key: cord-0021259-im1kr7fx
authors: Guo, Qianfang; Zou, Lirong; Yu, Jianxiang; Song, Yingchao; Liang, Lijun; Zhuang, Xue; Song, Tie; Wu, Jie
title: First Human Infection with Avian Influenza H9N2 — Guangdong Province, China, 2020
date: 2020-07-18
journal: China CDC Wkly
DOI: 10.46234/ccdcw2020.147
sha: 4f5105a461256d90caa3284087be8c3bd32fbba9
doc_id: 21259
cord_uid: im1kr7fx

nan

A case of avian influenza H9N2 was detected in a human in Zhuhai City, Guangdong Province through routine influenza surveillance on March 30, 2020. The patient was a 3-year-old child who developed fever and cough on March 22. A pharyngeal swab was collected on March 23, and the novel coronavirus nucleic acid test was negative. On March 26, the pharyngeal swab was sent to Zhuhai CDC for influenza virus tests and was found to be H9 influenza A positive, and on March 30, Guangdong Provincial CDC reexamined the pharyngeal swabs as positive for influenza A (H9N2). On March 28, the patient was hospitalized for isolation treatment, and oseltamivir and other antiviral drugs were given in the hospital. A pharyngeal swab was collected again for reexamination on March 28, and the H9 test was negative. Epidemiological investigation found that the patient had been exposed to chickens and ducks raised by her grandparents before onset of illness. Samples taken from 5 close contacts and the environment of her grandparents' home all tested negative for the H9 nucleic acid.

The pharyngeal swab samples collected on March 23 were inoculated into an 11-day-old specific pathogen free (SPF) chicken embryo in Guangdong Provincial CDC. On April 7, the chicken embryo's allantoic fluid was collected and identified as A(H9N2) positive, with the strain named A/Guangdong/Zhuhai/20SF8034/ 2020(H9N2). The isolated strain was sequenced and all 8 virus sequences of A(H9N2) were obtained. (1) (Figure 2 ). BLAST analysis of the internal gene segments (MP, NP, NS, PA, PB1, PB2) of the isolated strain found that these 6 segments all had the highest similarity with avian-derived A (H9N2) with molecular markers of avian-like viruses, suggesting that the risk of human infection was not higher than that of previous H9N2 avian influenza viruses.

H9N2 is the most common subtype of avian influenza in poultry, and human infection is relatively rare (3) (4) . A total of 11 cases of H9N2 have been reported since 2010 in Guangdong Province, all of which were mild cases and have recovered. The case of H9N2 detected this time is an occasional case of human infection with H9N2 avian influenza virus. We should continue to strengthen the risk monitoring and early warning of avian influenza on the basis of the existing surveillance of avian influenza. 

A/duck/China/D4/2018(H9N2)

A/chicken/Jiangxi/X1078/2018(H9N2)

A/chicken/Hubei/H1081/2018(H9N2)

A/chicken/Jiangxi/X2025/2017(H9N2)

A/chicken/Jiangxi/X2028/2017(H9N2)

A/chicken/Huibei/H2244/2016(H9N2)

A/Duck/Huibei/H2247/2016(H9N2)

A/chicken/Huibei/H2034/2016(H9N2)

A/chicken/Guangdong/G1301/2016(H9N2)

A/chicken/China/1103/2019(H9N2)

A/chicken/Shanghai/06/2018(H9N2)

A/chicken/China/71/2019(H9N2)

A/environment-air/Kunshan/NIOSH-BL25/2018(H9N2)

A/chicken/Fujian/SD037/2017(H9N2)

A/chicken/Shandong/k147/2017(H9N2)

A/chicken/Anhui/AH120/2015(H9N2)

A/chicken/Zhejiang/HZ03/2014(H9N2)

World Health Organization. Candidate vaccine viruses for A(H9N2)

The molecular characteristics of avian influenza viruses (H9N2) derived from air samples in live poultry markets

Genetic evolution of influenza H9N2 viruses isolated from various hosts in China from 1994 to 2013

Genetic and antigenic evolution of H9N2 subtype avian influenza virus in domestic chickens in southwestern China