School Outbreaks Research Articles

Investigation of a Norovirus GII outbreak in a primary school in Portugal,2023

Abstract Background The onset of acute gastroenteritis cases among students in a primary school class on September 19, 2023, prompted an immediate response from the local Public Health unit. A collaborative effort was initiated to investigate and contain the outbreak. Methods Epidemiological questionnaires were distributed to 166 students and 8 staff members, defining cases as individuals exhibiting symptoms including diarrhoea, vomiting, or nausea between September 19th and September 24th, 2023. Additionally, stool samples were collected from three individuals. Results Out of 166 students and 8 staff members, 39 individuals met the case definition, resulting in attack rates of 22% (37/166) and 25% (2/8) among students and staff, respectively. Laboratory analysis confirmed two cases of Norovirus GII among the tested specimens, with five students requiring medical attention. Conclusions Our investigation underscores the significance of continuous epidemiological surveillance and swift implementation of infection control measures in school settings. The detection of Norovirus transmission emphasizes the necessity for rigorous adherence to infection control best practices. Our findings advocate for sustained technical support from public health authorities to prevent and manage similar outbreaks effectively. Key messages • Study on Norovirus outbreak in a primary school highlights the imperative of infection control measures, emphasizing the importance of ongoing support from public health authorities. • The Norovirus outbreak investigation underscores the vital role of surveillance and swift response in containing infectious diseases within educational settings safeguarding all.

Epidemiological characteristics of influenza outbreaks in schools in Jiangsu Province, China, 2020–2023 post-COVID-19 pandemic

BackgroundThis study aimed to analyze the epidemic characteristics and influencing factors of school influenza outbreaks in Jiangsu Province, China from 2020 to 2023,following the COVID-19 pandemic, to inform prevention and control strategies.MethodsData on influenza-like illness(ILI) outbreaks from the Chinese Influenza Surveillance Information System and national-level influenza surveillance sentinel hospitals were analyzed. The temporal distribution, school type, virus strains, and outbreak scales were examined using descriptive statistics.ResultsFrom 2020 to 2023, 1142 influenza outbreaks occurred in schools, with primary schools(ages 6 to 12) accounting for 71.80%. Most large outbreaks were caused by A(H1N1) and A(H3N2), responsible for 8.99% of total outbreaks. Outbreaks were predominantly reported in the pre-peak periods of B(Victoria) and A(H1N1) circulation, accounting for 86.31% and 92.32% of their respective total outbreaks. No concurrent influenza and COVID-19 outbreaks were observed during the study period.ConclusionPrimary and secondary schools are high-risk settings for influenza outbreaks. A(H3N2) shows higher adaptability and is more likely to co-circulate with other subtypes/lineages, especially A(H1N1), leading to larger outbreaks. B(Victoria)-caused outbreaks are more frequent but smaller in scale. School influenza outbreaks are more likely to occur during the early stages of seasonal peaks, particularly for B(Victoria) and A(H1N1). This suggests that influenza outbreaks in schools may play a crucial role in seeding and accelerating the spread of the virus within the broader community.

Within-household SARS-CoV-2 transmission and vaccine effectiveness in the first three COVID-19 school outbreaks in northern Viet Nam, September-December 2021.

