Evidence for the occurrence of Trypanosoma brucei rhodesiense sleeping sickness outside the traditional focus in south-eastern Uganda.
The occurrence of Trypanosoma brucei rhodesiense west of the River Nile, in Masindi district in the mid-western part of Uganda, is confirmed. Masindi borders the traditional belt of T. b. gambiense infection in the north-west, Gulu in the north and the Democratic Republic of Congo in the west. Of the 702 persons tested for sleeping sickness in Masindi, 113 (16%) were positive by the card agglutination test for trypanosomiasis (CATT). Trypanosomes were observed in samples of cerebrospinal fluid (CSF) from two (0.3%) of the subjects: a 7-year-old girl, who had been ill for 2 weeks and yet was in good general condition, with three white blood cells (WBC)/microliter CSF; and a 47-year-old woman who had been ill for 8 months, looked sickly, had seven WBC/microliter CSF, but was still able to dig in her gardens. Rats and mice inoculated with blood from the two parasitologically confirmed cases became parasitaemic on day 3 post-inoculation, indicating that the parasites were T. b. rhodesiense. Isoenzyme analysis revealed that the parasites isolated from one of these confirmed cases belonged to a zymodeme (449) which has not been previously observed among isolates from south-eastern or north-western Uganda. Although the isolate shared PGM2 and ICD3 patterns with T. b. gambiense and T. b. rhodesiense, respectively, it did not have the SOD3:5 pattern characteristic of T. b. gambiense. The spread of T. b. rhodesiense beyond its traditional focus and the development of areas where this subspecies and T. b. gambiense are co-endemic will complicate the control of sleeping sickness in Uganda; although the CATT is very useful for the mass screening of populations for T. b. gambiense area, it is not applicable in the detection of T. b. rhodesiense.
Enyaru
J C
JC
Livestock Health Research Institute, Tororo, Uganda.
Odiit
M
M
Winyi-Kaboyo
R
R
Sebikali
C G
CG
Matovu
E
E
Okitoi
D
D
Olaho-Mukani
W
W
D000372:Agglutination Tests; D000818:Animals; D002648:Child; D005260:Female; D006801:Humans; D051379:Mice; D008875:Middle Aged; D009115:Muridae; D015995:Prevalence; D014347:Trypanosoma brucei gambiense / Q000302:isolation & purification*; D016833:Trypanosoma brucei rhodesiense / Q000302:isolation & purification*; D014353:Trypanosomiasis, African / Q000145:classification / Q000453:epidemiology*; D014454:Uganda / Q000453:epidemiology