Mosquito Net Use in Early Childhood and Survival to Adulthood in Tanzania.

BACKGROUND: It has been hypothesized that in high-transmission settings, malaria control in early childhood (<5 years of age) might delay the acquisition of functional immunity and shift child deaths from younger to older ages. METHODS: We used data from a 22-year prospective cohort study in rural southern Tanzania to estimate the association between early-life use of treated nets and survival to adulthood. All the children born between January 1, 1998, and August 30, 2000, in the study area were invited to enroll in a longitudinal study from 1998 through 2003. Adult survival outcomes were verified in 2019 through community outreach and mobile telephones. We used Cox proportional-hazards models to estimate the association between the use of treated nets in early childhood and survival to adulthood, adjusting for potential confounders. RESULTS: A total of 6706 children were enrolled. In 2019, we verified information on the vital status of 5983 participants (89%). According to reports of early-life community outreach visits, approximately one quarter of children never slept under a treated net, one half slept under a treated net some of the time, and the remaining quarter always slept under a treated net. Participants who were reported to have used treated nets at half the early-life visits or more had a hazard ratio for death of 0.57 (95% confidence interval [CI], 0.45 to 0.72) as compared with those who were reported to have used treated nets at less than half the visits. The corresponding hazard ratio between 5 years of age and adulthood was 0.93 (95% CI, 0.58 to 1.49). CONCLUSIONS: In this long-term study of early-life malaria control in a high-transmission setting, the survival benefit from early-life use of treated nets persisted to adulthood. (Funded by the Eckenstein-Geigy Professorship and others.).

Formative research to adapt the 'Diabetes Prevention Program- Power to Prevent' for implementation in Bamako, Mali.

BACKGROUND: There are few community-level behaviors change interventions for reducing diabetes and hypertension risk in Africa, despite increasing cases of type 2 diabetes and cardiovascular diseases. Thus, this study was designed to adapt the United States Centers for Disease Control and Prevention's "Diabetes Prevention Program Power to Prevent" (DPP-P2P) for use in low-income urban communities of Bamako, Mali. METHODS: Feedback was elicited on an initial French PowerPoint adaptation of the DPP-P2P session guidelines from stakeholders at the ministry of health, organizational partners, and medical care providers. Two community health centers in districts with high levels of diabetes or hypertension were selected to assist in developing the Malian adaptation. Focus groups were conducted with 19 community health workers (CHWs) of these centers. Based on feedback from these discussions, more graphics, demonstrations, and role plays were added to the PowerPoint presentations. The 19 CHWs piloted the proposed 12 sessions with 45 persons with diabetes or at-risk patients over a one-month period. Feedback discussions were conducted after each session, and changes in dietary and exercise habits were assessed pre and post participation in the program. This feedback contributed to finalization of a 14-session sequence. RESULTS: The DPP-P2P session guidelines were adapted for use by low-literacy CHWs, converting the written English guidelines into French PowerPoint presentations with extensive use of pictures, role plays and group discussions to introduce diabetes, diet, and exercise concepts appropriately for the Bamako context. CHWs recommendations for a strong family-oriented program led to expanded sessions on eliciting support from all adults in the household. The 45 participants in the pilot adaptation were enthusiastic about the program. At the end of the program, there were significant increases in the frequency of daily exercise, efforts to limit fat intake, and goals for more healthy diets and exercise levels. CONCLUSION: This study documents how an iterative process of developing the DPP-P2P adaptation led to the development of a culturally appropriate set of materials welcomed by participants and having promise for reaching the low-income, low-literacy population with or at risk for diabetes in Bamako, Mali.

Impact of Community-Based Mass Testing and Treatment on Malaria Infection Prevalence in a High-Transmission Area of Western Kenya: A Cluster Randomized Controlled Trial.

BACKGROUND: Global gains toward malaria elimination have been heterogeneous and have recently stalled. Interventions targeting afebrile malaria infections may be needed to address residual transmission. We studied the efficacy of repeated rounds of community-based mass testing and treatment (MTaT) on malaria infection prevalence in western Kenya. METHODS: Twenty clusters were randomly assigned to 3 rounds of MTaT per year for 2 years or control (standard of care for testing and treatment at public health facilities along with government-sponsored mass long-lasting insecticidal net [LLIN] distributions). During rounds, community health volunteers visited all households in intervention clusters and tested all consenting individuals with a rapid diagnostic test. Those positive were treated with dihydroartemisinin-piperaquine. Cross-sectional community infection prevalence surveys were performed in both study arms at baseline and each year after 3 rounds of MTaT. The primary outcome was the effect size of MTaT on parasite prevalence by microscopy between arms by year, adjusted for age, reported LLIN use, enhanced vegetative index, and socioeconomic status. RESULTS: Demographic and behavioral characteristics, including LLIN usage, were similar between arms at each survey. MTaT coverage across the 3 annual rounds ranged between 75.0% and 77.5% in year 1, and between 81.9% and 94.3% in year 2. The adjusted effect size of MTaT on the prevalence of parasitemia between arms was 0.93 (95% confidence interval [CI], .79-1.08) and 0.92 (95% CI, .76-1.10) after year 1 and year 2, respectively. CONCLUSIONS: MTaT performed 3 times per year over 2 years did not reduce malaria parasite prevalence in this high-transmission area. CLINICAL TRIALS REGISTRATION: NCT02987270.

