CDC Advisory on H5N1 Avian Influenza
Recombinomics Commentary
February 6, 2005
>> One instance of probable limited human-to-human transmission of influenza A (H5N1) virus was reported in Thailand between a child and her mother and aunt in September 2004. Health authorities in Vietnam are investigating two possible instances of limited human-to-human transmission in family clusters. One instance involves two brothers in Vietnam with confirmed influenza A (H5N1) infections; a third brother was hospitalized for observation only and did not become ill. In the second instance, a daughter developed symptoms within 6 days of her mother's onset of illness, which was confirmed as influenza A (H5N1). Investigations are exploring possible sources of exposure and looking for other signs of illness in family members, other close contacts, and the general community.
In addition, the first human case of influenza H5 infection in Cambodia has been confirmed in a woman who was hospitalized in Vietnam and died. A joint mission between the Cambodian Ministries of Health and Agriculture and WHO is in Cambodia investigating the circumstances surrounding this case.
As of February 4, 2005, the cumulative number of confirmed human cases of influenza A (H5N1) reported in Asia since January 28, 2004, is 55 cases (with 42 deaths), according to WHO. This total includes the case from Cambodia . <<
The CDC's health alert to professionals issued on Friday is a useful warning about added concerns in part due to additional examples of possible human to human transmission. However, the bimodal distribution of disease onset dates of the 9 familial clusters, strongly suggests that in these clusters the vast majority of the patients who are not index cases were infected by the index cases.
Therefore extreme caution should be exercised by family members and health care workers when treating bird flu suspect cases.