Fifty-six renal allograft recipients were studied prospectively for 3 months or longer after transplant. The polymerase chain reaction (PCR) was used to screen peripheral blood leucocyte (PBL) specimens for CMV, human herpesvirus 6 (HHV6) and human herpesvirus 7 (HHV7) DNA (DNAemia) in 67 healthy controls and in serial (fortnightly) PBL specimens from the 56 allograft recipients. None of the healthy controls had detectable CMV DNAemia, although HHV6 and HHV7 DNAemia was found in 7% and 9% of individuals respectively. In contrast, DNAemia due to CMV, HHV6 and HHV7 was found in 50%, 36% and 39% of patients respectively, at some time during the post-transplant period. Of the 28 patients who had CMV DNAemia, eight developed "CMV disease". The risk of progression to "CMV disease" was increased in patients with concurrent DNAemia to all three viruses (relative risk 3.7; 95% CI 1.3-10.5). The relative risk of "CMV disease" for patients with concurrent CMV and HHV7 was also increased (RR = 3.5; 95% CI = 1.1-11.6), while the association between CMV and HHV6 was inconclusive (RR = v2.1; 95% CI = 0.7-6.6). The first 26 patients recruited to the study also had serial serum samples tested for antibody responses to the three viruses. "CMV disease" was associated with rising antibody titres to HHV7 (Fisher's exact test, P = 0.02), and weakly so with HHV6 (P = 0.07). It is concluded that in patients with CMV DNAemia, concurrent infection/reactivation HHV7 (and possibly HHV6) is associated with an increased risk of progression to "CMV disease".

The age-related prevalence of antibodies to herpesviruses was compared in England and Hong Kong. Altogether 327 sera from England and 266 sera from Hong Kong were tested for antibodies to herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpesvirus 6 (HHV-6). Herpesvirus infections were common in both countries but generally were acquired earlier and were more prevalent in Hong Kong. Over 90% of children in Hong Kong were infected with VZV, EBV, and HHV-6 by 8 years of age. HSV and CMV were the least prevalent childhood infections in both countries, although, 30-40% of babies in Hong Kong became infected during the first year of life. CMV infections were rare throughout childhood in the English cohort. Overcrowding and early attendance at kindergarten may aid more efficient and earlier transmission of herpesvirus in Hong Kong. The high prevalence of CMV in particular may have implications for the management of young pregnant women and organ transplant recipients in Hong Kong.

The aim of this cross sectional case control study was to examine the serofrequency and serointensity of Toxoplasma gondii (Tg) IgG, IgM, and DNA among patients with schizophrenia. A total of 101 patients with schizophrenia and 55 healthy controls from Sungai Buloh Hospital, Selangor, Malaysia and University Malaya Medical Center (UMMC) were included in this study. The diagnosis of schizophrenia was made based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The presence of Tg infection was examined using both indirect (ELISA) and direct (quantitative real-time PCR) detection methods by measuring Tg IgG and IgM and DNA, respectively. The serofrequency of Tg IgG antibodies (51.5%, 52/101) and DNA (32.67%, 33/101) among patients with schizophrenia was significantly higher than IgG (18.2%, 10/55) and DNA (3.64%, 2/55) of the controls (IgG, P=0.000, OD=4.8, CI=2.2-10.5; DNA, P=0.000, OD=12.9, CI=2.17-10.51). However, the Tg IgM antibody between patients with schizophrenia and controls was not significant (P>0.005). There was no significant difference (P>0.005) in both serointensity of Tg IgG and DNA between patients with schizophrenia and controls. These findings have further demonstrated the strong association between the active Tg infection and schizophrenia.

Diagnosis of significant infections by human herpesvirus 6 (HHV6) and 7 (HHV7) in transplant patients has proved difficult because both viruses are ubiquitous and can cause persistent infections in their hosts. The significance of viral DNA detected in peripheral blood leukocytes (PBLs; DNAemia) by PCR is therefore unclear. The interpretation of serological results is complicated by the fact that both primary and secondary infections with other herpesviruses may be associated with a concurrent antibody response to HHV6. Fifty-four renal allograft recipients were studied prospectively and their serological response to HHV6, HHV7 and CMV were compared with the detection of viral DNAemia from the homologous and heterologous viruses. Serum and heparinished blood samples were collected prospectively from 54 renal allograft recipients. DNA was extracted from PBLs and tested for the presence of HHV6, HHV7 and CMV DNA by PCR. Antibodies to HHV6 and HHV7 were measured by an indirect immunofluorescence test and to CMV by an anticomplement immunofluorescence (ACIF) test. CMV IgM antibodies were detected by a commercial enzyme immunoassay. CMV and HHV7 DNAemia were each significantly associated with serological responses to the homologous virus but no such association was found for HHV6 DNAemia. However, patients with consecutively positive DNAemia to any of the viruses (including HHV6) were more likely to have a homologous serological response. Patients who had detectable CMV IgM without a concurrent rise in CMV antibodies were significantly less likely to have CMV DNAemia (odds ratio = 0.16; 95% CI 0.02-0.9). CMV IgM antibodies may be associated with HHV6 or HHV7 DNAemia (odds ratio 2.3; 95% CI 0.5-15). This serological profile may reflect a crossreactive response to HHV6, HHV7 or other herpesviruses. CMV IgM should not be used in isolation for the diagnosis of CMV infection or disease in this group of patients.

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