Objective: To review the characteristic of Coronavirus disease 2019 (COVID-19) outbreaks in mainland China, particularly post-Wuhan outbreaks, and to help design effective responses in the foreseeable future. Method: The data regarding COVID-19 outbreaks between December 2019 and March 16, 2022 were obtained from China’s publicly available databases. The data were analyzed using descriptive statistics. Five outbreak stages were defined according to distinct epidemiological characteristics across different time periods over the past two years. Result: Since the 2020 Wuhan outbreak, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) local infections were confirmed in 37 995 cases as of March 16, 2022. We identified 285 isolated outbreaks in unrelated people that occurred in four additional distinct stages, over 57% of which had been imported, such as imported infected travelers and fomite transmission. The basic reproduction number (R0) of original SARS-CoV-2 was about 2.79, while the Delta variant was about 5.08 and Omicron was 7.0 or greater, resulting in the disease being more contagious during the fourth (Delta) and fifth (Omicron) stages than previous stages. Conclusion: China has experienced various COVID-19 outbreaks of different levels since the start of the pandemic in Wuhan, and local transmission is mainly caused by imported sources. If the “dynamic COVID-zero” policy is not appropriately followed, it will be difficult to contain the spread in China from overseas and to cope with the Omicron variant.

Covaxin and Covishield have been granted approval for emergency medical use in India due to the severity of COVID-19. Both vaccines are safe and effective and have a good immunogenic response. There is no difference between Covaxin and Covishield in terms of dosages and both can be administered as 0.5 mL (containing 6 mg of virus antigen for Covaxin and 5×10¹⁰ virus particles for Covishield) in the upper arm region. Covaxin and Covishield are designed for a two dose schedule, and it is advised that the second dose of Covaxin be administered 4-6 weeks after the first dose while 12-16 weeks after the first dose for Covishield. These vaccines may have several side effects such as swelling and itching at the injection site, joint pain, dizziness, headache, allergic reaction, increased heartbeat, and fever. Appropriate counselling and suggestion should be provided for any symptoms associated with vaccination so that post-vaccinated issues can be managed. Physician and community pharmacists may play a vital role in the management of adverse drug event associated with vaccines.

Objective: To determine the prevalence of Helicobacter (H.) pylori infection among the population of east coast of Borneo and explore the relationship between demographic factors, ethnicity and risk of H. pylori infection. Methods: This cross-sectional study enrolled 211 patients who underwent elective oesophagogastroduodenoscopy in 2017. Demographic data, endoscopic indications as well as the results of the mucosal biopsy were obtained and analysed from the endoscopy unit registry. Results: A total of 211 patients from 14 ethnic groups were enrolled in the study, most of were Chinese (28.4%), followed by Dusun (14.7%) and Songgai (13.7%). Overall, the period prevalence for 2017 was 44.5%. Multivariate logistic regression analysis showed an association between ethnicity and H. pylori. Bajau (adjusted odds ratio=5.612, P=0.005) and Dusun ethnic groups (adjusted odds ratio=7.359, P=0.001) were at a significantly higher risk of H. pylori infection compared to Chinese. However, the regression model only explained 11.6% (Cox & Snell Pseudo R²) of the prevalence of H. pylori infection. Conclusions: The period prevalence for 2017 was 44.5%, with certain indigenous ethnic groups having a higher risk than others. Clinicians should consider obtaining further history regarding the ethnic’s culture and dietary practice prior to starting H. pylori eradication therapy.