The risk of transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from schoolchildren to their household and the protective effects of vaccination in these settings remain poorly understood. We assessed the transmission dynamics of schoolchildren with SARS-CoV-2 within their households and the protective effects of coronavirus disease (COVID-19) vaccination among household members in Viet Nam. We estimated the attack rate, vaccine effectiveness and adjusted risk ratio (aRR) of factors associated with SARS-CoV-2 transmission to household contacts of children confirmed to have COVID-19 who attended three schools in Ha Nam, Phu Tho and Thanh Hoa provinces between September and December 2021 using multivariable regression with household-level random effects. This retrospective cohort study included 157 children infected with SARS-CoV-2 and their 540 household contacts. The attack rate among household contacts was 24.6% (133/540). Overall, vaccine effectiveness among household contacts was 39% (95% confidence interval [CI]: -1 to -63), higher among males than females and higher in adults aged >40 years. COVID-19 transmission was greater among female household contacts compared with males (aRR: 1.35, 95% CI: 0.94 to 1.95), although not statistically significant, and highest among those aged 19-39 years (aRR: 2.51, 95% CI: 1.50 to 4.21). Fully vaccinated household contacts had significantly lower infection risk (aRR: 0.46, 95% CI: 0.26 to 0.84). We found substantial onward transmission of SARS-CoV-2 from schoolchildren to household members, and older people were more likely to be protected by vaccination. We recommend that schoolchildren and all household members living with schoolchildren receive at least two doses of a COVID-19 vaccine. Recognizing the role of schoolchildren in the onward transmission of COVID-19 is an important lesson learned by Viet Nam that can help not only in managing other outbreaks but also in protecting schoolchildren by predicting the progress of the outbreak and preparing for a timely response.

Epidemiological Characteristics and Spatiotemporal Clustering of Pulmonary Tuberculosis Among Students in Southwest China From 2016 to 2022: Analysis of Population-Based Surveillance Data.

Pulmonary tuberculosis (PTB), as a respiratory infectious disease, poses significant risks of covert transmission and dissemination. The high aggregation and close contact among students in Chinese schools exacerbate the transmission risk of PTB outbreaks. This study investigated the epidemiological characteristics, geographic distribution, and spatiotemporal evolution of student PTB in Chongqing, Southwest China, aiming to delineate the incidence risks and clustering patterns of PTB among students. PTB case data from students monitored and reported in the Tuberculosis Information Management System within the China Information System for Disease Control and Prevention were used for this study. Descriptive analyses were conducted to characterize the epidemiological features of student PTB. Spatial trend surface analysis, global and local spatial autocorrelation analyses, and disease rate mapping were performed using ArcGIS 10.3. SaTScan 9.6 software was used to identify spatiotemporal clusters of PTB cases. From 2016 to 2022, a total of 9920 student TB cases were reported in Chongqing, Southwest China, with an average incidence rate of 24.89/100,000. The incidence of student TB showed an initial increase followed by a decline, yet it remained relatively high. High school students (age: 13-18 years; 6649/9920, 67.03%) and college students (age: ≥19 years; 2921/9920, 29.45%) accounted for the majority of student PTB cases. Patient identification primarily relied on passive detection, with a high proportion of delayed diagnosis and positive etiological results. COVID-19 prevention measures have had some impact on reducing incidence levels, but the primary factor appears to be the implementation of screening measures, which facilitated earlier case detection. Global spatial autocorrelation analysis indicated Moran I values of >0 for all years except 2018, ranging from 0.1908 to 0.4645 (all P values were <.05), suggesting strong positive spatial clustering of student PTB cases across Chongqing. Local spatial autocorrelation identified 7 high-high clusters, 13 low-low clusters, 5 high-low clusters, and 4 low-high clusters. High-high clusters were predominantly located in the southeast and northeast parts of Chongqing, consistent with spatial trend surface analysis and spatiotemporal clustering results. Spatiotemporal scan analysis revealed 4 statistically significant spatiotemporal clusters, with the most likely cluster in the southeast (relative risk [RR]=2.87, log likelihood ratio [LLR]=574.29, P<.001) and a secondary cluster in the northeast (RR=1.99, LLR=234.67, P<.001), indicating higher reported student TB cases and elevated risks of epidemic spread within these regions. Future efforts should comprehensively enhance prevention and control measures in high-risk areas of PTB in Chongqing to mitigate the incidence risk among students. Additionally, implementing proactive screening strategies and enhancing screening measures are crucial for early identification of student patients to prevent PTB outbreaks in schools.

