VIROLOGY NEWS
Human Rabies -- New York, 1993
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SOURCE: MMWR 42(41) DATE: Oct 22, 1993
In August 1993, a fatal case of human rabies in an 11-year-old girl was
reported to the New York State Department of Health; this was the first
indigenously acquired fatal case diagnosed in New York in 39 years. This
report summarizes the investigation of this case.
On July 5, the girl complained of pain in the knuckles on her left hand.
During July 6-7, she had increasing pain that extended up to the left
shoulder. On July 8, a pediatrician diagnosed musculoskeletal pain and
bilateral ear effusions; a throat culture was obtained and amoxacillin was
prescribed.
On July 9, the patient developed fever, severe muscle spasms of the left
arm, difficulty walking, and hallucinations. On evaluation in an emergency
department on July 10, she had fever (101.1 F {38.6 C}), otitis media in her
left ear, nonexudative pharyngitis, and a maculopapular rash on the chest;
there were no focal neurologic or meningeal signs. The throat culture obtained
July 8 was positive for presumed streptococcus group A, and recurrent
streptococcal pharyngitis and otitis media were diagnosed. She was treated
with intravenous ceftriaxone, normal saline, and oral anti-pyretics and was
discharged with a prescription for cefaclor.
She subsequently would not drink, withdrew when offered a drink, and had
difficulty swallowing oral secretions. On evaluation in a hospital emergency
department on July 11, she had a temperature of 105.3 F (40.7 C), mild
meningismus but no focal neurologic findings; a white blood cell (WBC) count
was elevated at 13,300. A lumbar puncture revealed 23 WBCs per cubic
millimeter (mm superscript 3) (100% lymphocytes) and 1200 red blood cells per
mm superscript 3. Viral meningoencephalitis or meningococcal infection was
diagnosed. She was treated with ceftriaxone and dexamethasone intravenously
and transported by helicopter ambulance to a tertiary-care medical center.
On admission to the pediatric intensive-care unit, she was alert,
oriented, and cooperative but agitated; her pupils were unequal but reactive.
Acyclovir was added to her treatment regimen. The patient developed
respiratory distress, hypertension, and tachycardia and was placed on
mechanical ventilation; cardiac arrhythmias subsequently occurred, and she
suffered nonreversible cardiac arrest.
An autopsy was performed on July 12; although unfixed brain tissue was
not obtained for viral or bacterial diagnosis, cerebral edema was noted.
During August 2-3, examination of routine histopathologic slides of brain
tissue revealed encephalitis with severe involvement of the midbrain, pons and
medulla, and possible Negri bodies. Culture of cerebrospinal fluid (CSF)
obtained July 11 for rabies virus and tests of serum and CSF for rabies
antibody were negative at the New York State Department of Health. However,
specimens tested by the rabies fluorescent antibody technique (FA) indicated
fluorescent inclusions in the brain stem, midbrain, and Purkinje cells of the
cerebellum. Rabies diagnosis was confirmed at CDC by FA testing and histologic
examination of formalin-fixed and paraffin-embedded tissue. The RNA extracted
from formalin-fixed brain tissue was reverse transcribed and amplified by
polymerase chain reaction. The nucleotide sequence identified a viral variant
associated with rabies in insectivorous bats.
The patient lived in a heavily wooded area of the Catskill Mountains and
had no history of foreign travel. She had no known history of contact with a
bat, and examination of her home and outbuildings on the property revealed no
evidence of bat infestation. She had been active outdoors, and her family kept
horses, dogs, cats, rabbits, hamsters, and gerbils as pets; none of these pets
had died with clinical signs consistent with rabies or disappeared. A survey
of all neighbors on the same road indicated that no pets had died with
clinical signs consistent with rabies or disappeared during the preceding 6
months.
As a result of close contact with the patient and/or her secretions,
rabies postexposure prophylaxis was administered to 55 persons, including
eight family members, three friends, 35 health-care workers, five members of
the autopsy team, three transport personnel, and one mortician.
Reported by: JG Debbie, DVM, S Frantz, PhD, LF Novick, MD, CV Trimarchi, MS,
GS Birkhead, MD, Acting State Epidemiologist, New York State Dept of Health; M
Baker, MD, D Hill, MD, R Fuchs, MD, Pediatric Associates, Middletown; M
Valsamis, MD, C Vallejo, MD, B Roseman, MD, S Schroeder, MD, Westchester
County Medical Center, Valhalla. Viral and Rickettsial Zoonoses Br, Div of
Viral and Rickettsial Diseases, National Center for Infectious Diseases, CDC.
