Published Date: 2007-10-12 23:50:00
Subject: PRO/MBDS> Dengue - Viet Nam (14): adults, RFI
Archive Number: 20071012.3354
DENGUE - VIET NAM (14): ADULTS, REQUEST FOR INFORMATION
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: 12 Oct 2007
Source: Viet Nam Net [edited]
Alarm raised as dengue fever spreads among HCMC [Ho Chi Minh City] adults
The recent development of dengue fever in people over 15 years of age
is puzzling officials, reported local health centers. According to
the statistics, the Ho Chi Minh City Hospital for Tropical Diseases
has lately been receiving huge patient loads, with an average of
around 70-100 dengue fever cases per week. This disease, which
typically affects young children, is increasingly being diagnosed in adults.
Regardless of age, the hospital is not equipped to handle the
numbers. Patients have had to share beds or stay temporarily in
corridors. According to Mr. Nguyen Dac Tho, Vice Director of the
Preventive Health Center in HCMC, the risk of dengue fever is still
high. The outbreak areas in the suburbs of the city are currently
under control; however the districts in the inner city such as Binh
Thanh, Tan Binh, Districts 8 and 11, and others are now reported as
Around 300 dengue cases are being hospitalized every week for
diagnosis in the city. The patients are mostly immigrants who come
from other provinces and cities looking for work, and most are living
in the slums. Since the beginning of the year , the epidemic
has killed 6 including 2 adults.
The causes of the demographic change, from children to adults, have
not yet been brought to light. However, scientists theorize the
reasons may include a decline in general disease immunity within the community.
Symptoms of dengue fever can be more severe in adults than in
children, and may include high fever, severe headaches, nausea,
vomiting, bellyache, and diarrhea. Several serious clinical signs
such as myocarditis, hepatitis, and bleeding in the digestive tract
can occur among adult patients who have been infected by Type D
dengue fever [this moderator has not heard of type D dengue fever...
see discussion below - Mod.MPP]. Other symptoms may include a high
level of ALT and AST liver enzymes, accompanied by low blood sugar
and yellow skin.
The Steering Committee for Dengue Fever Protection asked the
localities and health centers to help curb the spread of dengue fever
by providing knowledge and education about the disease, transmission,
and prevention to all people. The committee also mandates that people
who have a fever come to health centers immediately for timely treatment.
[Dengue fever, and dengue hemorrhagic fever (DHF) are caused by 4
antigenically distinct but related flaviviruses referred to as DEN-1,
DEN-2, DEN-3, DEN-4. Current thinking is that infection with one
serotype provides lifelong immunity to that specific serotype, but
cross protection is not seen, so that an individual can have dengue
more than once if exposed to different serotypes. DHF may be related
to serotype involved and prior history of other dengue infections.
(For a nice overview of dengue worldwide, see the Centers for Disease
Control and Prevention website on dengue fever at
The observation that there has been an increase in dengue cases among
the adult population in HCMC is rather curious. The possibility
exists that currently circulating serotypes (DEN-1, DEN-2, and DEN-3
-- see prior PRO/MBDS posting Dengue - Viet Nam (10): DEN-1, DEN-2,
DEN-3 20070712.2226) include a serotype that has not been in
widespread circulation for 20 years or more so that there is a large
susceptible population in early adulthood. But, according to a WHO
SouthEast Asian Regional office (SEARO) document on virological
surveillance of dengue hemorrhagic fever in Viet Nam 1987-1999, that
is not the case. (see
Report findings/conclusions included:
"- The virological surveillance during 1987-1999 offered the
circulation patterns of the predominant dengue serotype by year as
well as the viral activity cycle, e.g., DEN-1, was prominent during
1989-1996 (8 years); DEN-2 from 1987 to 1997 (11 years) and DEN-3
from 1996 to 1999, and this serotype is still active. DEN-4 emerged
strongly in 1999 and will be a health threat in the future.
- The emergence of DEN-3 in 1995 provoked the largest DHF epidemic
in 1998, and this emerging trend has been on the decrease since 1999.
- In northern Viet Nam, dengue viruses were most often recovered in
adults, while in the south, they were most often recovered in
children between the age group 5-14 years."
It would be interesting to know the geographic origin of the adult
cases, and if they predominantly were from the north of the country,
which would be in keeping with the above report's observations as well.
Another possibility is the introduction of another virus into the
region that has a clinical picture similar to dengue fever... Over
the past 2 years there has been a major resurgence of chikungunya
fever in the Indian Ocean region with geographic extension throughout
the Indian Ocean, through the subcontinent (India and Sri Lanka), and
was reported in Malaysia and as far east as Hong Kong and Indonesia
in 2006/2007. It is worth quoting the 1st-hand report submitted to
ProMED-mail from a physician in Hong Kong:
"A 66-year-old Chinese man was seen in the Prince of Wales Hospital
(PWH) Infectious Diseases clinic on 24 Mar 2006, after returning from
a one-week stay in Mauritius. He attended the clinic the same day he
returned to Hong Kong. He had already been ill with fever, headache,
myalgia, arthralgia, and a rash for 2 days. He had been visiting
relatives in rural parts of Mauritius (there is a large Chinese
population there) and had been bitten by mosquitoes. The differential
diagnosis was dengue fever in the first instance, but recent postings
in ProMED-mail (see archive numbers: 20051231.3716, 20060121.0202,
20050519.1372) alerted us to the fact that he may also have
contracted chikungunya, so this test was also requested." (see
ProMED-mail posting Chikungunya - China (Hong Kong) ex Mauritius:
conf 20060402.0989 available at <http://www.promedmail.org>).
PRO/MBDS would greatly appreciate more information on the
epidemiology and laboratory findings of the dengue situation in HCMC.
Have the adult cases had laboratory confirmation of dengue viral
infection? And if so, which serotype, and where are they geographically from?
For maps of Viet Nam with provinces, see:
and <http://www.angelfire.com/co/hongnam/vnmap.html>. - Mod.MPP]