Thailand's Ministry of Public Health has today confirmed a further case of human infection with H5N1 avian influenza. The case, which was fatal, was a 9-year-old girl from the northern province of Phetchabun. She developed symptoms on 23 September, was hospitalized on 27 September, and died of severe respiratory disease on 3 October.
Investigation of the case has identified exposure to diseased chickens as the most likely cause of infection. Following the death of chickens in the child’s household, she assisted in preparation of the birds for cooking, including the plucking of feathers.
Since the beginning of this year, Thailand has reported 16 laboratory confirmed cases of H5N1 infection, of which 11 have been fatal. Four of these cases have occurred during the past four weeks.
Last week, Thai officials announced a probable case of human-to-human transmission in a family cluster of cases. Analysis of specimens from this cluster is presently under way at a WHO collaborating laboratory to determine whether the virus has changed its genetic make-up. Heightened surveillance for further cases has provided no evidence that efficient and sustained human-to-human transmission is presently occurring in Thailand.
A vaccine could reduce the high morbidity and mortality normally associated with influenza pandemics, if available sufficiently early. Significant efforts are needed to expedite vaccine development and thus take advantage of this preventive option.
Progress is needed on three fronts. First, countries experiencing outbreaks need to rapidly share human and animal viruses with laboratories in the WHO Global Influenza Surveillance Network. Analysis of these viruses determines the possible need for changes in the prototype vaccine “seed” strains which WHO makes available to the pharmaceutical industry.
Second, companies need to engage in research on pandemic vaccine development that includes pilot production of small batches for clinical testing. National licensing agencies in Europe and North America have developed regulatory guidelines for industry.