AVIAN INFLUENZA, HUMAN (30): VIET NAM (BAC KAN), CLUSTER SUSPECTED

[1]
Date: Wed 14 Apr 2010
Source: Reuters AlertNet [edited]
<http://www.alertnet.org/thenews/newsdesk/TOE63D045.htm>


Two people in northern Viet Nam have been infected with the H5N1 bird
flu virus [avian influenza A(H5N1) virus], and health authorities are
carrying out tests to see if 11 others who have come down with fever
have been infected. The 2 who tested positive -- a 22-year-old man
and a 27-month-old baby girl -- as well as the 11 suspected cases are
all residents in the same commune in Bac Kan province [see also:
Avian influenza, human (29): Viet Nam (BK), cluster, susp. 20100412.1188].

"All the patients have been isolated, and tests were taken to verify
the reason of their sickness," said Deputy Director Luu Xuan Hoa of
the Cho Moi Medical Centre in Bac Kan province. "She (the baby) is a
neighbour of the 1st man who has tested positive for the H5N1 virus,
while others live in the same hamlet," he said. Four people on the
suspect list have been discharged.

Disease clusters are a special concern because it may mean the agent
in this case, the avian influenza A(H5N1) virus, which kills up to 60
percent of those it infects, is gaining the ability to jump from
person to person. Vietnamese media, however, reported that dead
poultry had been seen in the village and that the patients had either
eaten or come in contact with sick birds. This opens the possibility
that the 2 patients may have been infected by the same source. "We
have no evidence to conclude that there is a human-to-human
infection," Hoa said. Viet Nam had 2 bird flu deaths earlier this
year [2010], a 38-year-old woman and a 3-year-old girl.

The H5N1 virus once was a disease confined largely to birds, only
rarely infecting people. Since 2003, it has infected 493 people,
killing 292, or nearly 60 percent, with Viet Nam reporting 59 deaths
[among 117 cases, not including the 2 cases described in this report.
- Mod.CP]. Almost all these infections were believed to have taken
place directly from bird to human.

There have been 2 sizeable clusters -- one in which 8 family members
died on the Indonesian island of Sumatra in 2006 and another in
Turkey in which 8 people were infected and 4 died. In the Sumatra
case, the virus [affected] 2 generations and then stopped; a
37-year-old woman was believed to have infected her 10-year-old
nephew who went on to infect his father.

Another smaller probable case of human-to-human transmission occurred
in Thailand in 2004, where a mother died after tending to her sick
daughter for hours.

[Byline: Ho Binh Minh]

--
Communicated by:
ProMED-mail Rapporteur Mary Marshall

******
[2]
Date: Tue 13 Apr 2010
Source: CIDRP News [edited]
<http://www.cidrap.umn.edu/cidrap/content/influenza/avianflu/news/apr1310avian.html>


Two patients who are part of a suspected H5N1 avian influenza case
cluster in northern Viet Nam's Bac Kan province are still
hospitalized, with 11 others isolated for flu-like symptoms, health
officials said today [13 Apr 2010]. The 2 hospitalized patients
include a 22-year-old man and a 27-month-old girl whose confirmed
infections were previously reported by the Vietnamese media.

Hoang Van Linh, deputy director of northern Bac Kan's health
department, told the news service that some of the isolated group
includes relatives of the 2 hospitalized patients. Hoang said the 11
people in isolation recovered after treatment with oseltamivir
(Tamiflu) and that he is awaiting test results to see if any were
infected with avian influenza A(H5N1) virus. The man was hospitalized
on 2 Apr 2010 and remains under care, and the toddler, admitted on 4
Apr 2010, is in stable condition.

Viet Nam's Health Ministry, in a Web posting, said dead chickens were
reported at the homes of the 2 hospitalized patients and that the
toddler's family reportedly slaughtered and ate some of the infected
poultry. A provincial infectious disease official said that all of
the isolated patients had contact with sick birds.

Bac Kan province, a mountainous area in northern Viet Nam, was among
2 areas cited in H5N1 outbreak reports that the country's agriculture
ministry submitted to the World Organization for Animal Health (OIE)
on 10 Apr 2010. The outbreak in Bac Kan started on 19 Mar 2010,
killing 318 of 550 birds in the affected village. The remaining 142
birds were destroyed to control the spread of the virus. The country
also reported that the virus struck birds in a village in Quang Ninh
province, located on Viet Nam's northeastern coast, killing 1231 of
1554 birds. The remaining poultry were destroyed. An investigation
into the source of the events suggested that introduction of new
animals, illegal movement of birds, and fomites were linked to the 2
avian influenza A(H5N1) virus outbreaks, the OIE report stated.

Geographic and family H5N1 clusters are relatively rare, and they
raise fears that the virus has improved its ability to infect humans,
which could increase the risk that the virus could become a pandemic
flu strain. For example, a cluster of confirmed and suspected H5N1
cases occurred in northwestern Pakistan in late 2007. The World
Health Organization (WHO) investigation revealed that the virus
probably spread among 4 brothers and went no further.

Also in late 2007, the father of a Chinese man who died of an H5N1
infection was hospitalized with avian influenza A(H5N1) virus
infection. Reports at the time were unclear about the men's exposure
to sick and dead birds.

Despite periodic reports of clusters, human-to-human transmission of
avian influenza A(H5N1) virus, though suspected in some instances,
has been confirmed in the laboratory only once, in a North Sumatra,
Indonesia family in 2006. That cluster involved 7 cases, 6 of them
fatal. A WHO investigation into the illnesses revealed that the virus
mutated slightly when it infected a 10-year-old boy, who then passed
the same virus to his father.

[Byline: Lisa Schnirring]
--
Communicated by:
ProMED-mail <promed@promedmail.org>

[Little new information has become available since the previous
report, and it is still unclear whether the avian influenza A (H5N1)
virus infection of the 22-year-old man and the 27-month-old child
have been officially confirmed. If the diagnosis has been confirmed
officially, the number of cases in Viet Nam will have risen to 119
since the beginning of the outbreak in 2003, the number of fatalities
remaining 59.

Likewise, no further information has emerged concerning the diagnosis
of the other 11 members of the suspected cluster (all of whom have
been treated and discharged). Nor is there any information to exclude
the likelihood of transmission directly from infected poultry or to
favour the possibility of human-to-human transmission of infection.
Further information is awaited.

Bac Kan province can be located in the map of the Northern Region of
Viet Nam at: <http://www.angelfire.com/co/hongnam/vnmap.html>. The
HealthMap/ProMED-mail interactive map of Viet Nam can be accessed at
<http://healthmap.org/r/01aL>. - Mod.CP]