Managing the largest school-based COVID-19 outbreak: insights and mitigation strategies

The COVID-19 pandemic, caused by SARS-CoV-2, has significantly impacted educational environments due to their role in community transmission. Early reports indicated low transmission rates in schools, but subsequent studies showed variability, including significant outbreaks like the one in Israel. This study investigates a large COVID-19 outbreak in a boarding school in Brazil, analyzing transmission dynamics and the effectiveness of control measures such as mass testing and isolation. A total of 291 individuals from the school community were tested, revealing an overall infection rate of 64.6%. Initial cases were identified through antigen testing, followed by extensive RT-qPCR testing. Mass testing and timely isolation of infected individuals significantly reduced transmission rates. Whole-genome sequencing was performed on seven positive samples, and environmental contamination was confirmed, with 11 of 35 surface samples testing positive for SARS-CoV-2. The outbreak was controlled within 30 days through rigorous testing, isolation, and environmental disinfection. The study emphasizes the importance of mass testing, including asymptomatic individuals, and highlights the role of environmental contamination in transmission. The findings contribute to understanding COVID-19 outbreaks in educational settings and provide practical insights into managing future outbreaks through comprehensive testing and control strategies. These results may guide policymakers and public health officials in improving pandemic response measures in similar environments.

AN ACUTE GASTROENTERITIS OUTBREAK IN A KINDERGARTEN

Objective: To detect the etiological cause of an acute gastroenteritis outbreak at St. Anna kindergarten in the village of Resilovo, region Kyustendil. Materials and Methods: A total of 22 faecal specimens from children (n = 18) and staff (n = 4) were tested. Multiplex RT-PCR with specific primer pairs detecting the most common viral causes of gastroenteritis (noroviruses, rotaviruses, sapoviruses, intestinal adenoviruses and intestinal astroviruses) was applied to detect the viral causative agent. Noroviruses were detected and sequenced and subsequent phylogenetic analysis was carried out. Results: Genogroup II noroviruses were detected in five samples from children and one sample from staff (6/22) or in 27.3% of the specimens. According to WHO criteria, this proves that noroviruses have caused the epidemic outbreak. Detected noroviruses were subjected to sequencing and subsequent phylogenetic analysis, with data identifying genotype 17 (GII.17) as the causative agent. Conclusion: Norovirus genotype 17 (GII.17) was first detected in Bulgaria in 2015 as the causative agent of an outbreak in a secondary school in the town of Pravets. In 2016, the circulation of this genotype was again established in sporadic cases, and in 2022 it was found to be the cause of the epidemic gastroenteritis outbreak in a kindergarten in the village of Resilovo. To protect public health, continuous monitoring and targeted search for viral intestinal agents is essential, regardless of the transient and usually mild course of the disease.

Risk Factors for Norovirus Outbreaks in Schools and Kindergartens - Beijing Municipality, China, July 2017-June 2022.

Norovirus is the leading cause of global acute gastroenteritis outbreaks. Norovirus outbreaks mainly occur in schools and kindergartens in China, always causing public health issues. Conditional logistic regression method was used to analyze the risk factors for norovirus outbreaks in schools and kindergartens, and found that students vomiting at school or kindergarten, case activity in public areas, and the first case's classroom less than 5 meters from toilets were risk factors. Effective measures to address these factors can help reduce the risk of norovirus outbreaks in schools and kindergartens.

Clinical characteristics of COVID-19 clusters in three schools in Beijing, China: A retrospective study

