ABSTRACT
UNLABELLED: This study investigated the levels of prepatent S. haematobium infection in water samples collected from Schistosomiasis haematobium transmission namely: International Institute of Tropical Agriculture (IITA) river and Eleyele river in Oyo state, Oyan dam and Shokori river in Ogun state, Badagry Lagoon and Lagoon (University of Lagos, Lagos state). METHODOLOGY: Polymerase chain reaction (PCR) assay amplifying the Dra I repeated sequence of S. haematobium cercariae from the water samples was used. Samples of cercariae obtained from a laboratory population of Bulinus globosus and Bulinus rohlfsi snails were assayed following DNA extraction as control. Physico-chemical parameters of the water bodies were determined. RESULTS: Physico-chemical parameters showed that salinity, conductivity and total dissolved solids were relatively high in the Lagoon front samples (41.91 ppt, 62400.87 micros/cm, 31000.14 mg/L and 7.79), and low in the river samples (13.27 ppt, 1325.67 micros/cm, 11470 mg/L and 8.36 respectively) while pH were similar. PCR showed that 3 out of the 6 water bodies sampled namely IITA river, Eleyele river and Oyan Dam are S. haematobium endemic sites as they gave positive signals. CONCLUSION: Three surveyed sites with relatively low salinity namely IITA river, Eleyele river and Oyan dam are high S. haematobium endemic areas and schistosomes survive perhaps best in low salinity environment. PCR could be a more valuable tool in the study of incidence and prevalence of S. haematobium infection compared with conventional cercariae shedding method. On the known strength of focal effects of environmental conditions, implications of these results in the epidemiology and design of control activities are encouraging.
Subject(s)
Bulinus/parasitology , Endemic Diseases/statistics & numerical data , Rivers , Schistosoma haematobium , Schistosomiasis haematobia , Animals , Cercaria , Disease Reservoirs/parasitology , Disease Reservoirs/statistics & numerical data , Disease Vectors , Epidemiological Monitoring , Incidence , Nigeria/epidemiology , Polymerase Chain Reaction/methods , Prevalence , Rivers/chemistry , Rivers/parasitology , Schistosoma haematobium/genetics , Schistosoma haematobium/isolation & purification , Schistosomiasis haematobia/epidemiology , Schistosomiasis haematobia/parasitology , Water QualityABSTRACT
OBJECTIVES: This study was carried out to screen the use of Helicobacter pylori stool antigen (HpSA) tests for diagnosis and monitoring of H pylori in Nigeria. METHODS: Seven hundred and forty participants were enrolled after informed consent was obtained, while 83 came back for a post-eradication test. The stool samples were taken from the patients at endoscopy and tested for HpSA. RESULTS: The proportion of patients that were positive at the pretest, 520 (70.3%) was significantly higher (Fisher's exact p = 0.001) than those positive at the post-test, 44 (53%). There was a significant difference (F = 4.106, p = 0.043) between the mean age of those that came for the pretest (40.0 +/- 14.5 years) and those that came for the post-test, 43.6 +/- 11.6 years. More males than females had the tendency to come back for a post-eradication test. CONCLUSION: Although potential bias was introduced during this study, HpSA using monoclonal antibody could still be used for diagnosis and monitoring of H pylori in Nigeria.
