Microsporidia are a group of obligate intracellular protistan parasites that have recently gained recognition as opportunistic infections in persons with AIDS or in those who are otherwise ...immunocompromised. To date, eight genera have been identified as human pathogens, Encephalitozoon, Enterocytozoon, Nosema, Vittaforma, Pleistophora, Trachipleistophora, Brachiola, and the collective genus Microsporidium. A frequent causative agent of microsporidial diarrhea and systemic infection among AIDS patients is Encephalitozoon intestinalis. This parasite can also cause chronic diarrhea in immunocompetent persons. However, many epidemiologic aspects of this infection remain poorly understood as the diagnostic tools for this parasite are not amenable to widespread use. In an attempt to improve this situation, we have developed an ELISA test to detect human serum antibodies reactive with Encephalitozoon intestinalis.
This study was undertaken to attempt to identify correlations between microsporidial seroprevalence data in man, clinical diseases and groups of people at the risk of HIV/AIDS infection. Groups of ...patients were selected according to the predilection of members of the genus Encephalitozoon for nervous and kidney tissue. Female prostitutes and alcohol and intravenous drug abusers were selected as groups at risk of HIV/AIDS infections. A total of 401 samples of human sera were examined for the presence of antimicrosporidial IgG antibodies by ELISA test with a titre of 600 considered borderline positivity. The highest occurrence of antimicrosporidial antibodies was found in the groups of alcohol abusers (16% from 43 patients), intravenous drug abusers (11% from 9 patients) and prostitutes (10% from 80 women) for E. cuniculi antigen and in the groups of psychiatric patients (14% from 44 patients), malaria patients (11% from 38 patients) and alcohol abusers (7% from 43 patients) for E. hellem antigen. The occurrence of specific antibodies of the six examined diagnostic units (glomerulonephritis chronica, pyelonephritis chronica, schizophrenia, dementia, multiple sclerosis and cerebral stroke) was statistically significant only in patients with pyelonephritis chronica and dementia (p < 0.05). No cases of microsporidial infection were found among the female prostitutes by parasitological examination, although one case of giardiasis was identified. Sera of patients with high anti-E. cuniculi and anti-E. hellem antibodies (titres in ELISA of 600 and above) were confirmed by Western blot using E. cuniculi and E. hellem polypeptides, respectively. These results suggest that the examined patients could show residual antibodies from past or latent infections.
The first case of one of the most frequent intestinal microsporidians, Encephalitozoon intestinale, is reported from an AIDS patient in the Czech Republic. The patient experienced diarrhoea and was ...found to have microsporidia spores in stool. Species determination by electron microscopy confirmed the diagnosis of the microsporidian, E. intestinale. The CD4-count at the time of the diagnosis was 73 cells/mm3, IRI = 0.21. Only after symptomatic therapy and rehydration the patient stopped the complaining, and although he refused an antimicrosporidial therapy, the CD4-count one month later increased to 200 cells/mm3 and patient didn't suffered from diarrhoea. Six months after the first finding of microsporidia, the patient was admitted to the hospital care for progressive encephalopathy and developing wasting syndrome again with the intermittent diarrhoea. The patient was treated with albendazole at that time. Nevertheless, after 14 days of albendazole therapy, he still remained positive for E. intestinale spores in the stool (urine specimens remained negative for all the time). The patient died after a two-month hospitalisation and the apparent cause of death was purulent bronchopneumonia, wasting syndrome with microsporidiosis, and HIV encephalopathy. Generalised mycobacteriosis (MAC) was also found from the autopsy material.
