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ABSTRACT Zika virus (ZIKV) is an enveloped, single-stranded RNA arbovirus belonging to the genus Flavivirus. It was first isolated from a sentinel monkey in Uganda in 1947. More recently, ZIKV has undergone rapid geographic expansion and has been responsible for outbreaks in Southeast Asia, the Pacific Islands, and America. In this review, we have highlighted the influence of viral genetic variants on ZIKV pathogenesis. Two major ZIKV genotypes (African and Asian) have been identified. The Asian genotype is subdivided into Southwest Asia, Pacific Island, and American strains, and is responsible for most outbreaks. Non-synonymous mutations in ZIKV proteins C, prM, E, NS1, NS2A, NS2B, NS3, and NS4B were found to have a higher prevalence and association with virulent strains of the Asian genotype. Consequently, the Asian genotype appears to have acquired higher cellular permissiveness, tissue persistence, and viral tropism in human neural cells. Therefore, mutations in specific coding regions of the Asian genotype may enhance ZIKV infectivity. Considering that mutations in the genomes of emerging viruses may lead to new virulent variants in humans, there is a potential for the re-emergence of new ZIKV cases in the future.
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ObjectiveTo analyze the characteristics and trends of notifiable infectious diseases in Yangpu District of Shanghai， from 1950 to 2020， and to provide scientific basis for the formulation of control measures. MethodsDescriptive epidemiological method was used to collect and analyze the epidemiological data of notifiable infectious diseases. ResultsA total of 1 186 675 cases from 38 types of infectious diseases were reported. The annual morbidity of Class A and Class B infectious diseases fluctuated between 138.22/105 and 7 861.45/105， showing a decreasing trend. Among the 3 785 cases of death， the top five were measles， viral hepatitis， dysentery， tuberculosis and epidemic cerebrospinal meningitis. The high incidence diseases were intestinal infectious diseases， and the respiratory infectious diseases fluctuated in a wide range. Furthermore， blood-borne infectious diseases and sexual -transmitted diseases had continued to increase in recent years. As the result of normative vaccination， the incidence of associated infectious disease showed a downward trend. ConclusionThe incidence of infectious diseases in Yangpu District was on the drop from 1950 to 2020. Prevention and control work should focus on respiratory infectious diseases， blood-borne infectious diseases and sexual -transmitted diseases in the future. Furthermore， it is important to guarantee normative vaccination， especially， for prevention and control of infectious diseases.
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The novel coronavirus disease 2019 (COVID-19) outbreak occurred in December last year and spread quickly in the world, causing great harm to people. The rapid progression of this epidemic makes scholars in various fields conduct research on the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). So far, the wildly accepted routes are droplets and close contact. Controversially, some researchers believe that other routes include aerosol diffusion, fecal-oral transmission, contacting urine, conjunctival infection, and mother-to-infant transmission may also infect people. In this article, combining the newest research and reports, the authors systematically analyzed the theoretical possibility and real-life probability of the transmission routes of the virus in order to help with the research and clinical judgment of the spread of infectious diseases in the future.
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Objective@#To explore the features of close contacts of coronavirus disease 2019 ( COVID-19 ) cases in Jiulongpo District, Chongqing, so as to provide evidence for the management of close contacts and the control of the epidemic.@*Methods@#Demographic characteristics, contact history and medical records of close contacts of COVID-19 cases in Jiulongpo District from January 22 to April 10, 2020 was collected according to the COVID-19 Prevention and Control Program ( sixth version ) . Descriptive statistical analysis was performed.@*Results@#Totally 602 close contacts were found, and 30 of them were infected, with an attack rate of 4.98%. Twenty-seven cases were diagnosed before February 10. The close contacts mainly aged from 20 to 59 years ( 457, 75.91% ) ; most were relatives of COVID-19 cases ( 219, 36.38% ) , and 64 (10.63%) were medical staff. Most contacted occasionally ( 338, 56.15% ), at home ( 190, 31.56% ) , and through the same meal ( 181, 30.07% ) . The attack rate of close contacts aged 40 years and over was 7.49%, which was higher than 2.37% of those aged under 40 years ( P<0.05 ). The attack rate of close contacts increased with contact frequency ( P<0.05 ) . The attack rates of close contacts were significantly different in different relations with cases, contact places and contact modes ( P<0.05 ); the attack rates of colleagues and relatives were 20.41% and 8.68%; the attack rates of close contacts in the workplace settings and family were 17.54% and 10.00%; the attack rates of sharing the same bed, living in the same room and working in the same room were 44.44%, 18.60% and 17.24%.@*Conclusions @#The close contacts of COVID-19 cases in Jiulongpo District, Chongqing who aged 40 years or above, exposed in family settings and in the workplace were associated with higher risk of infection.
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Objective @#To investigate a cluster of coronavirus disease 2019 (COVID-19) in Pingyang County,and to put forward targeted prevention and control suggestions.@*Methods@#According to the Prevention and Control Plan of COVID-19 (Third Edition),we carried out epidemiological investigation to collect the information of demographic features,diagnosis and treatment,clinical manifestations,laboratory examination,exposure history and close contact. We analyzed the mode and frequency of exposure,so as to figure out the route of transmission. @*Results@#This epidemic resulted in 6 confirmed cases of COVID-19 and 3 asymptomatic cases,with an attack rate of 6.52% (9/138). The median age of the cases was 48 years old. The confirmed cases mainly had imaging features of pneumonia, fever and cough. Their incubation period ranged from 4 to 9 days,and the median was 6 days. The first case,Wang,returned for the funeral of her grandmother from Wuhan with his husband and son on January 18 and lived with her mother. She had cough on January 19,and went to see her grandmother during January 19 to 23. She had contact with 6 cases,and the other 2 cases were Wang's mother and husband,who lived with Wang. All the cases except Wang had no COVID-19 related symptoms before the funeral,no contact history of COVID-19 cases or no other common exposure history except during the funeral. Therefore,Wang was determined as the source of the epidemic,staying in the same room and eating at the same table with her were risk factors for the infection of COVID-19 in this epidemic (P<0.05). @*Conclusions @#This was a local clustering epidemic caused by COVID-19 imported cases from Wuhan. It spread mainly by close contacts like staying in the same room and eating at the same table.
