Epidemiology and characteristics of identified early mpox cases in Guangdong Province,China:Implications for prevention and control

In June 2023,the 2022 global mpox(monkeypox)outbreak began to affect Guangdong Province,one of the first regions in China's Mainland to report mpox cases.By July 10,2023,93 mpox cases had been reported in Guangdong Province.This study describes the epidemiological characteristics of these patients by collecting and analyzing data on demographics,sexual behavior,medical history,travel history,clinical symptoms,and diagnostic pathways and processes.The 93 mpox cases were all men aged 20-48 years,95.70%were men who have sex with men(MSM),and 48.39%were HIV-positive.A few cases were married(to women)or living with children.The rash was present in almost all cases(98.91%),with the most common sites being the genital and perianal areas(70.33%).Intimate sexual contact was suspected to be the main route of infection,with a median incubation period of 8.5 days(IQR 5.0–11.8).The number of cases increased rapidly,and most patients had no history of international travel,suggesting sustained community transmission within the MSM population in Guangdong Province.In addition,93.55%of cases were detected by medical institutions,and more than half of these patients had two or more hospital visits before being diagnosed as an mpox case,indicating that clinicians need further training to increase their sensitivity to mpox.Targeted interventions should prioritize MSM while remaining vigilant for transmission to other populations,such as women and children.

A review of the epidemic and clinical study on scrub typhus in China(2010-2020)

Scrub typhus is an acute febrile vector-borne zoonotic disease caused by the obligate intracellular growth bacterium Orientia tsutsugamushi(Ot).Mites are the primary vectors and rodents play a pivotal role in the transmission of scrub typhus.Due to the climate warming,increased human activity and other factors,cases of scrub typhus have been increased sharply during the past decade in China,especially in the northern China.To understand the incidence trend,epidemic pattern,clinical sign,diagnosis and therapy of this diseases as well as genotype evolution of Orientia tsutsugamushi,we summarized and analyzed the current knowledge of scrub typhus in China from 2010 to 2020.The data indicated that the dominate genotypes of scrub typhus in China were Karp,Kato and Gilliam.Although the disease was distributed national wide,Yunnan,Guangzhou and Fujian showed the highest incidence rate.The main vector of scrub typhus in southwest,middle east and southeast of China appeared a geographic preference respectively.Seasonal timing,age and occupation were the key factors that relate to the peak incidence of scrub typhus.Notably,farmer was the occupation with the highest risk of Ot infection.Further study on the epidemic characteristics,risk factors,diagnosis and treatments of scrub typhus will be of benefit to a comprehensive guideline for prevention and control of this ancient disease.

Measles Virus IgG Avidity Assay for Use in Identification of Measles Vaccine Failures in Tianjin, China

Objective To identify measles vaccine failures in Tianjin, China using a measles virus Ig G avidity assay.Methods The China Information System for Disease Control and Prevention(CISDCP) was used to collect information about measles cases and blood specimens in Tianjin from 2013 to 2015. Measlesspecific Ig M and Ig G antibodies were detected using Enzyme-Linked Immunosorbent Assay(ELISA).Avidity testing for measles Ig G was performed using a commercial enzyme immunoassay(EIA).Results A total of 284 confirmed measles cases were identified. Of this total, 262(92.25%) were in patients aged ≥ 20 years. High avidity was exhibited in 172(60.56%) cases, while 80(28.17%) cases demonstrated low avidity. High avidity was detected in only 21.43% of cases in patients aged < 1 year.The proportion of high avidity increased with age, and was significantly higher in patients aged 30–39 years at 70.07%(χ~2 = 17.27, P = 0.002). Of the 52 measles cases in patients with a history of vaccinations,41(78.85%) cases showed high avidity, indicating secondary vaccine failures(SVF). In these vaccinations,there was no significant difference(P > 0.05) in clinical severity between high avidity and low avidity cases. However, regardless of vaccination status, clinical severity was significantly lower in high avidity cases(P < 0.001) than in low avidity cases. The percentages of positive measles Ig M results in high avidity and low avidity cases were 66.28% and 91.25%, respectively. Geometric Mean Concentration(GMC) was significantly lower in high avidity cases at 33.73 U/m L, compared to 166.07 U/m L in low avidity cases.Conclusions Low clinical severity and inconclusive Ig M antibody results are more likely in high avidity measles cases. Measles cases were more common in adults. Therefore, a further dose of vaccines should be recommended for 30–39 years in Tianjin.

