Use of serology, the urease test & histology in diagnosis of Helicobacter pylori infection in symptomatic & asymptomatic Indians.

Age-specific prevalence of IgA and IgG antibodies in 714 subjects without gastrointestinal complaints aged 6 months to 90 yr was measured by an enzyme linked immunoassay using an acid-glycine extract of H. pylori as the antigen. The urease test and histology were used for the diagnosis of H. pylori infection in 83 subjects with a clinical diagnosis of dyspepsia, and these results were compared with measurement of IgG, IgA and IgM antibodies. The age specific prevalence of IgG and IgA antibodies respectively was 57 and 43 per cent for subjects aged 6 months to 4 yr and showed an increase with age to a maximum of 90 per cent for IgG in subjects > 60 yr of age and to 87 per cent for IgA in subjects between 51 and 60 yr. In symptomatic patients, there was a high degree of correlation between severity of H. pylori infection on histopathological examination and IgG (P < 0.02) levels. The use of IgG and IgA estimation could have identified H. pylori infection without endoscopy in 50 of the 83 patients. Serology for IgG and IgA antibodies against H. pylori may play a major role in decreasing the need for endoscopy, but cut-off values must be determined for each assay based on the prevalence of antibodies in the population.

Enteric pathogens in southern Indian HIV-infected patients with & without diarrhoea.

This study was undertaken to determine the carriage rate of various enteric pathogens in southern Indian patients with HIV infection, both with and without diarrhoea. Stool from 111 consecutive HIV-positive patients (50 without and 61 with diarrhoea) was examined by microscopy and culture. Jejunal biopsy and fluid examination were carried out if diarrhoea persisted, with negative stool examination. Enteric pathogens were detected from stool in 57.4 per cent of diarrhoeal patients compared to 40 per cent of those without diarrhoea (P > 0.05). Jejunal biopsy and fluid examination provided 11 additional diagnoses. Protozoa accounted for 71.8 per cent of all pathogens isolated. Isospora was significantly more common in patients with (11/61) than in those without (2/50) diarrhoea (P < 0.05). Bacterial pathogens were isolated more commonly from patients with diarrhoea (12/61 compared to 2/50, P < 0.05). Isolation rate of pathogens was higher from patients with diarrhoea for more than 2 wk, compared to those with less than 2 wk duration. Remission of diarrhoea either spontaneously or with symptomatic therapy was observed in 22 patients with acute diarrhoea. A high enteric carriage of a number of pathogens was noted in HIV patients without diarrhoea, but I. belli and bacterial enteropathogens were more likely to be associated with diarrhoea.

A comparison of five staining methods for detection of Cryptosporidium oocysts in faecal specimens from the field.

Five staining methods for identification of Cryptosporidium oocysts in faecal smears were evaluated using samples obtained from asymptomatic south Indian villagers of all ages. The safranine-methylene blue technique was used as the gold standard and compared with 2 methods each using auramine and mepacrine, with potassium permanganate and carbol fuchsin as counterstains. All five methods identified all samples containing cryptosporidium oocysts, however false positive identifications were obtained by the standard auramine-phenol-potassium permanganate method. The auramine-carbol fuchsin and the mepacrine-carbol fuchsin techniques are the simplest and most rapid of the five methods compared. The mepacrine-carbol fuchsin technique is recommended for screening large numbers of stools, since it does not stain yeasts, is cheaper and less toxic than auramine.