a multi-strategy approach to accelerate HIV case finding in Malawi.

SETTING: Nineteen health facilities in rural, southeastern Malawi. OBJECTIVE: To describe the implementation and results of a 6-week intervention to accelerate human immunodeficiency virus (HIV) case finding. DESIGN: Six HIV testing strategies were simultaneously implemented. Routinely collected data from Ministry of Health registers were used to determine the number of HIV tests performed and of new cases identified. The weekly averages of the total number of tests and new cases before and during the intervention were compared. Testing by age group and sex was described. The percentage yield of new cases was compared by testing strategy. RESULTS: Of 29 703 HIV tests conducted, 1106 (3.7%) were positive. Of the total number of persons tested, 69.5% were women and 75.5% were aged >15 years. The yield of positive test results was 3.5% among women, 4.3% among men, 4.4% among those aged >15 years and 1.5% among those aged ⩽15 years. The average weekly number of tests increased 106.7% from 3337 to 6896 (P = 0.002). The average weekly number of positive cases identified increased 51.9% from 158 to 240 (P = 0.017). The testing strategy with the highest yield resulted in a 6.0% yield; the lowest was 1.3%. The yield for all strategies, except one, was highest in adult men. CONCLUSION: A multi-strategy approach to HIV testing and counseling can be an effective means of accelerating HIV case finding.

Burden of disease and risk factors for death among children treated for tuberculosis in Malawi.

SETTING: Tuberculosis (TB) is a leading cause of childhood death. Patient-level data on pediatric TB in Malawi that can be used to guide programmatic interventions are limited. OBJECTIVE: To describe pediatric TB case burden, disease patterns, treatment outcomes, and risk factors for death and poor outcome. DESIGN: We conducted a retrospective cohort study utilizing routine data. Odds ratios (ORs) for factors associated with poor outcome and death were calculated using generalized estimating equations. RESULTS: Children represented 8% (371/4642) of TB diagnoses. The median age was 7 years (interquartile range 2.8-11); 32.8% (113/345) were human immunodeficiency virus (HIV) infected. Of these, 54.0% were on antiretroviral therapy (ART) at the time of anti-tuberculosis treatment (ATT) initiation, 21.2% started ART during ATT, and 24.8% had no documented ART. The treatment success rate was 77.3% (11.2% cured, 66.1% completed treatment), with 22.7% experiencing poor outcomes (9.5% died, 13.2% were lost to follow-up). Being on ART at the time of ATT initiation was associated with increased odds of death compared to beginning ART during treatment (adjusted OR 2.75, 95%CI 1.27-5.96). CONCLUSION: Children represent a small proportion of diagnosed TB cases and experience poor outcomes. Higher odds of death among children already on ART raises concerns over the management of these children. Further discussion of and research into pediatric-specific strategies is required to improve case finding and outcomes.

Risk factors for mortality in Malawian children with human immunodeficiency virus and tuberculosis co-infection.

SETTING: A large urban pediatric human immunodeficiency virus (HIV) clinic in Lilongwe, Malawi. OBJECTIVE: To identify demographic and clinical risk factors for mortality in children co-infected with HIV and tuberculosis (TB). DESIGN: A retrospective cohort study of HIV-infected children (aged <18 years) enrolled between October 2004 and October 2010 with at least one current or historical TB diagnosis. Descriptive statistics and logistic regression analyses were performed to determine factors associated with mortality. RESULTS: A total of 1561 patients met the inclusion criteria, representing 32% of patients ever enrolled. Median age at TB diagnosis was 3.8 years (interquartile range 1.5-7.4); 60.9% had severe immune suppression and 47.6% of those with available data had some degree of acute malnutrition at TB diagnosis. Of the 1113 patients with known outcomes, 225 (20.2%) died. Children with TB-HIV co-infection not initiated on antiretroviral therapy (ART) at any time were 8.8 times more likely to die compared to those initiated on ART 0-2 months after initiation of anti-tuberculosis treatment (adjusted OR 8.83, 95%CI 4.42-17.63). Severe immunosuppression and World Health Organization Stage IV were also associated with mortality. CONCLUSIONS: Pediatric TB-HIV co-infection is common and mortality is high in this cohort of Malawian children. Prompt initiation of ART should be emphasized in this high-risk patient population.

Sexually Transmitted Infection (STI) screening, case and contact treatment, and condom promotion resulting in STI reduction two years later in rural Malawi.

