Silent HumanTrypanosoma brucei gambienseInfections around the Old Gboko Sleeping Sickness Focus in Nigeria

Abstract

Trypanosoma brucei gambiensecauses Gambian trypanosomosis, a disease ravaging affected rural parts of Sub-Saharan Africa. We screened 1200 human blood samples forT. b. gambienseusing the card agglutination test for trypanosomosis, characterized trypanosome isolates withTrypanosoma gambienseserum glycoprotein-PCR (TgsGP-PCR), and analyzed our data using Chi square and odds ratio at 95% confidence interval for statistical association. Of the 1200 samples, the CATT revealed an overall infection rate of 1.8% which ranged between 0.0% and 3.5% across study sites. Age and sex based infection rates ranged between 1.2% and 2.3%. We isolated 7 (33.3%) trypanosomes from the 21 seropositive samples using immunosuppressed mice which were identified asT. b. gambiensegroup 1 by TgsGP-PCR. Based on study sites, PCR revealed an overall infection rate of 0.6% which ranged between 0.0% and 1.5%. Females and males revealed PCR based infection rates of 0.3% and 0.8%, respectively. Infection rates in adults (1.3%) and children (0.1%) varied significantly (p<0.05). We observed silentT. b. gambienseinfections among residents of this focus. Risks of disease development into the second fatal stage in these patients who may also serve as reservoirs of infection in the focus exist.