Real-time Investigation of Measles Epidemics with Estimate of Vaccine Efficacy

As part of measles elimination effort, evaluation of the vaccination program and real-time assessment of the epidemic dynamics constitute two important tasks to improve and strengthen the control. The present study aimed to develop an epidemiological modeling method which can be applied to estimating the vaccine efficacy at an individual level while conducting the timely investigation of the epidemic. The multivariate renewal process model was employed to describe the temporal evolution of infection by vaccination history, jointly estimating the time-dependent reproduction number and the vaccine efficacy. Analyzing the enhanced surveillance data of measles in Aichi prefecture, Japan from 2007-08, the vaccine efficacy was estimated at 96.7% (95% confidence interval: 95.8, 97.4). Using an age structured model, the vaccine efficacy among those aged from 5-19 years was shown to be smaller than that among those from 0-4 years. The age-dependent vaccine efficacy estimate informs the age-groups to be targeted for revaccination. Because the estimation method can rest on readily available epidemiological data, the proposed model has a potential to be integrated with routine surveillance

Angiomyofibroblastoma of the vulva: a large pedunculated mass formation.

Angiomyofibroblastoma is a rare, usually small benign mesenchymal tumor that occurs in vulvar lesions of premenopausal women. A case of angiomyofibroblastoma that arose as a unique pedunculated and particularly large mass in the left vulva of a 48-year-old woman is presented herein. The patient had been aware of a gradually enlarged mass of 7 years duration without any other gynecological symptoms or signs. The maximum dimension of the tumor measured 11 cm. The resected tumor was well circumscribed with a bulging and glistening cut surface. Histological examination revealed an admixture of irregularly distributed hypercellular and hypocellular areas with spindled, plump spindled, or plasmacytoid stromal cells and abundant venular or capillary-sized vessels. Stromal cells characteristically cluster around delicate vessels within an edematous to collagenous matrix. In the present case, intralesional adipose tissue was present throughout the tumor. There was no significant nuclear atypia, and mitotic figures were very sparse. There was little stromal mucin throughout the tumor. Immunohistochemically, the stromal cells were characterized by strong reactivity for vimentin and CD34, with focal reactivity for desmin and alpha smooth muscle actin. Both estrogen and progesterone receptors were diffusely expressed in the stromal cells. These histological findings are consistent with angiomyofibroblastoma and support the hypothesis that angiomyofibroblastoma originates from perivascular stem cells with a capacity for myofibroblastic and fatty differentiation

The Time Required to Estimate the Case Fatality Ratio of Influenza Using Only the Tip of an Iceberg: Joint Estimation of the Virulence and the Transmission Potential

Estimating the case fatality ratio (CFR) of a novel strain of influenza virus during the early stage of the pandemic is one of key epidemiological tasks to be conducted as rapid research response. Past experience during the epidemics of severe acute respiratory syndrome (SARS) and influenza A (H1N1-2009) posed several technical challenges in estimating the CFR in real time. The present study aimed to develop a simple method to estimate the CFR based on readily available datasets, that is, confirmed cases and deaths, while addressing some of the known technical issues. To assess the reliability and validity of the proposed method, we examined the minimum length of time required for the assigned CFR to be included within the 95% confidence intervals and for the estimated CFR to be below a prespecified cut-off value by means of Monte Carlo simulations. Overall, the smaller the transmission potential was, the longer it took to compare the estimated CFR against the cut-off value. If policymaking and public health response have to be made based on the CFR estimate derived from the proposed method and readily available data, it should be noted that the successful estimation may take longer than a few months