Rapid Control of a SARS-CoV-2 B.1.617.2 (Delta) Variant COVID-19 Community Outbreak: The Successful Experience in Pingtung County of Taiwan.

The Severe Acute Respiratory Syndrome-associated Coronavirus 2 (SARS-CoV-2) was an outbreak in December, 2019 and rapidly spread to the world. All variants of SARS-CoV-2, including the globally and currently dominant Delta variant (Delta-SARS-CoV-2), caused severe disease and mortality. Among all variants, Delta-SARS-CoV-2 had the highest transmissibility, growth rate, and secondary attack rate than other variants except for the new variant of Omicron that still exists with many unknown effects. In Taiwan, the pandemic Delta-SARS-CoV-2 began in Pingtung from 14 June 2021 and ceased at 11 July 2021. Seventeen patients were infected by Delta-SARS-CoV-2 and 1 person died during the Pingtung outbreak. The Public Health Bureau of Pingtung County Government stopped the Delta-SARS-CoV-2 outbreak within 1 month through measures such as epidemic investigation, rapid gene sequencing, rapidly expanding isolation, expanded screening of the Delta-SARS-CoV-2 antigen for people who lived in regional villages, and indirect intervention, including rapid vaccination, short lockdown period, and travel restrictions. Indirect environmental factors, such as low levels of air pollution, tropic weather in the summer season, and rural areas might have accelerated the ability to control the Delta-SARS-CoV-2 spread. This successful experience might be recommended as a successful formula for the unvaccinated or insufficiently vaccinated regions.

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.

Ice-associated norovirus outbreak predominantly caused by GII.17 in Taiwan, 2015.

BACKGROUND: On 5 March 2015, Taiwan Centers for Disease Control was notified of more than 200 students with gastroenteritis at a senior high school during excursion to Kenting. We conducted an outbreak investigation to identify the causative agent and possible vehicle of the pathogen. METHODS: We conducted a retrospective cohort study by using a structured questionnaire to interview all students for consumed food items during their stay at the resort. Students were defined as a gastroenteritis case while having vomiting or diarrhea after the breakfast on 4 March. We inspected the environment to identify possible contamination route. We collected stool or vomitus samples from ill students, food handlers and environmental specimens for bacterial culture for common enteropathogens, reverse transcription polymerase chain reaction (RT-PCR) for norovirus and enzyme-linked immunosorbent assay (ELISA) for rotavirus. Norovirus PCR-positive products were then sequenced and genotyped. RESULTS: Of 267 students enrolled, 144 (54%) met our case definition. Regression analysis revealed elevated risk associated with iced tea, which was made from tea powder mixed with hot water and self-made ice (risk ratio 1.54, 95% confidence interval 1.22-1.98). Ice used for beverages, water before and after water filter of the ice machine and 16 stool and vomitus samples from ill students were tested positive for norovirus; Multiple genotypes were identified including GI.2, GI.4 and GII.17. GII.17 was the predominant genotype and phylogenetic analyses showed that noroviruses identified in ice, water and human samples were clustered into the same genotypes. Environmental investigation revealed the ice was made by inadequate-filtered and un-boiled water. CONCLUSIONS: We identified the ice made by norovirus-contaminated un-boiled water caused the outbreak and the predominant genotype was GII.17. Adequately filtered or boiled water should be strongly recommended for making ice to avoid possible contamination.

Characteristics and Risk Factors for Fatality in Patients with Dengue Hemorrhagic Fever, Taiwan, 2014.

An unprecedented dengue outbreak involving more than 15,000 infections, including 136 dengue hemorrhagic fever (DHF) cases and 20 fatalities, occurred in Taiwan in 2014. The median age of the DHF cases was 71 years (range: 4-92 years) and most of them (N = 100, 73.5%) had comorbidities, of which the majority were hypertension (56%) and diabetes mellitus (DM; 27%). Only approximately half of the DHF cases (59/136) were classified as severe dengue, based on the 2009 WHO-revised dengue classification. The fatality rate for this DHF outbreak was 14.7%. DM (odds ratio [OR] = 3.60, 95% confidence interval [CI] = 1.22-10.63) and presentation with severe plasma leakage (OR = 6.42, 95% CI = 1.76-23.63) were independent risk factors for fatality.

