30=20 August 2005

Children and H5N1: Ages, Fatalities, and Antiviral Limitations

The=20 World Health Organization has published the ages and clinical outcomes = for each=20 of the initial 50 patients with H5N1 avian influenza virus infection. = The data=20 was listed case by case in tabular form in a January 2005 document = posted online=20 (http://www.who.int/) titled = =93Assessing the=20 Pandemic Threat=94 (page 20-21). A striking finding is that, unlike SARS = virus=20 infection, children are clearly vulnerable to both infection and death = due to=20 the H5N1 virus. In addition, age restrictions on the FDA-licensed use of = the=20 neuraminidase inhibitor drugs (oseltamivir (oral), and zanamivir = (inhaled)) to=20 which this current H5N1 virus is susceptible have major implications for = the=20 prophylaxis and treatment of treatment of children and should be = anticipated in=20 planning for a pandemic.

A=20 summary table of the ages, number of persons in each 10 year age cohort, = and=20 number of fatalities in each 10 year age cohort can be created from the=20 individual WHO case demographics listed:

Age=20 range &nbs= p; =20 # of patients # = of=20 Deaths/ # of patients

0-10 = &nbs= p; =20 19 =20 &nbs= p; =20 16/19

11-20 &nbs= p; =20 15 =20 &nbs= p; =20 12/15

21-30 &nbs= p; =20 10 =20 &nbs= p; =20 = 7/10

31-40 &nbs= p; =20 4 &nbs= p; = ; =20 = 2/4

41-50 &nbs= p; =20 1 &nbs= p; = ; =20 = 0/1

51-60 &nbs= p; =20 1 &nbs= p; = ; =20 = 1/1

The=20 only oral drug to treat H5N1 infection is oseltamivir = (=93Tamiflu=94). This drug is NOT FDA-licensed = for=20 children under the age of 13. =20 Oseltamivir is not FDA-licensed for treatment of active influenza = infection in infants below the age of 1 year. It is approved for persons = over=20 the age of one year, and dose varies by child=92s weight up to the age = of 13=20 years. The shelf-life of oseltamivir in pediatric liquid solution = form in the past has been somewhat = shorter=20 than the capsule form for adults.

The=20 second neuraminidase anti-influenza drug, zanamivir, is not available in oral form = and is=20 only used as an inhaled drug. = In=20 addition, it is not FDA-licensed for prophylaxis for any age. Zanamivir = is only=20 FDA-licensed for treatment of active influenza infection for persons = over the=20 age of 6 years. These and other pediatric issues deserve more attention = as=20 pandemic influenza planning increases worldwide.

Daniel=20 R. Lucey, MD, MPH

Adjunct=20 Professor of Microbiology and Immunology

Georgetown=20 University School of Medicine

Director,=20 Center For Biologic Counterterrorism and Emerging = Diseases

Department=20 of Emergency Medicine, Washington Hospital Center

Washington, DC=20 &nbs= p; =20

e-mail:=20 Daniel.R.Lucey@Medstar.net