Mass drug administration for malaria.

BACKGROUND: Studies evaluating mass drug administration (MDA) in malarious areas have shown reductions in malaria immediately following the intervention. However, these effects vary by endemicity and are not sustained. Since the 2013 version of this Cochrane Review on this topic, additional studies have been published. OBJECTIVES: Primary objectives To assess the sustained effect of MDA with antimalarial drugs on: - the reduction in malaria transmission in moderate- to high-transmission settings; - the interruption of transmission in very low- to low-transmission settings. Secondary objective To summarize the risk of drug-associated adverse effects following MDA. SEARCH METHODS: We searched several trial registries, citation databases, conference proceedings, and reference lists for relevant articles up to 11 February 2021. We also communicated with researchers to identify additional published and unpublished studies. SELECTION CRITERIA: Randomized controlled trials (RCTs) and non-randomized studies comparing MDA to no MDA with balanced co-interventions across study arms and at least two geographically distinct sites per study arm. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for eligibility and extracted data. We calculated relative risk (RR) and rate ratios with corresponding 95% confidence intervals (CIs) to compare prevalence and incidence, respectively, in MDA compared to no-MDA groups. We stratified analyses by malaria transmission and by malaria species. For cluster-randomized controlled trials (cRCTs), we adjusted standard errors using the intracluster correlation coefficient. We assessed the certainty of the evidence using the GRADE approach. For non-randomized controlled before-and-after (CBA) studies, we summarized the data using difference-in-differences (DiD) analyses. MAIN RESULTS: Thirteen studies met our criteria for inclusion. Ten were cRCTs and three were CBAs. Cluster-randomized controlled trials Moderate- to high-endemicity areas (prevalence ≥ 10%) We included data from two studies conducted in The Gambia and Zambia.  At one to three months after MDA, the Plasmodium falciparum (hereafter, P falciparum) parasitaemia prevalence estimates may be higher compared to control but the CIs included no effect (RR 1.76, 95% CI 0.58 to 5.36; Zambia study; low-certainty evidence); parasitaemia incidence was probably lower (RR 0.61, 95% CI 0.40 to 0.92; The Gambia study; moderate-certainty evidence); and confirmed malaria illness incidence may be substantially lower,  but the CIs included no effect (rate ratio 0.41, 95% CI 0.04 to 4.42; Zambia study; low-certainty evidence).  At four to six months after MDA, MDA showed little or no effect on P falciparum parasitaemia prevalence (RR 1.18, 95% CI 0.89 to 1.56; The Gambia study; moderate-certainty evidence) and, no persisting effect was demonstrated with parasitaemia incidence (rate ratio 0.91, 95% CI 0.55 to 1.50; The Gambia study). Very low- to low-endemicity areas (prevalence < 10%) Seven studies from Cambodia, Laos, Myanmar (two studies), Vietnam, Zambia, and Zanzibar evaluated the effects of multiple rounds of MDA on P falciparum. Immediately following MDA (less than one month after MDA), parasitaemia prevalence was reduced (RR 0.12, 95% CI 0.03 to 0.52; one study; low-certainty evidence). At one to three months after MDA, there was a reduction in both parasitaemia incidence (rate ratio 0.37, 95% CI 0.21 to 0.55; 1 study; moderate-certainty evidence) and prevalence (RR 0.25, 95% CI 0.15 to 0.41; 7 studies; low-certainty evidence). For confirmed malaria incidence, absolute rates were low, and it is uncertain whether MDA had an effect on this outcome (rate ratio 0.58, 95% CI 0.12 to 2.73; 2 studies; very low-certainty evidence).  For P falciparum prevalence, the relative differences declined over time, from RR 0.63 (95% CI 0.36 to 1.12; 4 studies) at four to six months after MDA, to RR 0.86 (95% CI 0.55 to 1.36; 5 studies) at 7 to 12 months after MDA. Longer-term prevalence estimates showed overall low absolute risks, and relative effect estimates of the effect of MDA on prevalence varied from RR 0.82 (95% CI 0.20 to 3.34) at 13 to 18 months after MDA, to RR 1.25 (95% CI 0.25 to 6.31) at 31 to 36 months after MDA in one study. Five studies from Cambodia, Laos, Myanmar (2 studies), and Vietnam evaluated the effect of MDA on Plasmodium vivax (hereafter, P vivax). One month following MDA, P vivax prevalence was lower (RR 0.18, 95% CI 0.08 to 0.40; 1 study; low-certainty evidence). At one to three months after MDA, there was a reduction in P vivax prevalence (RR 0.15, 95% CI 0.10 to 0.24; 5 studies; low-certainty evidence). The immediate reduction on P vivax prevalence was not sustained over time, from RR 0.78 (95% CI 0.63 to 0.95; 4 studies) at four to six months after MDA, to RR 1.12 (95% CI 0.94 to 1.32; 5 studies) at 7 to 12 months after MDA. One of the studies in Myanmar provided estimates of longer-term effects, where overall absolute risks were low, ranging from RR 0.81 (95% CI 0.44 to 1.48) at 13 to 18 months after MDA, to RR 1.20 (95% CI 0.44 to 3.29) at 31 to 36 months after MDA. Non-randomized studies Three CBA studies were conducted in moderate- to high-transmission areas in Burkina Faso, Kenya, and Nigeria. There was a reduction in P falciparum parasitaemia prevalence in MDA groups compared to control groups during MDA (DiD range: -15.8 to -61.4 percentage points), but the effect varied at one to three months after MDA (DiD range: 14.9 to -41.1 percentage points).  AUTHORS' CONCLUSIONS: In moderate- to high-transmission settings, no studies reported important effects on P falciparum parasitaemia prevalence within six months after MDA. In very low- to low-transmission settings, parasitaemia prevalence and incidence were reduced initially for up to three months for both P falciparum and P vivax; longer-term data did not demonstrate an effect after four months, but absolute risks in both intervention and control groups were low. No studies provided evidence of interruption of malaria transmission.

