We report a familial cluster of 2019 novel coronavirus disease (COVID-19) to assess its potential transmission during the incubation period. The first patient in this familial cluster was identified during the presymptomatic period, as a close contact of a confirmed patient. Five family members had close contact with this first patient during his incubation period, with four of them confirmed positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the subsequent sampling tests.

This study aimed to assess the mortality risks for human infection with high (HPAI) and low (LPAI) pathogenicity avian influenza viruses. The HPAI case fatality rate (CFR) was far higher than the LPAI CFR [66.0% (293/444) vs. 68.75% (11/16) vs. 40.4% (265/656) vs. 0.0% (0/18) in the cases with H5N1, H5N6, H7N9, and H9N2 viruses, respectively; p < 0.001]. Similarly, the CFR of the index cases was greater than the secondary cases with H5N1 [100% (43/43) vs. 43.3% (42/97), p < 0.001]. Old age [22.5 vs. 17 years for H5N1, p = 0.018; 61 vs. 49 years for H7H9, p < 0.001], concurrent diseases [18.8% (15/80) vs. 8.33% (9/108) for H5N1, p = 0.046; 58.6% (156/266) vs. 34.8% (135/388) for H7H9, p < 0.001], delayed confirmation [13 vs. 6 days for H5N1, p < 0.001; 10 vs. 8 days for H7N9, p = 0.011] in the fatalities and survivors, were risk factors for deaths. With regard to the H5N1 clusters, exposure to poultry [67.4% (29/43) vs. 45.2% (19/42), p = 0.039] was the higher risk for the primary than the secondary deaths. In conclusion, old age, comorbidities, delayed confirmation, along with poultry exposure are the major risks contributing to fatal outcomes in human HPAI and LPAI infections.

SUMMARY: This study aimed to compare the virology and epidemiology of epidemic keratoconjunctivitis (EKC), pharyngoconjunctival fever (PCF) and acute haemorrhagic conjunctivitis (AHC) outbreaks worldwide caused by the human adenovirus (HAdV) from 1953 to 2013. Eighty-three hexon sequences from 76 conjunctivitis outbreaks were analysed and subtyped using Mega 5.05, Clustal X and SimPlot software. Epidemiology was performed for the area, age and seasonal distribution. A phylogenetic analysis indicated that all the isolates could be divided into three subgenetic lineages, without a common ancestor. The major causes of the outbreaks were Ad8, Ad7 and Ad2 co-infection with enterovirus 70 (EV70) in EKC, PCF and AHC, respectively. The epidemiological findings suggested that EKC and AHC were circulating predominantly in Asia during the early winter and spring, whereas PCF was circulating mainly in China, Australia and the United States during the summer. This study suggests that EKC, AHC and PCF outbreaks have different circulating patterns throughout the world and are caused by different adenovirus serotypes. A global surveillance system should be established to monitor conjunctivitis outbreaks in the future.

Adenovirus serotype 3 and 7 outbreaks have occurred periodically in northern, eastern, and southern China since 1955, but there has been no report since the adenovirus serotype 7 outbreak first occurred in Hangzhou, China, in 1991. Here we explored the epidemiology and etiology of two adenovirus serotype 3 outbreaks in Hangzhou in 2011. One acute respiratory outbreak was found in Chun'an County, where a total of 371 cases were confirmed in 5 of 23 towns from 4 to 31 May 2011. The outbreak affected 18.57% (13/70) of schools and 14.49% (90/621) of classes. The incidence was 5.18% (371/7,163). The population was distributed among individuals ages 7 to 15 years. No parents or teachers were infected. Another pharyngoconjunctival fever outbreak was discovered in the Chenjinglun Swimming Center located in the Xihu District between 1 and 15 July 2011. A total of 134 cases were confirmed in 900 amateur swimmers, with an incidence of 14.89% (134/900). The ages ranged from 4 to 9 years. The two outbreaks had no severe complications or death. The viruses in 66.67% (10/15) of throat swabs from children with acute respiratory infections and 100% (10/10) of the swabs from children with pharyngoconjunctival fever were confirmed to be adenovirus serotype 3 with 100% homology by PCR. Of these samples, 60.0% (12/20) had a classical characteristic cytopathic effect, presented as grape-like clusters at 72 h after infection in HEp-2 cells. In conclusion, the acute respiratory infection and pharyngoconjunctival fever outbreak in Hangzhou were caused by the completely homologous type 3 adenovirus in subgenus B. Moreover, these outbreaks demonstrated rapid transmission rates, possibly due to close contact and droplet transmission.

Scarlet fever has resurged in China starting in 2011, and the environment is one of the potential reasons. Nationwide data on 655,039 scarlet fever cases and six air pollutants were retrieved. Exposure risks were evaluated by multivariate distributed lag nonlinear models and a meta-regression model. We show that the average incidence in 2011–2018 was twice that in 2004–2010 [RR = 2.30 (4.40 vs. 1.91), 95% CI: 2.29–2.31; p < 0.001] and generally lower in the summer and winter holiday (p = 0.005). A low to moderate correlation was seen between scarlet fever and monthly NO₂ (r = 0.21) and O₃ (r = 0.11). A 10 μg/m³ increase of NO₂ and O₃ was significantly associated with scarlet fever, with a cumulative RR of 1.06 (95% CI: 1.02–1.10) and 1.04 (95% CI: 1.01–1.07), respectively, at a lag of 0 to 15 months. In conclusion, long-term exposure to ambient NO₂ and O₃ may be associated with an increased risk of scarlet fever incidence, but direct causality is not established.