INTRODUCTIONThis paper describes the epidemiology and control of a community outbreak of novel influenza A (H1N1-2009) originating from a dance club in Singapore between June and July 2009.

MATERIALS AND METHODSCases of novel influenza A (H1N1-2009) were confirmed using in-house probe-based real-time polymerase chain reaction (PCR). Contact tracing teams from the Singapore Ministry of Health obtained epidemiological information from all cases via telephone.

RESULTSA total of 48 cases were identified in this outbreak, of which 36 (75%) cases were patrons and dance club staff, and 12 (25%) cases were household members and social contacts. Mathematical modelling showed that this outbreak had a reproductive number of 1.9 to 2.1, which was similar to values calculated from outbreaks in naïve populations in other countries.

CONCLUSIONThis transmission risk occurred within an enclosed space with patrons engaged in intimate social activities, suggesting that dance clubs are places conducive for the spread of the virus.

Adolescent ; Adult ; Commerce ; Contact Tracing ; methods ; Dancing ; Disease Outbreaks ; Female ; Humans ; Influenza A Virus, H1N1 Subtype ; isolation & purification ; Influenza, Human ; diagnosis ; epidemiology ; Interviews as Topic ; Male ; Models, Statistical ; Polymerase Chain Reaction ; Singapore ; epidemiology ; Travel ; Young Adult

OBJECTIVETo develop a new transmission tracking analysis technique during incubation period of respiratory infectious diseases, and to discuss its practical value in the field survey of infectious diseases.

METHODSThe classical epidemiological theory was integrated with geographic information system. The transmission tracking analysis technique was established based on the modeling platform ArcGIS Engine Developer Kit 9.3, using the techniques of address matching, shortest path analysis and buffer analysis, and programming by Visual C++. Eight serious sever acute respiratory syndrome (SARS) cases in Shanghai in year 2003 were then chose as prototype to set up the test cases A-H. The electronic map and population density data were separately collected from Institute of Surveying and Mapping in Shanghai and Shanghai statistical yearbook 2003, to calculate and explore the parameters as length of transmission path, area of buffer zone and key departments by single and multi case analysis module.

RESULTSThe single case transmission tracking analysis showed that the length of transmission track of case A was 129.89 km during April 25th to 29th in 2003, including 12 tracing point and 108 intimate contacts, and the total area of buffer zone was 7.11 km(2) including 81 important institutes, naming 72 schools, 6 kindergartens and 3 gerocomiums. The multi-case transmission tracking analysis showed that the 8 cases shared 5 tracks without any temporal communication. However, there was a spatial communication whose length was 1.42 km and area was 0.60 km(2). There were no important institutes found in this communication area.

CONCLUSIONTransmission tracking technique is practicable and efficient to trace the source of infection, analyze the transmission tracks, establish the isolation buffer area and explore the important geographic positions in epidemiological investigation.

Contact Tracing ; methods ; Disease Transmission, Infectious ; statistics & numerical data ; Epidemiological Monitoring ; Geographic Information Systems ; Humans ; Infectious Disease Incubation Period ; Respiratory Tract Infections ; transmission ; Severe Acute Respiratory Syndrome ; transmission ; Software

OBJECTIVETo explore a new method for finding more HIV/AIDS.

METHODSIn September 2009, newly reported HIV-infected individuals from May to August, 2009 in Dehong prefecture were asked to participate in a survey which requested demographic characteristics, history of high-risk behaviors and contact information of individuals with whom they had high risky contacts. People with risky contacts with HIV-infected cases (index cases) were also approached to participate in this survey and HIV testing was provided.

RESULTSA total of 342 HIV-infected individuals were newly reported and served as index cases from May to August, 2009. Among them, 47.1% (161/342) were transmitted by regular sexual partners. Through three-round surveys, 218 contacts were traced and among them, 84.9% (185/218) were traced by regular heterosexual partners. HIV positive rate of the tested was 34.7% (60/173) in the first-round tracing and 12.5% (1/8) in the second one. Among the 560 individuals (index cases and their high-risk contacts), the proportions of having regular heterosexual partners, non-regular and non-commercial sexual partners, commercial sexual heterosexual partners and men having sex men were 87.9% (492/560), 18.9% (106/560), 22.3% (125/560) and 0.3% (1/318), respectively, while the proportion of having never used condoms when having sex with the above four types sexual partners were 73.8% (363/492), 72.6% (77/106), 63.2% (79/125) and 0.0% (0/1), respectively.