Safety, Tolerability, and Immunogenicity of Plasmodium falciparum Sporozoite Vaccine Administered by Direct Venous Inoculation to Infants and Young Children: Findings From an Age De-escalation, Dose-Escalation, Double-blind, Randomized Controlled Study in Western Kenya.

BACKGROUND: The whole Plasmodium falciparum sporozoite (PfSPZ) vaccine is being evaluated for malaria prevention. The vaccine is administered intravenously for maximal efficacy. Direct venous inoculation (DVI) with PfSPZ vaccine has been safe, tolerable, and feasible in adults, but safety data for children and infants are limited. METHODS: We conducted an age de-escalation, dose-escalation randomized controlled trial in Siaya County, western Kenya. Children and infants (aged 5-9 years, 13-59 months, and 5-12 months) were enrolled into 13 age-dose cohorts of 12 participants and randomized 2:1 to vaccine or normal saline placebo in escalating doses: 1.35 × 105, 2.7 × 105, 4.5 × 105, 9.0 × 105, and 1.8 × 106 PfSPZ, with the 2 highest doses given twice, 8 weeks apart. Solicited adverse events (AEs) were monitored for 8 days after vaccination, unsolicited AEs for 29 days, and serious AEs throughout the study. Blood taken prevaccination and 1 week postvaccination was tested for immunoglobulin G antibodies to P. falciparum circumsporozoite protein (PfCSP) using enzyme-linked immunosorbent assay. RESULTS: Rates of AEs were similar in vaccinees and controls for solicited (35.7% vs 41.5%) and unsolicited (83.9% vs 92.5%) AEs, respectively. No related grade 3 AEs, serious AEs, or grade 3 laboratory abnormalities occurred. Most (79.0%) vaccinations were administered by a single DVI. Among those in the 9.0 × 105 and 1.8 × 106 PfSPZ groups, 36 of 45 (80.0%) vaccinees and 4 of 21 (19.0%) placebo controls developed antibodies to PfCSP (P < .001). CONCLUSIONS: PfSPZ vaccine in doses as high as 1.8 × 106 can be administered to infants and children by DVI, and was safe, well tolerated, and immunogenic. CLINICAL TRIALS REGISTRATION: NCT02687373.

Community-based intermittent mass testing and treatment for malaria in an area of high transmission intensity, western Kenya: development of study site infrastructure and lessons learned.