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Objective@#To analyze three events of severe fever with thrombocytopenia syndrome （SFTS） among family members by exposure risk matrix, so as to provide reference for SFTS prevention and control.@*Methods @#The field investigation and clinical data of seven confirmed cases with SFTS reported in Linhai from 2014 to 2016 were collected. Exposure risk matrix was used to list the risk of exposure two weeks before the onset, such as the environment, duration of activity and protection, and evaluate the possible routes of transmission. @*Results@#The first event involved three sisters. Two of them had plucked tea together on a hill, and the possibility of infection through tick bites were 60% and 75%, respectively. Another sister was more likely to be infected by ticks in her residence after visiting her sister （no physical contact with the sick sister）, with a possibility of 74%. The second event involved two cases （mother and son）. They were more likely to be infected by ticks in the current residential area, and the possibility were 100% and 80%, respectively. The third event involved two cases （husband and wife）. The wife had 60% possibility of being infected by the ticks on the hill she picked arbutus, and 40% by the ticks in her residence. The husband was most likely to be infected through contacting with body fluids or blood of his wife （44%）, then through the ticks on the hill he picked arbutus （33%）. @*Conclusion@#Among seven cases with SFTS reported in Linhai from 2014 to 2016, six cases have more than 50% possibility of being infected by tick bites; one case has higher possibility of being infected by contacting with body fluids or blood of a patient, but tick bites could not be ruled out.
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Objective To understand the misreporting rate regarding the routes of transmission among the reported HIV patients in Yili prefecture of Xinjiang,since 2011.Methods An investigation focusing on the route of transmission among people living with HIV/AIDS was carried out to clarify the responsible reasons for the situation.Results The overall incorrect reporting rate on the route of transmission was 10.8％.The proportion of heterosexual transmission route was over estimated by 63.8％ to 72.0％.However,the proportion of injecting drug was underestimated by 27.5％ to 22.2％.The number of cases being confirmed as through heterosexual transmission but incorrectly reported was quite high,contributing 82.6％ of all the incorrectly reported cases.Most of the patients that incorrect reported,were moved from injecting drug use to heterosexual transmission,which contributed 79.5％ of all the total incorrectly reported cases.Results from multi-factor analysis showed that the risk related to incorrect reporting was 3.64 times in males than in females.People who anticipated to receive HIV testing were 2.23 times more than those who had not.Old-age groups were 3.511,4.053,4.415 and 6.524 times higher than those people who were aged below 16 years.Conclusions The proportion of heterosexual transmission route was over-estimated while the proportion on injecting drug use was underestimated.However,the transmission pattern had changed from injecting drug use at the early epidemic stage,to current sexual transmission mode.We recommended that more attentions should be paid to patients who were males,at older age or those who had no expectation in receiving the HIV testing,during the initial following-up stage.
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BACKGROUND: Scabies is an ectoparasite caused by the mite Sarcoptes scabiei var. hominis, an obligate human parasite. Although its incidence has been decreasing, it is not a rare dermatologic disease and is difficult to diagnosis. OBJECTIVE: To evaluate the clinical characteristics of scabies patients and find out etiologic factors in transmission. METHODS: Two hundred and ninety-five patients who were diagnosed with scabies at the Dermatologic Department, Myongji Hospital, Goyang city, Korea were enrolled. Medical records were evaluated in a retrospective manner. RESULTS: We studied 295 scabies patients who were diagnosed by the mineral oil test or skin biopsy. The mean age of the patients was 58.2 (male: 56.7/female: 61.2), and 74% of patients were over 60 years. There was seasonal variation in occurrence, and scabies was found to be most common in winter. The majority of suspected routes of infection were transmission through convalescent hospitals (38.1%) and caregivers (15.2%). Nosocomial infection and communal living were the major causes. 73.8% of scabies patients had underlying medical disease, such as hypertension (32.2%) and dementia (11.9%). CONCLUSION: Currently, scabies prevalence is still increasing in Goyang city, because of the increased number of convalescent hospitals.
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Humans , Biopsy , Caregivers , Cross Infection , Dementia , Hospitals, Convalescent , Hypertension , Incidence , Korea , Medical Records , Mineral Oil , Mites , Parasites , Prevalence , Retrospective Studies , Sarcoptes scabiei , Scabies , Seasons , SkinABSTRACT
Summary: To further investigate the vertical transmission route of human papillomavirus (HPV) and the indication for the choice of mode of delivery, the infective status of 152 asymptomatic pregnant wemen and the maternal-fetal transmission were studied. By using general primers in polymerase chain reaction (GP-PCR) combined with restriction fragment length polymorphism analysis, HPV DNA positive rate in cervical secretions and venous blood in asymptomatic pregnant women was 36.21 % and 52.78 %, respectively, and the identified genotypes were mainly HPV16 and 18. The maternal-fetal transmission rate of HPV via genital tract as well as blood was 40.91 % and 57.89 %, respectively. It was concluded that besides the transmission route of genital tract and amniotic fluid, there was also transplacental transmission of HPV in utero. Therefore,in our opinion, it is not an absolut indication to perform a cesarean delivery for the pregnant women with HPV asymtomatic genital infection.