BackgroundThis retrospective analysis aims to investigate the clinical characteristics of students infected with the SARS-CoV-2 Omicron variant in three Beijing schools. Additionally, we explore the dynamic trends of nucleic acid cycle threshold values (Ct values) and serum antibody titers throughout the disease course. MethodsDemographic, clinical, nucleic acid Ct values, and antibody titer data were collected from cases in a COVID-19 cluster in Beijing Ditan Hospital, Capital Medical University, spanning from September 6 to October 1, 2022. ResultsA total of 107 students infected with Omicron (BA.5.2 and BA.2.76) were identified across three schools. Primary clinical manifestations included fever and upper respiratory symptoms (85/107, 79.4 %), with the majority being classified as mild cases (96/107, 89.7 %). Notably, middle school students in the second school exhibited a higher peak body temperature compared to college students in the first and third schools (39.5 °C vs. 38.4 °C, adjusted P = 0.005; 39.5 °C vs. 38.6 °C, adjusted P = 0.002). Analysis of dynamic changes in Ct values revealed the lowest median Ct value in nasopharyngeal swabs on the third day of illness, reaching 35 after 9–11 days. Oropharyngeal swab nucleic acid median Ct value reached 35 approximately 3–5 days post-onset. Serum antibody detection showed continuous negativity of IgM antibody titers from days 1–10, while IgG antibody titers were positive on the first day and increased rapidly after one week. ConclusionsThe three COVID-19 cluster school outbreaks primarily resulted from Omicron infections, with no severe or fatal cases observed. Clinically, the selection of different types of SARS-CoV-2 nucleic acid swabs for virus detection can be tailored based on the infection's course.

Effect of an enhanced public health contact tracing intervention on the secondary transmission of SARS-CoV-2 in educational settings: The four-way decomposition analysis.

The aim of our study was to test the hypothesis that the community contact tracing strategy of testing contacts in households immediately instead of at the end of quarantine had an impact on the transmission of SARS-CoV-2 in schools in Reggio Emilia Province. We analysed surveillance data on notification of COVID-19 cases in schools between 1 September 2020 and 4 April 2021. We have applied a mediation analysis that allows for interaction between the intervention (before/after period) and the mediator. Median tracing delay decreased from 7 to 3.1 days and the percentage of the known infection source increased from 34-54.8% (incident rate ratio-IRR 1.61 1.40-1.86). Implementation of prompt contact tracing was associated with a 10% decrease in the number of secondary cases (excess relative risk -0.1 95% CI -0.35-0.15). Knowing the source of infection of the index case led to a decrease in secondary transmission (IRR 0.75 95% CI 0.63-0.91) while the decrease in tracing delay was associated with decreased risk of secondary cases (1/IRR 0.97 95% CI 0.94-1.01 per one day of delay). The direct effect of the intervention accounted for the 29% decrease in the number of secondary cases (excess relative risk -0.29 95%-0.61 to 0.03). Prompt contact testing in the community reduces the time of contact tracing and increases the ability to identify the source of infection in school outbreaks. Although there are strong reasons for thinking it is a causal link, observed differences can be also due to differences in the force of infection and to other control measures put in place. This project was carried out with the technical and financial support of the Italian Ministry of Health - CCM 2020 and Ricerca Corrente Annual Program 2023.

Analysis of factors influencing influenza outbreaks in schools in Taicang City, China.

This study aims to analyze the awareness of influenza prevention and control and the behavioral attitudes toward the work among parents and staff in schools in Taicang City and the impact of the vaccination rate among students on influenza outbreaks in schools. The findings can provide references for the development of effective control strategies for the spread of influenza. An anonymous questionnaire survey was conducted on 10,962 students from 20 schools in Taicang City, with class as the unit of analysis. The survey investigated their awareness of influenza prevention and control, their attitudes, and the vaccination coverage. From January to June 2023, a total of 388 influenza outbreaks were reported in schools in Taicang City, involving 77 schools. There were 3,475 confirmed cases, with an average infection rate of 18.53%. In schools where influenza outbreaks had occurred, the incidence rate of those who received influenza vaccine was significantly lower than those who did not, and the vaccine protection rate was 28.22%. The knowledge awareness rates of "the main transmission routes of influenza" and "influenza vaccination can prevent influenza" among parents of students were 95.49 and 93.16%, respectively. The differences between schools involved in the epidemic and non-epidemic were statistically significant (p < 0.05). The correct attitudes of parents toward "actively reporting relevant symptoms to teachers when their children show symptoms" and "avoiding classes with diseases when their children are suspected to be sick" are 98.80 and 96.26%, respectively. The differences between schools with and without epidemic are statistically significant (p < 0.05). The correct attitudes of the class teacher toward "correct management and control of students with flu like symptoms in the class" and "taking correct prevention and control measures in the event of a flu epidemic in the class" were 89.36 and 92.55%, respectively. The differences between epidemic related and non-epidemic related classes were statistically significant (p < 0.05). Enhance the knowledge level of influenza prevention and control among parents of students, Strengthening the training for class teachers in emergency response to infectious diseases and increasing vaccination coverage among students can effectively reduce the incidence of influenza and thereby the occurrence of cluster outbreaks in schools.

