[Genotyping on one case with Chikungunya infection introduced into Tianjin in China from Myanmar]

Objectives: A clinical case caused by Chikungunya virus (CHIKV) was introduced into Tianjin, China from Myanmar. The current study is aimed to phylogenetically analyzing this imported strain and to reveal the relationship between this virus and other circulating CHIKV strains. Methods: RNA was extracted from serum of the suspected patient presenting with symptoms compatible with CHIKV infections. Real-time reverse transcription PCR (RT-PCR) assay was used for diagnoses of the patient. For phylogenetic analysis, envelope glycoprotein 1 (E1) gene of CHIKV was amplified by two-step RT-PCR and the products were sequenced. Results: The phylogenetic analyses revealed that the imported CHIKV belong to Indian Ocean Lineage (IOL) derived from ECSA genotype and sharing the same cluster with the Aede albopitus-adapted strains that triggered the outbreaks in Pakistan (2016), Italy (2017) and Bangladesh (2017). Conclusion: The imported CHIKV strain has the potential to cause explosive outbreaks in China and this event happened in Tianjin calls for strengthening the monitoring programs on mosquito-borne diseases in China.

[Investigation and analysis on characteristics of a cluster of COVID-19 associated with exposure in a department store in Tianjin]

Objective: To describe the epidemiological characteristics of a cluster of COVID-19 cases reported in Baodi district of Tianjin as of 18 February, 2020, which might be associated with the exposure in a local department store, and provide suggestions for prevention and control strategy development. Methods: The basic characteristics, time and area distributions, clinical manifestations, epidemiological history and transmission mode of the COVID-19 cases associated with the department store exposure were analyzed. Results: A total of 40 COVID-19 cases were associated with the department store exposure, accounting for 75.47% of the total confirmed cases (53 cases) reported in Baodi district. The cases were mainly at the age of 60 years or older (35.00%) and farmers (40.00%). The main clinical manifestations included fever (95.00%), cough (35.00%), and diarrhea (15.00%). The proportion of confirmed severe cases was 32.50%. The incidence curve showed that the incidence peak occurred on 31 January, 2020. Among the 40 cases, 6(15.00%) were department store employees, 19 (47.50%) were customers and 15 (37.50%) were close contacts (secondary cases). The first case occurred on 21 January, 2020, this case was a department store employee who had a purchasing history at whole sale markets in other provinces and cities before the onset, and 3 employees were still on duty after symptom onsets. The median of the incubation period of customer cases was 6 days, and the median of the interval between onset and medical treatment of customer cases was 7 days. Conclusion: This was a cluster epidemic of COVID-19, which might be associated with the exposure in the department store. By now, the current prevention and control measures have achieved satisfied effects.