Entomological surveillance reveals transmission of malaria but not lymphatic filariasis in two communities in North-West Nigeria.

Malaria and lymphatic filariasis (LF) are two serious public health challenges in sub-Saharan Africa, and both diseases are transmitted by Anopheles mosquitoes. Successful control of both diseases requires detailed information on transmission dynamics; thus, this study investigated malaria and LF transmission indices in two (2) communities (Jidawa and Kargo) in North-West Nigeria. Anopheles mosquitoes were sampled from twenty-five (25) randomly selected houses from each of the two communities using pyrethrum spray collection (PSC). The samples were identified morphologically and molecularly characterised using polymerase chain reaction (PCR). Human biting rate (HBR), indoor resting density (IRD), sporozoite rate (SR) and entomological inoculation rate (EIR) were calculated using standard formulae. The thorax region of the collected samples were dissected and smeared; then, Plasmodium and Wuchereria bancrofti parasites were identified using microscopy. A total of 2417 Anopheles mosquitoes were collected, and all were identified morphologically as An. gambiae s.l. Further molecular identification of sibling species revealed that An. gambiae and An. arabiensis were the only sibling species present. A total of 818 Anopheles mosquitoes were screened for Plasmodium and Wuchereria bancrofti parasites. A total of 180 samples were positive for Plasmodium parasites (Jidawa = 151; Kargo = 29), and none was positive for W. bancrofti (0%). Result of entomological indices for malaria transmission showed that indoor resting density was higher in Jidawa (10 mosquitoes/room/night) while human biting rate (2.07 bites/person/night), sporozoite rate (29.3%) and entomological inoculation rate (0.61) were higher in Kargo. In total, 35.2% of the samples were blood-fed while 67.4% were parous. There is active transmission of malaria in the two communities but not LF, suggesting the effectiveness of mass drug administration for LF. Concerted efforts should be focused on malaria control as transmission of the disease persists.

Geospatial Mapping and Seasonal Profiling of Urinary Schistosomiasis in Ase-Niger River Settlements: A Data-Driven Population-Base Study in Delta State, Nigeria.

OBJECTIVES: This study is aimed to determine the geospatial, seasonal, age and gender prevalence and intensity of UgS; and to establish disease maps in the Ase-Niger River communities for effective drug administration. STUDY DESIGN: This study employed a 24 months longitudinal study design for parasitological investigations in 11 riparian communities of the Ase-Niger River basin, taking into cognizance their GPS locations imported into QGIS software for schistosomiasis mapping. METHODS: A total of 7,219 urine samples with WHO structured questionnaires were retrieved and subjected to parasitological evaluation using swinnex urine filtration techniques. RESULTS: An overall prevalence of 48.10% was established. Geospatially, prevalence ranges from 34.27% (Ivrogbo) to 52.29% (Ase) with seasonal significant difference (p < 0.05) accounting for 76.19% of the total variance. Ashaka had the highest prevalence for both males (55.73%) and females (53.32%) with significant difference in the study sites (p < 0.05) accounting for 96.47% of the total variance. Age-group 11-20 years consistently maintain a high prevalence at all sites. The peak geometric mean intensity of 105.69 was obtained in the dry season at Lagos Iyede. Ashaka, Igbuku, Iyede-Ame, and Onogboko had heavy-intensity levels in both seasons. Overall, the intensity was lower during the wet season than the dry season, with significant variations (p < 0.05) at Awah and Itobi-Ige. Geospatial prevalence and intensity have a robust and strong positive correlation (r = 0.7178; p = 0.0129), with 51.53% of intensity variability being influenced by prevalence (R2 = 0.5153). CONCLUSION: UgS is a significant public health issue in the Ase-Niger River basin, with prevalences surpassing the national average of 29.0% which calls for MDA in these settlements.