Epidemiological profile of dengue in Zhejiang Province, southeast China

Epidemiological Characteristics and Economic Burden of Dengue in Zhejiang Province, China

Dengue imposes a heavy economic burden on families and society. We used surveillance data reported in 2019 to characterize the dengue epidemic in Zhejiang Province, China, which provided guidance for dengue prevention and control. Dengue epidemics mostly occurred in July to October. People aged 30-44 years, males, and commercial service workers were more likely to suffer from dengue. The epidemic areas were mainly in Hangzhou and Wenzhou. Meanwhile, we assessed the economic cost of dengue in the province from both family and organizational perspectives. The direct economic burden of dengue patients was estimated to be USD 405,038.25, and the indirect economic burden was USD 140,364.90, for a total economic burden of USD 543,213.00. The direct economic burden of dengue patients should be reduced by increasing the coverage and reimbursement of health insurance. Additionally, the total annual cost of dengue prevention and control for the government and organizational sectors was estimated to be USD 7075,654.83. Quantifying the dengue burden is critical for developing disease control strategies, allocating public health resources, and setting health policy priorities.

Post-viral fatigue in COVID-19: A review of symptom assessment methods, mental, cognitive, and physical impairment

Coronavirus 2 is responsible for Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2), and the main sequela is persistent fatigue. Post-viral fatigue is common and affects patients with mild, asymptomatic coronavirus disease-2019 (COVID-19). However, the exact mechanisms involved in developing post-COVID-19 fatigue remain unclear. Furthermore, physical and cognitive impairments in these individuals have been widely described. Therefore, this review aims to summarize and propose tools from a multifaceted perspective to assess COVID-19 infection. Herein, we point out the instruments that can be used to assess fatigue in long-term COVID-19: fatigue in a subjective manner or fatigability in an objective manner. For physical and mental fatigue, structured questionnaires were used to assess perceived symptoms, and physical and cognitive performance assessment tests were used to measure fatigability using reduced performance.

The epidemiology and disease burden of children hospitalized for viral infections within the family Flaviviridae in China: A national cross-sectional study

Background

Viruses of the family Flaviviridae, including Japanese encephalitis virus (JEV), dengue virus (DENV), yellow fever virus (YFV) and hepatitis C virus (HCV), are widely distributed worldwide. JEV, DENV and YFV belong to the genus Flavivirus, whereas HCV belongs to the genus Hepacivirus. Children’s symptoms are usually severe. As a result, rates of hospitalization due to infection with these viruses are high. The epidemiology and disease burden of hospitalized children have rarely been described in detail to date. The objective of this study was to report the general epidemiological characteristics, clinical phenotype, length of stay (LOS), burden of disease, and potential risk factors for hospitalized children infected with JEV, DENV, YFV, or HCV in Chinese pediatric hospitals.

Methodology

A cross-sectional study of epidemiology and disease burden of children hospitalized for Flaviviridae virus infections between December 2015 and December 2020 in China was performed. Face sheets of discharge medical records (FSMRs) were collected from 27 tertiary children’s hospitals in the Futang Research Center of Pediatric Development and aggregated into FUTang Update medical REcords (FUTURE). Information on sociodemographic variables, clinical phenotype, and LOS as well as economic burden was included in FSMRs and compared using appropriate statistical tests.

Findings

The study described 490 children aged 0–15 years hospitalized for infections with Flaviviridae viruses. Japanese encephalitis (JE) cases are the highest, accounting for 92.65% of the total hospitalization cases caused by Flaviviridae virus infection. The incidence of JE peaked from July to October with a profile of a high proportion of severe cases (68.06%) and low mortality (0.44%). Rural children had a significantly higher incidence than urban children (91.63%). Most hospitalized dengue cases were reported in 2019 when dengue outbreaks occurred in many provinces of China, although only 14 dengue cases were collected during the study period. Yellow fever (YF) is still an imported disease in China. The hospitalizations for children with hepatitis C (HC) were not high, and mild chronic HC was the main clinical phenotype of patients. Among the four viral infections, JE had the highest disease burden (LOS and expenditure) for hospitalized children.

Conclusion

First, the present study reveals that JE remains the most serious disease due to Flaviviridae virus infection and threatens children’s health in China. Many pediatric patients have severe illnesses, but their mortality rate is lower, suggesting that existing treatment is effective. Both JEV vaccination and infection control of rural children should represent a focus of study. Second, although the dual risks of indigenous epidemics and imports of DENV still exist, the prevalence of DENV in children is generally manageable. Third, YFV currently shows no evidence of an epidemic in China. Finally, the proportion of children with chronic hepatitis C (CHC) is relatively large among hospitalized children diagnosed with HCV. Thus, early and effective intervention should be offered to children infected with HCV to ease the burden of CHC on public health.

