Epidemiological characteristics of infected patients aged 60 years and older during the outbreak of SARS-CoV-2 Omicron variant in Sanya, Hainan in 2022

Objective: To analyze the epidemic characteristics of coronavirus disease 2019 (COVID-19) cases aged 60 years or older during the outbreak epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant in Sanya City, Hainan Province, August-September 2022, and to provide scientific and effective basis for formulating strategies for the prevention and treatment of COVID-19 in the elderly in the future. Methods: The data of 1 785 COVID-19 cases aged 60 years reported from August 1 to September 8, 2022 in Sanya City, and 537 local COVID-19 inpatients aged 60 years treated in Sanya Central Hospital were collected and analyzed using WPS Office 2018 software for data cleaning, database assistance, and drawing, and SPSS 22.0 software was used to statistically describe and analyze the counting data. Results: A total of 1 785 local COVID-19 cases aged 60 years were reported in China's Disease Prevention and Control Information System, including 1 509 confirmed cases (84.54%) and 276 asymptomatic cases (15.46%). Of the confirmed cases, 1 448 were mild cases (95.96%), 40 were common cases (2.65%), 10 were severe cases (0.66%), and 11 were critical cases (0.73%), and no deaths were reported. The ratio of male to female was 0.88:1. The youngest was 60 years old, the oldest age was 107 years old, with a median age of 67 years old. Most of them (1 559 cases, 87.34%) were non-social employed personnel. Among them, 952 (53.33%) were from Tianya District and 733 (41.06%) from Jiyang District. Among the 537 COVID-19 elderly infected patients hospitalized in Sanya Central Hospital, infected patients with underlying diseases accounted for 287 (53.45%) cases of hypertension, diabetes and other types of basic diseases (chronic kidney disease, hyperlipidemia, chronic gastritis, gastric ulcer, etc.), and there were serious infections. Conclusions: Most of the elderly infected with Omicron variants were mild cases with few symptoms, but the elderly infected with Omicron variants were difficult to recover or even worsen the condition due to old age and underlying diseases. Therefore, by analyzing the various aspects of elderly infected cases, scientific and effective basis can be provided to prevent and control the epidemic situation in the future, and reduce the occurrence of severe, critical and death cases of COVID-19 in the elderly.

Epidemiological characteristics of a large-scale outbreak of SARS-CoV-2 omicron variant infection in Sanya, Hainan in 2022

Objective: To analyze the endemic characteristics of SARS-CoV-2 Omicron variant in Sanya, and to provide reference for the prevention and control of the Omicron variant. Methods: The information of coronavirus disease 2019 (COVID-19) infected persons (asymptomatic infected persons and confirmed cases) in Sanya City from August 1 to September 19, 2022 was collected through the Infectious Disease Reporting Information System of the Chinese Information System for Disease Control and Prevention. SPSS 25.0 software was used to analyze and compare the epidemiological characteristics of this Omicron variant outbreak between confirmed cases and asymptomatic infected persons. Results: A total of 15 651 cases of COVID-19 infection were reported in Sanya including 9 057 asymptomatic infections (57.87%) and 6 594 confirmed cases (42.13%), there were 0 deaths. The age ranged from 0 to 107 years old in which 0 to 5 years old, 6 to 18 years old, 19 to 64 years old and above 65 years old accounted for 5.64%, 15.03%, 71.83% and 7.51% respectively. The mean age of confirmed cases was (43.26..0.27) years old, which was significantly older than (31.89..0.16) years old of asymptomatic infection (Z=-37.89, P < 0.001). Sex ratio between men and women was 1:1.12. The occupation was mainly business service (8 239, 52.64%). The districts were mainly concentrated in Gangmen Village community of Jiyang District (10.02%), Danzhou Village community of Tianya District (9.69%) and Linchun Community of Jiyang District (8.11%). Asymptomatic and confirmed cases were 57.87% and 42.13% respectively. The differences between asymptomatic infected and confirmed cases in terms of gender, occupation and detection method were statistically significant (X2=17.63,1 632.44, 179.35, P all<0.001);the length of hospitalization of asymptomatic infected and confirmed cases was statistically significant (Z=-12.467, P < 0.001). Conclusions: This novel coronavirus outbreak was caused by Omicron BA.5.1.3 variant, which was discovered for the first time in China. The epidemiological mode is an outbreak mode, and the new Omicron variant is more insidious and infectious, and fast and decisive measures are needed to prevention and control the epidemic.

Rapid and Easy-Read Porcine Circovirus Type 4 Detection with CRISPR-Cas13a-Based Lateral Flow Strip.