Public Health Responses to Reemergence of Animal Rabies, Taiwan, July 16-December 28, 2013.

Taiwan had been free of indigenous human and animal rabies case since canine rabies was eliminated in 1961. In July 2013, rabies was confirmed among three wild ferret-badgers, prompting public health response to prevent human rabies cases. This descriptive study reports the immediate response to the reemergence of rabies in Taiwan. Response included enhanced surveillance for human rabies cases by testing stored cerebrospinal fluids (CSF) from patients with encephalitides of unknown cause by RT-PCR, prioritizing vaccine use for postexposure prophylaxis (PEP) during periods of vaccine shortage and subsequent expansion of PEP, surveillance of animal bites using information obtained from vaccine application, roll out of preexposure prophylaxis (PrEP) with vaccine stock restoration, surveillance for adverse events following immunization (AEFI), and ensuring surge capacity to respond to general public inquiries by phone and training for healthcare professionals. Enhanced surveillance for human rabies found no cases after testing 205 stored CSF specimens collected during January 2010-July 2013. During July 16 to December 28, 2013, we received 8,241 rabies PEP application; 6,634 (80.5%) were consistent with recommendations. Among the 6,501 persons who received at least one dose of rabies vaccine postexposure, 4,953 (76.2%) persons who were bitten by dogs; only 59 (0.9%) persons were bitten by ferret-badgers. During the study period, 6,247 persons received preexposure prophylaxis. There were 23 reports of AEFI; but no anaphylaxis, Guillain-Barré syndrome, or acute disseminated encephalomyelitis were found. During the study period, there were 40,312 calls to the Taiwan Centers for Disease Control hotline, of which, 8,692 (22%) were related to rabies. Recent identification of rabies among ferret-badgers in a previously rabies-free country prompted rapid response. To date, no human rabies has been identified. Continued multifaceted surveillance and interministerial collaboration are crucial to achieve the goal of rabies-free status in Taiwan.

First case of neurognathostomiasis in Taiwan--A Thai laborer presenting with eosinophilic meningitis and intracranial hemorrhage.

We report a case of neurognathostomiasis in a Thai laborer for the first time in Taiwan. For patients with eosinophilic meningitis, neurognathostomiasis should be considered when brain image discloses subarachnoid or intracranial hemorrhage and when an appropriate exposure risk is available, especially a history of raw freshwater fish consumption in endemic areas, even a long time ago.

Legionnaires' disease caused by Legionella longbeachae in Taiwan, 2006-2010.

The aim of the present study was to investigate the epidemiology of Legionnaires' disease (LD) caused by Legionella longbeachae in Taiwan during 2006-2010. A total of six cases were identified prospectively, accounting for 1.6% of all laboratory-confirmed LD cases and 4.4% of culture-positive LD cases. All six cases occurred between April and August. The male to female ratio was 0.5. These six LD patients had a higher median age than those with LD due to Legionella pneumophila. Four of the six patients presented with pleural effusion and five survived the infection episode. Only two patients had a potential soil contact history prior to LD onset. The patients resided in divergent geographical areas without a common exposure history. The individual genomic DNA banding patterns of the six L. longbeachae isolates analyzed by pulsed-field gel electrophoresis (PFGE) were unique, supporting the hypothesis that the L. longbeachae infections occurred sporadically.

Community outbreak of adenovirus, Taiwan, 2011.

In 2011, a large community outbreak of human adenovirus (HAdV) in Taiwan was detected by a nationwide surveillance system. The epidemic lasted from week 11 through week 41 of 2011 (March 14-October 16, 2011). Although HAdV-3 was the predominant strain detected (74%), an abrupt increase in the percentage of infections caused by HAdV-7 occurred, from 0.3% in 2008-2010 to 10% in 2011. Clinical information was collected for 202 inpatients infected with HAdV; 31 (15.2%) had severe infection that required intensive care, and 7 of those patients died. HAdV-7 accounted for 10%, 12%, and 41% of infections among outpatients, inpatients with nonsevere infection, and inpatients with severe infection, respectively (p<0.01). The HAdV-7 strain detected in this outbreak is identical to a strain recently reported in the People's Republic of China (HAdV7-HZ/SHX/CHN/2009). Absence of circulating HAdV-7 in previous years and introduction of an emerging strain are 2 factors that caused this outbreak.

