METHODS: A multi-host, multi-site transmission model was developed, taking into account the three areas (forest, farm, and village) where transmission is thought to occur. Latin hypercube sampling of model parameters was used to identify parameter sets consistent with possible prevalence in macaques and humans inferred from observed data. We then explore the consequences of increasing human-macaque contact in the farm, the likely impact of rapid treatment, and the use of long-lasting insecticide-treated nets (LLINs) in preventing wider spread of this emerging infection.
RESULTS: Identified model parameters were consistent with transmission being sustained by the macaques with spill over infections into the human population and with high overall basic reproduction numbers (up to 2267). The extent to which macaques forage in the farms had a non-linear relationship with human infection prevalence, the highest prevalence occurring when macaques forage in the farms but return frequently to the forest where they experience higher contact with vectors and hence sustain transmission. Only one of 1,046 parameter sets was consistent with sustained human-to-human transmission in the absence of macaques, although with a low human reproduction number (R(0H) = 1.04). Simulations showed LLINs and rapid treatment provide personal protection to humans with maximal estimated reductions in human prevalence of 42% and 95%, respectively.
CONCLUSION: This model simulates conditions where P. knowlesi transmission may occur and the potential impact of control measures. Predictions suggest that conventional control measures are sufficient at reducing the risk of infection in humans, but they must be actively implemented if P. knowlesi is to be controlled.
METHODS: Data was collected from 380 randomly selected antenatal care attendees of a hospital in Maiduguri, using structured questionnaires. This data was then used to test the Information-Motivation-Behavioural Skills (IMB) model, for model fit, and interrelations among the constructs, using the structural equation modelling analysis with Smart-PLS.
RESULTS: Information and motivation were significantly related to behavioural skills (r = 0.29, p
METHODS: This WHO-coordinated, prospective, observational cohort study was done at 279 clusters (villages or groups of villages in which phenotypic resistance was measurable) in Benin, Cameroon, India, Kenya, and Sudan. Pyrethroid long-lasting insecticidal nets were the principal form of malaria vector control in all study areas; in Sudan this approach was supplemented by indoor residual spraying. Cohorts of children from randomly selected households in each cluster were recruited and followed up by community health workers to measure incidence of clinical malaria and prevalence of infection. Mosquitoes were assessed for susceptibility to pyrethroids using the standard WHO bioassay test. Country-specific results were combined using meta-analysis.
FINDINGS: Between June 2, 2012, and Nov 4, 2016, 40 000 children were enrolled and assessed for clinical incidence during 1·4 million follow-up visits. 80 000 mosquitoes were assessed for insecticide resistance. Long-lasting insecticidal net users had lower infection prevalence (adjusted odds ratio [OR] 0·63, 95% CI 0·51-0·78) and disease incidence (adjusted rate ratio [RR] 0·62, 0·41-0·94) than did non-users across a range of resistance levels. We found no evidence of an association between insecticide resistance and infection prevalence (adjusted OR 0·86, 0·70-1·06) or incidence (adjusted RR 0·89, 0·72-1·10). Users of nets, although significantly better protected than non-users, were nevertheless subject to high malaria infection risk (ranging from an average incidence in net users of 0·023, [95% CI 0·016-0·033] per person-year in India, to 0·80 [0·65-0·97] per person year in Kenya; and an average infection prevalence in net users of 0·8% [0·5-1·3] in India to an average infection prevalence of 50·8% [43·4-58·2] in Benin).
INTERPRETATION: Irrespective of resistance, populations in malaria endemic areas should continue to use long-lasting insecticidal nets to reduce their risk of infection. As nets provide only partial protection, the development of additional vector control tools should be prioritised to reduce the unacceptably high malaria burden.
FUNDING: Bill & Melinda Gates Foundation, UK Medical Research Council, and UK Department for International Development.
METHODS: The study utilized a cross-sectional study design, using a structured and pre-tested questionnaire to obtain information from 380 respondents. Respondents were classified as ITN users if they slept under an ITN for at least 3 days in a week, while those who did not at all, or slept under it less frequently were classified as ITN non-users. Chi squared test was performed to test the bivariate association between ITN use and each of the items of the questionnaire. A further multivariate logistic regression was performed to determine the predictors of ITN use.
