Investigation of a COVID-19 cluster involving vertical transmission in a residential building, Taiwan, 2021.

We investigated a COVID-19 cluster involved seven case-patients lived in a high-rise building in September 2021. We used a simplified tracer-gas experiment and virus sequencing to establish the link between case-patients. Vertical transmission among vertically aligned apartments on different floors in a building was the most likely route of transmission.

Gender differences in risk exposures for acute hepatitis C infection in Taiwan: a nationwide case-control study.

BACKGROUND: In Taiwan, medical providers are required to report all acute hepatitis C (AHC) patients to National Notifiable Disease Surveillance System (NNDSS). Identifying factors associated with AHC may inform the strategies to prevent the spread of hepatitis C virus (HCV). We used the national surveillance data to assess gender difference in risk factors associated with AHC in Taiwan and propose control measures in at-risk groups. METHODS: We conducted a nationwide case-control study using data from NNDSS and AHC case investigation questionnaires, for the period of March 6, 2014-December 31, 2016. Cases were AHC confirmed in NNDSS; controls were reported AHC with negative HCV nucleic acid test and negative serum anti-HCV antibody. We used bivariate analysis to identify characteristics and risk exposures for AHC and conducted gender stratified analyses. RESULTS: We identified 602 AHC cases (66.9% males, median age 48 years) and 90 controls. Older age, male gender (OR: 1.85, 95% CI: 1.18-2.90), history of viral hepatitis (OR: 7.93, 95% CI:1.91-32.88), history of sexually transmitted infections (OR: 21.02, 95% CI: 2.90-152.43), and having healthcare-associated risk exposures (OR: 2.02, 95% CI: 1.25-3.25) were associated with AHC. Stratified analyses showed receiving intravenous infusion, history of hepatitis B, syphilis, and human immunodeficiency virus infection were risk factors for male AHC; receiving hemodialysis was risk factor for females. CONCLUSIONS: Our study demonstrates risk factors for AHC in Taiwan with gender difference. Proper infection control practices in healthcare settings and interventions targeting male patients with HIV and other STIs, remain crucial to prevent individuals from AHC.

Epidemiological investigation of the first locally acquired case of COVID-19 identified by influenza surveillance-Taiwan, February 2020.

BACKGROUND: COVID-19 and influenza have similar clinical presentations that can range from mild to severe disease. The World Health Organization recommends that countries use existing influenza surveillance to monitor COVID-19 transmission in communities. We aim to describe the surveillance and investigation of COVID-19 at the early stage of the pandemic in Taiwan. METHODS: In February 2020, the Taiwan Centers for Disease Control enhanced COVID-19 surveillance through its existing influenza surveillance. We retrospectively tested patients for SARS-CoV-2 who had symptoms of severe complicated influenza but were negative in influenza testing. We conducted an epidemiological investigation and contact tracing for the index patient and secondary cases to prevent virus transmission. RESULTS: We identified the first COVID-19 patient on February 15 through enhanced COVID-19 surveillance. He had no history of traveling abroad and an unclear history of contact with COVID-19 cases. He presented with influenza-like illness on January 27 and was hospitalized from February 3 to 15. We identified 39 close contacts of the index patient, including 11 family members and 28 healthcare workers. In total, four close family contacts of the index patient tested positive for SARS-CoV-2. An additional 84 close contacts of the four secondary cases were identified and traced; none was diagnosed with COVID-19. CONCLUSIONS: We recommend enhancing COVID-19 surveillance by testing patients with influenza-like illness. To prevent the spread of COVID-19, we recommend using appropriate personal protective equipment when in close contact with patients who present with influenza-like illness or when caring for patients with pneumonia of unknown etiology.

Probable Aerosol Transmission of SARS-CoV-2 through Floors and Walls of Quarantine Hotel, Taiwan, 2021.