Close Contacts among Student Contributing to an Influenza Outbreak in a Semi-boarding Sports School, Chiang Mai Province, Thailand, 2022

On 11 Sep 2022, the Department of Disease Control was notified of a cluster of influenza-like illnesses (ILI) in a semi-boarding sports school in Sanpatong District, Chiang Mai Province, Thailand. The investigation objectives were to confirm the outbreak, describe its epidemiological characteristics, determine risk factors, and recommend control measures. A descriptive study followed by a retrospective cohort study was conducted. A case was defined as a person presenting at the school from 22 Aug to 20 Sep 2022 and having at least two symptoms compatible with ILI. We observed dormitory conditions and students’ activities and collected throat and nasopharyngeal swab specimens. We identified 113 cases, resulting in an attack rate of 26.5% among the screened population and 18.9% among the total population. Almost all cases were students and none developed serious illness. Of 11 specimens tested, nine were positive for influenza A (H3N2). Key risk factors included attending a sports program with adjusted odds ratio (AOR) 2.9, 95% confidence interval (CI) 1.2–6.8, and being in close contact with other cases (AOR 2.3, 95% CI 1.4–3.7). Dormitory overcrowding and close contact during football practice were observed. We recommended regular ILI screening, especially for sports students, and adjusting the dormitory environment to maintain physical distancing.

The role of Xpert MTB/RIF using bronchoalveolar lavage fluid in active screening: insights from a tuberculosis outbreak in a junior school in eastern China.

Tuberculosis (TB) outbreaks in schools present a public health challenge. In order to effectively control the spread of transmission, timely screening, accurate diagnosis and comprehensive epidemiological investigations are essential. In July 2021, a TB outbreak occurred in a junior high school in Y City, Zhejiang Province. Students and faculty were screened for TB by symptom screening, chest radiography, and tuberculin skin test during four rounds of contact screenings. For sputum smear-negative and sputum-scarce patients, bronchoscopy was used to collect BAL samples for Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF). Whole-genome sequencing and bioinformatics analysis were performed on isolates to identify the strains of MTB isolates and predict drug resistance. Between July 2021 and November 2021, a total of 1,257 students and faculty were screened for TB during screenings. A total of 15 students (1.2% of persons screened) aged 15 years were diagnosed with TB. Eighty percent (12/15) of the cases were laboratory-confirmed (10/12 [83%] Xpert MTB/RIF-positive, 2/12 [17%] culture-positive). Most cases (12/15 [80%]) were in students from Class 2. All cases were asymptomatic except for the index case who had symptoms for more than two months. Seven MTB isolates were collected and belonged to lineage 2. Our findings demonstrated the potential of Xpert MTB/RIF using BAL as a screening tool in school TB outbreaks for sputum smear-negative and sputum-sparse suspects, which may not only rapidly improves diagnostic accuracy, but also facilitates epidemiological investigations and homology analysis.

Mitigating the Effects of Fire Outbreaks in Secondary Schools: Strategies for Safeguarding Children at Risk in Tanzania

This paper investigated alternative strategies for safeguarding Tanzania children from school fire disasters. The study was guided by change management theory. Data were collected from four secondary schools from two regions of Tanzania Mainland. A qualitative approach was employed and data were collected through face-to-face interviews, Focused Group Discussions and physical observations. The study involved 101 participants – 61 students, 35 teachers, 3 Heads of Schools and 2 members of the School Board. The study revealed that improved school infrastructures, provision of education to people, building harmony with the community, improved school security, installation of firefighting facilities in schools and identification of sources of fire were the appropriate strategies to manage fire. Combined efforts of the school, community, government and education supporters are of paramount importance for mitigating regular fire outbreaks in secondary schools.

