Summary of the second WHO consultation on clinical aspects of human infection with avian influenza A(H5N1) virus

19-21 March, 2007, Antalya, Turkey

Since the last meeting in Hanoi, May 2005, eight new countries have reported human infections with avian influenza A(H5N1) viruses. Clinicians, epidemiologists, virologists and public health specialists from the countries with human cases, and experts in pulmonary medicine, critical care, and influenza attended the meeting to share their experiences.

Participants agreed that standardizing care and promptly sharing clinical and treatment information are critically important to understanding the disease in humans and to improving clinical management.

Observations and experiences, including unpublished data, were shared by participants during the consultation. Several conclusions regarding management of patients with H5N1 illness support and expand current WHO guidance.

• Experiences with early oseltamivir treatment suggest its usefulness in reducing H5N1-associated mortality. In addition, evidence of prolonged H5N1 virus replication indicates that treatment is warranted even with late presentation.

• As previously discussed, modified regimens of oseltamivir treatment, including two-fold higher dosage, longer duration and possibly combination therapy with amantadine (in countries where the H5N1 virus is susceptible to amantadine) may be considered on a case by case basis, especially in patients with pneumonia or progressive disease. Ideally this should be done in the context of prospective data collection.

• Corticosteroid therapy has failed so far to show effectiveness, and prolonged or high dose corticosteroids can result in serious adverse events in H5N1 patients, including opportunistic infection. Corticosteroids should not be used routinely, except for persistent septic shock with suspected adrenal insufficiency.

• Antibiotic prophylaxis should not be used. When pneumonia is present, antibiotic treatment is appropriate initially for community-acquired pneumonia according to published evidence-based guidelines. When available, the results of microbiologic studies should be used to guide antibiotic usage in patients with A(H5N1) infection.

• Therapy for H5N1-associated ARDS should be based upon published evidence-based guidelines for sepsis-associated ARDS, specifically including lung protective mechanical ventilation with low tidal volume.

The observations from the meeting will be published in greater detail, as an updated WHO guidance on H5N1 clinical management followed by a meeting summary in the form of peer-reviewed article in the scientific literature.