Muriu, S. | bioRxiv Science

bioRxiv2019

Status of Soil-transmitted helminthiasis among pregnant women attending antenatal clinic in Kilifi county hospital, Kenya

Soil-transmitted helminthes (STH) refers to parasites whose life cycle depends on a period of development outside the human host typically in a moist or warm soil. The most important geohelminths are; roundworms (Ascaris lumbricoides), whipworms (Trichuris trichiura) and hookworms (Necator americanus and Ancylostoma duodenale). The study aimed at investigating the current epidemiological status of soil-transmitted helminth infections among pregnant women in Kilifi County hospital (KCH) following the intervention of preventive chemotherapy.\n\nData collection and analysis involved evaluation of transmission trends of geohelminths from the previous surveys/ hospital records, use of direct fecal smears and Kato-Katz smears in estimation of prevalence and infection intensity and the use of structured questionnaires for the assessment of the predisposing factors associated with STH infections. Logistic regression analysis was employed to determine the risk factors associated with STH infections.\n\nA total of 191 stool samples were collected and analyzed. Three species of soil-transmitted helminths (STHs) were identified with the overall prevalence of any STH infection being 16.75%. Trichuris trichiura was predominant (8.38 %), followed by A. lumbricoides (7.85%) then hookworms (6.29 %). About 10.99% of the participants had a single worm infection, 5.76 % had double co-infections and none of the participants had triple infection.\n\nPreventive chemotherapy appears to give maximal returns in terms of reducing significantly the number of geohelminths reported since 2001. The study recommended the routine stool analysis in the antenatal profile, provision of alternative sources of iron to the pregnant women in order to reduce the tendency for soil consumption and the associated risk of STH infections, provision of safe water for domestic use, improved sanitation and proper personal hygiene (WASH).

epidemiology↗

bioRxiv2019

Urban ecology of arboviral mosquito vectors along the Kenyan coast

BackgroundThe emergence and re-emergence of arboviral infections particularly Chikungunya, dengue hemorrhagic fever, rift valley fever, and yellow fever in humans around the world threatens global health and security. The purpose of this study was to determine the urban ecology of the common arboviral mosquito vectors in urban Coastal Kenya areas.\n\nMaterials and MethodsThe current study was conducted in urban settings of Kilifi and Mombasa counties in coastal Kenya in 2016 to 2017. Adult mosquitoes were collected both indoors and outdoors by CDC light traps and BG-Sentinel traps respectively. All blood fed mosquitoes were tested for blood meal sources by an Enzyme Linked Immunosorbent Assay (ELISA). Mosquito larvae were collected using standard dippers and pipettes. Egg survivorship in dry soil was evaluated by collecting of soil samples from dry potential breeding habitats, watering them for hatching and rearing of the eventual larvae to adults. Mosquitoes were screened for Flavivirus, Alphavirus, and Phlebovirus arboviruses using Reverse Transcriptase quantitative Polymerase Chain Reaction (RT qPCR).\n\nResultsA total of 3,264 adult mosquitoes belonging to ten species of Culex, Aedes and Anopheles were collected. Overall, the predominant species were Cx. quinquefasciatus 72.4% (n=2,364) and Ae. aegypti, 25.7%, (n=838). A total of 415 breeding habitat types were identified indoors (n=317) and outdoors (n=98). The most productive habitat types in both indoors and outdoors were: assorted small containers, water tanks, drainages, drums and jericans. Overall, 62% (n=18) of the soil samples collected from the two sites (Kilifi and Malindi) were positive for larvae which were used as proxy to measure the presence of eggs. The mosquitoes had high preference for human blood (29.81%) and chicken (3.73%) but none had fed on either goat or bovine. Of 259 mosquitoes tested for viral infection, 11.6% were positive for flavivirus only.\n\nConclusionDomestic and peri-domestic containers were identified to be the key breeding areas of arboviral vectors. Therefore, efforts should be put in place targeting the productive habitat types.

ecology↗