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.

Nosocomial neonatal legionellosis associated with water in infant formula, Taiwan.

We report 2 cases of neonatal Legionella infection associated with aspiration of contaminated water used in hospitals to make infant formula. The molecular profiles of Legionella strains isolated from samples from the infants and from water dispensers were indistinguishable. Our report highlights the need to consider nosocomial legionellosis among neonates who have respiratory symptoms.

Infrequent cross-transmission of Shigella flexneri 2a strains among villages of a mountainous township in Taiwan with endemic shigellosis.

BACKGROUND: Shigellosis is rare in Taiwan, with an average annual incidence rate of 1.68 cases per 100,000 persons in 2000-2007. However, the incidence rate for a mountainous township in eastern Taiwan, Zhuoxi, is 60.2 times the average rate for the entire country. Traveling between Zhuoxi's 6 villages (V1-V6) is inconvenient. Disease transmission among the villages/tribes with endemic shigellosis was investigated in this study. METHODS: Demographic data were collected in 2000-2010 for epidemiological investigation. Thirty-eight Shigella flexneri 2a isolates were subjected to pulsed-field gel electrophoresis (PFGE) genotyping and antimicrobial susceptibility testing (AST). RESULTS: Fifty-five shigellosis cases were identified in 2000-2007, of which 38 were caused by S. flexneri 2a from 2000-2007, 16 cases were caused by S. sonnei from 2000-2003, and 1 case was caused by S. flexneri 3b in 2006. S. flexneri 2a caused infections in 4 of the 6 villages of Zhuoxi Township, showing the highest prevalence in villages V2 and V5. PFGE genotyping categorized the 38 S. flexneri 2a isolates into 2 distinct clusters (clones), 1 and 2. AST results indicated that most isolates in cluster 1 were resistant to ampicillin, chloramphenicol, streptomycin, sulfamethoxazole and trimethoprim-sulfamethoxazole (ACSSuX); all isolates in cluster 2 were resistant to ACSSuX and tetracycline. Genotypes were primarily unique to different villages or tribes. Tribe V2-1 showed the highest endemic rates. Eighteen isolates recovered from V2-1 tribe members fell into 6 genotypes, where 5 were the same clone (cluster 1). An outbreak (OB2) in 2004 in village V2 was caused by different clonal strains; cases in tribe V2-1 were caused by 2 strains of clone 1, and those in tribe V2-2 were infected by a strain of clone 2. CONCLUSIONS: From 2000-2007, 2 S. flexneri 2a clones circulated among 4 villages/tribes in the eastern mountainous township of Zhuoxi. Genotyping data showed restricted disease transmission between the villages and tribes, which may be associated with difficulties in traveling between villages and limited contact between different ethnic aborigines. Transmission of shigellosis in this township likely occurred via person-to-person contact. The endemic disease was controlled by successful public health intervention.

An outbreak of human metapneumovirus infection in hospitalized psychiatric adult patients in Taiwan.

Human metapneumovirus (hMPV) is a paramyxovirus that is associated with respiratory tract infection (RTI) mostly in children, but these outbreaks have rarely been reported in adults. We encountered an outbreak of this disease involving 10 adults in a psychiatric ward in eastern Taiwan. The nasopharyngeal swab specimens from 13 patients with symptoms of RTI were obtained and analyzed. The RT-PCR tests were negative to influenza virus A/B, adenovirus, RSV, parainfluenza virus, coronavirus, Nipah virus and Legionella. The antigen tests were negative to Legionella, Chlamydia, and Mycoplasma. Blood culture was negative in all except patient no. 1, who was found positive for coagulase-negative staphylococci. The hMPV was identified in 10 of 13 adults (77%), but negative for the other virus. Cough was present in all (100%), fever in 90%, and X-ray evidence of pneumonia in 7 patients. One patient died of respiratory failure. We report this outbreak in a mental hospital to alert the medical profession that this unusual infection of hMPV can occur as an outbreak in an adult setting and is an occupational hazard for healthcare personnel.

Epidemiology of scrub typhus in eastern Taiwan, 2000-2004.

The epidemiology of scrub typhus in eastern Taiwan was studied by analyzing the data from the CDC Web reporting system. A total of 1,396 cases with 403 confirmed cases were reported in the period of 2000 to 2004. The cases were commonly found in all counties with the highest number in Yuli Township, Hualien County (53 cases) and Taitung City, Taitung County (40 cases). Monthly changes in the number of cases showed epidemic periods in the spring with a peak in May, and again in the fall, with an October-November peak. The occurrence of disease varied with age, gender, and occupation. Our results showed that the infection rates in the elderly (50-69 years old), males (62.8%), and farmers (25.6%) were higher than those in other age groups, females, and other occupations. Five major clinical symptoms, fever, headache, eschar, rash, and lymphadenopathy, were observed in 90.1, 61.9, 23.1, 21.6, and 10.7% of the cases, respectively. Almost 90% (89.3%) of the cases showed 1-3 clinical symptoms and some showed 4-5 symptoms (10%). Only one patient with no symptoms (0.8%) was found. This paper reports the status of scrub typhus in eastern Taiwan, and suggests that a health education program could train individuals to self-recognize the disease symptoms.

Molecular epidemiology of Shigella flexneri in a long-stay psychiatric nursing center during 2001 to 2003.

With six separate wards accommodating more than 1,600 patients, V Nursing Center (VNC) is a long-stay psychiatric nursing center in eastern Taiwan. During 2001 to 2003, 39 shigellosis cases occurred in VNC. Different from the notion that most cases of shigellosis are caused by Shigella sonnei, all except one of these cases were caused by S. flexneri, with the remaining one caused by an S. sonnei isolate. O-antigen serotyping showed that the 38 S. flexneri strains were of either type 1a (n = 20) or 4a (n = 18), two less prevalent serotypes in Taiwan. NotI-based pulsed-field gel electrophoresis analyses performed with 8 type 1a non-VNC strains and 9 type 4a non-VNC strains isolated from 1996 to 2003 for comparison divided the 28 type 1a strains and the 27 type 4a strains into 7 and 10 subtypes, designated subtypes P1A to P1G and subtypes P4A to P4J, respectively. Subtypes P1A and P4A, which appeared in three consecutive years in VNC as well as outside of VNC, are the most prevalent subtypes. Analyses of the relatedness of the VNC strains on the basis of the banding patterns grouped the type 1a and 4a strains into four and five clusters, respectively. All except one of the type 1a strains had 95% similarity, indicating that they had a common parent, whereas the type 4a strains had similarities that ranged from 77 to 93%, suggesting that they were of diverse origins. In two of the outbreaks, less related subtypes of the type 4a strains were found in the same VNC wards in consecutive years, suggesting the possible existence of different subtypes in VNC all the time. Antibiotic susceptibility testing showed that all except one of the S. flexneri strains were sensitive to at least seven antibiotics; the remaining isolate was sensitive to three antibiotics. The data from the latter tests should be helpful for selection of proper treatments for S. flexneri infections in Taiwan.