Addressing influenza outbreaks in schools

Abstract The Public Health Unit (PHU) of Albufeira received a communication from the director of the a public school about the occurrence of flu-like symptoms in a large number of students. No response protocols were in place for laboratorial analysis and control measures in this specific situation. The PHU started the necessary procedures to assess the situation and act according to the information obtained. In collaboration with the school, control measures were implemented, a communication network was established, and informative materials, such as leaflets, on preventive measures against the flu were produced and distributed, as well as pediatric masks and hand sanitizer. In partnership with the national network of sentinel flu doctors, five nasopharyngeal samples (three students, one teacher, and one parent) were also collected for laboratory analysis. Epidemiological investigations have identified 4 confirmed cases of influenza B, 17 probable cases, and one case with missing information. The attack rates were found to be high, with 95% of both students and teacher becoming ill. The research findings indicate that a majority of students exhibited symptoms consistent with flu infection, with fever and cough being the most prevalent. In addition, one parent was tested at the school and was also diagnosed with influenza B, indicating the spread of the virus within the community. Gaps were identified in the scope of public health, including the lack of outbreak response protocols and an effective communication network with schools. In order to address these shortcomings, it is intended to develop action protocols for outbreak scenarios in the school environment and establish a closer response between public health services, and the school community. The innovative approach of the Albufeira PHU can serve as a model for other settings and countries. Key messages • Effective collaboration between healthcare providers and schools is essential to mitigate the impact of infectious disease outbreaks in the school environment. • The development and implementation of outbreak response protocols is critical to ensure a coordinated response to infectious disease outbreaks.

Evaluation of the transmissibility of norovirus and the effectiveness of prevention and control measures for schools in Jiangsu Province

Objective This study aims to estimate the transmissibility of norovirus outbreaks in schools by different transmission routes, and to evaluate the effects of isolation, school-closure and disinfection measures under different intervention intensities, finally, scientific prevention and control suggestions are proposed. Method 23 outbreaks of norovirus infectious diarrhea occurring in Jiangsu Province’s school from 2012-2018 were selected and fitted to the model. The data includes various types of school places and pathogen genotype. A ‘SEIAQRW’ model with two transmission routes was established. The transmissibility of each outbreak was assessed using effective reproduction number, the efficacy of different intervention measures and intensities were evaluated by calculating the total attack rate and peak incidence. Results The mean effective reproduction number of noroviruses was estimated to be 8.92 for the human-to-human route of transmission and 2.19 for the water or food-to-human route of transmission. When all symptomatic cases were isolated, the median peak incidence for both transmission routes both being less than 1.8%. There was a smaller reduction in total attack rate compared to peak incidence, the median total attack rate for the two transmission routes decreased by 17.59% and 42.09%, respectively. When the effect of school-closure or disinfection is more than 90%, the total attack rate and peak incidence in the human-to-human route are reduced by more than 90% compared to no intervention, and the peak incidence in the water or food-to-human routes can be reduced to less than 1.4%, but the reduction in the total attack rate is only 50% or so. Conclusion Norovirus outbreaks have a high rate of transmission in schools. In the case of norovirus outbreaks, isolation should be complemented by other interventions, and the implementation of high-intensity school closures or disinfection of the external environment can be effective in reducing the spread of the virus.