BACKGROUND: Malaria transmission is high in western Kenya and the asymptomatic infected population plays a significant role in driving the transmission. Mathematical modelling and simulation programs suggest that interventions targeting asymptomatic infections through mass testing and treatment (MTaT) or mass drug administration (MDA) have the potential to reduce malaria transmission when combined with existing interventions. OBJECTIVE: This paper describes the study site, capacity development efforts required, and lessons learned for implementing a multi-year community-based cluster-randomized controlled trial to evaluate the impact of MTaT for malaria transmission reduction in an area of high transmission in western Kenya. METHODS: The study partnered with Kenya's Ministry of Health (MOH) and other organizations on community sensitization and engagement to mobilize, train and deploy community health volunteers (CHVs) to deliver MTaT in the community. Within the health facilities, the study availed staff, medical and laboratory supplies and strengthened health information management system to monitor progress and evaluate impact of intervention. RESULTS: More than 80 Kenya MOH CHVs, 13 clinical officers, field workers, data and logistical staff were trained to carry out MTaT three times a year for 2 years in a population of approximately 90,000 individuals. A supply chain management was adapted to meet daily demands for large volumes of commodities despite the limitation of few MOH facilities having ideal storage conditions. Modern technology was adapted more to meet the needs of the high daily volume of collected data. CONCLUSIONS: In resource-constrained settings, large interventions require capacity building and logistical planning. This study found that investing in relationships with the communities, local governments, and other partners, and identifying and equipping the appropriate staff with the skills and technology to perform tasks are important factors for success in delivering an intervention like MTaT.

Posttreatment HRP2 Clearance in Patients with Uncomplicated Plasmodium falciparum Malaria.

Background: The response to antimalarial treatment is assessed using serial microscopy. New techniques for accurate measurement of the Plasmodium falciparum histidine-rich protein 2 (HRP2) antigen have allowed for monitoring of the antigen concentration over time, offering a potential alternative for assessing treatment response. Methods: Posttreatment HRP2 concentrations were measured in samples obtained longitudinally from 537 individuals with P. falciparum malaria who were participating in efficacy trials in Angola, Tanzania, and Senegal. The HRP2 half-life was estimated using a first-order kinetics clearance model. The association between the HRP2 concentration 3 days after treatment and recrudescence of infection was assessed. Results: Despite substantial variation in HRP2 concentrations among participants at baseline, concentrations consistently showed a first-order exponential decline. The median half-life of HRP2 was estimated to be 4.5 days (interquartile range [IQR], 3.3-6.6 days) in Angola, 4.7 days (IQR, 4.0-5.9 days) in Tanzania, and 3.0 days (IQR, 2.1-4.5 days) in Senegal. The day 3 HRP2 concentration was predictive of eventual recrudescence, with an area under the receiver operating characteristic curve of 0.86 (95% confidence interval, .73-.99). Conclusions: Consistent HRP2 clearance dynamics following successful antimalarial treatment imply a common underlying mechanism of biological clearance. Patients who ultimately did not respond to treatment did not exhibit this same pattern of clearance, even in the absence of other indications of inadequate response to treatment.

Correction: Comparison of artemether-lumefantrine and chloroquine with and without primaquine for the treatment of Plasmodium vivax infection in Ethiopia: A randomized controlled trial.

[This corrects the article DOI: 10.1371/journal.pmed.1002299.].

Unresolved Splenomegaly in Recently Resettled Congolese Refugees - Multiple States, 2015-2018.

In 2014, panel physicians from the International Organization for Migration (IOM), who conduct Department of State-required predeparture examinations for U.S.-bound refugees at resettlement sites in Uganda, noticed an unusually high number of Congolese refugees with enlarged spleens, or splenomegaly. Many conditions can cause splenomegaly, such as various infections, liver disease, and cancer. Splenomegaly can result in hematologic disturbances and abdominal pain and can increase the risk for splenic rupture from blunt trauma, resulting in life-threatening internal bleeding. On CDC's advice, panel physicians implemented an enhanced surveillance and treatment protocol that included screening for malaria (through thick and thin smears and rapid diagnostic testing), schistosomiasis, and several other conditions; treatment of any condition identified as potentially associated with splenomegaly; and empiric treatment for the most likely etiologies, including malaria and schistosomiasis. CDC recommended further treatment for malaria with primaquine after arrival, after glucose-6-phosphate dehydrogenase testing, to target liver-stage parasites. Despite this recommended treatment protocol, 35 of 64 patients with available follow-up records had splenomegaly that persisted beyond 6 months after resettlement. Among 85 patients who were diagnosed with splenomegaly through abdominal palpation or ultrasound at any point after resettlement, 53 had some hematologic abnormality (leukopenia, anemia, or thrombocytopenia), 16 had evidence of current or recent malaria infection, and eight had evidence of schistosomiasis. Even though primaquine was provided to a minority of patients in this cohort, it should be provided to all eligible patients with persistent splenomegaly, and repeated antischistosomal therapy should be provided to patients with evidence of current or recent schistosomiasis. Given substantial evidence of familial clustering of cases, family members of patients with known splenomegaly should be proactively screened for this condition.

Socioeconomic health inequality in malaria indicators in rural western Kenya: evidence from a household malaria survey on burden and care-seeking behaviour.

