Influence of temporal variation and host condition on helminth abundance in the lizard Tropidurus hispidus from north-eastern Brazil.

Ecological characteristics and environmental variation influence both host species composition and parasite abundance. Abiotic factors such as rainfall and temperature can improve parasite development and increase its reproduction rate. The comparison of these assemblages between different environments may give us a more refined analysis of how environment affects the variation of helminth parasite abundance. The aim of the present study was to evaluate how temporal variation, host size, sex and reproduction affect helminth abundance in the Tropidurus hispidus lizard in Caatinga, Restinga and Atlantic Forest environments. Overall, larger-sized lizards showed higher helminth abundance. We found a monthly variation in the helminth species abundance in all studied areas. In the Caatinga area, monoxenic and heteroxenic parasites were related to the rainy season and to the reproductive period of lizards. In Restinga, monoxenic and heteroxenic helminth species were more abundant during the driest months. In the Atlantic Forest, the rainy and host reproductive season occurred continuously throughout the year, so parasite abundance was relatively constant. Nevertheless, heteroxenic species were more abundant in this area. The present results showed that the temporal variation, body size, sex, reproductive period and habitat type influence the abundance and composition of helminth species in T. hispidus.

Hepatitis C virus infection in patients with tuberculosis in Central Brazil.

SETTING: Goiânia City, Goiás State, Brazil. OBJECTIVES: To determine the prevalence of hepatitis C virus (HCV) infection, risk factors, HCV genotype/ subtype, HCV viral load and human immunodeficiency virus (HIV) status in patients with tuberculosis (TB) in Central Brazil. DESIGN: A cross-sectional study was carried out with 402 patients who were under tuberculosis (TB) treatment in the reference hospital for infectious diseases in Goiânia, Goiás, Central Brazil. RESULTS: The prevalence rates of HCV and HIV were respectively 7.5% and 27.6%. Two thirds of the HCV-infected patients (20/30) were HIV-positive. Age, injecting drug use (IDU) and HIV status were factors independently associated with HCV infection. HCV RNA was detected in 23 serum samples; HCV RNA levels were measured in 22/23 samples. HCV RNA level was slightly higher in HCV-HIV co-infected patients than in HCV monoinfected patients. Genotypes 1 (n = 17) and 3 (n = 6) were determined by LiPA. Using phylogenetic tree analysis of the NS5B region, subtypes 1a (n = 12), 1b (n = 2) and 3a (n = 6) were identified. CONCLUSION: These data indicate that patients with TB may benefit from integrated HIV and HCV screening, which may have an important impact upon TB management and treatment.