Chikungunya virus isolation using simplified cell culture technique in Mauritius.

During the chikungunya outbreak of 2005 - 2006, the only laboratory facilities available in Mauritius were virus isolation in cell culture tubes and serology. The laboratory was submerged with large numbers of blood samples. Comparative isolation was made in human embryonic lung (HEL) and VERO cells grown in 96-well plate. Culture on HEL cells was found to be more sensitive and presence of cytopathic effect (CPE) was observed earlier than in VERO cells. Out of the 18 300 blood samples inoculated on HEL, 11 165 were positive. This virus isolation method was of great help for the surveillance and control of the vectors. In cases of an outbreak a cheap, rapid and simple method of isolating chikungunya virus is described.

Seroprevalence of cytomegalovirus infection in Mauritian volunteer blood donors.

OBJECTIVE: To determine the seroprevalence of CMV antibodies in the Mauritian volunteer blood donor population and to establish a panel of CMV-seronegative blood donors. STUDY SUBJECTS AND METHODS: Five hundred and eighty four apparently healthy blood donors were screened for evidence of CMV infection by the complement fixation test. There were 551 males and 33 females with age ranging from 18 to 60 years. RESULTS: Complement-fixing antibodies were found in 93.5% of the blood donors. The prevalence was 93.1% in males and 100% in females. CONCLUSION: Our findings demonstrate that seroprevalence of CMV in the local blood donors is very high making CMV-seronegative blood very scarce. Therefore leucocyte-depleted blood should be used as an alternative to CMV-seronegative blood during transfusions.

Detection of cytomegalovirus in urine of hearing-impaired and mentally retarded children by PCR and cell culture.

This study was carried out to determine the prevalence of cytomegalovirus (CMV) excretion in urine among 30 deaf children and 91 mentally retarded children by cell culture and PCR. As a control, urine samples from 121 children without hearing disability or mental retardation were also tested. The study revealed that 15 of 30 (50%) deaf children and 16 of 91 (17.6%) mentally retarded children were excreting CMV in their urine. Among the control group we observed that only 2 of the 121 (1.8%) children were CMV excretors. As CMV excretion in urine is generally considered to indicate a congenital infection, it is very likely that congenital CMV is highly incriminated in mental retardation and deafness among children in Mauritius.

Evidence of chronic persistent infections with polyomaviruses (BK type) in renal transplant recipients.

Ten renal transplant recipients showing a significant increase in human polyomavirus antibodies, indicative of an acute infection, were followed up serologically over periods ranging from two months to more than two years. Fifty-four serum specimens were available for the study and they were tested by both haemagglutination-inhibition and complement-fixation. Polyomavirus antigens were prepared from the BK and SV40-like strains of polyomaviruses, and from the SV40 virus. One strain of polyomavirus, related to the BK strain was isolated from the urine of one of these patients. Two other BK strains were recovered from the urine and kidney, respectively, of transplant recipients not included in this study. Sera of these two patients were not obtained until the transplantation was made; they were already highly positive for polyomavirus antibodies, precluding the demonstration of an increase in antibody titer. Serologic results have shown that HAI antibodies persist at high titers throughout the observation period. This persistence ranged from two to four months (four cases), seven to eleven months (three cases) and thirteen to twenty months (three cases). In none of the cases could a decrease of high titer be demonstrated. Moreover, density gradient studies have shown that specific IgM antibodies also tend to persist over many months. Similar serologic results were obtained in complement-fixation tests with a BK antigen. Titers were at least 1 in 30 in the study group, but were not observed among healthy blood donors. All sera were uniformly negative for SV40 and SV40-like antigens. One polyomavirus isolation was successful from urine obtained six months after initial serologic evidence for a polyomavirus infection. The other two viruses were isolated from materials taken four and seven months after first detection of polyomavirus antibodies at high titer. Both serologic evidence and viral isolations seem to indicate that polyomaviruses (BK type) might cause a chronic infection in humans.