Estimation of Longevity using Survival Functions

Estimation of life expectancy and longevity are frequently used in several fields basically on convectional model. The study considers Longevity estimation models and variances as alternative to conventional model incorporating non-parametric, semi-parametric and parametric with relevant survival functions to formulate longevity models that will accommodate expected variables in the estimation of life expectancy. These models can be used to analyze both grouped and individual data. We consider Kaplan Meier model as nonparametric methods, Cox proportional model as semi parametric methods. The parametric methods considered are exponential, weibull and gompertz proportional models which are commonly used for analyzing discrete data. The derived variances of KM and Cox proportional longevity estimator models are equivalent this confirm the result of major work done in this field. The other derived longevity models have difference variances due to their peculiarities. We shall consider these models empirically in another paper

Hepatitis E virus infection in high-risk populations in Osun State, Nigeria

Hepatitis E virus (HEV) infection is an emerging infection that is of major public health concern, especially in some vulnerable groups like immunosuppressed individuals, pregnant women and HBV-coinfected individuals. HEV is transmitted faecal/oral or zoonotically depending on the HEV-genotype. This study aimed at investigating HEV infections among different at-risk populations in Osun State, Southwestern Nigeria. A total of 720 serum samples were collected from animal handlers, pregnant women, people living with HIV/AIDS, and Hepatitis B virus (HBV) infected individuals. Commercially available Enzyme-Linked Immunosorbent Assays (ELISA) were used for the detection of anti-HEV total and IgM antibodies. Polymerase chain reaction (PCR) was carried out in the HEV seropositive samples and all the samples from individuals infected with HBV. Descriptive analysis and chi-square test of association were performed. The anti-HEV total antibody seroprevalence in HIV-positive individuals, animal handlers and pregnant women was 11.4% (n = 47/411), 7.9% (n = 7/89), and 6.3% (n = 10/160), respectively. Markers of acute HEV infection (anti-HEV IgM) were detected in 2.2% of HIV-positive individuals (n = 9/411) and 1.8% of animal handlers (n = 2/89), respectively, and in 0.6% of pregnant women (n = 1/160). However, all samples were HEV RNA negative. This study analysed the presence of markers of HEV infection among different at-risk populations without clinical symptoms of HEV infection. Our results showed that HEV is an underestimated threat to public health in Nigeria and underlines the need of an HEV surveillance system to understand the distribution and transmission of HEV infection in animals and/to humans.Peer Reviewe