SARS-CoV-2 transmission patterns in educational settings during the Alpha wave in Reggio-Emilia, Italy

Different monitoring and control policies have been implemented in schools to minimize the spread of SARS-CoV-2. Transmission in schools has been hard to quantify due to the large proportion of asymptomatic carriers in young individuals. We applied a Bayesian approach to reconstruct the transmission chains between 284 SARS-CoV-2 infections ascertained during 87 school outbreak investigations conducted between March and April 2021 in Italy. Under the policy of reactive quarantines, we found that 42.5% (95%CrI: 29.5–54.3%) of infections among school attendees were caused by school contacts. The mean number of secondary cases infected at school by a positive individual during in-person education was estimated to be 0.33 (95%CrI: 0.23–0.43), with marked heterogeneity across individuals. Specifically, we estimated that only 26.0% (95%CrI: 17.6–34.1%) of students and school personnel who tested positive during in-person education caused at least one secondary infection at school. Positive individuals who attended school for at least 6 days before being isolated or quarantined infected on average 0.49 (95%CrI: 0.14–0.83) secondary cases. Our findings provide quantitative insights on the contribution of school transmission to the spread of SARS-CoV-2 in young individuals. Identifying positive cases within 5 days after exposure to their infector could reduce onward transmission at school by at least 30%.

Reconstruction of SARS-CoV-2 outbreaks in a primary school using epidemiological and genomic data

Mathematical modelling studies have shown that repetitive screening can be used to mitigate SARS-CoV-2 transmission in primary schools while keeping schools open. However, not much is known about how transmission progresses within schools and whether there is a risk of importation to households. During the academic year 2020–2021, a prospective surveillance study using repetitive screening was conducted in a primary school and associated households in Liège (Belgium). SARS-CoV-2 screening was performed via throat washing either once or twice a week. We used genomic and epidemiological data to reconstruct the observed school outbreaks using two different models. The outbreaker2 model combines information on the generation time and contact patterns with a model of sequence evolution. For comparison we also used SCOTTI, a phylogenetic model based on the structured coalescent. In addition, we performed a simulation study to investigate how the accuracy of estimated positivity rates in a school depends on the proportion of a school that is sampled in a repetitive screening strategy. We found no difference in SARS-CoV-2 positivity between children and adults and children were not more often asymptomatic compared to adults. Both models for outbreak reconstruction revealed that transmission occurred mainly within the school environment. Uncertainty in outbreak reconstruction was lowest when including genomic as well as epidemiological data. We found that observed weekly positivity rates are a good approximation to the true weekly positivity rate, especially in children, even when only 25% of the school population is sampled. These results indicate that, in addition to reducing infections as shown in modelling studies, repetitive screening in school settings can lead to a better understanding of the extent of transmission in schools during a pandemic and importation risk at the community level.

THE DEFENCE MECHANISMS USED BY HYSTERIA MALAY STUDENTS IN KELANTAN TO PROTECT THEMSELVES FROM UNCOMFORTABLE BEHAVIOURS

Malaysians frequently use the term hysteria to describe an illness caused by a subtle disturbance or ghost behaviour. The Malay community considers hysteria to be 'phantom ghost' or 'disturbed’. Such beliefs arose because the Malay community believed that the hysteria that occurred in girls and women was a symptom of ghosts, jinn, and satanic disturbances or anything related to disturbances of subtle and unseen things. The burden of mental illness in Malaysia is high, and it is increasing. Malaysian mental health-related burden comprises up to 37% of total disability. The National Health and Morbidity Survey (NHMS) 2015 revealed a prevalence of 29.2% of Malaysians above 16 years to have mental health problems, with three in ten Malaysians struggling with some form of mental health issues. From the perspective of looking after the future generations of Malaysians, the picture of adolescent mental health is also worrying. The objective of this study was to describe how the Malay students used defence mechanism to protect themselves from unpleasant behaviours. A qualitative approach, psychological tests and triangulation method were used for this study, in which 10 specific hysteria students was selected for in-depth interview. The psychological test were DASS-21 Test and Drawing Test. Snow ball sampling was used to select young girls in high schools who experienced mass hysteria. The results show that the hysteria respondents suffered from trauma, emotional problems, verbal abuse, sexual harassment, and a lacking of their parents’ attention. There are two types of problems: internal and external. The internal problem is their personality. The findings of the study may guide students in Kelantan to get proper treatment from medical professional. If mass hysteria in the Kelantan context is better understood, teachers can be empowered through health education to enable them to identify mass hysteria outbreaks in schools early, manage victims and observers more effectively and refer victims to health workers for treatment.

