Molecular approaches to the identification of Bulinus species in south-west Nigeria and observations on natural snail infections with schistosomes.

The current study considers the distribution of a small sample of 138 Bulinus snails, across 28 localities within eight Nigerian states. Snails were identified using a combination of molecular methods involving both DNA sequencing of a partial cytochrome oxidase subunit 1 (cox1) fragment and restriction profiles obtained from ribosomal internal transcribed spacer (its) amplicons. The results showed that the majority of Bulinus samples tested belonged to the species Bulinus truncatus while only two were Bulinus globosus. The use of RsaI restriction endonuclease to cleave the ribosomal its of Bulinus, as a method of species identification, was adopted for the majority of samples, this being a quicker and cheaper method better suited to small laboratory environments. Polymerase chain reaction (PCR) amplification of the schistosome Dra1 repeat within each of the collected Bulinus samples was employed to determine the extent and distribution of infected snails within the sample areas. Successful amplification of the Dra1 repeat demonstrated that 29.7% of snails were infected with schistosomes. Sequencing of the partial schistosome its from a small subset of snail samples suggested that some snails were either penetrated by both Schistosoma haematobium and Schistosoma bovis miracidia or hybrid miracidia formed from the two species.

Squamous cell abnormalities in exfoliated cells from the urine of Schistosoma haematobium-infected adults in a rural fishing community in Nigeria.

Schistosoma haematobium infection is endemic in Nigeria, with substantial transmissions in all the states of the federation and a high prevalence rate in schools. Literature has linked bladder cancer, mostly squamous cell type, with long-term S. haematobium infections. The objective of this descriptive study was to screen exfoliated cells in the urine of S. haematobium-infected patients for squamous cell abnormalities through cytopathological examinations. Study participants were drawn from Imala Odo, a community near Oyan Dam in Abeokuta North Local Government Area, Ogun state, Southwest Nigeria. Due to a considerable day-to-day variation of S. haematobium eggs in urine, 3 rounds of 200 ml of urine samples were collected on 3 different days from 32 infected patients and 10 uninfected controls and examined. Cytological preparations of the infected 15 males and 8 females and 10 controls (5 males and 5 females) were screened for squamous cell abnormalities. Severely dysplastic to frankly malignant squamous cells were observed in 1 (3.1%) male and 2 (6.3%) females, while no abnormality was observed in the controls.

Detection of schistosomes polymerase chain reaction amplified DNA by oligochromatographic dipstick.

The applications of highly specific and sensitive molecular techniques based on polymerase chain reaction (PCR) have constituted a valuable tool for the diagnosis of schistosomiasis and also for the detection of schistosome infections in the snail intermediate hosts. The common method of detecting PCR amplicons is gel electrophoresis in the presence of ethidium bromide, a carcinogen, which is followed by UV transillumination. Other methods, which are available for detecting PCR products, are real-time PCR, PCR-enzyme-linked immunosorbent assay (PCR-ELIZA) and mass spectrometry but they are cumbersome while they are sometimes complex and expensive. Therefore, a simple method of PCR product detection would be a welcome idea and a most valuable tool particularly in disease endemic countries with limited research facilities and resources. In this study, we applied a simple and rapid method for the detection of Schistosoma haematobium and Schistosoma mansoni PCR amplified DNA products using oligochromatographic (OC) dipstick. The amplicons are visualized by hybridization with a gold conjugated probe, while a control for the chromatographic migration is incorporated in the assay. The lower detection limit observed was 10fg of genomic DNA from each of the two species, while the dipstick was also specific for each of the species used in this study.

Sociocultural aspects of mass delivery of praziquantel in schistosomiasis control: the Abeokuta experience.

BACKGROUND: Schistosomiasis is a public health problem in Nigeria. Although there is an ongoing national program for its control, disease control programs in other countries have shown the need to understand the sociocultural aspects of disease transmission, prevention, and treatment in endemic communities before control efforts are undertaken. OBJECTIVE: To describe sociocultural factors that influence the distribution process of praziquantel for the mass treatment of schistosomiasis infection. METHODS: Data for the study were collected through focus group discussions held separately with adult males and females, male and female adolescents (13-19 years), and male and female children (5-12 years). In-depth interviews were similarly held with the drug distributors of praziquantel for mass treatment and with community/opinion leaders of six hyperendemic communities in Ogun State, Southwest Nigeria on mass treatment using praziquantel. These focus group discussions and in-depth interviews were held both before and following the drug distribution. The data were analyzed using the textual analysis program, Textbase Beta. RESULTS: Following a 3-week period of mass treatment in six communities, we observed an increased awareness of rivers/streams as a source of schistosomiasis. In addition, the communities reported overwhelming support for the mass treatment after receiving treatment. The reasons for this acceptance appear to include the perceived efficacy of praziquantel against the disease and its availability free of charge. The drug's distributors adhered to the originally specified systems-based protocol for mass treatment in only two of the six communities. The systems-based protocol adhered to strict distribution through primary health centers and schools. The four other communities used a community-based approach for mass treatment with praziquantel and attained greater coverage of treatment as a result. CONCLUSION: Obtaining community support and involvement before the implementation of mass treatment of schistosomiasis with praziquantel contributes to an effective treatment strategy for this disease. A detailed assessment of a community's health needs, before the initiation of the control efforts against endemic infections, should be undertaken.

Height as a substitute for weight for estimating praziquantel dosage.

The study evaluated height and weight measurements of 750 school children from five rural communities in western Nigeria. The measurements were taken by 12 trained community members designated as distributors in determining treatment dose with praziquantel for these children. A very strong correlation value, r=0.97, was obtained for the weight of treated children measured by the distributors and the research team. The distributors obtained a correlation coefficient value of r=0.87 on weight and height measurements, showing that height can be used by community distributors in lieu of weight for correct dose determination.

Willingness to pay for praziquantel treatment in a hyperendemic community of Ogun State, Nigeria.

BACKGROUND: Schistosomiasis is highly endemic in Nigeria. However, very little is known about the usage and social marketing of praziquantel in the control of schistosomiasis in endemic communities and on the persons willingness to pay for the drug to support its extensive use and thus aid control efforts in Nigeria. OBJECTIVE: The study examined the willingness of people in a hyperendemic community, to pay for treatment with praziquantel before and after provision of the drug, with a view to assess the feasibility of achieving widespread coverage. METHODS: Data were collected through focus group discussions among household heads and other adult family members and through the use of a questionnaire to survey household heads in Imala-Odo, a community hyperendemic for schistosomiasis, in southwest Nigeria. The main outcome measure was the respondents' willingness to pay for schistosomiasis treatment. RESULTS: The results showed that in contrast to the 92.3% of respondents who expressed willingness to buy the drug in the preintervention study, only 46.5% actually purchased the drug during intervention for the treatment of their infected household members. The respondents' level of education, occupation, and income influenced their willingness to pay (P<.05). Statistical tests showed that those willing to pay for treatment had a higher income score than those unwilling to do so. Most respondents preferred their community head and reliable persons chosen by the community as convenient outlets for drug distribution. The number of household members respondents were willing to treat increased from 4 to 6 at N320.00 (US $2.52) in the preintervention and postintervention phases, respectively. Gender factor was found to influence the respondents' perceived average treatment cost; the females wanted N300.00 (US $2.36) against N100.00 (US $0.79) among the males. CONCLUSION: Efforts need to be made and sustained to ensure that all families can afford to praziquantel drug to achieve the ultimate goal of controlling the infection in endemic communities of Nigeria.