Resumo

ANEZ, Néstor; ROJAS, Agustina  e  CRISANTE, Gladys. Evaluation of conventional serological tests for the diagnosis of American cutaneous leishmaniasis. Bol Mal Salud Amb [online]. 2007, vol.47, n.1, pp.55-62. ISSN 1690-4648.

Three serological tests (ELISA, IFAT, DAT) were evaluated using sera from selected individuals with different American cutaneous leishmaniasis (ACL) clinical conditions. Reactivity in at least 2 of the 3 named tests was established as a criterion for declaring a patient as sero-positive. Prior to serological testing, people were diagnosed by clinical (presence of lesion = pl or scar=Sc), parasitological (presence of parasites =pp), immunological (LST) and molecular (PCR) methods. For a statistical comparison of the evaluated tests 4 groups of people were made up: 1) patients with active leishmanial lesion (n=44; pl, pp, +LST, +PCR); 2) patients who had recovered from leishmanial infection (n=43; Sc, +LST, +PCR); 3) asymptomatic individuals from endemic areas showing evidence of having contacted Leishmania-parasites (n=40; +LST, +PCR) and 4) Leishmania-negative people from the above localities where leishmaniasis is endemic and living under the same risk conditions, considered as healthy controls (n=104; -LST, -PCR). Considering the above-established criteria for sero-positives, the analysis of the results obtained with the 3 tests employed revealed very low sensitivity values. Seropositive figures of 50% were recorded for the first group, 9% for the second group, and 12.5% for the third group. Statistical analysis also revealed a low positive predictive value (PPV=0.73), a low negative predictive value (NPV=0.49), and a low kappa coefficient value (k=0.114). The present results raise questions about the use of the 3 conventional serological tests compared here to detect ACL at any clinical condition.

Palavras-chave : American cutaneous leishmaniasis; diagnosis; serology.