We investigated a cluster of SARS-CoV-2 infections in a quarantine hotel in Taiwan in December 2021. The cluster involved 3 case patients who lived in nonadjacent rooms on different floors. They had no direct contact during their stay. By direct exploration of the space above the room ceilings, we found residual tunnels, wall defects, and truncated pipes between their rooms. We conducted a simplified tracer-gas experiment to assess the interconnection between rooms. Aerosol transmission through structural defects in floors and walls in this poorly ventilated hotel was the most likely route of virus transmission. This event demonstrates the high transmissibility of Omicron variants, even across rooms and floors, through structural defects. Our findings emphasize the importance of ventilation and integrity of building structure in quarantine facilities.

Inhaled Zanamivir vs Oral Oseltamivir to Prevent Influenza-related Hospitalization or Death: A Nationwide Population-based Quasi-experimental Study.

BACKGROUND: Meta-analyses of individual patient data from randomized, controlled trials show that early oseltamivir treatment for influenza cut the risk of pneumonia and hospitalization by 44% and 63%, respectively. However, data on the effectiveness of inhaled zanamivir in preventing hospitalization and death are lacking. METHODS: This nationwide, population-based, cohort study included all outpatients treated with inhaled zanamivir or oral oseltamivir within 48 hours after a clinical diagnosis of influenza before and after the rollout of inhaled zanamivir as the first-line antiviral in Taiwan. The main outcome was influenza-related hospitalization or death within 14 days. Those who developed the outcome within 2 days were excluded from analyses. Propensity score stratification was used to control confounding from covariates. RESULTS: A total of 865 032 eligible influenza outpatients were included in the analysis. The risk of developing the main outcome (adjusted hazard ratio [aHR], 1.01; 95% confidence interval [CI], .96 to 1.06) did not differ between the inhaled zanamivir group (n = 595 897, 68.9%, the reference) and the oral oseltamivir group (n = 269 135, 31.1%). Prespecified analysis on high-risk subgroups further showed that inhaled zanamivir is not inferior to oral oseltamivir in either patients aged ≥65 years (aHR, 1.14; 95% CI: 1.05 to 1.25) or patients with chronic lung diseases (aHR, 1.23; 95% CI: 1.08 to 1.41). CONCLUSIONS: Inhaled zanamivir is not inferior to oral oseltamivir as outpatient treatment in preventing influenza-related hospitalization or death for patients whose conditions do not require hospitalization within 2 days.

Hepatitis C outbreak in a respiratory care ward associated with frequent injections: Taiwan, 2017.

BACKGROUND: Healthcare-associated outbreaks of hepatitis C virus (HCV) infection pose serious risks of harm to patients. During May-July 2017, the Taiwan Centers for Disease Control were notified of four patients with acute HCV infection in a respiratory care ward (RCW). To prevent further infection, an investigation was conducted to identify the transmission route and risk factors for infection. METHODS: We tested patients and staff members of the RCW for HCV, reviewed medical records, observed infection control practices on-site, and undertook a case-control study. We defined cases as individuals who had stayed in the RCW 2 weeks to 6 months prior to the laboratory diagnosis date of the first case and were infected with HCV after admission. Patients who were hospitalized during the same period but whose HCV tests were negative were selected as controls. We used Mann-Whitney U test to compare the frequency of injections among cases and controls. RESULTS: Of 19 staff and 29 patients, we identified four case-patients and one patient with chronic hepatitis C whose HCV RNA similarity was >98%. Compared to the 12 controls, the case-patients received more injections per day (4.4 vs. 0.1; p = 0.01). The RCW lacked designated areas and standardized workflows for injection preparation. Disinfection of the environment and equipment was inadequate, which could possibly lead to blood contamination of the environment and parenteral medications. CONCLUSION: HCV infection was associated with frequent injections and infection control lapses. Healthcare workers should follow safe injection practices and reduce injection frequency to prevent HCV transmission.

Correlation between Negative Rapid Influenza Diagnostic Test and Severe Disease in Hospitalized Adults with Laboratory-Confirmed Influenza Virus Infection.