Use of a single-tube nested real-time PCR assay to facilitate the early diagnosis of acute Q fever.

We have developed a single-tube nested real-time PCR (STN-RT PCR) assay using the repetitive, transposon-like element IS1111 as the DNA target to facilitate early diagnosis of acute Q fever. The use of our proposed diagnostic procedures, including IgM detection by serology and the STN-RT PCR assay, significantly increased the diagnostic sensitivity for Q fever to 78%, compared to 29% when serology alone was used for subjects providing mainly acute-phase blood samples.

Using the Health Belief Model to understand caregiver factors influencing childhood influenza vaccinations.

OBJECTIVE: This study applied the Health Belief Model to investigate factors in the decision by caregivers to vaccinate their children for influenza. DESIGN: Cross-sectional study. SAMPLE AND MEASUREMENTS: Purposive sampling obtained 2,778 useable responses to surveys of 33 public health centers and 40 medical institutions participating in vaccination programs in southern Taiwan. Data were collected using the Caregiver Demographics and Children's Health History Questionnaire, Children's Influenza Vaccination History Questionnaire, and a Health Belief Model Questionnaire. Multiple logistic regression was used to analyze predictors of influenza vaccinations in children. RESULTS: Predictors of vaccination revealed by logistic regression analysis included age, current employment, and residence of the caregiver as well as chronic disease, hospitalization, and influenza histories of the child. Other predictors revealed by the Health Belief Model were perceived susceptibility of the children to influenza, perceived benefits of vaccinations to children, perceived barriers to vaccinations, and cues to action. Eleven items in the model were also significant predictors of vaccination. CONCLUSIONS: The survey results can be used to develop strategies for increasing influenza vaccination rates.

Serologic assessment of the risk of developing chronic Q fever in cohorts of acutely infected individuals.

OBJECTIVE: The aim of this study was to assess the clinical significance of serological profiles suggestive of chronic Q fever after acute infection. METHODS: A prospective follow-up study consisting of two separate cohorts was conducted to monitor the serological evolution of Q fever. The first cohort comprised subjects with acute Q fever diagnosed in 2004-2007 and the second enrolled subjects whose infection occurred in 2009. The indirect immunofluorescence assay was used for serological monitoring, with serum PCR testing added for subjects whose serological profiles revealed high titers of anti-phase I IgG≥800, titers suggestive of chronic Q fever. RESULTS: In the first cohort of 92 persons, seventeen (18%) subjects had serological profiles suggestive of chronic Q fever (titers of anti-phase I IgG: 1280-5120, median: 1280) after a median follow-up period of 606.5 days. After a further follow-up (median period: 592 days) exclusively for those seventeen subjects, serological resolution with fourfold decrease of titers of anti-phase I IgG was noted in five of them. In the second cohort, only one (4%) of the twenty-eight subjects had high levels of anti-phase I IgG 180 days after acute infection. All the eighteen subjects with high levels of anti-phase I IgG were asymptomatic and had negative serum PCR testing. The different prevalence of subjects with high titers of anti-phase I IgG in the two cohorts was associated with duration of follow-up period (P < .01). CONCLUSIONS: Subjects with high titers of anti-phase I IgG≥800 was not uncommon and might not be detected until more than six months after acute Q fever infection. Asymptomatic subjects with high levels of anti-phase I IgG alone should not be treated as chronic Q fever and might not need continued serological monitoring in the absence of predisposing factors to chronic Q fever.

Predictors and outcomes of respiratory failure among hospitalized pneumonia patients with 2009 H1N1 influenza in Taiwan.

