Project description:High case counts after the Gamma (P. 1) variant of severe acute respiratory syndrome coronavirus 2 emerged in Brazil raised concerns that previously infected persons might become reinfected. Investigation of a cluster of coronavirus disease cases in Parintins, in the Brazilian Amazon, suggested household transmission but did not identify high rates of reinfection.
Project description:Guangdong province, located in South China, is an important economic hub with a large domestic migrant population and was among the earliest areas to report COVID-19 cases outside of Wuhan. We conducted a cross-sectional, age-stratified serosurvey to determine the seroprevalence of antibodies against SARS-CoV-2 after the emergence of COVID-19 in Guangdong. We tested 14,629 residual serum samples that were submitted for clinical testing from 21 prefectures between March and June 2020 for SARS-CoV-2 antibodies using a magnetic particle based chemiluminescent enzyme immunoassay and validated the results using a pseudovirus neutralization assay. We found 21 samples positive for SARS-CoV-2 IgG, resulting in an estimated age- and sex-weighted seroprevalence of 0.15% (95% CI: 0.06-0.24%). The overall age-specific seroprevalence was 0.07% (95% CI: 0.01-0.24%) in persons up to 9 years old, 0.22% (95% CI: 0.03-0.79%) in persons aged 10-19, 0.16% (95% CI: 0.07-0.33%) in persons aged 20-39, 0.13% (95% CI: 0.03-0.33%) in persons aged 40-59 and 0.18% (95% CI: 0.07-0.40%) in persons ≥60 years old. Fourteen (67%) samples had pseudovirus neutralization titers to S-protein, suggesting most of the IgG-positive samples were true-positives. Seroprevalence of antibodies to SARS-CoV-2 was low, indicating that there were no hidden epidemics during this period. Vaccination is urgently needed to increase population immunity to SARS-CoV-2.
Project description:BackgroundIn Japan, a part of confirmed patients' samples have been screened for the variant of concern (VOC), including the variant alpha with N501Y mutation. The present study aimed to estimate the actual number of cases with variant alpha and reconstruct the epidemiological dynamics.MethodsThe number of cases with variant alpha out of all PCR confirmed cases was estimated, employing a hypergeometric distribution. An exponential growth model was fitted to the growth data of variant alpha cases over fourteen weeks in Tokyo.ResultsThe weekly incidence with variant alpha from 18-24 January 2021 was estimated at 4.2 (95% confidence interval (CI): 0.7, 44.0) cases. The expected incidence in early May ranged from 420-1120 cases per week, and the reproduction number of variant alpha was on the order of 1.5 even under the restriction of contact from January-March, 2021, Tokyo.ConclusionsThe variant alpha was predicted to swiftly dominate COVID-19 cases in Tokyo, and this has actually occurred by May 2021. Devising the proposed method, any country or location can interpret the virological sampling data.
Project description:Zika virus (ZIKV) is an emerging mosquito-borne flavivirus that can potentially threaten South China. A Chinese family of four returning from Venezuela to China was found to be positive for ZIKV when the youngest son's fever was first detected at an airport immigration inspection. They were isolated temporarily in a local hospital in Enping city, Guangdong province, where their clinical data were recorded and urine and saliva were collected to isolate ZIKV and to obtain viral sequences. All of them except the mother presented mild symptoms of rash and fever. Envelope gene sequences from the father, daughter and son were completely identical. Phylogenetic analysis demonstrated that this strain is similar to several imported strains reported in recent months, which are all clustered into a group isolated from 2015 ZIKA outbreaks in Brazil. Together with the climatic features in Venezuela, New York and Guangdong in February, it can be concluded that our subjects are imported cases from Venezuela. With the same viral sequence being shared between family members, neither direct human-to-human nor vector transmission can be ruled out in this study, but the former seems more likely. Although our subjects had mild illness, epidemiologists and public health officials should be aware of the risk of further expansion of ZIKV transmission by local competent vectors.
Project description:ObjectivesAn increased trend in the number of reported gonorrhoea cases has been observed between 2014 and 2017 in China. This study aims to describe the reported epidemic of gonorrhoea and potential driving forces in Guangdong Province, China.DesignA review of surveillance data.ParticipantsThree different sources of data from Guangdong Province were analysed: gonorrhoea cases reported to the Chinese sexually transmitted infections (STI) case report system (CRS); a clinic-based retrospective study conducted to collect information on annual gonorrhoea screening coverage and data from the Guangdong governmental sentinel surveillance network (SSN) to examine the gonorrhoea prevalence among males attending STI clinics.Outcome measuresReported incidence of gonorrhoea, number of reported gonorrhoea cases, number of screening tests for gonorrhoea and gonorrhoea prevalence.ResultsThe STI CRS data showed that the reported incidence of gonorrhoea has increased rapidly from 15.7 cases per 100 000 population in 2014 to 27.3 cases per 100 000 in 2017 in Guangdong (p<0.001). Regions with a reported incidence of gonorrhoea cases of more than 10 cases per 100 000 expanded from 7 cities in 2014 to 13 cities in 2017. The SSN data showed that the gonorrhoea prevalence among males attending STI clinics increased from 2.7% in 2015 to 3.6% in 2017 (p=0.14). The retrospective study showed that the increased rate of screening for gonorrhoea between 2014 and 2017 was 35.0%, which was much lower than the increased rate of the number of reported gonorrhoea cases (123.3%).ConclusionsThe number of gonococcal infections is rapidly rising in Guangdong, China. Expanded screening coverage, use of more sensitive diagnostics and increase of gonorrhoea prevalence are three potential contributors to the epidemic. Additional targeted intervention strategies are necessary in the future to control the epidemic.
Project description:Fascioliasis is a zoonotic disease caused by Fasciola spp. We report five serologically and molecularly confirmed cases in an emerging region in Iran. A retrospective, case series study, performed in Lorestan Province, west of Iran between January 2015 and June 2016. From 1256 patients examined, 16 patients had positive serum ELISA. Five cases were approved as infected with fasciolosis using stool exam and PCR. Age ranged from 24 to 80 yr with mean age of 45 years. All of patients were adults and four of them had abdominal and back pain. Other symptoms included fever and chills, coughing and sore throat, weight loss, cutaneous manifestations. All patients lived in the rural environment, and four reported the ingestion of raw aquatic plants such as watercress. In fecal examination for fluke eggs, four samples were positive for F. hepatica eggs. Conventional PCR analysis showed that five human stools were positive for F. hepatica. All of 5 patients were treated with the usual dose of triclabendazole. A history of recent consumption of raw aquatic plants (in 4 out of 5 patients) is an important finding, but in one patient the source of infection remained unclear. Lorestan should be considered as an emerging region for this disease and further research in this province should be carried out.