As part of a longitudinal cohort study in rural Malawi in 2000, 469 men and 758 women were asked to respond to a series of surveys, were tested for gonorrhea and chlamydia, and received their results and treatment, if applicable, for themselves and up to 2 partners if positive for either sexually transmitted infection (STI). Two years later, in 2002, 328 men and 525 women were again asked to respond to survey questions, tested again for gonorrhea and chlamydia, and were also tested for HIV--of these, 247 men and 453 women had also given urine samples in 2000. In 2000, the gonorrhea and chlamydia prevalence was 6.2% and 5.8% among men, and 3.6% and 4.9% among women. Two years later, prevalence of gonorrhea and chlamydia was 0.7% and 1.4% among men, and 1.3% and 1.1% among women. Although we did not test for HIV in the first round, the HIV prevalence in 2002 was 19.2%. The implications of the findings are discussed in the context of interventions for STI prevention and to reduce HIV transmission in sub-Saharan Africa.

Community-based distribution of sulfadoxine-pyrimethamine for intermittent preventive treatment of malaria during pregnancy improved coverage but reduced antenatal attendance in southern Malawi.

OBJECTIVE: To evaluate the impact of a 2-year programme for community-based delivery of sulfadoxine-pyrimethamine (SP) on intermittent preventive treatment during pregnancy coverage, antenatal clinic attendance and pregnancy outcome. METHODS: Fourteen intervention and 12 control villages in the catchment areas of Chikwawa and Ngabu Government Hospitals, southern Malawi, were selected. Village-based community health workers were trained in information, education and counselling on malaria control in pregnancy and the importance of attending antenatal clinics and promoted these messages to pregnant women. In the intervention group community health workers also distributed SP to pregnant women. RESULTS: In the control area, coverage of intermittent preventive treatment during pregnancy (>2 doses) was low before (44.1%) and during the intervention (46.1%). In the intervention area, coverage increased from 41.5% to 82.9% (P < 0.01). Antenatal clinic attendance (>2 visits) was maintained in control villages at above 90%, but fell in intervention villages from 87.3% to 51.5% (P < 0.01). Post-natal malaria parasitaemia prevalence fell in women from both study areas during the intervention phase (P < 0.05). Increasing the coverage of intermittent preventive treatment during pregnancy to >40% did not significantly improve maternal haemoglobin or reduce low birthweight prevalence. CONCLUSIONS: Better coverage of community-based intermittent preventive treatment during pregnancy can lower attendance at antenatal clinics; thus its effect on pregnancy outcome and antenatal attendance need to be monitored.

Genotypic analysis of the protease and reverse transcriptase of HIV type 1 subtype C isolates from antiretroviral drug-naive adults in Malawi.

The protease (PR) and reverse transcriptase (RT) regions of HIV-1 isolates from 21 antiretroviral (ARV)-naive Malawian adults were sequenced and analyzed to determine the prevalence of drug resistance-associated mutations in this population. Phylogenetic analysis confirmed that all isolates grouped with HIV-1 subtype C, the predominant subtype in Malawi. No major mutations associated with resistance to PR inhibitors (PIs), nucleoside RT inhibitors (NRTIs), or nonnucleoside RT inhibitors (NNRTIs) were found. In contrast, accessory mutations were found in the protease region at positions 10, 20, 36, 63, 77, and 93, and in the RT region at positions 118, 211, and 214. Further studies will be needed to determine the clinical impact of these polymorphisms on viral susceptibility to existing antiretroviral drugs.

Childhood tuberculosis in Malawi: caseload, diagnostic practices and treatment outcomes.

There were 22,982 cases of TB registered in Malawi in 1998, of which 2739 (11.9%) were children. Children accounted for 11.3% of all case notifications with smear-positive pulmonary TB (PTB), 21.3% with smear-negative PTB and 15.9% with extrapulmonary TB (EPTB). A significantly higher proportion of TB cases were diagnosed in central hospitals. Only 45% of children completed treatment. There were high rates of death (17%), default (13%) and unknown treatment outcomes (21%). Treatment outcomes were worse in younger children and in children with smear-negative PTB. In 2001, all 44 non-private hospitals in Malawi that register and treat children with tuberculosis (TB) were surveyed to determine actual diagnostic practice. This cross sectional study identified 150 children aged 14 years or below in hospital receiving anti-TB treatment, 98 with pulmonary TB (PTB) and 52 with extrapulmonary TB (EPTB). Median duration of illness was 8 weeks. Most patients had fever, no response to anti-malarial treatment and antibiotics, and 40% had a positive family history of TB. Nearly 45% had weight for age < 60%. Diagnosis was mainly based on clinical features and radiography, with less than 10% having tuberculin skin tests or HIV serology, and very few having other sophisticated investigations. Diagnostic difficulties make it difficult to accurately define the actual burden of childhood TB in Malawi. Diagnostic practices are poor and treatment outcomes unsatisfactory.