We performed a general epidemiological and disease burden assessment of 490 hospitalized children infected with any virus from the family Flaviviridae [Japanese encephalitis virus (JEV), dengue virus (DENV), yellow fever virus (YFV) and hepatitis C virus (HCV)] from December 2015 to December 2020 with confirmed clinical presentation and laboratory results. Our study found that hospitalization for Japanese encephalitis (JE) predominated in children who lived in rural areas, and the infection was rate was considerably higher in summer and autumn (July–October) compared with other months. In addition, children hospitalized with JE have the largest share of disease burden. However, the overall low rate of hospitalization and mortality of children shows that China’s JE prevention and control policies remain effective. However, the prevention, control and surveillance of JEV in rural areas should not be neglected. Dengue and yellow fever have not yet caused serious public health concerns among children in China, but the spatial and temporal distributions of viral infection must be assessed to be alert to the indigenous spread of imported cases. CHC is a refractory phenotype of HCV infection in children; thus, early screening and intervention are encouraged given the insidious appearance of symptoms in the early stages after HCV infection. These findings can help to understand the epidemic status of viruses classified in the family Flaviviridae in children and the disease burden of hospitalized children, which is conducive to precise prevention and control, optimization of the allocation of resources, and the formulation of more reasonable and effective policies.

Entomological Investigation and Detection of Dengue Virus Type 1 in Aedes (Stegomyia) albopictus (Skuse) During the 2018–2020 Outbreak in Zhejiang Province, China

Mosquito-borne diseases are still threats to public health in the Zhejiang province of China. Surveillance of mosquitoes and the mosquito-borne pathogen is a vital approach for early warning, prevention, and control of the infectious disease. In this study, from 2018 to 2020, a total of 141607 female mosquitoes were caught by means of the light trap method. The main species were Culex pipiens quinquefasciatus/pallens (41.32%), Culex tritaeniorhynchus (47.6%), Aedes albopictus (2.5%), Anopheles sinensis (5.87%), Armigeres subalbatus (2.64%) and other mosquito species (0.07%). Cx. pipiens s.l. were the dominant species in two urban habitats and rural residential areas while Cx. tritaeniorhynchus was the main dominant species in the rural livestock sheds. In terms of seasonal fluctuation, Cx. pipiens s.l fluctuated at a high level from May to October. The peaks of Cx. tritaeniorhynchus, An. sinensis and Ar. subalbatus were in July. In addition, a total of 693 Ae. albopictus were collected with Biogents Mosquitaire CO₂ traps in emergency surveillance of dengue fever (DF) and screened for dengue virus infection. There were three circumstances of collection: The first: the sampling time before mosquito control during the local outbreak of DF in Lucheng of Wenzhou, 2019; The second circumstance: the sampling time after mosquito control during the local outbreak of DF of other cities in 2018-2019; The third circumstance: past DF epidemic areas the sampling time before mosquito control during the local outbreak of DF in Lucheng, Wenzhou, Zhejiang, 2019. The pools formed by mosquitoes collected in these three circumstances were 3 (6.1%), 35 (71.5%), and 11 (22.4%) respectively. Of the 49 pools tested, only one in the first circumstance was positive. The full-length dengue virus sequence of ZJWZ/2019 was obtained by sequencing and uploaded to the NCBI as number OK448162. Full-length nucleotide and amino acid homology analyses showed that ZJWZ2019 and Wenzhou DF serum isolates ZJWZ-62/2019 (MW582816) and ZJWZ-18/2019 (MW582815) had the highest homology. The analysis of full genome and E gene phylogenetic trees showed that ZJWZ2019 belonged to serotype 1, genotype I, lineage II, which was evolutionarily related to OK159963/Cambodia/2019. It implies that ZJWZ2019 originated in Cambodia. This study showed the species composition, seasonal dynamics of mosquitoes in different habitats in Zhejiang province and confirmed the role of Ae. albopictus in the transmission cycle of in outbreak of DF in the Lucheng district of Wenzhou in 2019, suggesting the importance of monitoring of vector Aedes infected dengue virus in the prevention and control of DF.