BACKGROUND: Health inequality is a recognized barrier to achieving health-related development goals. Health-equality data are essential for evidence-based planning and assessing the effectiveness of initiatives to promote equity. Such data have been captured but have not always been analysed or used to manage programming. Health data were examined for microeconomic differences in malaria indices and associated malaria control initiatives in western Kenya. METHODS: Data was analysed from a malaria cross-sectional survey conducted in July 2012 among 2719 people in 1063 households in Siaya County, Kenya. Demographic factors, history of fever, malaria parasitaemia, malaria medication usage, insecticide-treated net (ITN) use and expenditure on malaria medications were collected. A composite socioeconomic status score was created using multiple correspondence analyses (MCA) of household assets; households were classified into wealth quintiles and dichotomized into poorest (lowest 3 quintiles; 60%) or less-poor (highest 2 quintiles; 40%). Prevalence rates were calculated using generalized linear modelling. RESULTS: Overall prevalence of malaria infection was 34.1%, with significantly higher prevalence in the poorest compared to less-poor households (37.5% versus 29.2%, adjusted prevalence ratio [aPR] 1.23; 95% CI = 1.08-1.41, p = 0.002). Care seeking (aPR = 0.95; 95% CI 0.87-1.04, p = 0.229), medication use (aPR = 0.94; 95% CI 0.87-1.00, p = 0.087) and ITN use (aPR = 0.96; 95% CI = 0.87-1.05, p = 0.397) were similar between households. Among all persons surveyed, 36.4% reported taking malaria medicines in the prior 2 weeks; 92% took artemether-lumefantrine, the recommended first-line malaria medication. In the poorest households, 4.9% used non-recommended medicines compared to 3.5% in less-poor (p = 0.332). Mean and standard deviation [SD] for expenditure on all malaria medications per person was US$0.38 [US$0.50]; the mean was US$0.35 [US$0.52] amongst the poorest households and US$0.40 [US$0.55] in less-poor households (p = 0.076). Expenditure on non-recommended malaria medicine was significantly higher in the poorest (mean US$1.36 [US$0.91]) compared to less-poor households (mean US$0.98 [US$0.80]; p = 0.039). CONCLUSIONS: Inequalities in malaria infection and expenditures on potentially ineffective malaria medication between the poorest and less-poor households were evident in rural western Kenya. Findings highlight the benefits of using MCA to assess and monitor the health-equity impact of malaria prevention and control efforts at the microeconomic level.

Comparison of artemether-lumefantrine and chloroquine with and without primaquine for the treatment of Plasmodium vivax infection in Ethiopia: A randomized controlled trial.

BACKGROUND: Recent efforts in malaria control have resulted in great gains in reducing the burden of Plasmodium falciparum, but P. vivax has been more refractory. Its ability to form dormant liver stages confounds control and elimination efforts. To compare the efficacy and safety of primaquine regimens for radical cure, we undertook a randomized controlled trial in Ethiopia. METHODS AND FINDINGS: Patients with normal glucose-6-phosphate dehydrogenase status with symptomatic P. vivax mono-infection were enrolled and randomly assigned to receive either chloroquine (CQ) or artemether-lumefantrine (AL), alone or in combination with 14 d of semi-supervised primaquine (PQ) (3.5 mg/kg total). A total of 398 patients (n = 104 in the CQ arm, n = 100 in the AL arm, n = 102 in the CQ+PQ arm, and n = 92 in the AL+PQ arm) were followed for 1 y, and recurrent episodes were treated with the same treatment allocated at enrolment. The primary endpoints were the risk of P. vivax recurrence at day 28 and at day 42. The risk of recurrent P. vivax infection at day 28 was 4.0% (95% CI 1.5%-10.4%) after CQ treatment and 0% (95% CI 0%-4.0%) after CQ+PQ. The corresponding risks were 12.0% (95% CI 6.8%-20.6%) following AL alone and 2.3% (95% CI 0.6%-9.0%) following AL+PQ. On day 42, the risk was 18.7% (95% CI 12.2%-28.0%) after CQ, 1.2% (95% CI 0.2%-8.0%) after CQ+PQ, 29.9% (95% CI 21.6%-40.5%) after AL, and 5.9% (95% CI 2.4%-13.5%) after AL+PQ (overall p < 0.001). In those not prescribed PQ, the risk of recurrence by day 42 appeared greater following AL treatment than CQ treatment (HR = 1.8 [95% CI 1.0-3.2]; p = 0.059). At the end of follow-up, the incidence rate of P. vivax was 2.2 episodes/person-year for patients treated with CQ compared to 0.4 for patients treated with CQ+PQ (rate ratio: 5.1 [95% CI 2.9-9.1]; p < 0.001) and 2.3 episodes/person-year for AL compared to 0.5 for AL+PQ (rate ratio: 6.4 [95% CI 3.6-11.3]; p < 0.001). There was no difference in the occurrence of adverse events between treatment arms. The main limitations of the study were the early termination of the trial and the omission of haemoglobin measurement after day 42, resulting in an inability to estimate the cumulative risk of anaemia. CONCLUSIONS: Despite evidence of CQ-resistant P. vivax, the risk of recurrence in this study was greater following treatment with AL unless it was combined with a supervised course of PQ. PQ combined with either CQ or AL was well tolerated and reduced recurrence of vivax malaria by 5-fold at 1 y. TRIAL REGISTRATION: ClinicalTrials.gov NCT01680406.