OBJECTIVES: The worldwide outbreak of a pandemic influenza A (H1N1) virus began in April 2009. We characterized the clinical features of the hospitalized pneumonia patients with 2009 H1N1 influenza in Taiwan and elucidated the risk of those patients for developing respiratory failure. METHODS: Severe complicated influenza infection is a notifiable disease in Taiwan and the hospitalized pneumonia patients with 2009 H1N1 influenza were reported accordingly. We reviewed the medical records of the eligible cases by September 8, 2009; development of respiratory failure was the primary endpoint. RESULTS: Of the 96 patients we studied, 22 (23%) developed respiratory failure. Among those, 10 (45%) died and all of the non-respiratory failure patients survived. Age distribution, presence of dyspnea, lymphopenia, leukopenia, PaO(2)/FiO(2) ratio, PaCO(2), SOFA score, infiltration on chest x-ray at admission were different between two groups by univariate analysis. The clinical course was also different, with longer duration from onset of symptoms to use of oseltamivir, longer hospital stay, and more complications during hospitalization in patients with respiratory failure. A multivariate logistic regression showed an association between development of respiratory failure and SOFA score > or = 4 at admission, initial lymphocyte count < or = 800/microL, and the duration from symptom onset to initiation of oseltamivir > 48 h. CONCLUSIONS: Respiratory failure in patients with 2009 H1N1 influenza leads to poor outcomes, including complications and death. Clinicians could apply the three predictors at admission to identify the high-risk pneumonic patients for developing respiratory failure. Further study is needed to validate the findings of this study in other settings.

Risk of recurrent nontyphoid Salmonella bacteremia in HIV-infected patients in the era of highly active antiretroviral therapy and an increasing trend of fluoroquinolone resistance.

BACKGROUND: Risk of recurrent nontyphoid Salmonella (NTS) bacteremia and trends of antimicrobial resistance of NTS remain unknown in human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART). METHODS: Ninety-three patients who received a diagnosis of NTS bacteremia from June 1994 through June 2006 were prospectively followed up. Incidence of recurrent NTS bacteremia was compared between the pre-HAART era (June 1994-March 1997) and the HAART era (April 1997-June 2006). Prevalence of antimicrobial resistance was compared among the NTS isolates obtained in the pre-HAART era, the early HAART era (April 1997-June 2002), and the late HAART era (July 2002-June 2006). RESULTS: Compared with patients enrolled in the pre-HAART era, patients who received HAART had an incidence of recurrent NTS bacteremia that was significantly reduced by 96%; the incidence of recurrent NTS bacteremia was 2.56 cases per 100 person-years in the HAART era, compared with 70.56 cases per 100 person-years in the pre-HAART era (rate ratio, 0.036; 95% confidence interval, 0.012-0.114; P<.001). In the HAART era, the incidence of recurrent NTS bacteremia did not increase among patients receiving fluoroquinolone prophylaxis for 30 days (3.95 cases per 100 person-years), with a rate ratio of 0.43 (95% confidence interval, 0.07-2.58). Although resistance to ampicillin, cotrimoxazole, and chloramphenicol decreased, the proportion of NTS isolates resistant to fluoroquinolones increased from 0% in the pre-HAART era to 6.2% in the early HAART era and 34.2% in the late HAART era (P=.002). CONCLUSIONS: The risk of recurrent NTS bacteremia decreased significantly in the HAART era, although NTS isolates obtained from HIV-infected patients were increasingly resistant to fluoroquinolones.

In vitro activities of various piperacillin and sulbactam combinations against bacterial pathogens isolated from Intensive Care Units in Taiwan: SMART 2004 programme data.

We investigated the in vitro activity of various piperacillin and sulbactam combinations against Gram-negative bacterial isolates from Intensive Care Units (ICUs) in Taiwan. Antimicrobial susceptibility testing of 1030 bacterial isolates recovered from ICUs of nine major teaching hospitals was performed using the agar dilution method. Sulbactam was added to piperacillin either at a fixed sulbactam concentration of 4 mg/L and 8 mg/L or at a piperacillin:sulbactam ratio of 2:1 and 4:1. Piperacillin/sulbactam at a ratio of 2:1 or a fixed 8 mg/L concentration of sulbactam had better activities against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Serratia marcescens than other piperacillin/sulbactam formulations. For Pseudomonas aeruginosa, piperacillin/sulbactam (2:1 or 4:1 ratios) had MIC(90) values (minimum inhibitory concentration for 90% of the organisms) of 64 mg/L (>90% susceptibility) compared with 64 mg/L for cefoperazone/sulbactam (68% susceptibility) and 128 mg/L for piperacillin/tazobactam (82% susceptibility). For Acinetobacter baumannii, both piperacillin/sulbactam (either 2:1 ratio or a fixed 8 mg/L sulbactam) and cefoperazone/sulbactam were the most potent agents. Adding sulbactam to piperacillin resulted in increased susceptibility rates among piperacillin-resistant P. aeruginosa (53-57% in either 2:1 or 4:1 ratios) and A. baumannii (38-46% in either 2:1 ratio or a fixed 8 mg/L concentration of sulbactam) isolates. Results of susceptibility tests with piperacillin/sulbactam are dependent on the method used. Piperacillin/sulbactam combinations possessed better in vitro activities than piperacillin alone or piperacillin/tazobactam against P. aeruginosa and A. baumannii.

