Observations on the biology of Postharmostomum ntowi Hodasi, 1967 (Trematoda: Brachylaimidae) based on intermediate and definitive hosts found in Nigeria.

Following the recovery of the metacercariae of a brachylaimid trematode from the rectum of the frog Amnirana galamensis from Ase in Delta State, Nigeria, we investigated the land snails in the locality to establish their roles in the life cycle of the parasite. Of the four land snails investigated from Ase (Limicolaria aurora, Archachatina marginata, A. papyracea, and Thapsia oscitans), and a Limicolaria sp. from Tombia (Bayelsa State), four harboured larval stages of the bracylaimid. Only L. aurora and the Limicolaria sp. harboured cercariogenous sporocysts and are therefore presumed to serve as the first intermediate hosts of the parasite. Metacercariae were recovered from the Limicolaria spp. and the Archachatina spp. and so serve as the second intermediate hosts. No larval brachylaimids were recovered from T. oscitans. Metacercariae from L. aurora and A. papyracea were cultured in vivo in 14 days old chicks of Gallus gallus domesticus. Parasites recovered from the experimental hosts 7, 14, 21 and 28 days post-infection, showed progressive development of the parasite with the full maturity attained by the 28th day post-infection. Adult parasites recovered from the experimental birds and from free range chicken purchased from Ase and Tombia showed that the brachylaimid infecting these birds was Postharmostomum ntowi, a parasite previously reported in domestic chicken in Ghana. There is need to investigate the host range of the parasite in Nigeria as this trematode is also known to infect the Guinea fowl in Ghana.

Contrasting epidemiology of urogenital schistosomiasis among pastoral communities surrounding three Ramsar wetland in Nigeria.

Suspected changes in the epidemiology of schistosomiasis due to several hybridization reports between human and livestock Schistosoma species in Africa calls for epidemiological investigations among potential high-risk groups and sites. Although the use of wetlands for pastoralism has been linked to schistosomiasis, there is limited information on the epidemiology of the disease among pastoralists in Nigeria. In this study, urine samples from 355 participants from pastoral communities settled around three Ramsar wetlands (Wetlands of International Importance) in Nigeria, (Dagona Sanctuary, Maladumba, and Pandam-Wase) were screened for the eggs of Schistosoma haematobium. Only participants in the Dagona Sanctuary were infected with 34.2% prevalence. Macrohematuria was however observed in some individuals at the Dagona Sanctuary wetland (2.5%) and Maladumba (2.8%). Regular praziquantel administration, functional health care facilities and awareness about schistosomiasis were contributory factors to the contrasting epidemiology of the disease among the study population. Schistosomiasis control requires the inclusion of pastoral and nomadic communities in mass drug administration of praziquantel based on a community-directed intervention strategy.