[Study of 50 patients with sporotrichosis. Clinical and laboratory assessment]. / Estudio de 50 pacientes con esporotricosis. Evaluación clínica y de laboratorio.

Because sporotrichosis is the most frequent subcutaneous mycosis in Mexico and the clinical aspect is not always characteristic, the aim of this study was to evaluate laboratory diagnosis techniques. Fifty patients with clinical diagnosis of subcutaneous sporotrichosis were studied including clinical and epidemiologic data. Metabolic antigen was used to elicit delayed hypersensitivity skin reaction in all patients. Exudate was plated on Sabouraud agar and biopsy material was submitted to indirect immunofluorescence and histopathology. Results showed that sporotrichosis frequency was higher in women (62%), in children and adolescents under 20 years of age (34%) and adults older than 50 years of age (28%). Disease was predominant in farmers (44%) followed by housewives (30%). Lymphangitic form accounted for 82% of cases and these were localized in upper limbs (54%). In 66% of cases, histopathology showed S. schenckii yeasts; hypersensitivity skin reaction was positive in 76% and culture in 94%. By indirect immunofluorescence, parasitic elements were demonstrated in all patients corresponding to both sensitivity and specificity 100%. In this work, indirect immunofluorescence was the most efficient sporotrichosis diagnostic method followed by culture, hypersensitivity skin reaction, and histopathologic study.

Prospective immunological follow-up in household contacts of Mexican leprosy patients.

A 6-year prospective study of 79 household contacts of leprosy cases was made in order to correlate the development of the disease with their specific T-cell immunity, measured by the Mitsuda test, and levels of anti-Mycobacterium leprae antibodies determined in three consecutive observations with the FLA-ABS test. Overall in the contacts, 71.7% were Mitsuda positive and 93.6% showed seropositivity, without regard to their age, sex, or leprosy type of their index case. Households were divided into lower-risk and higher-risk groups according to either the paucibacillary or multibacillary character of their index case. The lower-risk group consisted of 19 contacts of 2 tuberculoid (TT) and 5 indeterminate cases. The higher-risk group was made up of 60 household contacts of 18 active lepromatous (LL) cases. All but two contacts in the former group had a positive Mitsuda reaction; the most common antibody titer was 1:160, with a tendency to stabilize or decrease over time. In the two Mitsuda-negative contacts, increased antibody levels were observed. In the higher-risk group, 61.6% were Mitsuda positive and showed a humoral profile similar to those Mitsuda positive in the lower-risk group. In most of the Mitsuda-negative LL contacts, the antibody levels remained constant or progressively increased, suggesting a high probability of active subclinical infection. This assumption was partially supported by the finding of a new borderline lepromatous (BL) leprosy case in the Mitsuda-negative LL contact group. Nevertheless, the contribution of the close and extensive contact with a multibacilliferous case as a risk factor was difficult to evaluate because of the small size of the sample studied.