Editorial Note: Human rabies in the United States is uncommon, primarily
because of canine rabies-control programs and access to improved human rabies
biologicals. Since 1980, 16 human rabies cases have been reported in the
United States. Of these, seven were acquired from exposure outside the United
States; for nine of the 16 cases, no definitive history of exposure was
identified. Potential reasons for the failure of public health authorities to
establish definitive exposures include unrecognized exposure, communication
(i.e., language) barriers, and memory loss and impaired speech because of
encephalitis at presentation. Rabies is not usually diagnosed when patients
initially receive medical evaluation. Since 1980, of the 16 persons with
rabies diagnosed in the United States, rabies was diagnosed postmortem in
nine. In addition, six cases of human-to-human transmission were diagnosed
postmortem among recipients of transplanted corneas, whose donors died of an
illness unrecognized as rabies (1).
Although rabies occurs rarely in the United States, it should be
considered in the differential diagnosis of any acute progressive encephalitis
of unknown etiology. In the absence of a clear history of animal exposure, the
diagnosis of rabies may be difficult because of the nonspecific nature of
initial clinical presentation. In addition to encephalitis, other
manifestations suggestive of rabies in the case described in this report
included paresthesia, hydrophobia, and copious salivation. Antemortem
diagnosis of human rabies is possible through laboratory analysis of CSF,
serum, saliva, and biopsy of nuchal skin or brain tissue. Although an early
suspicion of rabies does not alter the prognosis, it may permit both
institution of measures to reduce the number of persons exposed to rabies
during patient care and identification of persons who are candidates for
postexposure prophylaxis. Consultation with state and federal health officials
is recommended for human rabies evaluation.
The case in this report is the sixth since 1980 in which insectivorous
bats were implicated. A definite history of exposure through a bat's bite was
identified for only one of the six cases, while contact with a bat was
associated with two additional cases; for three cases, the nature of exposure
was not determined, but bat rabies variants were identified by molecular
typing.
Bat rabies is enzootic in the United States, and cases have been reported
from all of the 48 contiguous states (2). The rabies virus variant identified
in this case, and in three of the other five occurring since 1980, is
associated with the silver-haired bat (Lasionycteris noctivagans), a solitary,
migratory species, with a preferred habitat of old-growth forest. This species
is infrequently submitted for rabies diagnosis. For example, of 7047 bats
submitted for rabies diagnosis and identified to species in New York from 1988
through 1992, 25 (0.4%) were L. noctivagans; of these, two were rabid (C.
Trimarchi, New York State Department of Health, unpublished data, 1993). The
rabies virus variant associated with this species (identified in 11 of 12
isolates from silver-haired bats) was rarely found in other bats (five {2.1%}
of 238 samples tested) or in terrestrial mammals (five {0.7%} of 700 samples).
Exposure to potentially rabid animals (e.g., paralyzed bats) should be
avoided. Postexposure prophylaxis is recommended for all persons bitten or
scratched by such animals and for nonbite exposures involving contamination of
lesions or mucous membranes with saliva or other potentially infectious
materials (3). Bat bites may be more difficult to recognize than those
inflicted by terrestrial animals. Treatment should be considered for any
physical contact with bats when bite or mucous membrane contact cannot be
excluded. Because reduction of bat populations is neither feasible nor
desirable as a means for controlling rabies in bats, efforts to prevent this
problem should be directed toward the exclusion of bats from human dwellings
to minimize direct contact with humans and companion animals. In addition, all
dogs and cats in the 48 contiguous states and Alaska should have a current
rabies vaccination (4).
References
1. Gode GR, Bhide NK. Two rabies deaths after corneal grafts from one donor.
Lancet 1988;2:791.
2. Krebs JW, Holman RC, Hines U, Strine TW, Mandel EJ, Childs JE. Rabies
surveillance in the United States during 1991. J Am Vet Med Assoc
1992;201:1836-48.
3. ACIP. Rabies prevention -- United States, 1991: recommendations of the
Immunization Practices Advisory Committee (ACIP). MMWR 1991;40(no. RR-3).
4. CDC. Compendium of animal rabies control, 1993: recommendations of the
National Association of State Public Health Veterinarians, Inc. MMWR
1993;42(no. RR-3).
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Sorry for the previous blank posting, fatal case of keyboard clumsiness.
I hope this one works OK.
Dr. Ruben Donis
Dept. of Veterinary and Biomedical Sciences
202 VBS
University of Nebraska,
Lincoln, NE 68583-0905
Phone: 402-472-6063
FAX to 402-472-9690
