Comparative study on the infection rates of different Glossina species for East and West African Trypanosoma vivax stocks.

Teneral male Glossina morsitans centralis, G. austeni, G. palpalis palpalis, G. p. gambiensis, G. fuscipes fuscipes, G. tachinoides and G. brevipalpis were fed on the flanks of Boran calves infected with Trypanosoma vivax stock ILRAD 2241 isolated from a cow in Likoni, Kenya; stock ILRAD 2337 isolated from a cow in Galana, Kenya; stock ILRAD 1392 isolated from a cow in Nigeria; or, stock EATRO 1721 isolated from G. m. submorsitans in Nigeria. The tsetse were fed on the infected hosts for 24 days and were then dissected to determine the infection rates. In G. m. centralis and G. brevipalpis, the mature infection rates of T. vivax from Kenya were 61.1%, and 75.3% for ILRAD 2241, and 36.2% and 58.2% for ILRAD 2337, respectively. In G. austeni and in the four palpalis group of tsetse, the rates for these two stocks were very low and ranged from 0% in G. p. palpalis to 1.8% in G. austeni for ILRAD 2241 and from 0% in G. f. fuscipes to 5% in G. tachinoides for ILRAD 2337. In contrast, the hypopharyngeal infection rates of T. vivax from Nigeria were quite high in all the 7 tsetse species and sub-species. They ranged from 55.5% in G. austeni to 91.9% in G. p. gambiensis for ILRAD 1392, and from 71.4% in G. austenei to 97.1% in G. brevipalpis for EATRO 1721.(ABSTRACT TRUNCATED AT 250 WORDS)