Visible Human to Human Bird Flu Transmission in Vietnam
Recombinomics Commentary
February 3, 2005
Recent statements from WHO scientists regarding human transmission are actively ignoring some rather obvious examples that have been covered extensively in the media. Each familial cluster contains at least one confirmed H5N1 case. The overall description of all six clusters is the same. One or two family members develop bird flu symptoms and die. After the death of the index case, one of more family members develop symptoms and at least one is positive for H5N1. This general description matches the case that was recently published in the New England Journal of Medicine.
The NEJM paper covers a cluster of 3 in Thailand this past summer. Although the index case was initially diagnosed as dengue fever and no sample was tested for avian influenza, the daughter was considered the index case of the cluster because both her mother and aunt developed symptoms after the daughter died and both tested positive. Initial test on the aunt were negative. Had the group not formed a cluster, it seems likely that none would have been diagnosed as having H5N1.
The cluster received significant attention because the mother was not present when the daughter first was infected, and then when she went to visit her daughter, there was limited exposure to any common source that might have been present. However, it was the time differential between the onset of symptoms that provided the strongest evidence for human to human transmission.
The clusters listed below match the Thailand cluster except the caregiver that became infected did have some common source exposure. However, in all six clusters the time differential was at least 7 days and the secondary case(s) developed symptoms after the index case died.
There is no data to indicate that all members of the clusters below are not H5N1 avian influenza cases. Those that are not confirmed either did not have samples collected or results have not yet been reported. The cases not in the official totals have all died from illness that looked like bird flu clinically and have a direct link to at least on H5N1 positive relative.
The under reporting of cases extends beyond these clusters. Many cases in Thailand last season had a high index of suspicion due to poultry deaths and clinical presentation. In 12 cases H5N1 was laboratory confirmed. 8 of the12 died, but none of the 12 laboratory confirmed cases are in the official tally.
The active exclusion of these obvious cases diminishes the utility of the fatality tallies and now the deficient database is being used to make comments and comparisons that are simply not supported by the facts. The faulty database covers up the clear deficiencies in the monitoring of the disease and the artificially low numbers are faithfully cited in media reports on a daily basis.
The monitoring and reporting of avian influenza in Asia remains scandalous and the H5N1 virus does not read press releases or media reports.
Hau Giang Cluster (Can Tho hospital)
Brother, 19, (initials PDC) died July 30 shortly after admission to hospital in Can Tho with bird flu symptoms. His cousin (22F initials PTKC) also died July 30 shortly after admission. No samples collected from either initial case. Elder sister, 25, Pham Thi Nha Tuc developed symptoms after her brother died. Positive for H5N1. In December OIE report indicated asymptomatic ducks present in Can Tho. January media reports indicated almost half of ducks tested were positive for H5N1.
Official outcome 1 confirmed death, no cluster.
Real outcome - 3 H5N1 fatalities with likely transmission from bother to sister.
Thailand Cluster
Index case, 11F, developed symptoms in Northern Thailand while staying with aunt. Initial diagnosis dengue fever. Mother , 26, traveled from Bangkok to visit daughter in hospital. After daughter dies mother developed symptoms as did aunt. No sample from index case/ Mother and aunt test positive for H5N1. Aunt survives.
Official outcome :1 confirmed death and 1 confirmed recovered. Likely human to human transmission from daughter to mother and aunt.
Real outcome 2 H5N1 fatalities, 1 recovered. Human to human transmission
Hanoi Cluster
Index case, Nguyen Huu Viet, 47M, is a confirmed fatality, died Jan 9 - onset date Dec 26. Brother, Nguyen, Thanh Hung, 42M, confirmed recovering case. Onset date Jan 10, discharge Jan 28. Conflicting status on third, 36M, brother - no symptoms but may be positive for virus. Dec 25 raw duck blood pudding meal not within 2-10 days of onset of symptoms for any members in cluster
Official outcome: 2 H5N1 infections, 1 survived.. Transmission under investigation
Real outcome 2 H5N1 infections, 1 survived.. Transmission from brother to brother
Dong Thap Cluster
Index case, Mai Thi Truc Li, 35F, developed symptoms Jan 14 admitted to local Dong Thap hospital Jan 14. Transferred to HCM City Jan 21 and died within hours of transfer. Confirmed, with multiple possible sources of infection (bath, swim, duck slaughter). Daughter, 13F, developed symptoms Jan 20, hospitalized Jan 22. Confirmed and (reported helped with duck slaughter). She reportedly bought duck in Dong Thap before visiting her uncle in Tay Ninh where she developed symptoms on Dec 16 and died Jan 8.
Official outcome. 2 H5N1 fatalities, transmission under investigation
Real outcome 2 H5N1 fatalities, transmission from mother to daughter
Bac Lieu Cluster
Index case Bui Tan Tai, 17M confirmed fatality admitted Jan 10, died Jan 15. Sister (22F) in critical condition. From Phuoc Long district.
Official outcome: 1 H5N1 fatality, second case pending
Real outcome 2 H5N1 fatalities, brother to sister transmission
Kampot Cluster
Index case, brother (14M) of Soc Khol. Died prior to Jan 21 after developing high fever, bad cough, and breathing problems. Sister, Soc Khol, (25F) admitted to hospital in Vietnam on Jan 28, died Jan 30. Reports of dying chickens and ducks in Dec in area.
Official outcome 1 H5N1 fatality
Real outcome 2 H5N1 fatalities, brother to sister transmission
Cluster total
Official outcome 8 H5N1 fatalities, 2 recovered, 1 human to human transmission likely, 2 under investigation
Real outcome 12 H5N1 fatalities, 2 recovered, 6 human to human
transmissions likely
Thailand 2004
Official outcome no new 2004 cases
Real outcome 21 laboratory confirmed cases, 14 died. More likely cases but no specimens for testing.