Prevalence and factors associated with persistent transmission of Schistosoma haematobium among primary school children after five rounds of mass drug administration using praziquantel: A cross sectional study in Mkuranga district, Tanzania.

Despite a human schistosomiasis control programme through praziquantel mass drug administration (MDA) between 2011 and 2015,there was still persistent transmission among primary schoolchildren (PSC) in Mkuranga district, Tanzania. Our cross-sectional study was conducted among 396 PSC who provided urine for diagnosis of Schistosoma haematobium infection. Observations were conducted to determine PSC water contact activities. Logistic regression was used to test association between dependent and independent variables. We found MDA uptake among PSC as 72.5%, and the prevalence of Schistosoma haematobium infection 5.8%. The risk of infection increased among PSC engaged in fetching water and adjusted odds ratio (AOR) for swimming, bathing, fishing, crossing ponds and paddy fields were 0.123, 0.166, 0.232, 0.202 and 0.093 respectively. Thus we conclude that multiple water contact activities and low participation in MDA is responsible for persistent Schistosoma transmission.

Community Knowledge and Perceived Effectiveness of Interventions to Reduce Malaria: Implications for Sustained Use of Malaria Interventions in Rufiji District, Southeastern Tanzania.

Insecticides treated-nets (ITNs) and artemether-lumefantrine (ALu), crucial for malaria elimination, depend on perceived effectiveness in reducing malarial fevers. We examined community knowledge and perceived effectiveness of ITNs and ALu for reducing malaria in Rufiji district. Heads of households were interviewed on causes of fever in underfives, fever history, and antimalarial use during the last 2 weeks, perceived effectiveness of, and willingness to continue using ALu and ITNs. A total of 1,885 respondents were interviewed, a majority (88.2%) females. Illnesses with fever (malaria-76.1% and respiratory conditions-58.9%) were major health problems. There was a very high recognition of fever as malaria symptom (95.1%). There were mixed perceptions on effectiveness of ALu and ITNs: ALu (52.8%) and on ITNs as highly effective (48.1%). Both ALu and ITNs were judged partially effective. Reorientation of social marketing to increase demand for ALu and ITNs for malaria control consolidation is crucial.

Impact of praziquantel mass drug administration campaign on prevalence and intensity of Schistosoma haemamtobium among school children in Bahi district, Tanzania.

As part of the Tanzania National Schistosomiasis Control Programme, Bahi district in central Tanzania, received two annual rounds of praziquantel mass drug administration (MDA) to control urinary schistosomiasis in schoolchildren. The objectives of this study were to assess the impact of the two rounds of MDA on prevalence and intensity of Schistosoma haemamtobium and the impact of MDA campaigns on knowledge of urinary schistosomiasis, safe water use and contact with potentially unsafe water bodies. A quantitative cross-sectional study was carried out among schoolchildren in March and April, 2013. A structured questionnaire was used to collect information on MDA uptake, knowledge of schistosomiasis, sources of water for domestic and other uses. Urine samples were collected from each pupil to examine prevalence and intensity of S. haematobium. Transmission of schistosomiasis was assessed by sampling Bulinus spp snails for cercarial shedding. Uptake of MDA was 39.5% in 2011 and 43.6% in 2012. Prevalence of S. haematobium significantly dropped by 50.0% from 26% in 2011 to 15% in 2012 (p = 0.000). Prevalence of S. haematobium was significantly low in MDA participating (3.1%) than non-participating (28.5%) schoolchildren (p = 0.000). MDA campaigns had significant impact on knowledge of the disease (p = 0.02) and borderline impact on safe water use (p = 0.04) but had no impact on avoidance of contact with unsafe water bodies (p = 0.06). Bulinus spp. snails were found shedding schistosome cercariae indicating environmental contamination with viable S. haematobium eggs. In conclusion, though MDA significantly reduced prevalence of S. haematobium, uptake was below 50.0% and below the World Health Assembly resolution 54.19 target of 75.0% for 2010. Non-participation in MDA was the likely source of S. haematobium eggs in the environment hence the observed 15.0% prevalence of S. haematobium infection; and cercarial shedding Bulinus spp. snails indicating continuity of transmission hence the need for further health promotion campaigns.

Impact of Praziquantel Mass Drug Administration Campaign on Prevalence and Intensity of Schistosoma haemamtobium Check for this Species in other Resources among Schoolchildren in Bahi District; Tanzania

As part of the Tanzania National Schistosomiasis Control Programme; Bahi district in central Tanzania; received two annual rounds of praziquantel mass drug administration (MDA) to control urinary schistosomiasis in schoolchildren. The objectives of this study were to assess the impact of the two rounds of MDA on prevalence and intensity of Schistosoma haemamtobium and the impact of MDA campaigns on knowledge of urinary schistosomiasis; safe water use and contact with potentially unsafe water bodies. A quantitative crosssectional study was carried out among schoolchildren in March and April; 2013. A structured questionnaire was used to collect information on MDA uptake; knowledge of schistosomiasis; sources of water for domestic and other uses. Urine samples were collected from each pupil to examine prevalence and intensity of S. haematobium. Transmission of schistosomiasis was assessed by sampling Bulinus spp snails for cercarial shedding. Uptake of MDA was 39.5 in 2011 and 43.6 in 2012. Prevalence of S. haematobium significantly dropped by 50.0 from 26 in 2011 to 15 in 2012 (p = 0.000). Prevalence of S. haematobium was significantly low in MDA participating (3.1) than non-participating (28.5) schoolchildren (p = 0.000). MDA campaigns had significant impact on knowledge of the disease (p = 0.02) and borderline impact on safe water use (p = 0.04) but had no impact on avoidance of contact with unsafe water bodies (p = 0.06). Bulinus spp. snails were found shedding schistosome cercariae indicating environmental contamination with viable S. haematobium eggs. In conclusion; though MDA significantly reduced prevalence of S. haematobium; uptake was below 50.0 and below the World Health Assembly resolution 54.19 target of 75.0 for 2010. Non-participation in MDA was the likely source of S. haematobium eggs in the environment hence the observed 15.0 prevalence of S. haematobium infection; and cercarial shedding Bulinus spp. snails indicating continuity of transmission hence the need for further health promotion campaigns

Prediction of Plasmodium falciparum resistance to sulfadoxine/pyrimethamine in vivo by mutations in the dihydrofolate reductase and dihydropteroate synthetase genes: a comparative study between sites of differing endemicity.

Plasmodium falciparum resistance to sulfadoxine/pyrimethamine (S/P) is due to mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhfr) genes. Large-scale screening of the prevalence of these mutations could facilitate the surveillance of the level of S/P resistance in vivo. The prevalence of mutations in dhfr and dhps in relation to S/P efficacy was studied in four sites of differing endemicity in Sudan, Mozambique, and Tanzania. The sites were organized in order of increasing resistance and a significant increase in the prevalence of triple mutations in codons c51, c59, and c108 of dhfr was observed. A similar trend was observed when dhfr genotypes were combined with c437 of dhps. Since the differences in S/P resistance between the sites were minor, but nevertheless revealed major differences in dhfr genotype prevalence, the role of dhfr as a general molecular marker seems debatable. The differences may reflect variation in the duration and magnitude of S/P usage (or other antifolate drugs) between the sites. Thus, triple dhfr mutations may prove suitable only as a general guideline for detecting emerging S/P resistance in areas where S/P has been introduced recently. However, changes in susceptibility within the same area with moderate levels of resistance may be possible by longitudinal surveillance of a subset of dhfr/dhps mutations that has been associated with S/P resistance in vivo in a defined location.