Complications table

primary influenza pneumonia

short termhigh

Common complication of Asian lineage A(H7N9) virus infection.

Treatment is with antivirals given as soon as possible, supplemental oxygen, and supportive therapy. Respiratory status should be monitored, and early ventilatory support considered.

respiratory failure

short termhigh

This is a common complication of Asian lineage A(H7N9) virus infection, usually due to acute respiratory distress syndrome. Has been documented among all affected age groups.

Antiviral and supportive therapy is necessary.

acute respiratory distress syndrome

short termhigh

The most common cause of respiratory failure.

Evidence-based, lung protective ventilation strategies are recommended.

multi-organ failure

short termhigh

Multi-organ failure, including renal or cardiac compromise, is a common complication of severely ill Asian lineage A(H7N9) virus-infected patients.

Supportive therapy is crucial, as is targeted therapy where applicable. Management should follow evidence-based management guidelines.


short termmedium

Septic shock requiring vasopressor support is a common complication of primary Asian lineage A(H7N9) virus infection.

Treatment is supportive and should follow existing evidence-based guidelines for the management of septic shock.


short termlow

Patients can have headaches, behavioural disturbances, and altered mental status, and may have seizures and coma, as a result of virus infection triggering cytokine dysregulation. Encephalitis is not recognised in Asian lineage A(H7N9) virus infection, but cases of central nervous system infection and detection of virus in cerebrospinal fluid have been described in severe illnesses caused by other influenza A viruses.

The underlying infection should be treated with antivirals as soon as possible, and supportive care provided as indicated.



Has occurred in approximately 39% of patients with confirmed Asian lineage A(H7N9) virus infection.

community-acquired pneumonia


While co-infection with bacterial pneumonia pathogens (Staphylococcus aureus, Streptococcus pneumoniae, group A Streptococcus) is well described with seasonal influenza A or B virus infections, as well as with influenza A(H1N1)pdm09 virus infection, concurrent bacterial community-acquired pneumonia appears to be uncommon in patients with Asian lineage A(H7N9) virus infection.

In most cases, empirical therapies for bacterial pneumonia and influenza virus infection are initiated before the Asian lineage A(H7N9) diagnosis is confirmed. Antibacterial therapy should follow evidence-based treatment guidelines, conform to local/regional standards of care, and target common community-acquired pneumonia pathogens from the region where infection occurred.

hospital-acquired pneumonia


Common complication of mechanical ventilation and one of the most frequent of all healthcare-associated infections (HCAIs).[193] Relevant bacterial species-associated HCAIs, including ventilator-associated pneumonia, have been identified in some hospitalised patients with A(H7N9) virus infection.[116][150]

Evaluation and treatment should follow evidence-based guidelines and local/regional policies.

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