RESUMO
ObjectiveTo understand the epidemiological characteristics of an outbreak of respiratory tract infections caused by Mycoplasma pneumoniae （MP） in a primary school in Huzhou City， Zhejiang Province， and to provide scientific reference for future prevention and control of school outbreaks of upper respiratory tract infections caused by M. pneumoniae. MethodsAccording to the requirements for investigating respiratory infectious disease outbreaks， basic information， clinical history and epidemiological information were collected from the cases. Throat swab samples of cases for COVID-19 nucleic acid testing， influenza A and B virus antigen testing， and serum samples for detecting total antibody of mycoplasma were also collected. ResultsA total of 47 cases related to M. pneumoniae infection were identified. The first case occurred on May 4， 2022， and the cases were concentrated between May 22 and May 31， 2022. The last case occurred on June 21， marking a duration of 48 days for the outbreak. All cases were second-grade students， with an incidence rate of 35.07% （47/134） in the affected classes， with Class 206 at 53.330% （24/45）， Class 207 at 38.64% （17/44）， and Class 211 at 13.33% （6/45）. There was a statistically significant difference in the incidence rates among the classes （χ2=16.57，P<0.05）. The incidence rate was 32.39% （23/71） for boys and 38.10% （24/63） for girls， with no statistically significant difference by gender （χ2=0.48，P>0.05）. The main clinical manifestations included cough， fever， and sore throat， and some cases exhibited signs of pneumonia. Pharyngeal swabs and serum samples were collected from 27 patients. The results were negative for pharynx swab samples， and positive for total mycoplasma antibody in 12 serum samples， with a positive rate of 44.44%. ConclusionSymptoms caused by M. pneumoniae are diverse in clinical manifestations， with atypical signs and a slow progression. Early cases tend to exhibit mild symptoms. The onset of the disease is not detected in time when students are attending classes. The school morning health checks fail to promptly detect it and trigger home isolation control measures， which all contribute to the outbreak of the epidemic. Schools should conduct relevant prevention and control campaigns， improve morning and afternoon health checks， and prevent students from attending classes while sick.
RESUMO
Objective To investigate the epidemiological characteristics of an outbreak of respiratory tract infection caused by human rhinovirus （HRV） in a school in Nanxun District of Huzhou City， and provide scientific evidence for prevention and control of outbreaks of upper respiratory tract infection caused by HRV in the future. Methods The investigation was performed according to the Guidelines for Response to Outbreaks of Influenza-like Illness （2018 version）. It mainly referred to the records of nonattendance due to illness， morning and afternoon examination， and hospital treatment records， to search for cases. Then CDC staffs carried out epidemiological investigation on cases， interviewed the head teacher， and inspected the site. Throat swabs were collected for detection of SARS-CoV-2 and subsequently 14 common viruses that may cause upper respiratory tract infection. Results A total of 68 cases with HRV infection were identified. The first case and last case occurred on May 20 and 30， respectively. After a 3-day longest incubation period， there was no emerging case， suggesting the end of the outbreak. The incidence was 25.00% （11/44） in Class 101， 30.23% （13/43） in Class 109， 25.58% （11/43） in Class 110， 35.26% （16/45） in Class 211， and 39.96% （17/46） in Class 307. There was no significant difference in the incidence among classes （ χ 2=1.67， P >0.05）. The patients aged from 7 to 9 years. The incidence was 27.19% （31 / 114） in male and 34.58% （37/107） in female， with no significant difference （ χ 2=1.41， P >0.05）. The symptoms were mild， with no hospitalization， severe illness or death. The patients had mainly cough （100.00%）， sore throat （61.76%）， and runny nose （47.06%）， whereas had little muscle soreness （4.41%）. Of the patients， 69.12% visited hospitals， 23.53% took medicine by themselves， while 7.35% did not seek any medical treatment or medicine. Throat swabs were collected from 22 cases， testing negative for SARS-CoV-2. Then 14 common respiratory viruses were examined， of which HRV was positive in 16 cases. Conclusion Children with HRV infection have milder symptoms compared to influenza infection， which is difficult to be noticed by school teachers and parents. Students should maintain personal hygiene and develop health habits. Moreover， schools should strength relevant health education， implement morning and afternoon health inspection， and prevent students with illness to routinely go to schools.
RESUMO
Objective To investigate the epidemiological characteristics of an outbreak of respiratory tract infection caused by human rhinovirus （HRV） in a school in Nanxun District of Huzhou City， and provide scientific evidence for prevention and control of outbreaks of upper respiratory tract infection caused by HRV in the future. Methods The investigation was performed according to the Guidelines for Response to Outbreaks of Influenza-like Illness （2018 version）. It mainly referred to the records of nonattendance due to illness， morning and afternoon examination， and hospital treatment records， to search for cases. Then CDC staffs carried out epidemiological investigation on cases， interviewed the head teacher， and inspected the site. Throat swabs were collected for detection of SARS-CoV-2 and subsequently 14 common viruses that may cause upper respiratory tract infection. Results A total of 68 cases with HRV infection were identified. The first case and last case occurred on May 20 and 30， respectively. After a 3-day longest incubation period， there was no emerging case， suggesting the end of the outbreak. The incidence was 25.00% （11/44） in Class 101， 30.23% （13/43） in Class 109， 25.58% （11/43） in Class 110， 35.26% （16/45） in Class 211， and 39.96% （17/46） in Class 307. There was no significant difference in the incidence among classes （ χ 2=1.67， P >0.05）. The patients aged from 7 to 9 years. The incidence was 27.19% （31 / 114） in male and 34.58% （37/107） in female， with no significant difference （ χ 2=1.41， P >0.05）. The symptoms were mild， with no hospitalization， severe illness or death. The patients had mainly cough （100.00%）， sore throat （61.76%）， and runny nose （47.06%）， whereas had little muscle soreness （4.41%）. Of the patients， 69.12% visited hospitals， 23.53% took medicine by themselves， while 7.35% did not seek any medical treatment or medicine. Throat swabs were collected from 22 cases， testing negative for SARS-CoV-2. Then 14 common respiratory viruses were examined， of which HRV was positive in 16 cases. Conclusion Children with HRV infection have milder symptoms compared to influenza infection， which is difficult to be noticed by school teachers and parents. Students should maintain personal hygiene and develop health habits. Moreover， schools should strength relevant health education， implement morning and afternoon health inspection， and prevent students with illness to routinely go to schools.
RESUMO
ObjectiveTo determine the epidemiological characteristics and transmission factors of a varicella outbreak in a school in Nanxun District of Huzhou City， and assess the effect of prevention and control measures， which may provide scientific evidence for improvement in the response to varicella outbreak. MethodsData were collected by field epidemiological survey and analyzed by descriptive epidemiology. Statistical analysis was performed by SPSS 22.0 software. ResultsA total of 80 varicella cases were identified in this outbreak， which lasted 68 days. There were four peaks of incidence， involving 21 classes. The total incidence rate was determined to be 4.14%. Before the public health intervention， some cases were not isolated in time， which led to the initial spread in the class. After the mid-term examination， the outbreak further spread to multiple classes. Breakthrough varicella cases accounted for 48.75% of all the cases in the outbreak， among which 94.87% had been vaccinated for more than five years. However， there was no significant difference in the incidence of fever and rash between the breakthrough cases and non-breakthrough cases（P>0.05）. ConclusionTimely report， prompt response， and strict implementation of prevention and control measures remain crucial for effective containment of varicella outbreak.