CONCLUSIONAs an epidemiological method for HIV/AIDS finding, contact tracing identified a large number of HIV infectors who were traced by newly reported HIV-infected individuals.

Acquired Immunodeficiency Syndrome ; epidemiology ; Adolescent ; Adult ; Child ; Child, Preschool ; China ; epidemiology ; Contact Tracing ; methods ; Female ; HIV Infections ; epidemiology ; Humans ; Infant ; Infant, Newborn ; Male ; Risk Factors ; Surveys and Questionnaires ; Young Adult

Adult ; Antitubercular Agents ; therapeutic use ; Contact Tracing ; Counseling ; Female ; Humans ; Latent Tuberculosis ; drug therapy ; prevention & control ; Male ; Multivariate Analysis ; Odds Ratio ; Pamphlets ; Practice Patterns, Nurses' ; Prospective Studies ; Singapore ; Smoking Cessation ; methods

BACKGROUND: To combat coronavirus disease 2019 (COVID-19), many countries have used contact tracing apps, including Japan's voluntary-use contact-confirming application (COCOA). The current study aimed to identify industry and workplace characteristics associated with the downloading of this COVID-19 contact tracing app. METHODS: This cross-sectional study of full-time workers used an online survey. Multiple logistic regression analysis was used to evaluate the associations of industry and workplace characteristics with contact tracing app use. RESULTS: Of the 27,036 participants, 25.1% had downloaded the COCOA. Workers in the public service (adjusted odds ratio [aOR] = 1.29, 95% confidence interval [CI] 1.14-1.45) and information technology (aOR = 1.38, 95% CI 1.20-1.58) industries were more likely to use the app than were those in the manufacturing industry. In contrast, app usage was less common among workers in the retail and wholesale (aOR = 0.87, 95% CI 0.76-0.99) and food/beverage (aOR = 0.81, 95% CI 0.70-0.94) industries, but further adjustment for company size attenuated these associations. Workers at larger companies were more likely to use the app. Compared with permanent employees, the odds of using the app were higher for managers and civil servants but lower for those who were self-employed. CONCLUSIONS Downloading of COCOA among Japanese workers was insufficient; thus, the mitigating effect of COCOA on the COVID-19 pandemic is considered to be limited. One possible reason for the under-implementation of the contact tracing app in the retail and wholesale and food/beverage industries is small company size, as suggested by the fully adjusted model results. An awareness campaign should be conducted to promote the widespread use of the contact tracing app in these industries.
Adult ; COVID-19/prevention & control* ; Contact Tracing/methods* ; Cross-Sectional Studies ; Female ; Humans ; Industry/classification* ; Japan/epidemiology* ; Male ; Middle Aged ; Mobile Applications/statistics & numerical data* ; SARS-CoV-2 ; Smartphone ; Workplace/statistics & numerical data*

Through literature review and group discussion, Special Expert Group for Control of the Epidemic of Novel Coronavirus Pneumonia of the Chinese Preventive Medicine Association formulated an update on the epidemiological characteristics of novel coronavirus pneumonia (NCP). The initial source of the 2019 novel coronavirus (2019-nCoV) was the Huanan seafood market in Wuhan, Hubei province, China, with pangolins as a potential animal host. Currently the main source of infection is NCP patients, and asymptomatic carriers may also be infectious. The virus is believed transmitted mostly via droplets or contact. People are all generally susceptible to the virus. The average incubation period was 5.2 days, and the basic reproductive number R(0) was 2.2 at the onset of the outbreak. Most NCP patients were clinically mild cases. The case fatality rate was 2.38%, and elderly men with underlying diseases were at a higher risk of death. Strategies for prevention and control of NCP include improving epidemic surveillance, quarantining the source of infection, speeding up the diagnosis of suspected cases, optimizing the management of close contacts, tightening prevention and control of cluster outbreaks and hospital infection, preventing possible rebound of the epidemic after people return to work from the Chinese Spring Festival holiday, and strengthening community prevention and control.
Aged ; Animals ; Asymptomatic Diseases/epidemiology* ; Betacoronavirus ; COVID-19 ; China/epidemiology* ; Contact Tracing ; Coronavirus ; Coronavirus Infections/epidemiology* ; Humans ; Infectious Disease Incubation Period ; Male ; Pandemics ; Pneumonia, Viral/epidemiology* ; Public Health Surveillance/methods* ; Quarantine ; SARS-CoV-2