Skip to main content
    • Aa
    • Aa

Epidemiology of trypanosome infections of the tsetse fly Glossina pallidipes in the Zambezi Valley

  • M. E. J. Woolhouse (a1), J. W. Hargrove (a2) and J. J. McNamara (a3)

The epidemiology of trypanosome infections of Glossina pallidipes was studied at a riverine site in the Zambezi Valley, Zimbabwe for a period of 13 months. Over 9000 flies were captured using a single trap. These flies were dissected, screened for trypanosome infection, sexed, and aged using both wing fray and (for females) ovarian category indices. Midgut infections were identified to species using recently developed DNA probes. The overall prevalence of mature infections was 5·5%, comprising 3·1% Trypanosoma vivax-type and 2·4% T. congolense-type (which included very low prevalences of T. brucei, T. simiae and another Nannomonas species). The prevalence of infection increased with age. For T. vivax-type infections in flies aged by ovarian category this relationship could be described by a simple ‘catalytic’ model assuming a constant per capita rate of infection. For T. congolense-type infections this model tended to over-estimate prevalence in older age classes, implying that the rate of infection decreases with age, and/or that infected flies have higher mortality rates, and/or that a significant fraction of the population is resistant to infection. Prevalences of infection also varied between months. This variation was more marked for T. vivax-type infections and was negatively correlated with both temperature and rainfall. The shape of the age-prevalence relationship, however, did not vary significantly between months. These observations are not fully explained by variation in the age-structure of the tsetse population and are consistent with temporal variation in the rate of infection (rather than in the trypanosome developmental period or in effects of infection on fly mortality). Possible causes of this variation are discussed.

Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

J. Ford & B. M. Leggate (1961). The geographical and climatic distribution of trypanosome infection rates in G. morsitans group of tsetse-flies. Transactions of the Royal Society of Tropical Medicine and Hygiene 55, 383–97.

J. P. Glasgow (1961). The feeding habits of Glossina swynnertoni Austen. Journal of Animal Ecology 30, 7785.

J. W. Hargrove (1981). Discrepancies between estimates of tsetse fly populations using mark-recapture and removal trapping techniques. Journal of Applied Ecology 18, 737–48.

A. M. Jordan (1976). Tsetse flies as vectors of trypanosomes. Veterinary Parasitology 2, 143–52.

J. J. McNamara , P. Dukes , W. F. Snow & W. C. Gibson (1989). Use of DNA probes to identify Trypanosoma congolense and T. simiae in tsetse flies from The Gambia. Acta Tropica 46, 5561.

I. Maudlin (1991). Transmission of African trypanosomiasis: interactions among tsetse immune system, symbionts, and parasites. Advances in Disease Vector Research 7, 117–48.

M. M. Mohamed-Ahmed , A. I. Ahmed & A. Ishag (1989). Trypanosome infection rate of Glossina morsitans submorsitans in Bahl el Arab, South Darfur Province, Sudan. Tropical Animal Health and Productivity 21, 239–44.

S. K. Moloo & M. K. Shaw (1989). Rickettsial infections of midgut cells are not associated with susceptibility of Glossina morsitans centralis to Trypanosoma congolense infection. Acta Tropica 46, 223–7.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0031-1820
  • EISSN: 1469-8161
  • URL: /core/journals/parasitology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 11 *
Loading metrics...

Abstract views

Total abstract views: 104 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 26th May 2017. This data will be updated every 24 hours.