Clinical and immunological responses to undiluted and diluted smallpox vaccine with vaccinia virus of Lister strain.

The potential to increase the supply of vaccine by diluting the vaccinia virus of Lister strain to face possible bioterrorism with smallpox was evaluated. Vaccinia-naïve subjects (n=97) were randomized to receive either undiluted or diluted (1:5, 1:10) vaccine, and previously vaccinated subjects (n=122) were randomized to receive either undiluted or diluted (1:10, 1:30) vaccine. Except two subjects who received 1:30 diluted vaccine, the vaccination of all subjects was successful clinically. All subjects had significant vaccinia-specific T cell and antibody responses. The diluted vaccine was not associated with decreased local or systemic reactions, lower T cell responses, or higher antibody titers when compared with undiluted vaccine. Here we show the diluted vaccine of Lister strain can be used in vaccinia-naïve subjects and previously vaccinated subjects if viral titer > or =10(8) and 10(7.5) pfu/mL after dilution, respectively. The reactogenicity of vaccinia virus may not be a dose-dependent response.

Community-acquired anaerobic bacteremia in adults: one-year experience in a medical center.

A prospective observational study was conducted to evaluate the clinical characteristics and outcome of community-acquired anaerobic bacteremia. From June 1 2001 through May 31 2002, 52 patients with community-acquired anaerobic bacteremia were enrolled at the emergency department in a teaching hospital. There were 19 patients (34%) with polymicrobial bacteremia and Escherichia coli was the most common copathogen (n = 6). Of 62 anaerobic isolates, species of the Bacteroides fragilis group were the most common isolates (n = 28, 45%), followed by Clostridium spp. (n = 11, 18%). Among the 52 patients enrolled, up to 27% had underlying malignancy and the gastrointestinal tract accounted for 48% of the sources of infection. Clinical manifestations suggesting anaerobic infections were common and three-quarters (n = 39) of 52 patients received adequate empirical antimicrobial treatment. Documentation of anaerobic bacteremia seldom influenced antimicrobial treatment. The 30-day mortality was 25%. Although univariate analysis revealed that underlying malignancy (p=0.003), leukopenia (p=0.044) and absence of fever (p=0.047) were associated with mortality, only malignancy (p=0.007) was an independent risk factor in the multivariate analysis.

Meningitis due to Histoplasma capsulatum and Mycobacterium tuberculosis in a returned traveler with acquired immunodeficiency syndrome.

Histoplasmosis has rarely been reported in Taiwan, and its clinical manifestations may be similar to those of tuberculosis. With increasing international travel, physicians need to be aware of the possibility of this disease when caring for patients with advanced human immunodeficiency virus (HIV) infection who have traveled to endemic areas. A 55-year-old Chinese male from Burma presented with concurrent histoplasmosis and tuberculous meningitis as the initial opportunistic infection of acquired immunodeficiency syndrome. Fever, altered mentation, pancytopenia, splenomegaly and marked elevations of serum lactate dehydrogenase (3601 U/L) and ferritin (>10(6) ng/mL) were noted. Despite treatment with amphotericin B and antituberculous therapy, the patient died on the 25th day of hospitalization. This case illustrates the complexity and challenges of management of opportunistic infections in travelers returning from Southeast Asia who are in the advanced stage of HIV infection.