The levels of cockroach allergen in relation to cockroach species and allergic diseases in Thai patients.

Recently, cockroaches have been established as the second most Important allergen, producing allergic diseases, especially in low socioeconomic populations. In Thailand, about 44-61% of atopic patients were positive to cockroach extract by a skin-prick test. This study examined cockroach allergen levels in relation to cockroach species and allergic diseases in the houses of cockroach-sensitive patients. Sixty households of allergic patients in the Bangkok metropolitan area were surveyed using open- and closed-ended questionnaires. Cockroaches were collected using commercial cockroach traps, while dust samples were obtained from the bedrooms, kitchens and living rooms of the houses using a vacuum cleaner. The cockroaches were counted and their species Identified. The levels of cockroach allergens were determined by specific monoclonal antibodies using a monoclonal antibody-polyclonal antibody based sandwich ELISA kit. Six cockroach species were Identified: Periplaneta americana (American cockroach, 72.15%), Supella longlpalpa (2.75%, found in only one house), Periplaneta brunnea (0.78%), Periplaneta australaslae (0.78%), Neostylopyga rhombifolla (0.78%), Blattella germanica (German cockroach, 0.39%) and nymphs (22.35%). Allergens of the predominant species, P. americana, were detectable in all homes studied, with the highest levels in the kitchen areas. The range of allergen levels in house dust varied from 0.40-162.00 microg per g of dust. The median and mean allergen levels in kitchen dust were 59.16 microg and 62.80 microg per g of dust, respectively, while the median allergen level in bedroom dust was only 15.90 microg per g of dust. The German cockroach allergen (Bla g 2) was undetectable in any of the houses. IN CONCLUSION: P. americana was the most common cockroach and may be the species causing allergic diseases, especially asthma, in Thailand, which differs from the USA and Europe

Intestinal microsporidiosis in HIV-infected children with diarrhea.

Intestinal microsporidiosis is a common opportunistic disease associated with diarrhea in adult AIDS patients in Thailand; the data regarding this infection in children are scarce. The present study was designed to investigate the prevalence and clinical features of intestinal microsporidiosis in hospitalized HIV-infected and uninfected (free of HIV) children with diarrhea. Of the 95 HIV-infected children and 87 uninfected children, 24 (25.3%) and 13 (14.9%) respectively were diagnosed with intestinal microsporidiosis. Species identification of microsporidia spores, by transmission electron microscopy, demonstrated Enterocytozoon bieneusi in 5 cases. Cryptosporidium parvum was a common coinfective parasite; pneumonia was the most frequent concurrent disease found in children with intestinal microsporidiosis. Malnutrition was commoner in the HIV-infected group (79.2% vs 23.1%; p = 0.003). This study indicates that intestinal microsporidiosis is an important disease in both HIV-infected and uninfected Thai children with diarrhea.

In vitro effect of antifungal drugs on pathogenic Naegleria spp.

An ameba of the genus Naegleria causing fatal meningoencephalitis in human subjects was investigated for its sensitivity to antifungal drugs: amphotericin B, ketoconazole, fluconazole and itraconazole. The efficacy of these antifungal drugs for pathogenic Naegleria spp was investigated in three strains isolated from patients who had died of primary amebic meningoencephalitis infection at Siriraj Hospital (1986), Ramathibodi Hospital (1987) and Chachoengsao Hospital (1987). All of the isolates were maintained in axenic culture in the Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand. The sensitivities of the antifungal drugs (MIC50) were: amphotericin B (0.05-0.5 microg/ml), ketoconazole (0.125 microg/ml), fluconazole (0.5-2.0 mg/ml), and itraconazole (10 mg/ml) (p < 0.05). It is important to explain that ketoconazole is slightly more effective than amphotericin B because its action is directed of the permeability of the amebic membrane. The amebae were more resistant ot fluconazole and itraconazole due to the action of the cytochrome P450 multienzyme (in the case of fluconazole) and the direct effect on heme-iron, blocking cytochrome P450-dependent chitin synthesis (in the case of itraconzole). We conclude that amphotericin B and ketoconazole remain the main drugs with proven activity against pathogenic Naegleria spp.