Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-28T02:21:15.199Z Has data issue: false hasContentIssue false
  • English
  • Français

Transmission of urinary schistosomiasis in Sukumaland, Tanzania. 1. Snail infection rates and incidence of infection in school children

Published online by Cambridge University Press:  05 June 2009

N. J. S. Lwambo
N. J. S. Lwambo
Affiliation:
National Institute for Medical Research, Mwanza Centre, P.O. Box 1462, Mwanza, Tanzania.
Get access Rights & Permissions [Opens in a new window]

Abstract

Seasonal density fluctuations of Bulinus nasutus populations with accompanying Schistosoma haematobium infection rates in relation to rainfall and habitat water volumes were studied at Ukiriguru, Mwanza, Tanzania. Alongside the snail investigations, 50 school children initially negative for urinary schistosomiasis were examined regularly to determine seasonal incidence rates for the infection. Of the 17 646 B. nasutus collected in 2 years, 156 (0.88%) were found shedding cercariae. Snail populations fluctuated seasonally as influenced by rainfall through its effects on habitat water volume. Monthly snail infection rates ranged from 0.09% to 3.19% and were highest in February and March, at the time of the short dry period. Monthly incidence of S. haematobium in school children ranged between 2.6% and 12.5%, being highest in April and May. There was a significant linear association between monthly snail infection rates and S. haematobium incidence rates in school children ( in 1983/84) suggesting that the maximum transmission period for urinary schistosomiasis in the area occurs during the short dry period, sometime in February/March so that most of the infections in the community would be detected in April/May.

Keywords

Schistosoma haematobiumBulinus nasutusTanzaniaepidemiologyincidenceinfection rates
Type
Research Papers
Information
Journal of Helminthology , Volume 62 , Issue 3 , September 1988 , pp. 213 - 217
Copyright
Copyright © Cambridge University Press 1988

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Appleton, C. C. (1978) Review of literature on abiotic factors influencing the distribution and life cycles of bilharziasis intermediate host snails. Malacological Review, 11, 1–25.Google Scholar
Baalawy, S. S. & Moyo, H. G. (1970) Studies on the population dynamics of B. (P.) nasutus and natural S. haematobium infection rates in relation to rainfall at Misungwi and Usagara, Mwanza. East African Medical Journal, 47, 472–478.Google Scholar
Lwihula, G. K. (1985) Human behavioural factors associated with the transmission and control of Schistosoma haematobium in Ifakara, Tanzania. PhD Thesis, University of London.Google Scholar
Mccullough, F. S., Eyakuze, V. M., Msinde, J. & Nditi, H. (1968) Water resources and bilharziasis transmission in the Misungwi area, Mwanza district, North-West Tanzania. East African Medical Journal, 45, 295–308.Google Scholar
Oliver, L. & Schneiderman, M. (1956) A method for estimating the density of aquatic snail populations. Experimental Parasitology, 5, 109–117.Google Scholar
Oliver, L. & Uemura, K. (1973) Techniques, statistical methods and recording forms. In: Epidemiology and control of schistosomiasis (Bilharziasis),(editor, Ansari, N.).Karger: Basel, pp. 620–747.Google Scholar
Smith, M., Clegg, J. A. & Webbe, G. (1976) Culture of Schistosoma haematobium in vivo and in vitro. Annals of Tropical Medicine and Parasitology, 70, 101–107.CrossRefGoogle ScholarPubMed
Webbe, G. (1962) The transmission of Schistosoma haematobium in an area of Lake Province, Tanganyika. Bulletin of the World Health Organization, 27, 59–85.Google Scholar