Saturday, January 01, 2005

US shows no urgency

The Viet Namese avian influenza A(H5N1) epidemic in poultry is worsening and the country has reported an additional human case in a 16 year old girl (see here and here), the country's 28th since January. Seventy percent of the cases have died (20 of 28). Seventeen human cases have also been reported from Thailand (12 fatal) and a mild case was recently reported in Japan among workers culling infected poultry last February. Four other Japanese workers showed evidence of infection (see previous posts here and here). In addition to high case fatality, the disease has a predilection for young victims (ten cases reported in the New England Journal ranged in age from 5 to 23 years old, median age 13- 14 years old). Usual influenza mortality curves are U-shaped, with the very young and the very old most at risk. The 1918 pandemic was unusual because it was W-shaped, with the middle bulge being young adults. The current H5N1 cases look more like the 1918 age-mortality pattern. Incubation periods are relatively short, 2 - 4 days.

The worsening poultry epidemic in Viet Nam was signaled by a report of bird deaths in the northern province of Nam Dinh. Truc Ninh also had an affected flock of almost 1000 chickens, following reports of forced culling of nearly 11,000 fowl in six southern localities. WHO is warning that the poultry epidemic in Viet Nam will worsen in the coming cold weather and likely be associated with "sporadic human cases." As the Lunar New Year holiday approaches in early February there will be increased poultry marketing, transportation and preparation, increasing the frequency of human contact with infected birds. The recently released Japanese investigation suggests there may be many covert asymptomatic infections, leading to the potential for a reassortment of H5N1 genes with co-infecting human strains.

Whatever the exact numbers, it is clear that the influenza A(H5N1) epidemic in poultry is spreading in Viet Nam and this has its neighbor China worried. Southeast asia or China are considered the likely incubators of a potential pandemic strain. Xinhua News Agency reports that China is stepping up its preparations:
Large cities have stepped up surveillance measures on flu.

Guangzhou, capital of south China's Guangdong Province neighboring Hong Kong, has built up 19 surveillance sites at hospitals. [snip]

Local health department will keep close watch on patients suffering from fever, cough and sore throat for three days.

Hong Kong Special Administrative Region (SAR) has drafted a plan outlining a clear command and response coordination structure for any influenza outbreak, catering for three different response levels, "alert," "serious" and "emergency."

The Hong Kong SAR government proposed to the Legislative Council Panel on Health Services ordering 1.1 million antiviral doses in advance of the peak winter influenza season.

Shanghai has set up 43 surveillance sites to monitor flu cases. Nine municipal surveillance sites will collect typical flu samples for Shanghai Municipal Disease Control and Prevention Center.
These preparations are visible and are assuming high priority in China. Why do we hear so little in the US? Experts have been warning for some time now of the danger of a pandemic in the near future, but there seems little sense of urgency on the part of US federal health officials.