The predictive validity of naturally acquired delayed-type hypersensitivity to leishmanin in resistance to Leishmania major-associated cutaneous leishmaniasis.

Afif Ben Salah (1) , Hechmi Louzir (2) , Sadok Chlif (1) , Mourad Mokni (3) , Amor Zaatour (1) , Mohamed Raouene (4) , Riadh Ben Ismail (1) , Koussay Dellagi (2)

1 Laboratoire d'Epidémiologie et d'Ecologie parasitaire, Institut Pasteur de Tunis
2 LVGM - Laboratoire d'Immunopathologie, Vaccinologie et Génétique Moléculaire
3 Dermatology Unit
4 Regional Directorate of Health of Tataouine

To accurately quantify the different outcomes of Leishmania major infection and to evaluate the fraction of zoonotic cutaneous leishmaniasis (ZCL) cases prevented by naturally acquired leishmanin skin test (LST) reactivity, a cohort of 470 children was followed up in 2 endemic foci, Remada and Dhiba, in southern Tunisia. During May 1997, before the ZCL emergence season, LST was performed, and results were reassessed 12 months later. Active case detection during the ZCL emergence season showed a high incidence of ZCL: 57.0% in Remada and 13.7% in Dhiba. The preventive fraction of ZCL conferred by LST reactivity increased proportionally with the reaction size before the emergence season, revealing a dose-response effect of approximately 70%. In addition, asymptomatic L. major infection appeared to be a significant form of natural immunization, particularly in the context of relatively low transmission. These findings may help in the design and evaluation of vaccines.

Domains: Life Sciences [q-bio]

Afif Ben Salah, Hechmi Louzir, Sadok Chlif, Mourad Mokni, Amor Zaatour, et al.. The predictive validity of naturally acquired delayed-type hypersensitivity to leishmanin in resistance to Leishmania major-associated cutaneous leishmaniasis.. Journal of Infectious Diseases, 2005, 192 (11), pp.1981-7. ⟨10.1086/498042⟩. ⟨pasteur-00874052⟩