Background: Despite substantial progress in the fight against human immunodeficiency virus and acquired immunodeficiency syndrome globally, it remains a threat to global adolescent health. This study assessed the level of HIV knowledge among vocational school students and identified the relevant factors. Methods: This was an analytical cross-sectional study conducted from August to September 2019. A total of 345 students aged 15 to 19 years were selected from three vocational schools in Phitsanulok Province, Thailand, using a multistage random sampling technique. The HIV Knowledge Questionnaire (18 item version) was used to collect the data, which were analysed by mean, frequency, Chi- square and binary logistic regression. Results: Only 38.8% of participants were fully aware of HIV knowledge; five individual items showed a significant difference in knowledge of HIV between males and females; two items relating to HIV prevention knowledge (P=0.021, 0.009); two items relating HIV transmission (P=0.028, 0.035); one item relating to HIV diagnosis (P=0.008). Factors that were significantly associated with HIV knowledge included gender (male vs. female, OR 1.83, 95% CI 1.01-3.34), residence (sub-district municipality area vs. sub-district of administrative organization area, OR 0.44, 95% CI 0.23-0.84), education (2nd and 3rd academic year vs. 1st, OR 7.00, 95% CI 2.40-20.41; OR 6.40, 95% CI 2.05-20.01) and source of income (from both parents vs. self, OR 0.07, 95% CI 0.04-0.64). Conclusions: There are serious deficits and disparities in the knowledge of male and female adolescents on HIV transmission, prevention and diagnosis, and there is a need to expand the provision of gender-focused sexual health education programs.

Objective: To investigate the genetic mechanism and prevalence of antibiotic resistance among the practitioners of two bathing beaches in tropical China. Methods: Totally 259 strains were isolated from the rectal swabs of the practitioners and screened by MacConkey agar. A questionnaire survey was conducted. Kirby-Bauer test was used for phenotype, and double disc inhibition synergy test was used for extended-spectrum β -lactamase-producing Enterobacteriaceae (ESBL-E), which was further confirmed by VITEKII instrument. The genotype was detected by polymerase chain reaction, and the similarities of ESBL-E were analyzed using pulsed-field gel electrophoresis. Results: The prevalence of ESBL-E was 13.1% (34/259), of which, CTX-M genes accounted for 44.1% (15/34), mainly CTX-M-14 and CTX-M-27. Moreover, 19.1% (4/21) of the isolates were homologous. The resistance phenotypes of ESBL-E to chloramphenicol, ciprofloxacin, levofloxacin, ceftazidime, cefepime and gentamicin were different between two beaches(P<0.05). The prevalence of ESBL-E was caused by CTX-M genes at the island beach, while a high prevalence of ESBL-E was found at the city beach and clone transfer occurred. Conclusions: ESBL-E-associated gentamicin antibiotic resistance risk may be greater for island beach practitioners. The city beach populations could face more potential risks owing to severe resistance and metastatic ability of ESBL-E. The environmental exposure mechanisms and transfer role of antibiotic resistance at public beaches with high density should be investigated.

Objective: To identify the mosquito species collected in the field of 8 cities/counties of Hainan province, China and to analyze the characteristics of genetic differentiation of the predominant mosquito species. The types, contents and composition characteristics of the midgut microbiota of various mosquito species were explored to provide evidence for the control and prevention of mosquito-borne diseases in Hainan province. Methods: Adult mosquitoes were collected in the field using light traps, human lure or cattle lure methods. Morphology and DNA-barcoding technology (COI gene) were applied to identify the mosquito species. The V3-V4 hypervariable region of microbes 16S rRNA was used for high-throughput sequencing of the midgut microbiota, and SPSS 21.0 and R v3.1.1 software were employed to perform statistical analysis of the sequencing results and the Beta diversity analysis. Results: Aedes (Ae.) albopictus, Armigeres (Ar.) subalbatus and Culex (Cx.) pipiens pallpens were the three predominant species of the mosquito samples. Ae. albopictus was closely related to MK736660 (India) and JQ235749 (Yunnan), while MT541282 (DF, Dongfang) was a relatively independent population. The composition and structure of bacterial communities significantly varied among most of the samples (P<0.05). At the genus levels, 16 genera overlapped in the midgut in Ae. albopictus, 20 in Ar. subalbatus and 26 in Ar. subalbatus. Besides, Ae. albopictus, Ar. subalbatus and Cx. pipiens pallpens shared 15 out of the 16 overlapping genera. Conclusions: Ae. albopictus, Ar. subalbatus and Cx. pipiens pallpens were close within the same species in Hainan. The main exchange of mosquito species occurs within Hainan province, but also occurs across provincial or even national boundaries. The gut microbiota of mosquito species collected from the same sites were similar. Most of the core bacteria found in the midgut of Ae. albopictus were also present in Ar. subalbatus and Cx. pipiens pallpens, indicating that the breeding environment of Ae. albopictus may cover the breeding environment of Ar. subalbatus and Cx. pipiens pallpens.

