Rates of a disfiguring infection seem to be plummeting among soldiers in Iraq. But much of that decline is due to a failure to report new
cases—and civilian doctors could miss a life-threatening form of the disease among returning vets and contractors.
cases—and civilian doctors could miss a life-threatening form of the disease among returning vets and contractors.
US Army reports fewer cases of leishmaniasis, but a complex threat persists
by Bryant Furlow
EPI NEWS
June 3, 2007—The US Army has received markedly
fewer reports of soldiers with leishmaniasis in Iraq
and Afghanistan since a major outbreak in 2003,
according to a report by the Army Medical
Surveillance Activity (AMSA) office. But medical
experts caution that much of the change may actually
be due to incomplete
case reporting rather
than fewer infections.
Known as the
"Baghdad boil" among troops, leishmaniasis is
caused by a protozoan parasite spread by biting
sand flies. It is usually a disfiguring, nonlethal skin
disease, but sometimes spreads to the spleen and
liver, causing a life-threatening visceral disease
known as kala-azar or black fever.
According to the AMSA report, at least 1,300 soldiers
have been diagnosed with "clinically significant"
cases of leishmaniasis since deployment to
Afghanistan or Iraq. Other reports put the number at
2,500. Many more are infected but have not
developed skin lesions. Mercifully few have
developed visceral leishmaniasis. Army sources are
vague about the number of visceral cases, but agree
that it is "very low." No soldiers have died of the
disease, according to Jaime Cavazos, an Army
Medical Command (MEDCOM) spokesman.
Ninety-six percent of soldiers affected are male,
according to the AMSA report, and 90 percent were
infected in Iraq. The number of civilian contractors
with leishmaniasis is unknown.
Medical intelligence warnings ignored
In October 2002, well prior to the invasions of Iraq
and Afghanistan, the US Defense Intelligence
Agency's Armed Forces Medical Intelligence Center
(AFMIC) warned that leishmaniasis would be a
danger for troops. However, military sources say that
insect repellant and bed nets were frequently in short
supply, and that many unit commanders failed to
emphasize the risk to their troops.
Reduced infection rates—and less reporting
Declining infection rates are due in part to
improvements in living conditions, sand fly eradication
efforts near US installations, and soldiers' increased
use of DEET and permethrin-treated uniforms,
experts agree.
"I believe that the reduction in cases seen in Iraq is
largely due to the reduction of exposure to sand fly
vectors through prevention and control measures
taken after the initial outbreak was observed,"
comments Richard Reithinger, a Senior Study
Director and epidemiologist at Westat. "However,
caution is warranted, as sandfly—and thus
leishmaniasis—abundance can be extremely variable
depending on seasonal rainfall and temperature."
Colonel Naomi Aronson of the Uniformed Services
University of Health Sciences further cautions that
seeming declines in leishmaniasis rates could really
be due to incomplete case reporting since 2004.
That's because Army policy during the initial 2003
outbreak required that all soldiers with confirmed
cases be evacuated to the Walter Reed Army Medical
Center for treatment. In 1991, during Operation
Desert Storm, 40 US soldiers had been diagnosed
with leishmaniasis, but 12 developed the deadly
visceral form of the disease. As an initial precaution,
Aronson explains, the Army therefore evacuated all
leishmaniasis patients from Iraq and Afghanistan.
[See the Army policy memo.] However, only 4 of the
soldiers evacuated by early 2004 had developed the
deadly visceral kala-azar, Aronson says, so
evacuations were discontinued. Instead, soldiers
were treated in Iraq or Afghanistan, where cases
frequently go unreported.
EPI NEWS
June 3, 2007—The US Army has received markedly
fewer reports of soldiers with leishmaniasis in Iraq
and Afghanistan since a major outbreak in 2003,
according to a report by the Army Medical
Surveillance Activity (AMSA) office. But medical
experts caution that much of the change may actually
be due to incomplete
case reporting rather
than fewer infections.
Known as the
"Baghdad boil" among troops, leishmaniasis is
caused by a protozoan parasite spread by biting
sand flies. It is usually a disfiguring, nonlethal skin
disease, but sometimes spreads to the spleen and
liver, causing a life-threatening visceral disease
known as kala-azar or black fever.
According to the AMSA report, at least 1,300 soldiers
have been diagnosed with "clinically significant"
cases of leishmaniasis since deployment to
Afghanistan or Iraq. Other reports put the number at
2,500. Many more are infected but have not
developed skin lesions. Mercifully few have
developed visceral leishmaniasis. Army sources are
vague about the number of visceral cases, but agree
that it is "very low." No soldiers have died of the
disease, according to Jaime Cavazos, an Army
Medical Command (MEDCOM) spokesman.
