Unprotected People Reports: Rabies
Florida Man Dies from Rabies Eight Months After Receiving Dog Bite in Haiti
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|The Immunization Action Coalition (IAC)
publishes articles about people who have suffered or died from
vaccine-preventable diseases and periodically devotes an IAC Express issue
to such an article. This is the 78th in our series.
|The following case report recounts the experience of a man hospitalized for
four days before dying from undiagnosed rabies. The man's wife reported he
had been bitten on the finger by a dog on a visit to Haiti eight months
prior to hospitalization. Postmortem laboratory tests conducted by CDC
determined the cause of death was a canine variant of the rabies virus
present in Haiti.
|Titled "Human Rabies--Florida, 2004," the case report first appeared in MMWR
on August 12, 2005. It is reprinted below in its entirety with the exception
of footnotes and acknowledgements.
|Rabies is a viral infection of the central nervous system, usually
contracted from the bite of an infected animal, and nearly always fatal
without postexposure prophylaxis. In February 2004, a man aged 41 years died
after a 4-day hospitalization in Broward County, Florida. A diagnosis of
rabies was considered on the day before the patient's death; however, no
antemortem samples were obtained for testing. In March 2004, postmortem
samples of fixed brain material were sent to CDC, where laboratory testing
confirmed a diagnosis of rabies, the 47th case of human rabies reported in
the United States since 1990 (CDC, unpublished data, 2005). This report
summarizes results of the subsequent investigation led by the Broward County
Health Department and laboratory testing at CDC, which determined that the
rabies virus was a canine variant present in Haiti, where the man had
traveled and reportedly been bitten by a dog. Rabies should be considered in
persons after a dog bite, especially if the bite occurs in a country where
canine rabies is enzootic.
The man arrived at the hospital emergency department with a 2-day history of
dysphagia accompanied by hyperventilation and agitation when he attempted to
swallow liquids. The problem had worsened by the time of admission; he was
noted as "almost phobic" to liquids. The patient reported having a brief
period of mild fever. He was able to swallow soft, solid food and did not
complain of throat pain or discomfort. Upon physical examination of his
mouth and throat, the patient became agitated and experienced
hyperventilation. He was admitted for further observation and diagnostic
evaluation. On the day of admission, a neurology consultant concluded that
the dysphagia etiology was unknown and recommended infectious disease,
gastrointestinal, and pulmonary consultations. Examination results by a
gastrointestinal consultant on the same day were unremarkable, except for
dysphagia and phobia to liquids.
The patient reported a history of malaria and ureteral stricture and
surgery. Magnetic resonance imaging study results were unremarkable. Results
of examinations of the patient's ear, nose, and throat, including a swallow
test (i.e., cervical esophagram), and radiographs of neck and soft tissue
were normal. Because examination elicited substantial agitation and
hyperventilation in the patient, anti-anxiety medical management was
instituted, and the patient was referred for psychiatric evaluation.
On his third day of hospitalization, the patient had a consistent fever of
103 degrees F (39.4 degrees C) and an elevated white blood cell count of
14.5/microliter (normal: 3.6-11.0/microliter). An infectious disease
consultant recommended a lumbar puncture and testing for viral illness,
especially rabies. The patient's wife reported that her husband had been
bitten on the fingertip by a dog 8 months earlier while he was visiting
Haiti. The wife reported that the dog was still alive; however, that could
not be confirmed by investigators. She said her husband had not traveled
back to Haiti during the interim. Anti-malarial treatment of the patient
also was empirically initiated pending the results of malaria testing.
On the fourth day of hospitalization, the patient experienced diplopia and
was decreasingly responsive. He went into cardiopulmonary arrest and died.
Antemortem rabies testing was under consideration, but the patient died
before samples were collected. On histopathologic examination of the
cerebral cortex, pons, hippocampus, and spinal cord, the medical examiner
described cytoplasmic inclusions consistent with Negri bodies. Unstained
slides of formalin-fixed samples of brain material were sent to CDC for
diagnosis and typing. Rabies virus antigen was detected by a modification of
the direct fluorescent antibody test. A reverse transcription-polymerase
chain reaction assay produced an amplicon sequence that was compatible with
a canine rabies-virus variant present in Haiti. This variant has not been
documented among domestic or wild animal reservoirs in the United States.
