Abstract

PAVILLARD, Ana A et al. Reactivity of the skin test with paracoccidioidin and histoplasmin in farmers from the Aragua state. Comunidad y Salud [online]. 2009, vol.7, n.2, pp.52-60. ISSN 1690-3293.

The skin tests with paracoccidiodin or histoplasmin allow to demonstrate previous infections by Paracoccidiodes brasiliensis or Histoplasma capsulatum. In Venezuela, these delayed hypersensitivity skin tests have demonstrated to be very useful in oriented investigations to describe the epidemiology of the infection caused by these microorganisms. In most of these studies readings are taken at 24 and 48 hours post-administration of the antigens, which has generated discrepancies in the found skin reactivities. Consequently, it was determined if the time of reading the intraskin test with paracoccidioidin and histoplasmin, influences in the skin reactivity obtained in 131 farmers from a geographic zone of the Aragua state where both fungi coexist. Results revealed that percentage of intradermopositivity were lower at 24 hours, as for the paracoccidiodin (54.2%) and the histoplasmin (45.8%) as well, in comparison with the obtained ones at 48 hours (90.1% and 72.5% for the paracoccidiodin and histoplasmin respectively). The differences were statistically significant (p<0.001) when the 72 farmers were evaluated, who atended at the 24 hours to perform the reading, these farmers were evaluated at the 48 hours. Similar differences also were found when the farmers were distributed according to age, sex and time of working as farmers. The obtained findings suggest them readings to the 48 hours are more advisable to evaluate these cutaneous reactions, at endemic areas where P. brasiliensis and H. capsulatum coexist and in populations with high occupational risk to contract the infection by these fungi.

Keywords : Paracoccidiodes brasiliensis; Para-occidiodomycosis; Paracoccidiodin; Histoplasma capsulatum; Histoplasmosis; Histoplasmin; Skin test; Farmers.