Detection of bloodstream pathogens in a bacille Calmette-Guérin (BCG)-vaccinated pediatric population in Malawi: a pilot study.

Children in Malawi receive bacille Calmette-Guérin (BCG) vaccination within the first 3 days of life. Thus, we hypothesized that Malawian children infected with the human immunodeficiency type 1 virus (HIV-1) might be particularly vulnerable to dissemination of the BCG Mycobacterium bovis strain with which they were vaccinated. Following informed consent by parents, we studied children admitted to a Malawi general hospital during the 1998 wet and dry seasons. Blood from cohorts of acutely ill children was cultured for bacteria, including mycobacteria, and fungi, and tested for anti-HIV-1 antibodies. It was shown that non-typhi Salmonella and Escherichia coli were the predominant bloodstream pathogens during the wet and dry seasons, and that bloodstream dissemination of the BCG M. bovis strain is uncommon in HIV-1-infected children who receive the BCG vaccine.

Age-related differences in cell-specific cytokine production by acutely ill Malawian patients.

Age-related changes in human cell-specific cytokine responses to acute illness have not been well examined. We therefore evaluated age-related differences in T, B and natural killer (NK) peripheral blood lymphocyte cytokine responses of 309 acutely ill hospitalized people in Malawi, Africa, < 1 month-61 years of age. We used four-colour flow cytometry and performed Wilcoxon rank sum and Kruskal-Wallis tests, Pearson (rp) and Spearman (rs) correlations, and linear and logistic regression analyses to control for human immunodeficiency virus infection (HIV) status, the percentages of lymphocytes expressing CD4, and the nature of the acute infection. The percentages of CD8- and CD8+ T cells producing induced IL-8 decreased with age (rs = -0.44 and -0.53). The percentages of T cells producing TNF-alpha were higher, and the percentages producing IL-10 were lower, in those > or =13 than those < 13 years old (medians: 17.7 versus 10.5 and 1.4 versus 3.0, respectively). The percentages of CD8- T cells producing IFN-gamma were higher and stable in those > or =1 year old compared to infants (medians: 23.5 versus 10.4); the percentages of NK producing IFN-gamma were higher post-infancy and then declined to relatively low levels with increasing age. The percentages of T cells producing IL-2 were highest in those 5- <31 years old (median 5.6) and lowest in those > or =31 years old (median 1.9). The ratios of the percentages of T cells producing IL-4 to those producing IL-8 and to those producing IL-10 both increased with age. These data suggest that innate immunity, represented by NK IFN-gamma production, dominates in early life. A number of shifts occur after infancy and before adolescence, including a proinflammatory shift from IL-8 to TNF-gamma and a type 2 shift from IL-10 to IL-4 dominance. These findings suggest distinct age-related differences in the human response to acute illness and may be useful in directing future efforts at immunomodulatory therapies.

The effects of iron deficiency on lymphocyte cytokine production and activation: preservation of hepatic iron but not at all cost.

Worldwide, over 40% of children have iron deficiency anaemia, frequently associated with infections. Certain cytokines are involved in both immune activation/response to infection and iron transport/metabolism. We therefore assessed the relations among iron deficiency, cytokine production and lymphocyte activation markers in 142 hospitalized Malawian children. We examined peripheral blood lymphocyte antigens/cytokine production using four- colour flow cytometry and serum transferrin receptor (TfR) levels, an inverse measure of iron status unaffected by acute illness or infection, with an enzyme-linked immunosorbent assay. Wilcoxon rank sum tests and logistic regression analyses (LRA) were performed. Iron deficiency (TfR > or = 10 microg/ml) versus TfR < 10 microg/ml, was associated with higher percentages of lymphocytes producing: (a) induced or spontaneous IL-6 (medians: induced, 15.9% for iron-deficient children versus 8.8% for iron-replete children, P = 0.002; spontaneous, 24.4% versus 13.0%, P < 0.001) and (b) induced IFN-gamma (medians:18.4% versus 12.4%, P = 0.006). The percentages of CD8(+) T cells spontaneously producing IL-6 and of all lymphocytes producing induced TNF-alpha and IFN-gamma in the same cell had the strongest relationships to iron deficiency (b = + 0.0211, P = 0.005 and b = + 0.1158, P = 0.012, respectively, LRA) and were also positively related to the co-expression of the T cell activation markers HLA DR and CD38. Severe iron deficiency (TfR > or = 30 microg/ml) was associated with the percentage of lymphocytes producing induced IL-4 (medians: 0.5% versus 1.6%, P < 0.010). The cytokine patterns associated with iron deficiency in our study would preserve iron stores but also preferentially retain the activation capabilities of T cells, albeit not necessarily other immune cells, until a critical level of iron depletion is reached.