Community-based intermittent mass testing and treatment for malaria in an area of high transmission intensity, western Kenya: study design and methodology for a cluster randomized controlled trial.

Most human Plasmodium infections in western Kenya are asymptomatic and are believed to contribute importantly to malaria transmission. Elimination of asymptomatic infections requires active treatment approaches, such as mass testing and treatment (MTaT) or mass drug administration (MDA), as infected persons do not seek care for their infection. Evaluations of community-based approaches that are designed to reduce malaria transmission require careful attention to study design to ensure that important effects can be measured accurately. This manuscript describes the study design and methodology of a cluster-randomized controlled trial to evaluate a MTaT approach for malaria transmission reduction in an area of high malaria transmission. Ten health facilities in western Kenya were purposively selected for inclusion. The communities within 3 km of each health facility were divided into three clusters of approximately equal population size. Two clusters around each health facility were randomly assigned to the control arm, and one to the intervention arm. Three times per year for 2 years, after the long and short rains, and again before the long rains, teams of community health volunteers visited every household within the intervention arm, tested all consenting individuals with malaria rapid diagnostic tests, and treated all positive individuals with an effective anti-malarial. The effect of mass testing and treatment on malaria transmission was measured through population-based longitudinal cohorts, outpatient visits for clinical malaria, periodic population-based cross-sectional surveys, and entomological indices.

Within-host competition and drug resistance in the human malaria parasite Plasmodium falciparum.

Infections with the malaria parasite Plasmodium falciparum typically comprise multiple strains, especially in high-transmission areas where infectious mosquito bites occur frequently. However, little is known about the dynamics of mixed-strain infections, particularly whether strains sharing a host compete or grow independently. Competition between drug-sensitive and drug-resistant strains, if it occurs, could be a crucial determinant of the spread of resistance. We analysed 1341 P. falciparum infections in children from Angola, Ghana and Tanzania and found compelling evidence for competition in mixed-strain infections: overall parasite density did not increase with additional strains, and densities of individual chloroquine-sensitive (CQS) and chloroquine-resistant (CQR) strains were reduced in the presence of competitors. We also found that CQR strains exhibited low densities compared with CQS strains (in the absence of chloroquine), which may underlie observed declines of chloroquine resistance in many countries following retirement of chloroquine as a first-line therapy. Our observations support a key role for within-host competition in the evolution of drug-resistant malaria. Malaria control and resistance-management efforts in high-transmission regions may be significantly aided or hindered by the effects of competition in mixed-strain infections. Consideration of within-host dynamics may spur development of novel strategies to minimize resistance while maximizing the benefits of control measures.

The impact of inflammation on the obesity paradox in coronary heart disease.

BACKGROUND: Despite the well-known adverse effects of obesity on almost all aspects of coronary heart disease, many studies of coronary heart disease cohorts have demonstrated an inverse relationship between obesity, as defined by body mass index (BMI), and subsequent prognosis: the 'obesity paradox'. The etiology of this and the potential role of inflammation in this process remain unknown. PATIENTS AND METHODS: We studied 519 patients with coronary heart disease before and after cardiac rehabilitation, dividing them into groups based on C-reactive protein ((CRP)⩾3 mg l-1 and CRP<3 mg l-1 after cardiac rehabilitation). BMI was calculated and body fat was measured using the skin-fold method. Lean mass index (LMI) was calculated as (1-%body fat) × BMI. The population was divided according to age- and gender-adjusted categories based on LMI and body fat and analyzed by total mortality over >3-year follow-up by National Death Index in both CRP groups. RESULTS: During >3-year follow-up, all-cause mortality was higher in the high inflammation and in the low BMI group. In proportional hazard analysis, even after adjusting for ejection fraction and peak O2 consumption, higher BMI was associated with lower mortality in the entire population (hazard ratio (HR) 0.38; confidence interval 0.15-0.97) and a trend to lower mortality in both subgroups (HR 0.45 in low CRP, P=0.24 vs HR 0.32, P=0.06 in high CRP). High body fat, however, was associated with significantly lower mortality in the high CRP group (HR 0.22; P=0.03) but not in the low CRP group (HR 0.73; P=0.64). Conversely, high LMI was associated with markedly lower mortality in the low CRP group (HR 0.04; P=0.04). CONCLUSIONS: The obesity paradox has multiple underlying etiologies. Body composition has a different role in different populations with an obesity paradox by BMI. Especially in the subpopulation with persistently high CRP levels, body fat seems protective.