Key Social Determinants to Narrow the Gap between Health-adjusted Life Expectancy and Life Expectancy in Megacities

Objective Improvement in the quality of life is reflected in the narrowing of the gap between healthadjusted life expectancy(HALE)and life expectancy(LE).The effect of megacity expansion on narrowing the gap is rarely reported.This study aimed to disclose this potential relationship.Methods Annual life tables were constructed from identified death records and population counts from multiple administrative sources in Guangzhou,China,from 2010 to 2020.Joinpoint regression was used to evaluate the temporal trend.Generalized principal component analysis and multilevel models were applied to examine the county-level association between the gap and social determinants.Results Although LE and HALE in megacities are increasing steadily,their gap is widening.Socioeconomic and health services are guaranteed to narrow this gap.Increasing personal wealth,a growing number of newborns and healthy immigrants,high urbanization,and healthy aging have helped in narrowing this gap.Conclusion In megacities,parallel LE and HALE growth should be highly considered to narrow their gap.Multiple social determinants need to be integrated as a whole to formulate public health plans.

Nucleotide sequence characterization and phylogenetic analysis of hantaviruses isolated in Shandong Province,China

Background China is the most severe endemic area of hemorrhagic fever with renal syndrome （HFRS） in the world with 30 000-50 000 cases reported annually, which accounts for more than 90% of total number of cases worldwide. The incidence rate of the syndrome in Shandong Province is one of the highest in China, which has ever reached 50 per 100 000 persons per year. However, the molecular characteristics of hantaviruses （HV） epidemic in Shandong Province remain unclear. Therefore it is useful to clarify nucleotide sequence and phylogenetic characteristics of HV isolated in Shandong Province in order to provide better advices to control and prevent HFRS. Methods RNAs were extracted from sera of clinically diagnosed patients and positive rodent lungs that were detected by indirect immunofluorescent assay （IFA）. Partial M segments of HV were amplified from the RNAs with reverse transcription nested polymerase chain reactions （nested PCR） using hantavirus genotype specific primers. The nested PCR products were sequenced and compared with those from previously epidemic isolates in Shandong and with other representative HV sequences from GenBank. Phylogenetic tree analyses were performed based on the sequences of the M genes. Results Thirty-four HV isolates in Shandong showed 67.1%-100% nucleotide identities. The nucleotide homologies among 6 Hantaan viruses （HTNV） isolates in Shandong were 78.1%-98.7%, while the homologies among 28 Seoul virus （SEOV） isolates in Shandong were 93.7%-100%. There were at least 3 subtypes HTNV （H2, H5, H9） and 2 subtypes SEOV （S2, S3） in Shandong Province. Conclusions In Shandong Province, the homologies of HTNV were lower and there were no predominant subtypes, while the homologies of SEOV were higher and S3 was the predominant subtype. The homologies of SEOV from rodents were higher than those from patients. The distribution of subtypes in Shandong was similar to that of the adjoining provinces. Phylogenetic analyses of the sequences showed geographic clustering of HV in Shandong.

District prediction of cholera risk in China based on environmental factors

The epidemics of cholera are impacted by many climatic and environmental factors such as precipitation, temperature, elevation and so on. The paper analyzed the suitable degree of V. cholerae in China using MaxEnt based on some geographic and climatic factors, and predicted the cholera risk in each district of China according to the suitable degree. The result shows that the areas in coastal southeast, central China and western Sichuan Basin are relatively suitable for V. cholerae and the suitable degree is higher in the Xinjiang Basin than in surrounding areas. The variables of precipitation, temperature and DEM are three main environmental risky factors that affecting the distribution of cholera in China. The variables of relative humidity, the distance to the sea and air pressure also have impacts on cholera, but sunshine duration and drainage density have little impact. The AUC value of MaxEnt based model is above 0.9 which indicates a high accuracy.