Detection of HBV genome by gene amplification method in HBsAg negative blood donors.

The incidence of post-transfusion hepatitis has been reduced greatly by screening blood donors for hepatitis B surface antigen (HBsAg). However, hepatitis B virus infection still accounts for a certain number of cases of post-transfusion hepatitis. The purpose of this study was to detect HBV DNA in the HBsAg negative blood samples by using nested PCR with two primer pairs specific to core region. Two hundreds blood samples from HBsAg negative donors, and 14 samples from HBsAg positive donors were provided by the blood bank of Ramathibodi Hospital. The results showed that HBV DNA was detected in all 14 HBsAg positive blood samples and in 7 (3.5%) of 200 HBsAg negative blood samples. This study showed that the absence of HBsAg in otherwise apparently healthy individuals may not be enough to ensure lack of circulating HBV. The more sensitive ELISA technique is still in need. Otherwise, the safety of blood transfusion can be enhanced by careful selection of blood donors and careful consideration of risks and benefit of the patients who need blood transfusions.

Primary human herpesvirus 6 infection in young children.

BACKGROUND: Human herpesvirus 6 (HHV-6) is a recently discovered virus that, on the basis of serologic evidence, appears to infect most children by the age of three years. However, the clinical manifestations of primary HHV-6 infection have not been well defined. METHODS: We studied consecutive children two years old or younger who presented to an emergency ward with febrile illnesses. Our evaluation included the isolation of HHV-6 from peripheral-blood mononuclear cells, an immunofluorescent-antibody assay, the detection of HHV-6 by the polymerase chain reaction (PCR), and restriction-endonuclease-fragment profiles of HHV-6 isolates. RESULTS: HHV-6 was isolated from 34 of 243 acutely ill children (14 percent). The children with viremia had irritability, high temperatures (mean, 39.7 degrees C), and inflammation of tympanic membranes (in 21), but few other localizing signs. Two children were hospitalized, but all 34 recovered after an average of four days of fever. The rash characteristic of roseola, which has been associated with HHV-6 infection, was noted in only three children. In 29 children (85 percent), serum samples obtained during convalescence had at least a fourfold increase in IgG antibody titers; 4 infants less than three months old who presumably had maternal antibody did not have this increase. HHV-6 was isolated from blood obtained during convalescence in only one child, but in two thirds of the children the virus could be detected by PCR. The isolates had genomic heterogeneity, indicating the presence of multiple strains. CONCLUSIONS: Primary infection with HHV-6 is a major cause of acute febrile illness in young children. Such infection is associated with varied clinical manifestations, viremia, and the frequent persistence of the viral genome in mononuclear cells.

Serosurvey of rubella antibody among health personnel of Songklanagarind University Hospital, Thailand.

A serosurvey of rubella antibody among health personnel using the hemagglutination inhibition (HAI) antibody test was carried out. All 366 health workers including 256 females were from Songklanagarind University Hospital, of which 116 (31.7%) health workers had no detectable HAI antibody. Of these, 93 were females which represented 36.3% of the total 256 in the series, while 20.9% of the males had no antibody. Females are more susceptible. Among 250 seropositive persons 3 males and 3 females had detectable rubella IgM antibody. All the seronegatives (titer less than 1 :8) were given rubella vaccination (RA 27/3, Wistar strain) and all converted. Among these, 13 (11.2%) developed side effects about two weeks after vaccination. All symptoms subsided within a week without symptomatic therapy. It is advocated that health personnel should be screened for rubella HAI antibody and that seronegative persons should be vaccinated.