RESULTS: The respondents' ages ranged from 15 to 45 years, with median (interquartile range) age of 25 (8) years. Eighty percent of them were aware of ITN, but 50.5% believed ITNs could be dangerous. Only 5.5% and 0.8% respectively felt that sleeping under and ITN was either just bad or very bad for their health. Thirty-five percent of the respondents were ITN users. Not having a previous miscarriage (OR = 2.38; 95% CI 1.41-4.03, p = 0.001), knowledge that ITNs were not to be washed after every 1 month (OR = 3.60; 95% CI 1.18-11.06), significant others thinking they should sleep under an ITN (OR = 3.06; 95% CI 1.35-6.96), ability to effectively persuade others to sleep under an ITN (OR = 2.37; 95% CI 1.14-4.94) were significantly associated with ITN use.
CONCLUSIONS: A large proportion of pregnant women in this study were not sleeping under ITNs. The development of health promotion interventions aimed at boosting their self-efficacies for ITN use, and improving social support from their spouses are, therefore, recommended. Health education on ITN use should also be incorporated into post-abortal management.
METHODS: On Ambae Island, blood samples were collected from 231 and 282 individuals in 2003 and 2007, respectively. Parasite prevalence was determined by microscopy. Antibodies to three Plasmodium falciparum (PfSE, PfMSP-119, and PfAMA-1) and three Plasmodium vivax (PvSE, PvMSP-119, and PvAMA-1) antigens, as well as the Anopheles-specific salivary antigen gSG6, were detected by ELISA. Age-specific seroprevalence was analysed using a reverse catalytic modelling approach to estimate seroconversion rates (SCRs).
RESULTS: Parasite rate decreased significantly (P
METHODS: This narrative systematic review addressed MSAs targeted to MMPs in Myanmar for malaria prevention. We searched relevant studies in electronic databases and present the narrative findings in 4 domains: stakeholder groups, net coverage and utilization, social determinates, and facilitators/barriers.
RESULTS: Nine studies were included. The review identified stakeholders involved in intersectoral collaboration. Net ownership was higher than utilization rates in the MARC zones and rates remained below the WHO recommended target of 100%. There was inadequate description of roles and responsibilities for implementation and on channels of communication within the partnerships and with the Government.
CONCLUSIONS: Findings show that interventions to distribute treated bed nets were supported by the multiple stakeholders. Due to the design of the primary studies, analysis of the added value of intersectoral collaboration was limited. More attention must be paid to designing studies to document and evaluate the contributions and outcomes of intersectoral collaboration.
METHODS: Anopheles gambiae (s.l.) mosquitoes were identified to species level using PCR techniques. Standard WHO insecticide susceptibility bioassays were carried out to detect resistance to deltamethrin (0.05%), DDT (4%) and bendiocarb (0.1%). TaqMan assays were performed on random samples of deltamethrin-resistant phenotyped and pyrethrum spray collected individuals to determine Vgsc-1014 knockdown resistance mutations.
RESULTS: Anopheles arabiensis accounted for 99.9% of any anopheline species collected across all sites. Bioassay screening indicated that mosquitoes remained susceptible to bendiocarb but were resistance to deltamethrin and DDT in all areas. There were significant increases in deltamethrin resistance over the four years, with overall mean percent mortality to deltamethrin declining from 81.0% (95% CI: 77.6-84.3%) in 2011 to 47.7% (95% CI: 43.5-51.8%) in 2014. The rate of increase in phenotypic deltamethrin-resistance was significantly slower in the LLIN + IRS arm than in the LLIN-only arm (Odds ratio 1.34; 95% CI: 1.02-1.77). The frequency of Vgsc-1014F mutation varied spatiotemporally with highest frequencies in Galabat (range 0.375-0.616) and New Halfa (range 0.241-0.447). Deltamethrin phenotypic-resistance correlated with Vgsc-1014F frequency.
CONCLUSION: Combining LLIN and IRS, with different classes of insecticide, may delay pyrethroid resistance development, but the speed at which resistance develops may be area-specific. Continued monitoring is vital to ensure optimal management and control.