Hepatitis B virus (HBV) remains a substantial public health safety concern drawing considerable attention in China and globally. The detection of HBV serological markers can enable the assessment of HBV infection and replication status in vivo and evaluate the body\'s protection against HBV. Therefore, this study aims to identify the epidemiological and clinical characteristics of HBV infection in children to prevent and control HBV infection in Wuhan areas.
We conducted an extensive retrospective cohort analysis of 115,029 individuals aged 0-18 years who underwent HBV serological markers detection for HBV infection in hospital between 2018 and 2021 using Electrochemiluminescence immunoassay. We generated descriptive statistics and analysed HBV infection\'s epidemiological and clinical characteristics between different sex and age groups.
The overall positive detection rates of HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb in all participants were 0.13%, 79.09%, 0.17%, 2.81%, and 5.82%, respectively. The positive rate of HBeAb and HBcAb in males was significantly lower than that in females (2.64% vs. 3.13%, 5.56% vs. 6.29%) (P < 0.05). Twenty-two distinct HBV serological expression patterns were revealed. Among them, 8 common expression patterns accounted for 99.63%, while the remaining 14 uncommon expression patterns were primarily observed in neonatal patients with HBV infection. There are no significant differences in serological patterns based on sex (P < 0.05). The overall HBV infection detection rate was 5.82% [range 5.68-5.95] and showed a declining yearly trend. The rate in females was higher than that in males 6.29% [6.05, 6.35] vs. 5.56% [5.39, 5.59]. The overall HBV diagnostic rate over 4 years was 0.20% [0.17, 0.22], and the rate declined yearly. The prevalence of acute infection was higher than that of other infection types before 2019, but the incidence of unclassified infection showed a significant upward trend after 2019.
While the overall HBV infection detection rate in children has decreased year by year, the infection rate remains high in children under one year and between 4 and 18 years. This continued prevalence warrants heightened attention and vigilance.

BACKGROUND: People living in malaria endemic areas are at risk of suffering from the recurrent malaria episodes. The recurrent episode of malaria can be determined by various factors and will bring some serious impacts on all life aspects. This study aims to identify malaria demographics and factors associated with the recurrent episodes of malaria in Timika, Papua.
METHODS: This observational study used medical record data from the Naena Muktipura Sub-District Health Center, Timika Papua in 2020. Plasmodium infection was identified based upon microscopic examination. Subjects were then categorized into positive and negative malaria followed by the determination of the positivity rate. Each case of malaria was traced regarding frequency, time, and type of Plasmodium. The recurrent episodes of malaria were defined as Plasmodium infections occurred more than once in a year. Demographic data including age, sex, and ethnicity were then analyzed using Chi square.
RESULTS: The incidence of recurrent malaria in Timika Papua was 16% with the highest positivity rate occurred in June. The most recurrent episodes of malaria were 2 episodes (77.2%) in which men were more at risk (OR 2.512). Meanwhile, ethnicity and age were not associated with recurrent episodes. Most of recurrent episodes of malaria are caused by the similar plasmodium species, particularly Plasmodium falciparum (82.25%) with the shortest interval between episodes of 14 days.
CONCLUSIONS: Malaria is mostly experienced by men, of productive age and Javanese ethnicity. Men were found more at risk of experiencing recurrent episodes of malaria. The identification of these demographic factors is important to issue the policies on malaria elimination and malaria transmission termination in Timika, Papua.