Mixed infections of trypanosomes in tsetse and pigs and their epidemiological significance in a sleeping sickness focus of Côte d'Ivoire

V. JAMONNEAU a1a2, S. RAVEL a2, M. KOFFI a1a2, D. KABA a1, D. G. ZEZE a1, L. NDRI a1, B. SANE a1, B. COULIBALY a1, G. CUNY a2 and P. SOLANO a1a2c1
a1 Institut Pierre Richet, BP 1500, Bouake, Côte d'Ivoire, France
a2 IRD UR 035, LRCT IRD/CIRAD, Montpellier, France

Article author query
jamonneau v   [PubMed][Google Scholar] 
ravel s   [PubMed][Google Scholar] 
koffi m   [PubMed][Google Scholar] 
kaba d   [PubMed][Google Scholar] 
zeze dg   [PubMed][Google Scholar] 
ndri l   [PubMed][Google Scholar] 
sane b   [PubMed][Google Scholar] 
coulibaly b   [PubMed][Google Scholar] 
cuny g   [PubMed][Google Scholar] 
solano p   [PubMed][Google Scholar] 


In a sleeping sickness focus of Côte d'Ivoire, trypanosomes were characterized in humans, pigs and tsetse using various techniques. Out of 74 patients, all the 43 stocks isolated by KIVI (Kit for In Vitro Isolation) appeared to belong to only one zymodeme of Trypanosoma brucei gambiense group 1 (the major zymodeme Z3). The only stock isolated on rodents belonged to a different, new, zymodeme (Z50), of T. b. gambiense group 1. From 18 pigs sampled in the same locations as the patients, PCR showed a high proportion of mixed infections of T. brucei s. l. and T. congolense riverine-forest. Zymodemes of T. brucei s. l. from these pigs were different from those found in humans. From a total of 16260 captured tsetse (Glossina palpalis palpalis), 1701 were dissected and 28% were found to be infected by trypanosomes. The most prevalent trypanosome was T. congolense riverine-forest type, followed by T. vivax, T. brucei s. l. and T. congolense savannah type, this latter being associated to the forest type of T. congolense in most cases. Mixed infections by 2 or 3 of these trypanosomes were also found. Use of a microsatellite marker allowed us to distinguish T. b. gambiense group 1 in some of the mature infections in tsetse. Differences in infection rates and in trypanosome genotypes according to the host might indicate that the pig may not be an active animal reservoir for humans in this focus.

(Received February 18 2004)
(Revised April 2 2004)
(Accepted April 2 2004)

Key Words: sleeping sickness; Côte d'Ivoire; Trypanosoma; tsetse; microsatellite; animal reservoir; mixed infection.

c1 Institut Pierre Richet, s/c représentation IRD, rue Chevalier de Clieu, 15 BP 917 Abidjan 15, France. Tel: +225 21 24 37 79. Fax: +225 21 75 47 26. E-mail: