[Clinical, epidemiological and etiological studies of adult aseptic meningitis: Report of 13 cases with mumps meningitis]

Cost-effectiveness analyses of monovalent mumps vaccination programs for Japanese children

BACKGROUND

The most common preventative measure against mumps is vaccination with mumps vaccine. Over 122 countries have implemented mumps vaccine routine immunization programs, mostly via Measles-Mumps-Rubella (MMR) vaccine. In Japan, the unexpectedly high incidence of aseptic meningitis caused by mumps vaccine led to the discontinuation of the MMR national vaccination program in 1993, inadvertently resulting in the re-emergence of mumps. Plans of introducing monovalent mumps vaccine into routine vaccination schedule have become one of the emerging topics in health policy that has warranted the need in evaluating its value for money.

METHODS

We conducted cost-effectiveness analyses with Markov model and calculated incremental cost-effectiveness ratios (ICERs) of two different vaccination programs (a single-dose program at one-year-old, a two-dose program with second dose uptakes at five) compared to status quo from both payers' and societal perspectives. Transition probabilities and utility weights in estimating quality-adjusted life-year (QALY), and disease treatment costs were either estimated or obtained from literature. Costs per vaccination were assumed at ¥6140 (US$58;1US$ = ¥106).

RESULTS

Both programs reduce disease treatment costs compared to status quo, while the reduction cannot offset vaccination cost. ICER of either program is found to be under ¥5,000,000 (US$47,170)/QALY willingness-to-pay (WTP) threshold from either perspective. Results of probabilistic sensitivity analyses expressed by net monetary benefit indicated that at the WTP threshold, the acceptability is at 92.6% for two-dose vaccination program, 0% for single-dose vaccination program, and 7.4% for current no vaccination program. Two-dose program was optimal among the alternatives. One-way sensitivity analyses revealed that proportion of mumps-related hearing loss among mumps cases and vaccine effectiveness (VE) were key variables in changing the ICERs.

CONCLUSION

Routine vaccination program of single- and two-dose programs were cost-effective from both payers' and societal perspectives. Between the two, the two-dose vaccination program was observed to be more favorable.

Origin and evolution analysis and genetic characteristics of echovirus 9 in China

Background

Echovirus 9 (E9) is associated with a wide variety of diseases and medical conditions, and the clinical symptoms of sporadic cases caused by E9 often are severe. With a high global prevalence, E9 has caused multiple outbreaks worldwide. However, little is known about the genetic and geographic population dynamics of E9.

Method

A total of 131 VP1 gene sequences, including15 generated in this study and 116 obtained from GenBank, were used to coestimate time-resolved phylogenies to infer viral evolution and transmission in worldwide. Overlapping fragments representing whole genomes were amplified by reverse transcription polymerase chain reaction (RT-PCR) using specific primers. Then, we reported the genetic characteristics of fifteen E9 strains in the Chinese Mainland. Similarity plots and bootscanning analysis were used to determine recombination patterns of E9.

Results

The estimated mean evolutionary rate of global E9 VP1 gene was 4.278 × 10⁻³ substitutions per site per year (95% confidence interval [CI], 3.822 × 10⁻³/site/year to 4.710 × 10⁻³/site/year), and the common ancestor of E9 likely emerged around 1868 (95% CI, 1840 to 1892). The full-length genomic sequences of the fifteen E9 strains showed 76.9–79.6% nucleotide identity and 95.3–95.9% amino acid identity with E9 Barty strain. 11 of 15 E9 whole genome sequence present four recombination patterns, and E9 recombinants have extensive genetic exchanges in the 2C and P3 regions with other Enterovirus B (EV-B) circulated in China. Four of six E9 strains were temperature sensitive, and two were temperature resistant, and a comparative genomics analysis suggested that 411, 865 and 867 amino acid substitution in the P1 region was related to temperature sensitivity.

Conclusion

This study highlights a persistent transmission network of E9 in worldwide, provides valuable information regarding the molecular epidemiology of E9.

The spectrum of aseptic central nervous system infections in southern Germany - demographic, clinical and laboratory findings

BACKGROUND AND PURPOSE

Aseptic infections of the central nervous system (CNS) are frequently observed in Germany. However, no study has systematically addressed the spectrum of aseptic CNS infections in Germany.

METHODS

Data on 191 adult patients diagnosed from January 2007 to December 2014 with aseptic meningitis or encephalitis/meningoencephalitis at our hospital were collected by chart review and analyzed for demographic, clinical and laboratory findings. Patients were stratified according to the causative virus and findings were compared between groups.

RESULTS

In our cohort, meningitis was caused in 36% by enterovirus (EV), 15% by herpes simplex virus (HSV), 12% by varicella zoster virus (VZV) and 5% by tick borne encephalitis (TBE). Encephalitis/meningoencephalitis was caused in 13% by HSV, 13% by VZV, and three out of 11 tested patients were positive for TBE. The highest incidence of EV infections was between 25 and 35 years and of HSV infections between 30 and 60 years. VZV infections had a bimodal distribution peaking below 30 and above 70 years. VZV and EV infections were more frequently observed during summer, whereas HSV infections showed no seasonal preference. Inflammatory changes in cerebrospinal fluid (CSF) were highest in HSV and lowest in EV infections.

CONCLUSIONS

Polymerase chain reaction tests for HSV, VZV and EV in CSF and TBE serology determined the causative virus in over 60% of tested patients. The age of affected patients, seasonal distribution, disease course and inflammatory changes in CSF differ between groups of patients affected by the most common viral infections.