Primary varicella zoster infection compared to varicella vaccine reactivation associated meningitis in immunocompetent children.

We diagnosed varicella zoster virus (VZV) meningitis in a healthy adolescent boy who presented without a rash or fever. We aim to compare VZV reactivation meningitis in children after primary VZV infection and VZV vaccination. We reviewed the literature up until June 2020 using Pubmed/MEDLINE and EMBASE databases using 'varicella zoster', 'meningitis' and 'children' as keywords. Only English articles were included. Twenty-five cases were included in this review. Children who had VZV reactivation meningitis after vaccination were younger (7 ± 3.4 years vs. 11.9 ± 3.6 years, P = 0.0038), had a shorter interval between first exposure to reactivation (5.6 ± 2.9 years vs. 8.8 ± 3.2 years, P = 0.018) and more likely to have a rash (100% vs. 55%, P = 0.04). VZV reactivation meningitis occurs after both primary VZV infection and VZV vaccination. The absence of exanthem, fever or meningism does not rule out VZV meningitis.

Comparison of influenza disease burden in older populations of Hong Kong and Brisbane: the impact of influenza and pneumococcal vaccination.

BACKGROUND: Influenza and pneumococcal vaccine uptake in the older population aged 65 years or over of Hong Kong dramatically increased since the 2003 SARS outbreak. This study is aimed to evaluate the impact of increased coverage of influenza and pneumococcal vaccines by comparing the change of disease burden in the older population of Hong Kong, with the burden in the older population of Brisbane with relatively high vaccine coverage in the past fifteen years. METHODS: Time series segmented regression models were applied to weekly numbers of cause-specific mortality or hospitalization of Hong Kong and Brisbane. Annual excess rates of mortality or hospitalization associated with influenza in the older population were estimated for the pre-SARS (reference period), post-SARS and post-pandemic period, respectively. The rate ratios (RRs) between these periods were also calculated to assess the relative change of disease burden. RESULTS: Compared to the pre-SARS period, excess rates of mortality associated with influenza during the post-SARS period in Hong Kong decreased for cardiorespiratory diseases (RR = 0.90, 95% CI 0.80, 1.01), stroke (RR = 0.74, 95% CI 0.50, 1.09), and ischemic heart diseases (RR = 0.45, 95% CI 0.34, 0.58). The corresponding RRs in Brisbane were 0.79 (95% CI 0.54, 1.15), 0.33 (0.13, 0.80), and 1.09 (0.62, 1.90), respectively. Only the mortality of ischemic heart diseases showed a greater reduction in Hong Kong than in Brisbane. During the post-pandemic period, excess rates of all-cause mortality increased in Hong Kong, but to a lesser extent than in Brisbane (RR = 1.41 vs 2.39). CONCLUSION: A relative decrease (or less of an increase) of influenza disease burden was observed in the older population of Hong Kong after increased coverage of influenza and pneumococcal vaccines in this population, as compared to those of Brisbane where vaccination rates remained stable. The lack of significant findings in some disease categories highlights the challenges of evaluating the benefits of vaccination at the population level.

A prospective case control study of the association of Gianotti-Crosti syndrome with human herpesvirus 6 and human herpesvirus 7 infections.

Gianotti-Crosti syndrome (GCS) is known to be associated with hepatitis B and Epstein-Barr virus (EBV) infections. Apart from a single case report based on serology alone, there are no published data on an association between GCS and human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7) primary infections or reactivations. Our aim was to investigate the association between GCS and HHV-6 and HHV-7 infections. Ten patients diagnosed with GCS at a primary care practice over an 18-month period were recruited. Controls were age- and sex-matched patients with unrelated symptoms requiring venepuncture for other indications. Blood specimens were collected from patients and controls at presentation, and from patients 4 weeks later. Virologic evidence of HHV-6 and HHV-7 infection was sought in peripheral blood leukocytes and plasma using polymerase chain reaction (PCR) for viral DNA, reverse transcriptase polymerase chain reaction (RT-PCR) for HHV-6 U91 mRNA transcripts, and serology. Serology for EBV and hepatitis B virus was done. In contrast to the 10 controls, 2 patients (both infants) with clinically diagnosed GCS had evidence of active HHV-6 infection. This was demonstrated by detection of viral DNA in the absence of antibody in the acute plasma specimens and HHV-6 DNA viral loads of more than 5.3 log10 genome copies/5 microl in the whole blood specimens, a profile previously shown to be diagnostic of recent primary HHV-6 infection. None of the patients had evidence of recent EBV or hepatitis B infection. We conclude that primary HHV-6 infection may be associated with GCS in some infants.