One close family member underwent postexposure prophylaxis for exposure to
the patient's secretions.
Of the 47 cases of human rabies reported in the United States since 1990,
four occurred in organ transplant recipients and were associated with an
undetected case of rabies in a single organ donor; the remainder apparently
were acquired from contact with animals with rabies virus infections.
Thirty-eight (81%) of the infections were acquired in the United States.
Among the nine infections acquired elsewhere, two were acquired in Haiti
(the 2004 case described in this report and a 1994 case), two in Mexico
(1993 and 1994), and one each in India (1992), Southeast Asia (1996), Ghana
(2000), the Philippines (2001), and El Salvador (2004).
The greatest risk for naturally acquired rabies in the United States is from
encounters with and bites from insectivorous bats. In particular, a
rabies-virus variant associated with two small-bodied bats, the eastern
pipistrelle bat (Pipistrellus subflavus) and silver-haired bat (Lasionycteris
noctivagans) was identified in 20 (69%) of 29 persons with samples tested.
Human rabies is preventable if the exposure is recognized and the patient
receives appropriate wound care and postexposure prophylaxis before clinical
signs of rabies are evident. Postexposure prophylaxis consists of rabies
immune globulin infiltrated at the site of the exposure and 1 dose of rabies
vaccine administered in the deltoid (or anterolateral thigh of infants and
small children) on days 0, 3, 7, 14, and 28. When applied appropriately,
this combination has been effective in preventing death after an exposure.
However, the continued availability of rabies vaccine currently relies upon
only one licensed manufacturer in the United States; a second manufacturer
suspended and has not resumed production after a voluntary recall of its
rabies vaccine in March 2004.
In the United States, mandatory vaccination and stray-dog control programs
have virtually eliminated circulation of any canine rabies-virus variant
among dogs. In comparison, occurrence of rabies in dogs remains a problem in
Haiti and other developing countries. Because of the risk for rabies
exposure in these countries, travelers are advised to avoid contact with
dogs and other animals, and rabies pre-exposure prophylaxis (consisting of 3
intramuscular doses of rabies vaccine on days 0, 7, and 21 or 28) is
recommended for persons planning to stay 30 or more days in remote areas
without access to medical facilities. The patient described in this
investigation reportedly was bitten by a dog in Haiti 8 months before
clinical signs of rabies became evident. This was the longest incubation
period among 12 U.S. rabies cases with exposure history reported since 1997
(median: 39 days; range: 21-240 days); however, longer incubation periods of
11 months to 6 years were suggested by findings in three cases previously
Although human rabies is rare in the United States, it should be considered
in the postmortem differential diagnosis of fatal viral encephalitis cases
with short morbidity periods if no cause of disease has been established.
Hospitalized patients with encephalitis of unknown etiology should be on
contact precautions, and rabies should be part of antemortem differential
diagnosis in these patients. Both antemortem and postmortem testing for
rabies are available at CDC and can be arranged through state health
departments. Antemortem diagnostic samples consist of a full thickness skin
biopsy (4-6 mm in diameter) from the nape of the neck, fresh saliva, serum,
and cerebrospinal fluid. Although postmortem rabies diagnosis can be
performed on formalin-fixed brain material, fresh brain material provides
the optimal sample for maximum sensitivity, specificity, and time
With the recent report from Wisconsin of a
survivor of clinical rabies, rapid diagnosis of rabies is even more critical
to managing a patient's clinical course, despite a poor prognosis. In
addition to enabling consideration of novel interventions, advantages of
early diagnosis include prompt implementation of appropriate
infection-control measures, thereby limiting the number of persons exposed
or potentially exposed who require postexposure prophylaxis. Retrospective
detection of four transplant-associated rabies cases and retrospective
identification of an additional case in California in an immigrant from El
Salvador, brought the total number of 2004 cases in the United States to
eight, the highest number of human rabies cases reported since 1956, when 10
cases were reported.
|8/12/05 • REPORT #78
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