Possible Origin Of Haiti Cholera Outbreak Found
PORT-AU-PRINCE, HAITI -- The Haitian Ministry of Public Health and
Population has received the results of laboratory testing showing that
the cholera strain linked to the current outbreak in Haiti is most
similar to cholera strains found in South Asia. More information about
this strain, including the possibility that it might be found in other
regions of the world, is anticipated from additional studies. The
findings were reported as part of laboratory collaboration between the
National Public Health Laboratory (NPHL) in Haiti and the U.S. Centers
for Disease Control and Prevention (CDC) in Atlanta.
The rapid identification of the outbreak strain as Vibrio cholerae
serogroup O1, serotype Ogawa and antimicrobial susceptibility profiles
were reported last week by the NPHL. The new findings from CDC's
laboratory are based on a method of "DNA fingerprinting" called pulsed
field gel electrophoresis (PFGE), which analyzes DNA patterns that can
then be compared with PFGE patterns of cholera strains from other
regions of the world. The PFGE testing was performed on 13 bacterial
isolates recovered from patients with cholera in Haiti. The PFGE
analysis shows that these isolates are identical, indicating that they
are the same strain and similar to a cholera strain found in South Asia.
The lab findings are not unexpected and provide information about the
relatedness of the cholera outbreak strain to strains found elsewhere in
the world.
"Although these results indicate that the strain is non-Haitian, cholera
strains may move between different areas due to global travel and
trade," said Minister of Health Dr. Alex Larsen. "Therefore, we will
never know the exact origin of the strain that is causing the epidemic
in Haiti. This strain was transmitted by contaminated food or water or
an infected person."
Global travel and trade provide many opportunities for infectious
diseases such as cholera to spread from one country to another. In most
instances, cholera does not spread widely within a country if drinking
water and sewage treatment are adequate. When water and sewage treatment
is inadequate, as in post-earthquake Haiti, cholera can spread rapidly.
Current preventive measures being used to control the outbreak include
treating ill people with oral rehydration solution, providing access to
safe water, and encouraging good hygiene and sanitation practices. The
Haitian Ministry of Public Health and Population is leading a response
that prioritizes measures to protect families at the community level,
strengthen primary health care centers already operating across the
nation, and establish a network of special cholera treatment centers and
designated hospitals for treatment of severe cases.
In the coming weeks, additional laboratory testing, including whole
genome DNA sequencing will be conducted, but investigating officials
note that such testing may never fully explain how cholera was
introduced into Haiti.
"Our primary focus here is to save lives and control the spread of
disease," said CDC medical epidemiologist Dr. Jordan Tappero, who is
leading the CDC cholera response team in Haiti. "We realize that it's
also important to understand how infectious agents move to new
countries. However, we may never know the actual origin of this cholera
strain."
CDC, in collaboration with the U.S. government through U.S. Agency for
International Development, is assisting the government of Haiti, the Pan
American Health Organization, and several other international health
agencies in this outbreak.