False-negative rapid influenza diagnostic test (RIDT) results could mislead physicians to exclude an influenza diagnosis. We sought to evaluate the association between negative RIDT and intensive care unit (ICU) admission. We reviewed data from hospitalized adults with laboratory-confirmed influenza virus infections in a tertiary referral hospital in Taiwan from July 2009 to February 2011. The diagnosis was documented by real-time PCR or virus culture. Of 134 hospitalized adults infected with influenza virus, 38 (28%) were admitted to the ICU. Compared with RIDT-positive patients, the percentage of ICU admission was significantly higher among RIDT-negative patients (46% versus 13%, P < 0.001). The RIDT-negative patients had higher percentages of lower respiratory symptoms and more chest radiograph infiltrates. The time interval between the RIDT and antiviral treatment was longer in RIDT-negative than RIDT-positive patients (1.94 days versus 0.03 days, P < 0.001). Among patients presenting with mild illness, only a negative RIDT and delayed antiviral treatment were associated with ICU admission after adjusting for potential confounding factors. To conclude, patients with a negative RIDT were more likely to have severe disease and a delay in initiating antiviral treatment. Our findings should help improve treatment outcomes of hospitalized patients with influenza infection.

Investigation of a salmonellosis outbreak linked to French toast sandwich with the use of surveillance camera, Taiwan, 2018.

Salmonella is a leading cause of foodborne outbreaks in Taiwan. On 27 April 2018, a salmonellosis outbreak among customers of a restaurant was reported to the Taiwan CDC. We investigated the outbreak to identify infection sources and prevent further transmission. We interviewed ill customers and their dining companions. We conducted a case-control study to identify foods associated with the illness. Case-patients were those who had diarrhoea within 72 h after eating at the restaurant during 16-27 April 2018. Specimens, food samples and environmental samples were collected and tested for enteric pathogens. Salmonella isolates were analysed with pulse-field gel electrophoresis and whole-genome sequencing. We inspected the restaurant sanitation and reviewed kitchen surveillance camera recordings. We identified 47 case-patients, including one decedent. Compared with 44 controls, case-patients were more likely to have had a French toast sandwich (OR: 102.4; 95% CI: 18.7-952.3). Salmonella Enteritidis isolates from 16 case-patients shared an indistinguishable genotype. Camera recordings revealed eggshell contamination, long holding time at room temperature and use of leftovers during implicated food preparation. Recommendations for restaurant egg-containing food preparation are to use pasteurised egg products and ensure a high enough cooking temperature and long enough cooking time to prevent Salmonella contamination.

Clinical and epidemiological characteristics of imported dengue fever among inbound passengers: Infrared thermometer-based active surveillance at an international airport.

BACKGROUND: Dengue fever is endemic in tropical and subtropical areas, especially Southeast Asia. International air travel facilitates the spread of dengue across and within borders. To date, no predictive factors have been established for assessing risk of dengue among febrile travelers. METHODS: Since 2006, Taiwan has operated a program of infrared thermometer-based non-contact active surveillance at Taoyuan International Airport (TPE). All inbound passengers from dengue-endemic countries who are febrile (tympanic temperature ≥38°C) undergo routine laboratory testing for dengue. We analyzed clinical and epidemiological characteristics of all tested passengers entering Taiwan via TPE in 2011 to identify the predictive factors of dengue infection. RESULTS: In 2011, of the 3,719 febrile passengers from dengue-endemic countries, 74 (2.0%) had laboratory-confirmed dengue infection. Multivariable logistic regression analysis revealed that those who were aged ≥60 years (adjusted odds ratio [aOR], 8.7; 95% confidence interval [CI], 2.6-29.6) and had self-reported fever (aOR, 2.5; 95% CI, 1.5-4.1), skin rashes (aOR, 11.0; 95% CI, 3.4-35.1), or a tympanic temperature ≥39°C (aOR, 2.9; 95% CI, 1.7-4.9) were significantly more likely to have dengue (all p values < 0.05). Compared with travelers who stayed in dengue-endemic countries for ≤7 days, those who traveled 8-14, 15-21, 22-28, and ≥29 days were also more likely to be infected (aORs of 10.2, 14.9, 39.0 and 12.0, respectively). CONCLUSION: These clinical and epidemiological features can facilitate timely recognition and diagnosis of imported dengue in febrile inbound passengers and therefore help prevent domestic transmission of dengue virus.

