Global dynamics of COVID-19 epidemic model with recessive infection and isolation.

In this paper, we present an SEIIaHR epidemic model to study the influence of recessive infection and isolation in the spread of COVID-19. We first prove that the infection-free equilibrium is globally asymptotically stable with condition R0<1 and the positive equilibrium is uniformly persistent when the condition R0>1. By using the COVID-19 data in India, we then give numerical simulations to illustrate our results and carry out some sensitivity analysis. We know that asymptomatic infections will affect the spread of the disease when the quarantine rate is within the range of [0.3519, 0.5411]. Furthermore, isolating people with symptoms is important to control and eliminate the disease.

Investigation on the acute gastroenteritis outbreak caused by sapovirus infection in Yangzhou City / 公共卫生与预防医学

Objective To investigate the characteristics of outbreaks of acute gastroenteritis caused by sapovirus infection among primary school students in Yangzhou. Methods An on-site epidemiological investigation was carried out to analyze the clinical symptoms and risk factors of epidemic transmission. Samples of patients were collected for nucleic acid detection of sapovirus. Follow-up observations were carried out on cases with positive detection to explore the duration of intestinal detoxification of sapovirus infection. Samples of close contacts without clinical symptoms were collected to analyze recessive infection status. Results A total of 30 cases were reported from two outbreaks of sapovirus infection. As a main symptom, the incidence rate of vomiting was 93.33%. The duration of intestinal detoxification of the cases was 3 to 19 days, with an average of 11.12 days. The rate of recessive infection was 26.32%. The risk factor for sapovirus infection was exposure to vomit or feces within 1 meter (OR=12.94, 95%CI 1.19-140.37), and the protective factor was washing hands before eating (OR=0.064, 95%CI 0.007-0.56). Conclusion The main symptom of sapovirus infection was vomiting, with a high rate of recessive infection and a long detoxification period. It is easy to cause an outbreak in primary schools. Exposure to vomit or feces within 1 meter could increase the risk of sapovirus infection. Washing hands before eating could reduce the risk of sapovirus infection.

Survey on the recessive infection of pathogen to hand-foot-mouth disease among healthy adults and children in Guangdong province / 中华流行病学杂志

Objective To understand the pathogen-carrying status of hand-foot-mouth disease (HFMD) among healthy people in Guangdong province.Methods Stool specimens were collected randomly on 7 age groups from 7 cities in Guangdong province.Real-time RT-PCR was used to detect enterovirus (EV),enterovirus 71 (EV71) and coxsackie virus A16 (CA16).Results Altogether,1285 stool specimens were collected.The positive rates of EV71,CA16 and other enterovirus were 0.39％ (5/1285),0.23％ (3/1285) and 7.00％ (90/1285),respectively.The highest EV71 positive rate (1.79％) was among the 4-6-year-old group,followed by the age group 0-3 with positive rate as 0.67％.EV71 was not found among the rest age groups.The highest CA16 positive rate (1.35％) was among the 4-6 year-olds group,but the CA16 was not found among the rest age groups.EV71 was only found among native population,with the positive-rate as 0.47％.CA16-positive rate was 0.19％ among the native population and 0.85％ among floating population,with no significant difference found (P＞0.05).The EV71 positive rate was 0.36％ among rural residents and 0.54％ among urban residents,but with no significant difference (P＞0.05).All CA16 was found among the urban residents.Conclusion Recessive infection of EV71 and CA16 were only found among 0-6 year-old group but not found among other groups,which suggested that the approaches on prevention and control should be targeted to all children especially on pre-school children.