Issue
Number 309
April 22, 2002
UNPROTECTED PEOPLE: Stories of
people who have suffered or died from vaccine-preventable diseases
Story #44:
FATAL YELLOW
FEVER IN A TRAVELER RETURNING FROM
AMAZONAS, BRAZIL, 2002
----------------------------------------------------------
Back to Top
(1 of 1)
April 22, 2002
UNPROTECTED PEOPLE #44: "FATAL YELLOW FEVER IN A TRAVELER
RETURNING FROM AMAZONAS, BRAZIL, 2002"
On April 19, 2002, the Centers for Disease Control and
Prevention (CDC) published "Fatal Yellow Fever
in a Traveler Returning from Amazonas,
Brazil, 2002" in the Morbidity and Mortality
Weekly Report (MMWR, vol. 51, no.15). The
article describes the case of a previously healthy
47-year-old male who traveled to Brazil for a
fishing trip in March of this year, contracted yellow
fever, returned to his home state of Texas,
became severely ill, and died. The man's death is
the third reported death from yellow
fever in a U.S. citizen following travel to
the Amazon region since 1996, according to the
Editorial Note to the article.
The Immunization Action Coalition (IAC) is republishing
this story as the 44th in our series of stories
about people who have suffered or died from
vaccine-preventable diseases. We usually try to
choose stories that are
written for a general audience. Sometimes, however, a
powerful story appears in a technical
medical or public-health source that we think almost all readers will
appreciate. Today's MMWR story about an
adult traveler's death from yellow fever infection
contains information for clinicians and
epidemiologists, but it also provides case details
that are useful for all international travelers.
Many of us in the United States do not even know what
yellow fever is; it's a viral disease found in parts
of Africa and South America that is
transmitted by mosquito bite. The fatality rate
for the disease is approximately
20 percent.
Travelers, even if your tour group or company informs you
that yellow fever vaccination certification is
not required in the country or countries
you plan to visit, please consult with a travel
medicine specialist and weigh
the minor inconvenience and cost of getting vaccinated
against the possible cost of serious or
even fatal illness. (Please note that the person
whose death is documented in this article was
given incorrect advice about vaccination
from his travel agency, as you will read.) This is a
simple, one-dose vaccine that lasts 10
years. It can be received at a designated yellow
fever center, typically a local health
department. As the Editorial Note to this article states,
vaccination should be obtained at least 10
days before departure in order to allow for
an adequate immune response.
To see the Centers for Disease Control and Prevention
(CDC) Comprehensive Yellow Fever
Vaccination Requirements web page, which includes
a list of the countries for which vaccination is
required or recommended, go to:
http://www.cdc.gov/travel/yfever.htm
For general information on yellow fever, go to the CDC
Yellow Fever Disease and Vaccine web page at:
http://www.cdc.gov/ncidod/dvbid/yellowfever/index.htm
The entire article reads as follows:
******************************
Yellow fever (YF) is a mosquitoborne viral disease that
has caused deaths in U.S. and European
travelers to sub-Saharan Africa and tropical South America (1-5). Although
no specific treatment exists for YF and the
case-fatality rate for severe YF is approximately
20%, an effective vaccine is available
(6). This report describes a case of fatal
YF in an unvaccinated traveler who had returned from
a 6-day fishing trip on the Rio Negro west
of Manaus in the state of Amazonas, Brazil.
Because information from some commercial
outfitters and travel agents might underestimate
health risks, health-care providers and
travelers should review vaccination and other traveler's
health recommendations from public health
agencies.
On return from Brazil on March 10, 2002, a previously
healthy man aged 47 years from Texas
presented to an emergency department (ED) with a
4-day history of crampy abdominal pain and a 1-day
history of fever of 102.8 degrees F (39.3 degrees
C) and severe headache. At the ED, he received
symptomatic treatment and doxycyline for a
possible rickettsial disease and was discharged. His fever
and headache worsened, and on March 12 he was hospitalized
for intractable vomiting.
On admission, physical examination revealed an ill-appearing, febrile man.
Laboratory tests documented leukopenia (2,300/mm3
[normal: 4,800-10,800/mm3]), anemia (hemoglobin
10.5 g/dL [normal: 14-18 g/dL]),
thrombocytopenia (36,000/mm3 [normal: 150,000-450,000/mm3]), abnormal
coagulation (prothrombin time: 29
seconds [normal: 10.5-13.0 seconds] and INR 6.3), renal
failure (creatinine: 5.5 mg/dL [normal:
0.6-1.0 mg/dL] and blood urea nitrogen: 65 mg/dL
[normal: 6--20 mg/dL]), and liver
failure (ALT: 7,600 U/L [normal: 30--65 U/L],
AST: 13,700 U/L [normal: 15--37 U/L], and bilirubin: 3.3
mg/dL [normal: 0--1.0 mg/dL]). The patient was
presumptively treated for malaria. Bacterial cultures of
blood, urine, and cerebrospinal fluid showed no growth,
and a malaria smear of peripheral blood was
negative. Three days after admission, the patient
developed shock, seizures, and excessive bleeding
at venipuncture sites; he
died the following day.