Ninety-six percent of soldiers affected are male,
according to the AMSA report, and 90 percent were
infected in Iraq. The number of civilian contractors
with leishmaniasis is unknown.
Medical intelligence warnings ignored
In October 2002, well prior to the invasions of Iraq
and Afghanistan, the US Defense Intelligence
Agency's Armed Forces Medical Intelligence Center
(AFMIC) warned that leishmaniasis would be a
danger for troops. However, military sources say that
insect repellant and bed nets were frequently in short
supply, and that many unit commanders failed to
emphasize the risk to their troops.
Reduced infection rates—and less reporting
Declining infection rates are due in part to
improvements in living conditions, sand fly eradication
efforts near US installations, and soldiers' increased
use of DEET and permethrin-treated uniforms,
experts agree.
"I believe that the reduction in cases seen in Iraq is
largely due to the reduction of exposure to sand fly
vectors through prevention and control measures
taken after the initial outbreak was observed,"
comments Richard Reithinger, a Senior Study
Director and epidemiologist at Westat. "However,
caution is warranted, as sandfly—and thus
leishmaniasis—abundance can be extremely variable
depending on seasonal rainfall and temperature."
Colonel Naomi Aronson of the Uniformed Services
University of Health Sciences further cautions that
seeming declines in leishmaniasis rates could really
be due to incomplete case reporting since 2004.
That's because Army policy during the initial 2003
outbreak required that all soldiers with confirmed
cases be evacuated to the Walter Reed Army Medical
Center for treatment. In 1991, during Operation
Desert Storm, 40 US soldiers had been diagnosed
with leishmaniasis, but 12 developed the deadly
visceral form of the disease. As an initial precaution,
Aronson explains, the Army therefore evacuated all
leishmaniasis patients from Iraq and Afghanistan.
[See the Army policy memo.] However, only 4 of the
soldiers evacuated by early 2004 had developed the
deadly visceral kala-azar, Aronson says, so
evacuations were discontinued. Instead, soldiers
were treated in Iraq or Afghanistan, where cases
frequently go unreported.
| Total reported cases for Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF), according to Army Medical Surveillance Activity: 1,287 Total cases according to Army Medical Command as of May 31, 2007: 1,300 A recent report in the Boston Globe puts the number at 2,500. Numbers have not been reported for civilian contractors' infection rates. Annual numbers of leishmaniasis diagnoses reported for active duty US soldiers (and reservists). 2001 0 (0 reservists) 2002 3 (1) 2003 481 (89) 2004 368 (91) 2005 79 (41) 2006 58 (23) |
| Further reading Army Medical Surveillance Activity (AMSA). Leishmaniasis in relation to service in Iraq/ Afghanistan, US Armed Forces, 2001-2006. Medical Surveillance Monthly Report, 2007; 14(1):2-5. Centers for Disease Control (CDC) Leishmaniasis US Army Center for Health Promotion and Preventive Medicine Leishmaniasis Iraqinfections.org |
Prior to this policy change, Aronson believes that
"virtually all clinically apparent cases" were probably
reported. "Since 2004, however, cases are treated or
clinically followed...in the deployed setting; and such
cases would likely not be accounted for in this analysis."
Reithinger agrees. "I have heard also that a big
problem for the Army is that once soldiers are back
from their tours of duty, they are lost to the Army
medical services," he says.
"Unless the U.S. Army has carried out a large
cross-sectional survey of a random sample of
soldiers—using clinical diagnosis, or even better
a so-called Montenegro skin test—it will be difficult to
estimate what the true number of infected soldiers may
have been," Reithinger says. "A clinical survey with
microscopic examination or PCR testing of
biopsies of soldiers surveyed clinically
would go a long way to establish the
true burden of leishmaniasis in
deployed military personnel."
The Montenegro skin test involves
injecting dead leishmania parasites under the skin,
similar to a tuberculosis test. However, the Army is not
utilizing such tests in the post-deployment health
assessment process, military sources say.
"The Montenegro skin test is not FDA approved for use
in the US," notes Colonel Glenn M. Wortmann of the
Walter Reed Army Medical Center. "Screening for
cutaneous leishmaniasis occurs during post-
deployment evaluations, and I believe relies mostly on
patient's complaining of skin sores."
Future problems for civilian hospitals?
"There are probably many more cases of cutaneous
Leishmaniasis than have been reported," says
Wortmann. "Fortunately, for the vast majority of
patients, the type of cutaneous leishmaniasis in Iraq
heals even without treatment, and doesn't result in long-
term problems."