Intravenous Artesunate for the Treatment of Severe and Complicated Malaria in the United States: Clinical Use Under an Investigational New Drug Protocol.

BACKGROUND: Quinidine gluconate, the only U.S. Food and Drug Administration-approved treatment for life-threatening malaria in the United States, has a problematic safety profile and is often unavailable in hospitals. OBJECTIVE: To assess the safety and clinical benefit of intravenous artesunate as an alternative to quinidine. DESIGN: Retrospective case series. SETTING: U.S. hospitals. PATIENTS: 102 patients aged 1 to 72 years (90% adults; 61% men) with severe and complicated malaria. Patients received 4 weight-based doses of intravenous artesunate (2.4 mg/kg) under a treatment protocol implemented by the Centers for Disease Control and Prevention between January 2007 and December 2010. At baseline, 35% had evidence of cerebral malaria, and 17% had severe hepatic impairment. Eligibility required the presence of microscopically confirmed malaria, need for intravenous treatment, and an impediment to quinidine. MEASUREMENTS: Clinical and laboratory data from each patient's hospital records were abstracted retrospectively, including information from baseline through a maximum 7-day follow-up, and presented before a physician committee to evaluate safety and clinical benefit outcomes. RESULTS: 7 patients died (mortality rate, 6.9%). The most frequent adverse events were anemia (65%) and elevated hepatic enzyme levels (49%). All deaths and most adverse events were attributed to the severity of malaria. Patients' symptoms generally improved or resolved within 3 days, and the median time to discharge from the intensive care unit was 4 days, even for patients with severe liver disease or cerebral malaria. More than 100 concomitant medications were used, with no documented drug-drug interactions. LIMITATION: Potential late-presenting safety issues might occur outside the 7-day follow-up. CONCLUSION: Artesunate was a safe and clinically beneficial alternative to quinidine.

Sleeping arrangements and mass distribution of bed nets in six districts in central and northern Mozambique.

OBJECTIVE: Universal coverage with insecticide-treated bed nets is a cornerstone of modern malaria control. Mozambique has developed a novel bed net allocation strategy, where the number of bed nets allocated per household is calculated on the basis of household composition and assumptions about who sleeps with whom. We set out to evaluate the performance of the novel allocation strategy. METHODS: A total of 1994 households were visited during household surveys following two universal coverage bed net distribution campaigns in Sofala and Nampula provinces in 2010-2013. Each sleeping space was observed for the presence of a bed net, and the sleeping patterns for each household were recorded. The observed coverage and efficiency were compared to a simulated coverage and efficiency had conventional allocation strategies been used. A composite indicator, the product of coverage and efficiency, was calculated. Observed sleeping patterns were compared with the sleeping pattern assumptions. RESULTS: In households reached by the campaign, 93% (95% CI: 93-94%) of sleeping spaces in Sofala and 84% (82-86%) in Nampula were covered by campaign bed nets. The achieved efficiency was high, with 92% (91-93%) of distributed bed nets in Sofala and 93% (91-95%) in Nampula covering a sleeping space. Using the composite indicator, the novel allocation strategy outperformed all conventional strategies in Sofala and was tied for best in Nampula. The sleeping pattern assumptions were completely satisfied in 66% of households in Sofala and 56% of households in Nampula. The most common violation of the sleeping pattern assumptions was that male children 3-10 years of age tended not to share sleeping spaces with female children 3-10 or 10-16 years of age. CONCLUSIONS: The sleeping pattern assumptions underlying the novel bed net allocation strategy are generally valid, and net allocation using these assumptions can achieve high coverage and compare favourably with conventional allocation strategies.

Are Tanzanian patients attending public facilities or private retailers more likely to adhere to artemisinin-based combination therapy?

