Clinical analysis and parasite genetic diversity in human immunodeficiency virus/Chagas' disease coinfections in Brazil.

Abstract

To evaluate the possible role of parasitemia on Chagas' disease reactivation in Chagas' disease/human immunodeficiency virus (HIV) coinfection cases and the impact of HIV coinfection on Trypanosoma cruzi genetic diversity, 71 patients with Chagas' disease (34 HIVϩ and 37 HIV-) were surveyed. Moreover, 92 T. cruzi stocks from 47 chronic chagasic patients (29 HIVϩ and 18 HIV-) were isolated and analyzed by multilocus enzyme electrophoresis and a random amplified polymorphic DNA procedure. High parasitemia appeared to play a major role in cases of Chagas' disease reactivation. In HIVϩ patients, the genetic diversity and population structure (clonality) of T. cruzi was similar to that previously observed in HIV-patients, which indicates that immunodepression does not modify drastically genotype repartition of the parasite. There was no apparent association between given T. cruzi genotypes and specific clinical forms of Chagas' disease/HIV associations. Chagas' disease, the American trypanosomiasis, is widespread from the southern United States (where the indigenous cases are rare) to northern Argentina. It is characterized by two successive phases, an acute one, with high parasitemia, and a chronic one, with low parasitemia. Although efficient measures of transmission control have been implemented in some countries (by eliminating the insect vector), Chagas' disease still is a priority health problem in Latin America. Chagas' disease/human immunodeficiency virus (HIV) associations appear to be a growing threat in large Latin American cities, and can be extremely pathogenic, with severe cases involving the central nervous system (CNS) with either tumoral lesions or meningoencephalitis. 1-5

2 nd Brazilian Consensus on Chagas Disease, 2015

“…High levels of parasitemia are indicative of reactivation. However, there is no record of patients who developed low parasitemia (219) .…”

Co-infection Trypanosoma cruzi/HIV: systematic review (1980 - 2010)

“…However, just as there are difficulties to know the exact number of individuals co-infected, this also occurs regarding the frequency that these reactivate the Chagas disease, a pathognomonic clinical event. However, when the parasitemia is analyzed by xenodiagnosis or blood culture, the co-infected individuals have a higher chagasic parasitemia than patients without the co-infection with the HIV, suggesting that this reactivation may occur asymptomatic, with a higher frequency 44,60,61 . In this revision, it was reported the occurrence of 41,2% of reactivations, this percentage higher than the ones related in series of cases, which varies between 10 and 15% 81,93,97 , reflecting that, probably, the more severe cases must have been diagnosed and related.…”

Exacerbation of HIV viral load simultaneous with asymptomatic reactivation of chronic Chagas' disease.

“…8 HIV-infected patients with chronic Chagas' disease have higher T. cruzi parasitemia than HIV-negative individuals. 9 The persistent immune activation induced by T. cruzi might lead to a sustained increase in the rate of HIV replication, which may affect HIV disease progression.…”