Objective: To investigate the associations between dietary intakes, eating habits, socioeconomic determinants and malnutrition in children under 5 years old in south China. Method: A case-control study with 182 malnourished (case) and 254 normal (control) children was conducted in four towns using anthropometric measurements and questionnaires. Results: The dietary intakes of calory, protein, vitamin and minerals of malnourished children were lower than their normal counterparts. Overall, 37.9% children ‘monthly or never’ ate egg and egg products, 61.5% ‘monthly or never’ ate beans and soy products, but 76.7% had candies or cakes ‘daily or weekly’. Four identified determinants of malnutrition were: 1) low education level of mother (OR 1.65; 95% CI 1.02-2.67); 2) more children in one family (OR 1.86; 95% CI 1.14-3.03); 3) absence of independent eating habit (OR 1.75; 95% CI 1.13-2.72); and 4) long dining time (≥20 min) (OR 1.91; 95% CI 1.12-3.24). Conclusions: Inadequate dietary intake, lower socioeconomic status and inappropriate eating habits were the major determinants of childhood malnutrition in south China. Nutritional intervention focusing on education and behavior change are warranted to help reduce the rate of malnourishment among the children of rural families in the future.

Objective: To access complete immunization coverage among children aged 18-23 months living in the rural area of Mon State, Myanmar, and study the affecting factors. Methods: A cross-sectional study was conducted in the rural area of Mon State in 2017. Totally 353 caregivers who had children aged 18 to 23 months were selected using multistage random sampling. Face-to-face interview was applied in data collection. Complete immunization status was defined according to the current practice of routine immunization in Myanmar. Chi-square test and multivariate logistic regression analysis were utilized in data analysis. Results: Most of the caregivers were mothers (86.1%). Among 353 children, 293 [83% (95% CI 79.1-86.9)] had been immunized completely. The majority of caregivers had good levels of knowledge (77.1%) and attitude (71.4%) towards routine immunization. Some children (17.6%) had minor adverse events after immunization such as fever, pain and redness at the site of vaccination. Caregivers’ knowledge and attitude towards immunization, and the occurrence of adverse events after immunization in previous immunization session were significantly related to the status of complete immunization coverage (P<0.001). Conclusions: Complete immunization coverage among children living in the rural area of Mon State stands at 83% and should be improved. Health education campaigns with appropriate strategies should be reinforced or strengthened to enhance immunization coverage.

To prevent and control COVID-19, COVID-19 vaccines are being developed, tested, and approved at an unprecedented rate. As of September 24, 2021, 22 types of COVID-19 vaccines have been approved for conditional marketing or emergency use by at least one country worldwide. Vaccine efficacy/effectiveness is a crucial concern for vaccination. This article provides an overview of efficacy of phase III clinical trials, vaccination, effectiveness of real-world studies as well as challenges of COVID-19 vaccine.

According to the statistics of the World Health Organization, malaria is still one of the main diseases affecting human health, especially in Africa, and inflicts a heavy disease burden and a huge economic burden in endemic countries. At present, the widespread emergence of antimalarial drug resistance and unresolved drug availability issues have led researchers to turn their attention to the development of antimalarial vaccines. This review aims at highlighting the recent development of malaria vaccines and discussing the challenges.