Current status of bancroftian filariasis in rural communities of the lower cross river basin, Nigeria: parasitological and clinical aspects

Genetic Variations in Bionomics of Culex quinquefasciatus (Diptera: Culicidae) Mosquito Population in Minna, North Central Nigeria

The need to have an improved knowledge on the bioecology of Culex quinquefasciatus, a prerequisite in the development of cost-effective control strategies, has informed the present preliminary investigation to put in better perspective variations that exist in the egg rafts of the species. Freshly laid egg rafts were collected and incubated at ambient temperature in well-labeled plastic trays. The results showed overall inconsistency in all indices monitored for the egg rafts. Generally, survivorship was high for the species. All immature stage and adult parameters measured varied significantly among the egg rafts and between/within sexes of the species. Therefore, this study suggests the presence of inherent variation in the bionomics of egg rafts of C. quinquefasciatus, probably influenced by the environment and hence underscores the need for additional studies to further elucidate the roles of genetics and environment in vectorial competence of the species, in order to develop robust sustainable mosquito vector control protocols.

Lymphatic filariasis and associated morbidities in rural communities of Ogun State, Southwestern Nigeria

Lymphatic filariasis caused by Wuchereria bancrofti is a serious public health problem in rural communities of Nigeria. The study assessed the prevalence of lymphatic filariasis and associated clinical morbidities in Ado-Odo Ota Local Government Area of Ogun State. Microscopic examination of thick blood smears of 500 participants of both sexes and age ranging from 1 to 79 years was conducted. Visual observations of clinical manifestations of chronic infection were also conducted. The overall prevalence and intensity of infection were 21% and 21.4 mf/mL of blood respectively. Microfilaraemic prevalence was significantly higher in males (27.1%) than in females (16%) (P < 0.001). However, intensity of infection was not gender and age dependent (P > 0.05). The overall prevalence of all clinical manifestations of infection due to W. bancrofti is 15% with hydrocele, limb and breast elephantiasis constituting 16.9%, 4.6% and 5.1% of the total population respectively. Prevalence of hydrocele and limb elephantiasis was significantly higher in the older age groups (P < 0.05). Occurrence of elephantiasis of the breast in women however was not associated with age (P > 0.05). Integrated approach through chemotherapy and vector control is therefore advocated to reduce morbidity due to infection in this study area.

Lymphatic filariasis among the Yakurr people of Cross River State, Nigeria

BACKGROUND

In order to initiate a disease elimination programme for lymphatic filariasis based on mass drug administration, a proper understanding of the geographical distribution and degree of risk is essential.

METHODS

An investigation of lymphatic filariasis due to Wuchereria bancrofti was carried out among 785 people in four communities of Yakurr Local Government Area of Cross River State, Nigeria between March and August, 2009. Finger prick blood smear samples collected from the subjects were examined for W. bancrofti using standard parasitological protocol. The subjects were also screened for clinical manifestations of lymphatic filariasis.

RESULTS

Of the 785 persons examined, 48 (6.1%) were positive for microfilariae in their thick blood smear. There was a significant difference in the prevalence of lymphatic filariasis among the various age groups (P < 0.01) although peak prevalence occurred between 41-60 years. There was no significant difference in prevalence and density with respect to sex (P > 0.05). The overall mean microfilarial density of the infected individuals was 5.6 mf/50 μl. There was a significant variation (P < 0.01) in mean microfilarial density within the communities, ranging from 4.7 to 6.4 mf/50 μl. The only clinical sign found in the study area was lymphoedema of the leg recording 2 (0.3%) prevalence.

CONCLUSIONS

The National Lymphatic Filariasis Elimination Programme should intervene by expanding the distribution of albendazole and ivermectin to all endemic areas including Yakurr Local Government Area of Cross River State, Nigeria.