First identified as a new circovirus in Hunan Province in China in 2019, porcine circovirus (PCV4) is now widely detected in other Chinese provinces and South Korea. In recent years, the virus has threatened pig health and operations in the pig industry. Hence, early PCV4 detection and regular surveillance are required to control the spread of infection and prevent collateral damage to the industry. Due to PCV4 being difficult to isolate in vitro, molecular detection methods, such as conventional PCR and real-time PCR, and serological assays are currently the main methods used for the detection of PCV4 infection. However, they are time-consuming, labor-intensive, and complex and require professional personnel. To facilitate rapid pen-side PCV4 diagnoses, we used clustered regularly interspaced short palindromic repeats (CRISPR) and Cas13a technology to develop a quick testing kit. Five recombinase-aided amplification (RPA) primer sets were designed based on the conserved PCV4-Cap gene nucleotide region, which were used to determine several key lateral flow strip (LFD) characteristics (sensitivity, specificity, and accuracy). The results showed that the RPA-Cas13a-LFD reaction could detect PCV4 within 1.5 h in genomic DNA harboring a minimum of a single copy. Furthermore, the assay showed good specificity and absence of cross-reactivity with PCV2, PCV3, or other porcine viruses. When we tested 15 clinical samples, a high accuracy was also recorded. Therefore, we successfully developed a detection assay that was simple, fast, accurate, and suitable for on-site PCV4 testing.

Sexual Behavior and Perceived Loneliness in Elderly People Living with HIV in China during the COVID-19 Pandemic.

BACKGROUND: The proportion of elderly people living with HIV (PLHIV) is increasing in China. To advance targeted interventions and substantially improve their quality of life, we investigate indicators of loneliness and sexual behavior among elderly PLHIV in 10 districts/counties in China during the COVID-19 pandemic. METHODS: The demographic information and laboratory test results of the potential respondents were initially collected from the China Information System for Disease Control and Prevention. A two-stage stratified cluster sampling was used. The questionnaire survey was individually provided to all PLHIV aged +60. RESULTS: We recruited 1017 valid respondents with a median age of 66 years (interquartile range of 63-71), of which 776 (76.3%) were male. Overall, 341 respondents (33.5%) lived alone, and 304 (29.9%) felt lonely. A total of 726 respondents (71.4%) informed others of their HIV diagnosis. Among the 726 respondents, children were the most common group with whom the older people shared their HIV infection status, accounting for 82.9%. Approximately 20% of the older PLHIV engaged in sexual behavior in the last year, and 70% reported not using condoms. A significantly greater risk of loneliness was found among the females (AOR = 1.542, CI: 1.084, 2.193), those who suffered discrimination from informed people (AOR = 4.719, CI: 2.986, 7.459), were diagnosed <1 year prior (AOR = 2.061, CI: 1.345, 3.156), those living alone (AOR = 2.314, CI: 1.632, 3.280), those having no friends (AOR = 1.779, CI: 1.327, 2.386), and those who had a divorced or widowed marital status (AOR = 1.686, CI: 1.174, 2.421). CONCLUSIONS: Compared with non-lonely participants, the lonely participants were more likely to have a rural registered residence, a lower education level, no friends, be divorced or widowed, live alone, and lack knowledge of smartphones and reproductive health. The influence of COVID-19 had caused social activities to be more confined to the community, which impacts elderly HIV patients suffering from severe discrimination within families and communities.

Risk Analysis of Viral Diseases in Infected Pig Farms during the Lockdown Period in China, January to May 2020.

Biosecurity plays a critical role in preventing and controlling the introduction and spread of infectious diseases. The COVID-19 pandemic in China triggered a nationwide lockdown policy which reduced most of the daily activities of people, but the pig industry was encouraged to ensure the pork supply. An investigation of biosecurity practices in intensive pig farms across several provinces in China was conducted in June 2020 via questionnaire to evaluate the factors that may pose viral diseases risk to the farms during the lockdown period from January to May 2020. A total of 50 farms in 12 provinces of China were engaged. Fourteen of them were classified as positive farms since at least one viral disease was presented during this period, including porcine reproductive and respiratory syndrome (seven farms), porcine epidemic diarrhea (three farms), and pseudorabies (one farm). The other three farms only reported their disease positive status but refused to release disease names. The overall farm level prevalence of viral disease was 28.0% (95%CI: 16.3-42.5%). A logistic regression model was built to identify risk/protective factors for farm positivity. In the multivariable logistic regression model, the risk factor of dead pig 'removal by the others' (OR = 8.0, 95%CI: 1.5, 43.5) was found to be significantly associated with viral disease positivity. On-farm incineration pits are highly recommended to be the administered for the harmless treatment of dead pigs. This is not only crucial for controlling the transmission of viral diseases but also plays a key role in reducing activity in the illegal dead meat business. According to previous studies, factors such as adapting an all-in-all-out system, on-farm incineration pits, and requiring workers to wash their hands regularly would reduce the risk of virus transmission, even though these factors did not show significance in our study. The results of our study could help to design better surveillance strategies in China and other countries.