Comparison of serum and cell-specific cytokines in humans.

Cytokines function at the cellular, microenvironmental level, but human cytokine assessment is most commonly done at the macro level, by measuring serum cytokines. The relationships between serum and cellular cytokines, if there are any, are undefined. In a study of hospitalized patients in Malawi, we compared cytometrically assessed, cell-specific cytokine data to serum interleukin 2 (IL-2), IL-4, IL-6, IL-8, IL-10, gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) levels in 16 children and 71 (IL-2, -4, -6, -10) or 159 (IL-8, IFN-gamma, and TNF-alpha) adults, using Wilcoxon rank sum tests and Pearson's (r(p)) and Spearman's (r(s)) rank correlations. For the entire study group, correlations between identical serum and cellular cytokines mainly involved IL-8 and IFN-gamma, were few, and were weakly positive (r < 0.40). Blood culture-positive persons had the most and strongest correlations, including those between serum IL-2 levels and the percentages of lymphocytes spontaneously making IL-2 (r(s) = +0.74), serum IL-8 levels and the percentages of lymphocytes spontaneously making IL-8 (r(p) = +0.66), and serum IL-10 levels and the percentages of CD8(+) T cells making TNF-alpha (r(p) = +0.89). Human immunodeficiency virus (HIV)-positive persons had the next largest number of correlations, including several serum IL-8 level correlations, correlation of serum IL-10 levels with the percentages of lymphocytes producing induced IL-10 (r(s) = +0.36), and correlation of serum IFN-gamma levels and the percentages of lymphocytes spontaneously making both IL-6 and IFN-gamma in the same cell (r(p) = +0.59). HIV-negative, malaria smear-positive, and pediatric patients had few significant correlations; for the second and third of these subgroups, serum IL-8 level was correlated with the percentage of CD8(-) T cells producing induced IL-8 (r(s) = +0.40 and r(s) = +0.56, respectively). Thus, the strength of associations between serum and cellular cytokines varied with the presence or absence of bloodstream infection, HIV status, and perhaps other factors we did not assess. These results strongly suggest that serum cytokines at best only weakly reflect peripheral blood cell cytokine production and balances.

Seasonal variation in the etiology of bloodstream infections in a febrile inpatient population in a developing country.

OBJECTIVES: Published data suggest that Streptococcus pneumoniae, non-typhi Salmonella species, and Mycobacterium tuberculosis are the predominant causes of bloodstream infection (BSI) in hospitalized populations in sub-Saharan Africa. This study was conducted during the wet season to ascertain the etiology and prevalence of BSI among febrile inpatients in a hospital where the dry season BSI profile in a similar study population had already been documented. METHODS: In the period from March to May 1998, consecutive febrile (> or = 37.5 degrees C) adult (> or = 14 y) patients presenting to a Malawi hospital were enrolled after providing informed consent. Following clinical evaluation, blood was drawn for culture (bacteria, mycobacteria, and fungi), human immunodeficiency virus (HIV) testing, and malaria smears. RESULTS: Of 238 enrolled patients, 173 (73%) were HIV-positive and 67 (28%) had BSI. The predominant wet season BSI pathogens were non-typhi Salmonella species (41%), M. tuberculosis (19%), and Cryptococcus neoformans (9%) (cf. the predominant dry season pathogen was S. pneumoniae). Mycobacteremia was more likely in HIV-positive than in HIV-negative patients (13/173 vs. 0/65; P < 0.05). A logistic regression model yielded clinical predictors of BSI that included chronic fever, oral candidiasis, or acute diarrhea. CONCLUSION: Pathogens causing BSI in febrile inpatients in a Malawi teaching hospital vary by season. Season- and country-specific studies, such as this one, provide data that may facilitate empirical therapy of febrile illnesses whose etiologies vary by season.