Workplace Secondhand Tobacco Smoke Exposure Among U.S. Nonsmoking Workers, 2015.

Secondhand tobacco smoke (SHS) exposure contributes to ill health and disease, including heart disease, lung cancer, and stroke (1). Although cigarette smoking has declined among U.S. workers, workplace exposure to SHS remains high, particularly among workers in certain industries, such as construction (2,3). Implementation of smoke-free laws has proven to be beneficial in reducing SHS exposure in general (1). CDC analyzed data from the 2015 National Health Interview Survey (NHIS) Occupational Health Supplement to assess the prevalence of self-reported workplace SHS exposure among nonsmoking workers by smoke-free policy status in the workers' states of residence and in detailed industry categories and subcategories. In 2015, 19.9% of nonsmoking workers reported any exposure to SHS at work during the 12 months preceding the interview, and 10.1% reported frequent exposure (twice a week or more). Nonsmoking workers who resided in states with comprehensive smoke-free laws in all three categories of venues (private worksites, bars, and restaurants) were least likely to report frequent exposure to workplace SHS. Nonsmoking workers employed in the commercial and industrial machinery and equipment repair and maintenance industry reported the highest prevalences of any workplace SHS exposure (65.1%), whereas the construction industry had the highest reported number of exposed workers (2.9 million); these industry categories/subcategories include outdoor workplaces and other settings that are unlikely to be protected by smoke-free laws. Identifying specific at-risk workplaces and implementing targeted intervention strategies could help reduce SHS exposure at work and protect workers' health.

Comparative epidemiology of influenza B by lineage in intensive care unit-admitted patients with complications: A nationwide study in Taiwan, 2013-2017.

BACKGROUND: We describe the relative proportions and epidemiological features of influenza B/Victoria and B/Yamagata, using data from nationwide surveillance systems. METHODS: We collected respiratory samples from outpatients with influenza-like illness (ILI) and intensive care unit (ICU)-admitted patients with complications (pulmonary or neurological complications, myocarditis/pericarditis or invasive bacterial infection) for virus isolation and lineage typing. Demographics, epidemiological features, and vaccination history from ICU-admitted patients with complications were analyzed. RESULTS: From July 2013-June 2017, 21% of 11517 influenza isolates were influenza B. B/Victoria was the predominant circulating strain in 2013-2014, accounted for 56% of all influenza B positive samples and B/Yamagata was predominant in 2014-2017 (82%, 69%, and 85%, respectively). Among all typed viruses, the proportion of B/Yamagata was higher among specimens from ICU-admitted patients with complications (77%, 154/199) than from ILI outpatients (66%, 276/418, p<0.005). Compared to B/Victoria, B/Yamagata infected ICU-admitted patients with complications were older, median age (71 vs. 59 years, p<0.05), had longer durations of hospitalization (15 vs. 7.5 days, p<0.05) and ICU stays (8.5 vs. 5.5 days, p<0.05). CONCLUSIONS: Two lineages of influenza B viruses co-circulate annually in Taiwan. Among ICU-admitted patients with complications, B/Yamagata causes more severe illness than B/Victoria.

Health Insurance Coverage Among U.S. Workers: Differences by Work Arrangements in 2010 and 2015.