Molecular Characterization and Phylogenetic Analysis of the 2019 Dengue Outbreak in Wenzhou, China

In 2019, a dengue outbreak occurred with 290 confirmed cases in Wenzhou, a coastal city in southeast China. To identify the origin of the dengue virus (DENV) from this outbreak, viral RNA was extracted from four serum samples and sequenced for whole genome analysis. Then, phylogenetic analysis, gene mutation, secondary structure prediction, selection pressure analysis, and recombination analysis were performed. DENV strains Cam-03 and Cam-11 were isolated from patients traveling from Cambodia, while ZJWZ-18 and ZJWZ-62 strains were isolated from local patients without a record of traveling abroad. The whole genome sequence of all four strains was 10,735 nucleotides long. Phylogenetic tree analysis showed that the four strains belonged to genotype 1 of DENV-1, but the local Wenzhou strains and imported strains clustered in different branches. ZJWZ-18 and ZJWZ-62 were closely related to strain MF033254-Singapore-2016, and Cam-03 and Cam-11 were closely related to strain AB608788-China : Taiwan-1994. A comparison of the coding regions between the local strains and the DENV-1 standard strain (EU848545-Hawaii-1944) showed 82 amino acid mutations between the two strains. A total of 55 amino acid mutations were found between the coding regions of the local and imported strains. The overall secondary structure of the 3' UTR of the local strains had changed: apparent changes in the head and tail position were observed when compared to DENV-1 standard strain. Furthermore, selection pressure analysis and recombination detection using the 4 isolates and 41 reference strains showed two credible positive selection sites and eight credible recombination events, which warrant further studies. This study may enhance the understanding of viral replication, infection, evolution, virulence, and pathogenicity of DENV.

Infectious diseases prevention and control using an integrated health big data system in China

BACKGROUND

The Yinzhou Center for Disease Prevention and Control (CDC) in China implemented an integrated health big data platform (IHBDP) that pooled health data from healthcare providers to combat the spread of infectious diseases, such as dengue fever and pulmonary tuberculosis (TB), and to identify gaps in vaccination uptake among migrant children.

METHODS

IHBDP is composed of medical data from clinics, electronic health records, residents' annual medical checkup and immunization records, as well as administrative data, such as student registries. We programmed IHBDP to automatically scan for and detect dengue and TB carriers, as well as identify migrant children with incomplete immunization according to a comprehensive set of screening criteria developed by public health and medical experts. We compared the effectiveness of the big data screening with existing traditional screening methods.

RESULTS

IHBDP successfully identified six cases of dengue out of a pool of 3972 suspected cases, whereas the traditional method only identified four cases (which were also detected by IHBDP). For TB, IHBDP identified 288 suspected cases from a total of 43,521 university students, in which three cases were eventually confirmed to be TB carriers through subsequent follow up CT or T-SPOT.TB tests. As for immunization screenings, IHBDP identified 240 migrant children with incomplete immunization, but the traditional door-to-door screening method only identified 20 ones.

CONCLUSIONS

Our study has demonstrated the effectiveness of using IHBDP to detect both acute and chronic infectious disease patients and identify children with incomplete immunization as compared to traditional screening methods.

Resistance of House Fly, Musca domestica L. (Diptera: Muscidae), to Five Insecticides in Zhejiang Province, China: The Situation in 2017

Objectives

High dependency on pesticides could cause selection pressure leading to the development of resistance. This study was conducted to assess the resistance of the house fly, Musca domestica, to five insecticides, namely, permethrin, deltamethrin, beta-cypermethrin, propoxur, and dichlorvos, in Zhejiang Province.

Methods

Field strains of house flies were collected from the 12 administrative districts in Zhejiang Province in 2011, 2014, and 2017, respectively. Topical application method was adopted for the bioassays. The probit analysis was used to determine the median lethal doses with the 95% confidence interval, and then the resistance ratio (RR) was calculated. The insecticides resistance in different years and the correlations of the resistance between different insecticides were also analyzed.

Results

The resistance of field strains house flies to insecticides in Zhejiang Province was relatively common, especially for permethrin, deltamethrin, and beta-cypermethrin. The reversion of the resistance to dichlorvos was found, and most of the field strains in Zhejiang Province became sensitive to dichlorvos in 2017. Propoxur was much easier to cause very high level of resistance; the Hangzhou strain had the highest RR value more than 1000 in 2014, and five field strains had the RR value more than 100 in 2017. Compared to 2011 and 2014, the resistance of the house flies to propoxur and deltamethrin increased significantly in 2017. The resistance of permethrin, deltamethrin, beta-cypermethrin, and propoxur was significantly correlated with each other, and the resistance of dichlorvos was significantly correlated with beta-cypermethrin.

Conclusions

Our results suggested that resistance was existed in permethrin, deltamethrin, beta-cypermethrin, and propoxur in the house flies of Zhejiang Province, while the resistance reversion to dichlorvos was found.