Cytokines and malaria parasitemia.

The balance between pro- and antiinflammatory cytokines may be important in malaria presentation and outcome. Malaria tends to be more severe in children than in adults, presumably because partial immunity develops with age. However, the full nature of, and age-related differences in, anti-malarial immunity are unknown. We compared: (1) serum and cell-specific cytokines of patients with acute malaria to those of patients with other acute illnesses and to those of healthy adults and (2) the cytokine responses of parasitemic children and parasitemic adults. Flow cytometry was done on the peripheral blood mononuclear cells of 148 hospitalized children, 161 febrile hospitalized adults, and 20 healthy adults in Malawi, Africa, a malaria-endemic country. Serum cytokines were also assessed for 80 of these patients. Thirty-eight participants were parasitemic with Plasmodium falciparum. Serum interleukin (IL)-10 (an antiinflammatory, immunoregulatory, and type 2 cytokine) levels were higher in malaria patients than in other patients (medians 502 pg/mL vs 16 pg/mL, P = 0.002), and the percentages of various lymphocyte populations making IL-6 (a proinflammatory, type 2 cytokine regulating iron distribution) were lower in malaria patients than in other patients (e.g., for spontaneous production by children's CD8(+) T cells: medians 1.4% vs 33.1%, P = 0.004). For adult patients, the percentages of lymphocytes spontaneously making IL-4 (a type 2 cytokine) were significantly lower in those with malaria than in those without malaria (medians 0.9% vs 2.1%, P = 0.005). The percentages of monocytes spontaneously making IL-8 (a chemotactic, proinflammatory chemokine) were higher in parasitemic children than in parasitemic adults (medians 5.8% vs 1.7%, P = 0.003). A number of cellular proinflammatory, type 1 parameters were significantly higher in all children (with or without malaria) than in all adults; these included the percentages of various lymphocyte populations making IL-6, both IL-6 and interferon-gamma, or IL-8. These data support the importance of IL-10 in malaria parasitemia. Given the lack of an IL-4 (type 2) response, IL-10's primary role may be immunoregulatory rather than type 2 in nature. In this study, the immune response to malaria was more proinflammatory in children than in adults. This difference, if corroborated by other studies, could be related to malaria's greater severity in children.

Efficacy of mefloquine and sulfadoxine-pyrimethamine for the treatment of uncomplicated Plasmodium falciparum infection in Machinga District, Malawi, 1998.

In response to the spread of chloroquine-resistant Plasmodium falciparum, Malawi changed its first-line antimalarial drug in 1993 from chloroquine to sulfadoxine-pyrimethamine (SP). Surveillance data has suggested that resistance to SP may be increasing. We compared the efficacy of SP with a potential successor, mefloquine (MQ). By use of a modified World Health Organization in vivo protocol, children infected with P. falciparum were randomized to receive SP (sulfadoxine 25 mg/kg) or MQ (15 mg/kg). We observed combined RII and RIII parasitologic failures of 20.0 and 22.0% in the SP and MQ arms, respectively. Among those in the MQ arm, the relative hazard of failing with a Day 2 drug level < 500 ng/mL was 10.6 times higher than those with levels > or = 500 ng/mL. Given the decreased efficacy of the first-line antimalarial drug and the high failure rates of MQ at this lower dosage, Malawi should consider assessing the efficacy and feasibility of alternative drugs to treat uncomplicated falciparum malaria.

Natural T, gammadelta, and NK cells in mycobacterial, Salmonella, and human immunodeficiency virus infections.

NK cells, gammadelta T cell antigen receptor chain-positive cells, and CD3(+)CD16/56(+) (natural T [NT]) cells are involved in innate immunity and immunoregulation; however, their role in clinical infection is not well defined. Cytofluorometric analysis was used to examine peripheral blood from bacteremic, nonbacteremic, and healthy human immunodeficiency virus (HIV)-positive and -negative persons in Malawi, Africa. Mycobacteremia was associated with a higher proportion of CD3(+)CD8(-) gammadelta cells (median, 16.6% vs. 0.7% for all other cells; P<.001), and Salmonella bacteremia was associated with a higher proportion of NT cells (4.3% vs. 2.2%; P=. 002). HIV plasma RNA levels were weakly positively correlated with NT cells (rs=.39; P=.002), NK cells (rs=.38; P=.003), and gammadelta cells (rs=.43; P<.001). Compared with patients who survived, patients who died had a higher percentage of NT cells (3.7% vs. 1. 9%; P=.017) and a higher percentage of NT cells that spontaneously produced interferon-gamma (2.4% vs. 1.2%; P=.035). The data support the clinical relevance of gammadelta and NT cells in mycobacterial, Salmonella, and HIV infections and of NT cells in mortality.

