Human infections with H7N9 viruses can cause severe pneumonia and even death. To characterize the epidemiology and genetics of the H7N9 viruses circulating during from October 2016 to April 2017 in Suzhou, China, all pharyngeal swab samples were collected from severe acute respiratory infections (SARI) cases during this fifth wave of infection, and we amplified the H7N9 H7 and N9 genes using a real-time polymerase chain reaction (PCR). Positive samples were subjected to virus isolation and gene sequencing to analyze the evolution and variation of the H7N9 strains. The epidemiological features of H7N9 patients have not changed and there were no significant mutations in the key sites of the hemagglutinin (HA) gene sequence, but we identified the K526R and E627 K substitutions in the PB2 protein. In the neuraminidase (NA) protein, drug-resistant mutations (R294 K and H276Y) occurred in a few strains. Most of the H7N9 viruses isolated from Suzhou had no drug resistance mutations, but it is necessary to closely monitor and analyze the probable emergence of mutations and the spread of resistant strains. The reduction of the N-glycosylation site at position 42 of NA was observed in some strains.

Human-to-human transmission of influenza A(H7N9) virus most likely occurred in this household. The three-amino-acid mutations in HA protein were discovered in this study, which might have increased the binding affinity of influenza A(H7N9) virus to the receptor on trachea epithelial cells to facilitate viral transmission among humans.

Avian influenza A(H5N6) keeps evolving, causing outbreaks in birds and sporadic infections in human. Here, we report a fatal paediatric infection caused by a novel reassortant H5N6 virus. The patient was an obese 9‐year‐old girl. She initiated with fever and cough, then developed pneumonia, acute respiratory distress syndrome (ARDS) and respiratory failure. Lower respiratory tract aspirates and anal swabs were serially taken till the patient's death. Viral isolation, genome sequencing and phylogenetic analysis were conducted. A novel reassortant H5N6 virus was isolated from the patient. Except the PA gene, all other 7 genes of the virus belonged to H5N6 genotype A (S4‐like virus). The PA gene was probably obtained from Eurasian waterfowl influenza viruses. The H5N6 virus was consistently detected from the patient's respiratory samples till the 17th day after symptom onset, but not from anal swabs or urine sample by real‐time reverse transcription polymerase chain reaction (RT‐PCR). Significantly elevated (32‐fold) serum antibodies to H5N6 virus were observed during the patient's course of disease. Aside from the identified novel reassortant H5N6 viral strain, obesity, delayed confirmation of aetiology and specific antiviral treatment, and prolonged virus shedding could have contributed to the poor clinical outcome.

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ObjectivesThis study aimed to examine the real prevalence of late presentation of HIV infection and to identify factors associated with late HIV presentation among patients with newly diagnosed HIV/AIDS in Suzhou, China.MethodsPatients with newly diagnosed HIV/AIDS who registered in national AIDS surveillance system from 2017 to 2020 were included in this study. Late presentation (LP) of HIV infection was defined as HIV diagnosis with a CD4 count < 350 cells/μL or an AIDS-defining event. Multivariable logistic regression analyses were used to identify factors associated with LP.ResultsA total of 2,300 patients were enrolled. 1,325 were classified as late presenters, showing a high percentage of 57.6% (95% CI: 54.5–60.7%) and a rise (P = 0.004) over the four-year period. Patients with newly diagnosed HIV/AIDS who were older than 24 years of age (aOR = 1.549, P = 0.001 for 25-39 years; aOR = 2.389, P < 0.001 for 40 years and older), were Suzhou registered residents (aOR = 1.259, P = 0.026), and were from inpatient and outpatient (aOR = 1.935, P < 0.001) were more likely to be late presentation.ConclusionsThis study showed a high percentage and a rise of late presentation of HIV infection among patients with newly diagnosed HIV/AIDS in Suzhou, China, which is a challenge for future prevention and control of AIDS. Targeted measures should be urgently implemented to reduce late HIV diagnosis.