Epidemiologic characteristics and influencing factors of influenza outbreaks in Guangdong Province, 2015-2022

Objective: To grasp the epidemiological characteristics of influenza outbreaks in Guangdong Province by analyzing the outbreaks of influenza-like cases reported in Guangdong Province from January 2015 to the end of August 2022. Methods: In response to the outbreak of epidemics in Guangdong Province from 2015 to 2022, information on on-site epidemic control was collected, and epidemiological analysis was conducted to describe the characteristics of the epidemics. The factors that influence the intensity and duration of the outbreak were determined through a logistic regression model. Results: A total of 1 901 influenza outbreaks were reported in Guangdong Province, with an overall incidence of 2.05%. Most outbreak reports occurred from November to January of the following year (50.24%, 955/1 901) and from April to June (29.88%, 568/1 901). A total of 59.23% (1 126/1 901) of the outbreaks were reported in the Pearl River Delta region, and primary and secondary schools were the main places where outbreaks occurred (88.01%, 1 673/1 901). Outbreaks with 10-29 cases were the most common (66.18%, 1 258/1 901), and most outbreaks lasted less than seven days (50.93%,906/1 779). The size of the outbreak was related to the nursery school (aOR=0.38, 95%CI:0.15-0.93), the Pearl River Delta region (aOR=0.60, 95%CI:0.44-0.83), the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=3.01, 95%CI:1.84-4.90), the influenza A(H1N1) (aOR=2.02, 95%CI:1.15-3.55) and the influenza B (Yamagata) (aOR=2.94, 95%CI: 1.50-5.76). The duration of outbreaks was related to school closures (aOR=0.65, 95%CI: 0.47-0.89), the Pearl River Delta region (aOR=0.65, 95%CI: 0.50-0.83) and the time interval between the onset of the first case and the time of report (>7 days compared with ≤3 days: aOR=13.33, 95%CI: 8.80-20.19; 4-7 days compared with ≤3 days: aOR=2.56, 95%CI: 1.81-3.61). Conclusions: An influenza outbreak in Guangdong Province exhibits two peaks, one in the winter and spring seasons and the other in the summer. Primary and secondary schools are high-risk areas, and early reporting of outbreaks is critical for controlling influenza outbreaks in schools. Furthermore, comprehensive measures should be taken to prevent the spread of the epidemic.

TO IDENTIFY THE FACTORS OF MALAY STUDENTS INVOLVED IN HYSTERIA BY USING DASS21, DRAWING TEST AND IN-DEPTH INTERVIEW

The prevalence of mental illness is significant and increasing in Malaysia. 37% of all impairments in Malaysia are mental health-related. Hysteria is considered to be a symptom of emotional distress and a mental illness that frequently affects teenage girls. In colleges, it frequently takes place in class. Hysteria frequently begins with one student and quickly expands to up to 20–50 additional students. Spontaneous shouting, writhing, uncontrollable weeping, babbling, and bodily immobility are some of its peculiar symptoms. They became hysterical for a number of reasons. Psychological factors, family background, culture, and religion all had an influence on the mass hysteria incidents that happened in Kelantan schoolchildren because the respondents came from typical, underdeveloped traditional states. A qualitative approach, psychological tests like dass 21, drawing test and triangulation method were used for this study. The hysteria students were selected from secondary school age 13 until 17. The findings of the study may guide health workers in Kelantan to manage victims of mass hysteria appropriately and to diagnose the episodes timely. Mass hysteria in the Kelantan context is better understood, teachers can be empowered through health education to enable them to identify mass hysteria outbreaks in schools early, manage victims and observers more effectively and refer victims to health workers for treatment.