BACKGROUND: Artemisinin combination therapy (ACT) is first-line treatment for malaria in most endemic countries and is increasingly available in the private sector. Most studies on ACT adherence have been conducted in the public sector, with minimal data from private retailers. METHODS: Parallel studies were conducted in Tanzania, in which patients obtaining artemether-lumefantrine (AL) at 40 randomly selected public health facilities and 37 accredited drug dispensing outlets (ADDOs) were visited at home and questioned about doses taken. The effect of sector on adherence, controlling for potential confounders was assessed using logistic regression with a random effect for outlet. RESULTS: Of 572 health facility patients and 450 ADDO patients, 74.5% (95% CI: 69.8, 78.8) and 69.8% (95% CI: 64.6, 74.5), respectively, completed treatment and 46.0% (95% CI: 40.9, 51.2) and 34.8% (95% CI: 30.1, 39.8) took each dose at the correct time ('timely completion'). ADDO patients were wealthier, more educated, older, sought care later in the day, and were less likely to test positive for malaria than health facility patients. Controlling for patient characteristics, the adjusted odds of completed treatment and of timely completion for ADDO patients were 0.65 (95% CI: 0.43, 1.00) and 0.69 (95% CI: 0.47, 1.01) times that of health facility patients. Higher socio-economic status was associated with both adherence measures. Higher education was associated with completed treatment (adjusted OR = 1.68, 95% CI: 1.20, 2.36); obtaining AL in the evening was associated with timely completion (adjusted OR = 0.35, 95% CI: 0.19, 0.64). Factors associated with adherence in each sector were examined separately. In both sectors, recalling correct instructions was positively associated with both adherence measures. In health facility patients, but not ADDO patients, taking the first dose of AL at the outlet was associated with timely completion (adjusted OR = 2.11, 95% CI: 1.46, 3.04). CONCLUSION: When controlling for patient characteristics, there was some evidence that the adjusted odds of adherence for ADDO patients was lower than that for public health facility patients. Better understanding is needed of which patient care aspects are most important for adherence, including the role of effective provision of advice.

Quality assurance of malaria rapid diagnostic tests used for routine patient care in rural Tanzania: microscopy versus real-time polymerase chain reaction.

BACKGROUND: The World Health Organization (WHO) recommends parasitologic confirmation of suspected malaria cases before treatment. Due to the limited availability of quality microscopy services, this recommendation has become scalable following increased use of antigen-detecting malaria rapid diagnostic tests (RDTs) in many malaria-endemic countries. This study was carried out to monitor quality of RDT performance in selected health facilities using two quality assurance (QA) methods: reference microscopy and detection of parasite DNA by real-time quantitative polymerase chain reaction (qPCR) on dried blood spots (DBS). METHODS: Blood samples for QA were collected from patients undergoing RDT for diagnostic confirmation of malaria during two to three consecutive days per month in 12 health facilities in rural Tanzania. Stained blood smears (BS) were first examined at the district hospitals (BS1) and then at a reference laboratory (BS2). Discordant BS1 and BS2 results prompted a third examination. Molecular analysis was carried out at the Ifakara Health Institute laboratory in Bagamoyo. RESULTS: Malaria RDTs had a higher positivity rate (6.5%) than qPCR (4.2%) or microscopy (2.9% for BS1 and 2.5% for BS2). Poor correlation was observed between RDT and BS results: BS1 (K = 0.5), BS2 (K = 0.43) and qPCR (K = 0.45), challenging the utility of these tests for RDT QA. In addition, many challenges related to qPCR processing were recorded and long delays in obtaining QA test results for both microscopy and qPCR. CONCLUSIONS: Overall there was limited agreement among the three diagnostic approaches and neither microscopy nor qPCR appear to be good QA options for RDTs under field conditions.

Evaluation of a universal coverage bed net distribution campaign in four districts in Sofala Province, Mozambique.

BACKGROUND: Malaria is the leading cause of death in Mozambique in children under five years old. In 2009, Mozambique developed a novel bed net distribution model to increase coverage, based on assumptions about sleeping patterns. The coverage and impact of a bed net distribution campaign using this model in four districts in Sofala Province, Mozambique was evaluated. METHODS: Paired household, cross-sectional surveys were conducted one month after the 2010 distribution of 140,000 bed nets and again 14 months after the campaign in 2011. During household visits, malaria blood smears were performed and haemoglobin levels were assessed on children under five and data on bed net ownership, access and use were collected; these indicators were analysed at individual, household and community levels. Logistic regression was used to evaluate predictors of malaria infection and anaemia. RESULTS: The campaign reached 98% (95% CI: 97-99%) of households registered during the precampaign listing, with 81% (95% CI: 77-85%) of sleeping spaces covered by campaign bed nets and 85% (95% CI: 81-88%) of the population sleeping in a sleeping space with a campaign bed net designated for the sleeping space. One year after the campaign, 65% (95% CI: 57-72%) of sleeping spaces were observed to have hanging bed nets. The proportion of sleeping spaces for which bed nets were reported used four or more times per week was 65% (95% CI: 56-74%) in the wet season and 60% (95% CI: 52-68%) in the dry season. Malaria parasitaemia prevalence in children under five years old was 47% (95% CI: 40-54%) in 2010 and 36% (95% CI: 27-45%) in 2011. Individual-level malaria infection and anaemia were significantly associated with community-level use of bed nets. CONCLUSIONS: The campaign using the novel distribution model achieved high coverage, although usage was not uniformly high. A significant decrease in malaria parasitaemia prevalence a year after the campaign was not observed, but community-level use of bed nets was significantly associated with a reduced risk for malaria infection and anaemia in children under five.