Untreated human infections by Trypanosoma brucei gambiense are not 100% fatal - PubMed (original) (raw)

doi: 10.1371/journal.pntd.0001691. Epub 2012 Jun 12.

Hamidou Ilboudo, Jacques Kaboré, Dramane Kaba, Mathurin Koffi, Philippe Solano, André Garcia, David Courtin, Claude Laveissière, Kouakou Lingue, Philippe Büscher, Bruno Bucheton

Affiliations

Untreated human infections by Trypanosoma brucei gambiense are not 100% fatal

Vincent Jamonneau et al. PLoS Negl Trop Dis. 2012.

Abstract

The final outcome of infection by Trypanosoma brucei gambiense, the main agent of sleeping sickness, has always been considered as invariably fatal. While scarce and old reports have mentioned cases of self-cure in untreated patients, these studies suffered from the lack of accurate diagnostic tools available at that time. Here, using the most specific and sensitive tools available to date, we report on a long-term follow-up (15 years) of a cohort of 50 human African trypanosomiasis (HAT) patients from the Ivory Coast among whom 11 refused treatment after their initial diagnosis. In 10 out of 11 subjects who continued to refuse treatment despite repeated visits, parasite clearance was observed using both microscopy and polymerase chain reaction (PCR). Most of these subjects (7/10) also displayed decreasing serological responses, becoming progressively negative to trypanosome variable antigens (LiTat 1.3, 1.5 and 1.6). Hence, in addition to the "classic" lethal outcome of HAT, we show that alternative natural progressions of HAT may occur: progression to an apparently aparasitaemic and asymptomatic infection associated with strong long-lasting serological responses and progression to an apparently spontaneous resolution of infection (with negative results in parasitological tests and PCR) associated with a progressive drop in antibody titres as observed in treated cases. While this study does not precisely estimate the frequency of the alternative courses for this infection, it is noteworthy that in the field national control programs encounter a significant proportion of subjects displaying positive serologic test results but negative results in parasitological testing. These findings demonstrate that a number of these subjects display such infection courses. From our point of view, recognising that trypanotolerance exists in humans, as is now widely accepted for animals, is a major step forward for future research in the field of HAT.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Figure 1

Figure 1. “Classic” and possible alternative natural progressions of HAT.

Cpl = CATT on plasma, considered positive (Cpl+) if end titres ≥1/8 TL = Trypanolysis test, considered positive (TL+) if positive to at least one variant P = Parasitological investigations in blood and/or lymph fluid (P+ = presence of trypanosome).

Similar articles

Cited by

References

    1. Simarro PP, Diarra A, Ruiz Postigo JA, Franco JR, Jannin JG. The human African trypanosomiasis control and surveillance programme of the World Health Organization 2000–2009: the way forward. PLoS Negl Trop Dis. 2011;5:e1007. - PMC - PubMed
    1. Brun R, Blum J, Chappuis F, Burri C. Human African trypanosomiasis. Lancet. 2010;375:148–159. - PubMed
    1. Checchi F, Filipe JA, Haydon DT, Chandramohan D, Chappuis F. Estimates of the duration of the early and late stage of gambiense sleeping sickness. BMC Infect Dis. 2008;8:16. - PMC - PubMed
    1. Steverding D. The history of African trypanosomiasis. Parasit Vectors. 2008;1:3. - PMC - PubMed
    1. WHO. Control and surveillance of African trypanosomiasis. Report of a WHO Expert Committee. WHO Technical Report Series 881. 1998. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources