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The 2014–2015 Ebola epidemic was considered to be the largest and most complex outbreak, which caused 11,310 reported deaths. The epidemic disease can cause a mental health crisis, however, there is only a small amount of scientific literature available related to this health issue so far. We evaluated the psychological symptoms of 161 participants including Ebola survivors and healthcare workers in Sierra Leone, analyzed the impact of job classification, education level on psychological status. We found that the order of total general severity index (GSI) scores from high to low was EVD survivors, SL medical staff, SL logistic staff, SL medical students, and Chinese medical staff. There were 5 dimensions (obsession-compulsion, anxiety, hostility, phobic anxiety, and paranoid ideation) extremely high in EVD survivors. GSI were associated with university education negatively. We believed our information is necessary to develop the comprehensive emergency response plan for emerging infectious disease outbreak.

Quantiles, which are also known as values-at-risk in finance, frequently arise in practice as measures of risk. This article develops asymptotically valid confidence intervals for quantiles estimated via simulation using variance-reduction techniques (VRTs). We establish our results within a general framework for VRTs, which we show includes importance sampling, stratified sampling, antithetic variates, and control variates. Our method for verifying asymptotic validity is to first demonstrate that a quantile estimator obtained via a VRT within our framework satisfies a Bahadur-Ghosh representation. We then exploit this to show that the quantile estimator obeys a central limit theorem (CLT) and to develop a consistent estimator for the variance constant appearing in the CLT, which enables us to construct a confidence interval. We provide explicit formulae for the estimators for each of the VRTs considered.

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In Taiwan, the nation-wide Hepatitis-B virus (HB) vaccination program was first launched in July 1984 and was directed to those infants born to hepatitis B surface antigen (HBsAg) carrier mothers in Taiwan. From July 1986 onwards, all infants born in Taiwan were immunized against HB. This study examined the HB-infection status amongst students at a Taiwanese university 18 years subsequent to the implementation of universal HB vaccination. A total of 1,969 new university entrants in 2005 were grouped into 1 of 3 distinct birth cohorts according to their HB-vaccination schedule (cohort-1 students born prior to July 1, 1984; cohort-3 students born subsequent to June 30, 1986) and were examined for their serum HBsAg, antibody to hepatitis B surface antigen (anti-HBs), and antibody to hepatitis B core antigen (anti-HBc) status. Immunity arising from vaccination was defined as an anti-HBs level 10 mIU/ml. We observed a trend toward a decreasing anti-HBc-positive rate and a decreasing HBsAg carrier rate from, respectively, 26.5 and 8.7% for cohort-1 to 4.7 and 1.7% for cohort-3 students. The prevalence of students featuring seronegativity for all three HB markers increased from 12.3% for cohort-1 to 48.8% for cohort-3 individuals. Amongst the 1,695 subjects revealing seronegativity for HBsAg and anti-HBc, their anti-HBs level was analyzed according to their birth year. The prevalence of students featuring a non-protective anti-HBs level increased from 11.9% for birth-year 1984 individuals to 48.2% for birth-year 1987 students. The introduction of HB vaccine has effectively reduced the transmission of HBV infection in Taiwan, 18 years subsequent to the commencement of the universal HB-vaccination program. A "waning-off" effect of anti-HBs seropositivity acquired from the HB vaccination program has also been observed.