Tests performed at CDC on serum samples collected on the
second day of illness were negative for IgM
and IgG antibody to South American arboviruses
(i.e., YF, dengue, St. Louis encephalitis, and
Venezuelan equine encephalomyelitis
viruses); serum samples collected on days 3-7 also
were negative for IgM and IgG antibody to YF
virus. Serum specimens collected on days 4, 5, and 7 of
illness and a postmortem liver sample were
positive for YF virus RNA by RT-TaqMANT PCR tests.
Virus isolation was attempted by inoculation of
serum samples onto Vero and AP-61 cells in tissue
culture, and by inoculation of
postmortem plasma onto Vero cells in tissue culture and
intracerebrally into suckling mice. No virus was recovered.
Histopathologic examination of a postmortem percutaneous
needle sample of the liver demonstrated
massive acidophilic hepatocellular necrosis with
minimal inflammation. Immuno-histochemistry (IHC)
tests using a cross-reactive, polyclonal
flavivirus antibody and a polyclonal YF-virus--specific antibody
were positive. IHC tests for New World arenaviruses (Machupo,
Guanarito, and Sabia viruses), spotted
fever rickettsiae, dengue virus, and Leptospira
spp. were negative. A postmortem serum sample was
negative for IgM and IgG antibody to Leptospira
spp. and New World arenaviruses, and negative for
Machupo virus by ELISA antigen capture. A
blood sample collected on day 2 was negative for
malaria by PCR test.
The deceased traveler was one of 15 U.S. citizens who
visited the Amazon as part of a fishing trip. The
patient slept aboard an air-conditioned
fishing boat and wore DEET-impregnated clothing
while fishing. Before traveling
to the Amazon, the traveler had not received medical
consultation, YF vaccine, or malaria
prophylaxis. Information on the outfitter's
website stated, "The International medical
community suggests yellow fever and
malaria prophylaxis for the Amazon region. This is not a
requirement to enter Brazil, but merely a
suggestion." A brochure from the group's travel
agent stated, "We do not suggest
any inoculations of any kind for this trip.... But
to make sure you are worry free, consult with your
personal physician."
The 15 U.S. citizens living aboard this
fishing boat (including the patient) were
interviewed or investigated by the Texas
Department of Health. Other than the patient, none
reported febrile illnesses. Eight (53%) were
appropriately vaccinated for YF according to World Health
Organization (WHO) guidelines (i.e.,
within the preceding 10 years and 10 or more days
before arrival in Manaus). Of the
seven that were not appropriately vaccinated, one had
received YF vaccine 11 years earlier, one had
been vaccinated 5 days before arrival in
Manaus, and one was unsure whether he had been
vaccinated in the military >30
years earlier. Of the four persons (including the patient)
who were never vaccinated, three stated
that they had been "unconcerned" about the risk
for YF. Three (20%) of the 15 reported
taking malaria prophylaxis.
Reported by: P Hall, MD, M Fojtasek, MD, J Pettigrove, MD,
Corpus Christi Medical Center--Bay Area; N
Sisley, MD, Corpus Christi-Nueces County Public
Health District, Corpus Christi, Texas. J Perdue,
K Hendricks, MD, S
Stanley, MD, D Perrotta, PhD, Texas Dept of Health. AA
Marfin, MD, GL Campbell, MD, RS Lanciotti,
PhD, LR Petersen, MD, Div of Vector-Borne
Infectious Diseases; PE Rollin, MD, TG
Ksiazek, PhD, Div of Viral and Rickettsial
Diseases; MS Cetron, MD, D Sharp, MD, Div of Global
Migration and Quarantine, National Center for Infectious
Diseases; KG Julian, MD, EIS Officer, CDC.
Editorial Note:
This case represents the third reported YF death in a U.S.
citizen following travel to the Amazon region
since 1996 (1,2). YF can initially manifest
as fever, headache, myalgias, arthralgias,
epigastric pain, or vomiting (6).
Illness can progress to liver and renal failure, and
thrombocytopenia and abnormal coagulation
can cause hemorrhagic symptoms and signs.
