23
January 2006
Monday
WHO updates
facts on H5N1 virus, including use of a 7-day incubation period for monitoring
contacts, and consideration of 7-10 day therapy with oseltamivir (Tamiflu) for
severe infection.
This
weekend the WHO posted on their website a five-page document with important
updates on their “Fact sheet” for avian influenza (“bird flu”).
The
WHO update includes eight (8) topics: the disease in birds, the role of
migratory birds, countries affected by outbreaks in birds, the disease in
humans, history and epidemiology, assessment of possible cases, clinical
features, and countries with human cases.
Eight
(8) important clinical features warrant emphasis:
1.
“The
incubation period for H5N1 avian influenza may be longer than that for normal
seasonal influenza, which is around 2 or 3 days. Current data for H5N1 infection
indicate an incubation period ranging from 2 to 8 days and possibly as long as
17 days...WHO currently recommends than an incubation period of 7 days be used
for field investigations and the monitoring of patient
contacts.”
2.
“Watery
diarrhea without blood appears to be more common in H5N1 avian influenza than in
normal seasonal influenza.”
3.
“On
present evidence, difficulty in breathing develops around 5 days following the
first symptoms…most recently, blood-tinged respiratory secretions have been
observed in Turkey.”
4.
“Another
common feature is multiorgan dysfunction, notably involving the kidney and
heart.”
5.
“Common
laboratory abnormalities include lymphopenia, leucopenia, elevated
aminotransferases, and mild-to-moderate thrombocytopenia with some instances of
disseminated intravascular coagulation”.
6.
“As
the duration of viral replication may be prolonged in cases of H5N1 infection,
clinicians should consider increasing the duration of treatment to 7 to 10 days
in patients who are not showing a clinical response.”
7.
“In
cases of severe infection with the H5N1 virus, clinicians may need to consider
increasing the recommended daily dose or the duration of treatment, keeping in
mind that doses above 300mg per day are associated with increased side
effects.”
8.
“In
severely ill H5N1 patients or in patients with severe gastrointestinal symptoms,
drug absorption may be impaired. This possibility should be considered when
managing these patients.”
With
the additional of two more H5N1-infected young people from Indonesia today, the
total number of WHO-lab confirmed patients has now reached 151 with 82
fatalities (54%). The update on clinical, epidemiologic, and avian-veterinary
issues by the WHO is timely and very helpful.
A
request to the WHO:
A
detailed clinical, epidemiologic, and demographic summary of the all
lab-confirmed patients, including recent ones from Turkey, Indonesia, and China
would be very valuable and greatly appreciated by clinicians and hospital and
public health planners worldwide.
For
example, how often do clinically significant kidney and cardiac manifestations
of H5N1 infection, mentioned in this WHO update, occur? How many patients have
received oseltamivir (Tamiflu) within 48 hours of onset of illness, how many
within 72, 96, or 120 hours of onset of illness, what data is available for
adjunctive use of steroids for H5N1 lung disease (steroids were also used for
SARS pneumonia as that epidemic unfolded), how many patients have been placed on
ventilators, and of those how many have survived, what evidence is there
regarding efficacy of N-95 respirators or surgical masks to prevent H5N1
infection, what data is there regarding patients with H5N1 infection who have
received 7-10 days of oseltamivir therapy or 300 mg per day rather than the
standard 150 mg (75 mg every 12 hours) for seasonal influenza, and other such
key clinical issues that would benefit clinicians and planners everywhere?
Daniel
R. Lucey, MD, MPH
Director,
Center for Biologic Counterterrorism and Emerging Diseases
EROne
Institutes, Washington Hospital Center
Co-Director,
Master of Science (M.S.) Program in Biohazardous Threat Agents and Emerging
Infectious Diseases, Georgetown Medical School
Washington,
DC.
Website:
http://www.bepast/
Email:
Daniel.R.Lucey@Medstar.net;
cell: 202-299-4398