No abstract

In 1993, Malawi became the first African country to replace chloroquine with sulfadoxine-pyrimethamine nationwide in response to high rates of chloroquine-resistant falciparum malaria. To determine whether withdrawal of chloroquine can lead to the reemergence of chloroquine sensitivity, the prevalence of the pfcrt 76T molecular marker for chloroquine-resistant Plasmodium falciparum malaria was retrospectively measured in Blantyre, Malawi. The prevalence of the chloroquine-resistant pfcrt genotype decreased from 85% in 1992 to 13% in 2000. In 2001, chloroquine cleared 100% of 63 asymptomatic P. falciparum infections, no isolates were resistant to chloroquine in vitro, and no infections with the chloroquine-resistant pfcrt genotype were detected. A concerted national effort to withdraw chloroquine from use has been followed by a return of chloroquine-sensitive falciparum malaria in Malawi. The reintroduction of chloroquine, ideally in combination with another antimalarial drug, should be considered in areas where chloroquine resistance has declined and safe and affordable alternatives remain unavailable.

No abstract

Identifying the specific genetic characteristics of successfully transmitted variants may prove central to the development of effective vaccine and microbicide interventions. Although human immunodeficiency virus transmission is associated with a population bottleneck, the extent to which different factors influence the diversity of transmitted viruses is unclear. We estimate here the number of transmitted variants in 69 heterosexual men and women with primary subtype C infections. From 1,505 env sequences obtained using a single genome amplification approach we show that 78% of infections involved single variant transmission and 22% involved multiple variant transmissions (median of 3). We found evidence for mutations selected for cytotoxic-T-lymphocyte or antibody escape and a high prevalence of recombination in individuals infected with multiple variants representing another potential escape pathway in these individuals. In a combined analysis of 171 subtype B and C transmission events, we found that infection with more than one variant does not follow a Poisson distribution, indicating that transmission of individual virions cannot be seen as independent events, each occurring with low probability. While most transmissions resulted from a single infectious unit, multiple variant transmissions represent a significant fraction of transmission events, suggesting that there may be important mechanistic differences between these groups that are not yet understood.

Summary Background Women’s groups and health education by peer counsellors can improve the health of mothers and children. We assessed their effects on mortality and breastfeeding rates in rural Malawi. Methods We did a 2×2 factorial, cluster-randomised trial in 185 888 people in Mchinji district. 48 equal-sized clusters were randomly allocated to four groups with a computer-generated number sequence. 24 facilitators guided groups through a community action cycle to tackle maternal and child health problems. 72 trained volunteer peer counsellors made home visits at five timepoints during pregnancy and after birth to support breastfeeding and infant care. Primary outcomes for the women’s group intervention were maternal, perinatal, neonatal, and infant mortality rates (MMR, PMR, NMR, and IMR, respectively); and for the peer counselling were IMR and exclusive breastfeeding (EBF) rates. Analysis was by intention to treat. The trial is registered as ISRCTN06477126. Findings We monitored outcomes of 26 262 births between 2005 and 2009. In a factorial model adjusted only for clustering and the volunteer peer counselling intervention, in women’s group areas, for years 2 and 3, we noted non-significant decreases in NMR (odds ratio 0·93, 0·64–1·35) and MMR (0·54, 0·28–1·04). After adjustment for parity, socioeconomic quintile, and baseline measures, effects were larger for NMR (0·85, 0·59–1·22) and MMR (0·48, 0·26–0·91). Because of the interaction between the two interventions, a stratified analysis was done. For women’s groups, in adjusted analyses, MMR fell by 74% (0·26, 0·10–0·70), and NMR by 41% (0·59, 0·40–0·86) in areas with no peer counsellors, but there was no effect in areas with counsellors (1·09, 0·40–2·98, and 1·38, 0·75–2·54). Factorial analysis for the peer counselling intervention for years 1–3 showed a fall in IMR of 18% (0·82, 0·67–1·00) and an improvement in EBF rates (2·42, 1·48–3·96). The results of the stratified, adjusted analysis showed a 36% reduction in IMR (0·64, 0·48–0·85) but no effect on EBF (1·18, 0·63–2·25) in areas without women’s groups, and in areas with women’s groups there was no effect on IMR (1·05, 0·82–1·36) and an increase in EBF (5·02, 2·67–9·44) . The cost of women’s groups was US$114 per year of life lost (YLL) averted and that of peer counsellors was $33 per YLL averted, using stratified data from single intervention comparisons. Interpretation Community mobilisation through women’s groups and volunteer peer counsellor health education are methods to improve maternal and child health outcomes in poor rural populations in Africa. Funding Saving Newborn Lives, UK Department for International Development, and Wellcome Trust.