Toxocariasis/cysticercosis seroprevalence in a long-term rural settlement, São Paulo, Brazil.

Seroprevalence of Toxocara and Taenia solium and risk factors for infection with these parasites were explored in a long-term rural settlement in São Paulo state, Brazil. An ELISA for the detection of anti-Toxocara IgG and IgE and anti-T. solium cysticerci was standardized using Toxocara excretory-secretory antigens (TES) obtained from the cultured second-stage larvae of T. canis and by vesicular fluid antigen from Taenia crassiceps cysticerci (VF). For cysticercosis, the reactive ELISA samples were assayed by Western blot using 18 kDa and 14 kDa proteins purified from VF. Out of 182 subjects, 25 (13.7%) presented anti-Toxocara IgG and a positive correlation between total IgE and the reactive index of specific anti-TES IgE (P=0.0265) was found amongst the subjects found seropositive for anti-Toxocara IgG. In these individuals 38.0% showed ocular manifestations. The frequency of anti-T. solium cysticerci confirmed by Western blot was 0.6%. Seropositivity for Toxocara was correlated with low educational levels and the owning of dogs. Embryonated eggs of Toxocara spp. were found in 43.3% of the analysed areas.

Mycobacterium leprae is identified in the oral mucosa from paucibacillary and multibacillary leprosy patients.

In leprosy, the nasal mucosa is considered as the principal route of transmission for the bacillus Mycobacterium leprae. The objective of this study was to identify M. leprae in the oral mucosa of 50 untreated leprosy patients, including 21 paucibacillary (PB) and 29 multibacillary (MB) patients, using immunohistochemistry (IHC), with antibodies against bacillus Calmette-Guérin (BCG) and phenolic glycolipid antigen-1 (PGL-1), and polymerase chain reaction (PCR), with MntH-specific primers for M. leprae, and to compare the results. The material was represented by 163 paraffin blocks containing biopsy samples obtained from clinically normal sites (including the tongue, buccal mucosa and soft palate) and visible lesions anywhere in the oral mucosa. All patients and 158 available samples were included for IHC study. Among the 161 available samples for PCR, 110 had viable DNA. There was viable DNA in at least one area of the oral mucosa for 47 patients. M. leprae was detected in 70% and 78% of patients using IHC and PCR, respectively, and in 94% of the patients by at least one of the two diagnostic methods. There were no differences in detection of M. leprae between MB and PB patients. Similar results were obtained using anti-BCG and anti-PGL-1 antibodies, and immunoreactivity occurred predominantly on free-living bacteria on the epithelial surface, with a predilection for the tongue. Conversely, there was no area of predilection according to the PCR results. M. leprae is present in the oral mucosa at a high frequency, implicating this site as a potential means of leprosy transmission.

Sero-epidemiology of toxocariasis in a rural settlement in São Paulo state, Brazil.

The seroprevalence of Toxocara canis and risk factors for infection with this parasite were explored in a rural settlement in São Paulo state, Brazil. Total IgA and IgE levels in 79 subjects were determined by turbidimetry and chemiluminescence, respectively. Total counts of leucocytes and erythrocytes and differential counts of leucocytes were made by flow cytometry. ELISA for the detection of anti-Toxocara IgG, IgA and IgE were standardized using Toxocara excretory-secretory antigens (TES) obtained from the cultured second-stage larvae of T. canis. Seventeen (21.5%) of the subjects were found positive for anti-Toxocara IgG, with no significant differences in such seropositivity with age or gender. Thirty (38%) of the subjects showed eosinophilia and 70 (89%) had elevated levels of total IgE. Among the 17 subjects found seropositive for anti-Toxocara IgG, the percentage of leucocytes represented by eosinophils (P=0.0069) and total levels of IgE (P=0.0452) were positively correlated with the levels of anti-TES IgE. Although anti-TES IgA was detected in 10 (59%) of the subjects, there was no significant correlation between the levels of total IgA and those of Toxocara-specific IgA. Only one of the 17 subjects found positive for anti-Toxocara IgG had attended a secondary school and all but two belonged to households with monthly incomes of