INTRODUCTION: For most Americans, health insurance is obtained through employers. Health insurance coverage can lead to better health outcomes, yet disparities in coverage exist among workers with different sociodemographic and job characteristics. This study compared uninsured rates among workers with different work arrangements. METHODS: Data from the 2010 and 2015 National Health Interview Survey-Occupational Health Supplements were used to capture a representative sample of the U.S. civilian, non-institutionalized population. Associations between work arrangement and lack of health insurance were analyzed, adjusting for covariates. Analyses were performed during 2016-2018. RESULTS: The percentage of workers aged 18-64years without health insurance coverage decreased significantly by 6.8% among workers in all work arrangement categories between 2010 and 2015. However, workers in nonstandard work arrangements were still more likely than standard workers to have no health insurance coverage. In 2015, for workers to have no health insurance the ORs were 4.92 (95% CI=3.91, 6.17) in independent, 2.87 (95% CI=2.00, 4.12) in temporary or contract, and 2.79 (95% CI=0.34, 0.41) in other work arrangements. Standard full-time workers in small establishments and standard part-time workers were also more likely to have no health insurance coverage (OR=2.74, 95% CI=2.27, 3.31, and OR=1.65, 95% CI=1.25, 2.18, respectively). CONCLUSIONS: Important disparities in health insurance coverage among workers with different work arrangements existed in 2010 and persisted in 2015. Further research is needed to monitor coverage trends among workers.

Case Investigations of Infectious Diseases Occurring in Workplaces, United States, 2006-2015.

Workers in specific settings and activities are at increased risk for certain infectious diseases. When an infectious disease case occurs in a worker, investigators need to understand the mechanisms of disease propagation in the workplace. Few publications have explored these factors in the United States; a literature search yielded 66 investigations of infectious disease occurring in US workplaces during 2006-2015. Reported cases appear to be concentrated in specific industries and occupations, especially the healthcare industry, laboratory workers, animal workers, and public service workers. A hierarchy-of-controls approach can help determine how to implement effective preventive measures in workplaces. Consideration of occupational risk factors and control of occupational exposures will help prevent disease transmission in the workplace and protect workers' health.

Seasonal influenza prevention and control in Taiwan-Strategies revisited.

Influenza remains a serious public health threat in Taiwan. During 2017-18, Taiwan experienced two seasonal influenza epidemics caused by A/H3N2 and B, respectively. In addition to national influenza vaccination campaign, Taiwan Centers for Diseases Control and Infectious Disease Control Advisory Committee has multi-faceted strategies for seasonal influenza prevention and control to mitigate the risk of disease transmission among vulnerable groups and decrease influenza-related morbidity and mortality. In this article, we reviewed the key elements of the prevention and control strategies-enhanced influenza surveillance, antiviral drugs stockpile and management, critical care and medical resources reallocation, public risk communication and infection control measures. Given the complexity and challenging nature of controlling seasonal influenza epidemics, collaboration between health professionals is crucial to optimize the health of Taiwanese people.

Occupational coccidioidomycosis surveillance and recent outbreaks in California.

Workers in Coccidioides-endemic areas performing soil-disturbing work or exposed to windy and dusty conditions are at increased risk for coccidioidomycosis. Four occupational coccidioidomycosis outbreaks from 2007 to 2014 in California are described, involving construction workers in a number of excavation projects and an outdoor filming event involving cast and crew. These outbreaks highlight the importance of identifying industries and occupations at high risk for coccidioidomycosis, conducting targeted occupational health surveillance to assess the burden of illness, developing and implementing prevention strategies, and setting research priorities.

Measles Outbreak at a Privately Operated Detention Facility: Arizona, 2016.