Increased carriage of trimethoprim/sulfamethoxazole-resistant Streptococcus pneumoniae in Malawian children after treatment for malaria with sulfadoxine/pyrimethamine.

Treatment of malaria with sulfadoxine/pyrimethamine and of presumed bacterial infections with trimethoprim/sulfamethoxazole (cotrimoxazole) was assessed to see if either increases the carriage of cotrimoxazole-resistant Streptococcus pneumoniae in Malawian children. Children <5 years old treated with sulfadoxine/pyrimethamine, cotrimoxazole, or no antimicrobial agent were enrolled in a prospective observational study. Nasopharyngeal swabs were taken before treatment and 1 and 4 weeks later. Pneumococci were tested for antibiotic susceptibility by broth microdilution. In sulfadoxine/pyrimethamine-treated children, the proportion colonized with cotrimoxazole-nonsusceptible pneumococci increased from 38.1% at the initial visit to 44.1% at the 4-week follow-up visit (P=.048). For cotrimoxazole-treated children, the proportion colonized with cotrimoxazole-nonsusceptible pneumococci increased from 41.5% at the initial visit to 52% at the 1-week follow-up visit (P=.0017) and returned to 41.7% at the 4-week follow-up. Expanding use of sulfadoxine/pyrimethamine to treat chloroquine-resistant malaria may have implications for national pneumonia programs in developing countries where cotrimoxazole is widely used.

Cerebral malaria in Malawian children hospitalized with Plasmodium falciparum infection.

A hospital-based, prospective study was undertaken at Mangochi District Hospital (MDH) and Kamuzu Central Hospital (KCH) in Malawi. The malaria-transmission patterns in the catchment areas of these two hospitals are very different, transmission being continuous around MDH and seasonal, occurring mostly during the rainy season, around KCH. The main purpose of the study was to determine and compare the prevalences of cerebral malaria (CM) among young, hospitalized children (aged < 5 years) at both sites. Among 8600 of such children admitted to the two hospitals, the overall prevalence of CM was 2.3% (2.2% at KCH and 2.5% at MDH). The prevalences of CM on admission were similar at the two sites during the rainy season (at 3.2%), but the prevalence at MDH during the dry season was statistically higher than that at KCH over the same period (2.1% v. 1.0%; P = 0.0078). A nearly significant difference was noted between the two sites in the prevalences of parasitaemia on admission (11.9% at KCH v. 9.2% at MDH; P = 0.07), and of severe malarial anaemia (SMA) on admission (5.4% at KCH v. 4.2% at MDH; P = 0.06). No inter-site differences were noted in the prevalences of CM or SMA when analysed by mean age, weight, haemoglobin, body temperature, weight-for-age Z-scores, duration of hospitalization, or proportion with high parasite score on admission. These findings differ from those by researchers in other parts of sub-Saharan Africa, where the prevalence of CM has been found to be higher in areas with seasonal transmission patterns. It appears that the epidemiology of CM can differ within the same country, with location and season. Whenever possible, therefore, plans to control CM in any sub-Saharan country should be based on locally generated data.

Chloroquine in Africa: critical assessment and recommendations for monitoring and evaluating chloroquine therapy efficacy in sub-Saharan Africa.

Chloroquine-resistant malaria is a major public health threat in sub-Saharan Africa. While a few countries have already replaced chloroquine as the first-line therapy for uncomplicated malaria or are in the process of doing so, other countries are faced with the complicated task of assessing the current status of drug resistance, making national policy-level decisions about whether to replace chloroquine or not, and initiating a monitoring system to track changes in the efficacy of malaria therapy. There is currently no standardized approach for collecting and interpreting data on therapy efficacy. There is also no agreement as to how much chloroquine resistance or treatment failure is acceptable and how much warrants a change in treatment policy. Using data collected in 10 sites in eastern and southern Africa between 1990 and 1996, we have assessed the therapeutic response to chloroquine and investigated predictors of clinical success or failure. Based on these experiences and analyses, a standardized protocol for in vivo studies of the efficacy of malaria therapy and for approaches to designing monitoring systems are proposed. The process of making policy-level decisions based on data collected by these systems is also discussed.