Evaluation of Paracoccidioides brasiliensis Infection by gp 43 Intradermal Test in Rural Settlements in Central-West Brazil

Abstract

Epidemiological studies of paracoccidioidomycosis have been based on surveys achieved with intradermal tests, and paracoccidioidin is the most common antigen used in most cases. The glycoprotein of 43-kDa (gp43) has been used in intradermal tests. It is the most antigenic component of Paracoccidioides brasiliensis, and it provides greater specificity to evaluate infection for this fungus. In this study, the prevalence of P. brasiliensis infection was estimated with intradermal tests involving gp43 for 695 people in rural Central-West Brazil. The infection rate was 45.8 % (95 % CI = 42.1-49.5), and the average age of those infected was 45.8 ± 18.2 years. The prevalence did not show gender-based differences but increased with age. The results demonstrate the importance of P. brasiliensis infection in rural settlements and the early exposure of children in the region to the fungus. Despite the high antigenicity and specificity of gp43, its usage must be standardized, so that epidemiological surveys will be comparable and more accurately reflect P. brasiliensis infection in endemic areas.

Prevalence of Paracoccidioidomycosis Infection by Intradermal Reaction in Rural Areas in Alfenas, Minas Gerais, Brazil

“…The multiparametric statistical analysis confirmed these results (Table 3). Prevalence of cases in male gender observed in this study is in accordance with numerous other studies 5,11,16 although recently MARQUES et al (2013) 17 showed different results.…”

“…Argentina has lower prevalence rates of PCM compared to other Latin American countries, a variation being observed in prevalence between 1.6% 16 to 10.2%[38]. Some authors have currently used exoantigen purified gp43 in epidemiological surveys for the delimitation of endemic areas, also noting variable results (4-45%) 9,11,17,30,31 . In this study, we found a prevalence of 46.67% of positive tests in rural areas of Alfenas, MG, Brazil using gp43 paracoccidioidin (Table 1).…”

Paracoccidioidomycosis

“…When the same test was applied in Brazil where PCM is of greater importance, the incidence rates were higher especially in the southern, southeastern, and mid-western regions [1,12]. Additionally, when the gp43 antigen was used for this purpose, higher (43 %) prevalence rates of infection were recorded [21,22]. Overall, the disease prevalence rates in Latin America are low, 0.33-3 cases per 100,000 inhabitants [23,24].…”

“…As a disease process, PCM is more often diagnosed in males than in females (ratio of 13:1), even though paracoccidioidin skin testing has shown similar infection rates in both sexes [1,6,[20][21][22]. This mycosis is relatively uncommon in children, with approximately 5 % of all patients being less than 10 years of age.…”

“…In the rare instances, when the primary infection is not checked by the host's immune responses, P. brasiliensis disseminates through the lymphohematogenous route resulting in the acute-or juvenile-type disease [1,42,49,50]. Overall, the prevalence of the disease is low even in endemic areas, while that of infected-only individuals is high, reaching up to 46 % of the population in certain highly endemic settings according to skin testing studies [1,[20][21][22]51].…”