BACKGROUND: We describe a measles outbreak and control measures implemented at a privately operated detention facility housing US Immigration and Customs Enforcement detainees in 2016. METHODS: Case-patients reported fever and rash and were either laboratory-confirmed or had an epidemiological link to a laboratory-confirmed case-patient. Immunoglobulin G (IgG) avidity and plaque reduction neutralization tests distinguished between primary acute and reinfection case-patients. Measles-specific IgG was measured to assess detainee immunity levels. We compared attack rates (ARs) among detainees and staff, between IgG-negative and IgG-positive detainees, and by detainee housing units and sexes. RESULTS: We identified 32 measles case-patients (23 detainees, 9 staff); rash onsets were during 6 May-26 June 2016. High IgG avidity and neutralizing-antibody titers >40000 to measles (indicating reinfection) were identified in 18 (95%) and 15 (84%) of 19 tested case-patients, respectively. Among 205 unit A detainees tested for presumptive immunity, 186 (91%) had detectable IgG. Overall, the AR was 1.65%. ARs were significantly higher among detainees in unit A (7.05%) compared with units B-F (0.59%), and among male (2.33%) compared with female detainees (0.38%); however, ARs were not significantly different between detainees and staff or between IgG-negative and IgG-positive detainees. Control measures included the vaccination of 1424 of 1425 detainees and 190 of 510 staff, immunity verification for 445 staff, case-patient isolation, and quarantine of affected units. CONCLUSIONS: Although ARs were low, measles outbreaks can occur in intense-exposure settings, despite a high population immunity, underscoring the importance of high vaccination coverage and containment in limiting measles transmission.

Influenza A(H3N2) virus variants and patient characteristics during a summer influenza epidemic in Taiwan, 2017.

We report a summer influenza epidemic caused by co-circulation of multiple influenza A(H3N2) variants in clade 3C.2a. Compared with other clades, a putative clade 3C.2a.3a was more commonly isolated from severely ill patients; 3C.2a.4 was more commonly isolated in outbreak cases. Time from vaccination to illness onset was significantly shorter in severely ill patients infected with clade 3C.2a.3; characteristics and outcomes of patients infected with different clades were similar. No resistance to antiviral medications was found.

Occupational Animal Exposure Among Persons with Campylobacteriosis and Cryptosporidiosis - Nebraska, 2005-2015.

Campylobacter and Cryptosporidium are two common causes of gastroenteritis in the United States. National incidence rates measured for these pathogens in 2015 were 17.7 and 3.0 per 100,000 population, respectively; Nebraska was among the states with the highest incidence for both campylobacteriosis (26.6) and cryptosporidiosis (≥6.01) (1). Although campylobacteriosis and cryptosporidiosis are primarily transmitted via consumption of contaminated food or water, they can also be acquired through contact with live animals or animal products, including through occupational exposure (2). This exposure route is of particular interest in Nebraska, where animal agriculture and associated industries are an important part of the state's economy. To estimate the percentage of disease that might be related to occupational animal exposure in Nebraska, the Nebraska Department of Health and Human Services (NDHHS) and CDC reviewed deidentified investigation reports from 2005 to 2015 of cases of campylobacteriosis and cryptosporidiosis among Nebraska residents aged ≥14 years. Case investigation notes were searched for evidence of occupational animal exposures, which were classified into discrete categories based on industry, animal/meat, and specific work activity/exposure. Occupational animal exposure was identified in 16.6% of 3,352 campylobacteriosis and 8.7% of 1,070 cryptosporidiosis cases, among which animal production (e.g., farming or ranching) was the most commonly mentioned industry type (68.2% and 78.5%, respectively), followed by employment in animal slaughter and processing facilities (16.3% and 5.4%, respectively). Among animal/meat occupational exposures, cattle/beef was most commonly mentioned, with exposure to feedlots (concentrated animal feeding operations in which animals are fed on stored feeds) reported in 29.9% of campylobacteriosis and 7.9% of cryptosporidiosis cases. Close contact with animals and manure in feedlots and other farm settings might place workers in these areas at increased risk for infection. It is important to educate workers with occupational animal exposure about the symptoms of enteric diseases and prevention measures. Targeting prevention strategies to high-risk workplaces and activities could help reduce disease.