Definitive diagnosis is made by viral culture
of blood or tissue specimens or by
identification of YF virus antigen or nucleic acid in
tissues (especially liver) using IHC, ELISA
antigen capture, or PCR tests. Although antibodies
are not always present in the first week of
illness, detection of YF-specific IgM antibody by capture ELISA with
confirmation of >4-fold rise in
neutralizing antibody titers between acute- and
convalescent-phase serum samples also
is diagnostic.
On returning home, viremic travelers can establish new
foci of YF transmission where susceptible
vectors are present. The geographic range of Aedes
aegypti, a mosquito that transmits YF virus among
humans, includes the southern United
States. Patients with suspected or confirmed YF
should be isolated from contact with mosquitoes
during at least the first 5 days of illness, and local or state
health departments must be notified
immediately (7). YF is one of three diseases
(along with cholera and plague)
designated by the International Health Regulations as
internationally quarantinable and requires
international reporting of all suspected and
confirmed cases within 24 hours (8).
Commercial outfitters and travel agents should ensure that
health information provided to travelers is
consistent with CDC and WHO YF vaccination and
malaria prophylaxis recommendations.
Undervaccination of travelers at risk for
YF might be an increasing problem. Using a mathematical
model based on U.S. arrivals to countries where YF
transmission occurs and on YF vaccine doses sold
to U.S. civilians, overall coverage among U.S.
travelers to regions where YF is endemic might
have declined 50% from
1992 to 1998 (9). The degree to which inaccurate health
information contributes to apparently
decreasing coverage is unknown.
Because of the severity of YF illness, the potential for
epidemics, and the availability of an efficacious
vaccine, CDC recommends vaccination of
persons aged 9 months or greater traveling to
nonurban areas where YF is endemic
(i.e., sub-Saharan Africa and tropical South America,
including Amazonas states in Brazil and
Venezuela). To allow for an adequate immune
response, vaccination should be
completed at least 10 days before travel. Some countries,
other than the United States, require YF
vaccination for travelers returning from countries
where YF is endemic and may impose quarantine if
the traveler does not have official
vaccination documentation or a written medical waiver.
Although recent reports described
occurrence of severe systemic illness potentially
related to recent YF vaccination (10), the rarity
of these events does not warrant changes in YF
vaccination recommendations. Before
international travel, persons should review CDC
recommendations (http://www.cdc.gov/travel)
for prevention of vectorborne and other
travel-related diseases.
References
- McFarland JM, Baddour LM, Nelson JE, et al. Imported
yellow fever in a United States citizen. Clin
Infect Dis 1997;25:1143-7.
- CDC. Fatal yellow fever in a traveler returning from
Venezuela, 1999. MMWR 2000;49:303-5.
- Barros MLB, Boecken G. Jungle yellow fever in the
central Amazon. Lancet 1996;348:969-70.
- World Health Organization. Yellow fever,
1998-1999. Wkly Epidem Rec 2000;75:322-8.
- World Health Organization. Outbreak news: imported case
of yellow fever, Belgium (update). Wkly Epidem Rec
2001;76:365.
- Monath TP. Yellow fever. In: Plotkin SA, Orenstein WA,
eds. Vaccines. 3rd ed. Philadelphia, Pennsylvania: WB
Saunders, 1999:815-79.
- Chin J, ed. Control of communicable diseases manual.
17th ed. Washington, DC: American Public Health
Association, 2000.
- World Health Organization. International health
regulations (1969): 3rd annotated ed. Geneva,
Switzerland: World Health Organization, 1983.
- Monath TP, Cetron MS. Preventing yellow fever in
travelers to the tropics. Clin Infec Dis (in press).
- CDC. Fever, jaundice, and multiple organ system
failure associated with 17D-derived yellow fever
vaccination, 1996-2001. MMWR 2001;50:643-5.
******************************
To view this article on CDC's website, go to:
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5115a2.htm
To obtain a camera-ready (PDF format) copy of this entire
issue of MMWR, go to:
http://www.cdc.gov/mmwr/PDF/wk/mm5115.pdf
To see other IAC Unprotected People stories in either HTML
or camera-ready (PDF) format, go to:
http://www.immunize.org/stories
DISCLAIMER: The Immunization Action Coalition (IAC)
publishes Unprotected People stories for the
purpose of making them available for our readers' review. We have not
verified this story's content, for which the authors are
solely responsible.
DO YOU KNOW OF STORIES OF UNPROTECTED PEOPLE? Please let
us know if you have personal stories of people who have
suffered or died from vaccine-preventable diseases or if
you know of stories that have appeared in the media
describing suffering that occurred because someone was not
immunized. Send your stories or case reports to IAC
Express by email to kristine@immunize.org or by
fax to (651) 647-9131.
|
