Browsing by Autor "Patrick Wincker"

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Different Behavior of TwoTrypanosoma cruziMajor Clones: Transmission and Circulation in Young Bolivian Patients
(Elsevier BV, 1998) Simone Frédérique Brénière; Marie-France Bosseno; Jenny Telleria; Brigitte Bastrenta; Nina Yacsik; François Noireau; Jose-Luis Alcazar; Christian Barnabé; Patrick Wincker; Michel Tibayrenc
High correlation between Chagas' disease serology and PCR-based detection of<i>Trypanosoma cruzi</i>kinetoplast DNA in Bolivian children living in an endemic area
(Oxford University Press, 1994) Patrick Wincker; Marie-France Bosseno; Constança Britto; Nina Yaksic; Micaela Cardoso; Carlos MÃ©dicis Morel; Simone FrÃ©dÃ©rique BreniÃ ̈re
The detection of Trypanosoma cruzi kinetoplast DNA by polymerase chain reaction (PCR) amplification is a potentially powerful tool for the parasitological diagnosis of Chagas' disease. We have applied this technique in a field situation in Bolivia, where 45 children from a primary school were subjected to serological testing, buffy coat analysis and PCR diagnosis. 26 of the 28 serology-positive individuals were also positive by PCR. In addition, two serology-negative children gave a positive result by PCR, including one who was positive in the buffy coat test. These results suggest that PCR detection of T. cruzi DNA in blood can be a very useful complement to serology in Chagas' disease diagnosis in Bolivia.
Immune Response to Trypanosoma cruzi Shed Acute Phase Antigen in Children from an Endemic Area for Chagas' Disease in Bolivia
(Instituto Oswaldo Cruz, Ministério da Saúde, 1997) Simone Frédérique Brénière; Nina Yaksic; Jenny Telleria; Marie-France Bosseno; François Noireau; Patrick Wincker; Daniel O. Sánchez
A field study of the immune response to the shed acute phase antigen (SAPA) of Trypanosoma cruzi was carried out in the locality of Mizque, Cochabamba department, Bolivia. Schoolchildren (266), with an average of 8.6 +/- 3.6 years, were surveyed for parasitological and serological diagnosis, as well as antibodies directed against SAPA using the corresponding recombinant protein in ELISA. The antibodies against SAPA were shown in 82% of patients presenting positive serological diagnosis (IgG specific antibodies). The positive and negative predictive values were 0.88. Antibodies anti-SAPA were shown in 80.8% of the chagasic patients in the initial stage of the infection (positive IgM serology and/or positive buffy coat (BC) test) and in 81.4% of the patients in the indeterminate stage of the infection (positive IgG serology with negative BC and IgM tests). These results show that the anti-SAPA response is not only present during the initial stage of the infection (few months) but extends some years after infection.
PCR-based diagnosis for Chagas' disease in Bolivian children living in an active transmission area: comparison with conventional serological and parasitological diagnosis
(Cambridge University Press, 1997) Patrick Wincker; Jenny Telleria; M. F. Bosseno; Micaela Cardoso; Patrícia Marques; Nina Yaksic; Christine Aznar; P. LIEGEARD; Mireille Hontebeyrie; François Noireau
A large field study has been performed in the Cochabamba region of Bolivia with the aim of comparing the polymerase chain reaction (PCR) with other diagnostic methods for Chagas' disease. The amplification of Trypanosoma cruzi-specific kinetoplast DNA sequences in blood samples was compared with classical serological methods, specific IgM detection and direct parasite visualization for 268 school children in a single village where Chagas' disease transmission is active. Of 113 children positive by classical serology or buffy coat examination, 106 were detected by PCR (sensitivity: 93.8%). We did not observe any significant difference of PCR sensitivity between initial (IgM and/or buffy coat positive) and indeterminate stage (only IgG positive) patients. Among the remaining 155 children unconfirmed as chagasic (who were either only IgM positive, IgG-, IgM-, and buffy coat-negative) only 1 case was PCR positive. This case may be due to DNA contamination, or to a very recent infection not detected otherwise, or to specific immune depression. These results show that PCR is a very sensitive parasitological test for Chagas' disease in active transmission regions. The future follow-up of the possibly infected patients who were only IgM-positive should clarify the interest of PCR and IgM tests in the detection of starting infections.