That's true, other experts agree, but leishmaniasis can
take many months—in some cases, over a year—to
develop. Perhaps the greatest concern is that visceral
infections will go undiagnosed by civilian doctors
unfamiliar with its symptoms.
"Both cutaneous and visceral leishmaniasis have a so-
called pre-patent period—the time between actual
infection and the onset of symptoms," explains
Reithinger. Pre-patent periods are extremely variable
and range from two weeks onwards, he says.
A 2004 AMSA report expresses similar concerns, noting
that visceral leishmaniasis "can be clinically inapparent
for long periods, and the first clinical manifestations can
be non-specific and difficult to diagnose—especially
when they present to practitioners ...who are unfamiliar
or have no experience with the disease."
Reithinger points out that in Spain and France, co-
infection of leishmaniasis and HIV/AIDS is "becoming
quite an important issue."
"It is perfectly feasible that a soldier gets infected,
presents no signs, becomes immuno-suppressed years
later and then develops the clinical signs," he says.
"Physicians and other primary care providers should
include leishmaniasis among possible diagnoses among
veterans of military service in Iraq, Afghanistan, or
Kuwait," recommends Col. Aronson.
The AMSA study was funded by the US Army Center for
Health Promotion and Preventive Medicine (CHPPM).
"virtually all clinically apparent cases" were probably
reported. "Since 2004, however, cases are treated or
clinically followed...in the deployed setting; and such
cases would likely not be accounted for in this analysis."
Reithinger agrees. "I have heard also that a big
problem for the Army is that once soldiers are back
from their tours of duty, they are lost to the Army
medical services," he says.
"Unless the U.S. Army has carried out a large
cross-sectional survey of a random sample of
soldiers—using clinical diagnosis, or even better
a so-called Montenegro skin test—it will be difficult to
estimate what the true number of infected soldiers may
have been," Reithinger says. "A clinical survey with
microscopic examination or PCR testing of
biopsies of soldiers surveyed clinically
would go a long way to establish the
true burden of leishmaniasis in
deployed military personnel."
The Montenegro skin test involves
injecting dead leishmania parasites under the skin,
similar to a tuberculosis test. However, the Army is not
utilizing such tests in the post-deployment health
assessment process, military sources say.
"The Montenegro skin test is not FDA approved for use
in the US," notes Colonel Glenn M. Wortmann of the
Walter Reed Army Medical Center. "Screening for
cutaneous leishmaniasis occurs during post-
deployment evaluations, and I believe relies mostly on
patient's complaining of skin sores."
Future problems for civilian hospitals?
"There are probably many more cases of cutaneous
Leishmaniasis than have been reported," says
Wortmann. "Fortunately, for the vast majority of
patients, the type of cutaneous leishmaniasis in Iraq
heals even without treatment, and doesn't result in long-
term problems."
That's true, other experts agree, but leishmaniasis can
take many months—in some cases, over a year—to
develop. Perhaps the greatest concern is that visceral
infections will go undiagnosed by civilian doctors
unfamiliar with its symptoms.
"Both cutaneous and visceral leishmaniasis have a so-
called pre-patent period—the time between actual
infection and the onset of symptoms," explains
Reithinger. Pre-patent periods are extremely variable
and range from two weeks onwards, he says.
A 2004 AMSA report expresses similar concerns, noting
that visceral leishmaniasis "can be clinically inapparent
for long periods, and the first clinical manifestations can
be non-specific and difficult to diagnose—especially
when they present to practitioners ...who are unfamiliar
or have no experience with the disease."
Reithinger points out that in Spain and France, co-
infection of leishmaniasis and HIV/AIDS is "becoming
quite an important issue."
"It is perfectly feasible that a soldier gets infected,
presents no signs, becomes immuno-suppressed years
later and then develops the clinical signs," he says.
"Physicians and other primary care providers should
include leishmaniasis among possible diagnoses among
veterans of military service in Iraq, Afghanistan, or
Kuwait," recommends Col. Aronson.
The AMSA study was funded by the US Army Center for
Health Promotion and Preventive Medicine (CHPPM).
Military Disease Surveillance
The global distribution of leishmaniasis. (Source: http://www.geo.arc.nasa.gov)
'It will be difficult to estimate
the true number of infected
soldiers'
the true number of infected
soldiers'
Returning soldiers and contractors who harbor infections
could go undiagnosed by civilian doctors unfamiliar with
leishmaniasis
could go undiagnosed by civilian doctors unfamiliar with
leishmaniasis
Leishmaniasis Facts
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