Rabies is a viral infection of the central nervous system, usually contracted
from the bite of an infected animal, and is nearly always fatal without proper
postexposure prophylaxis (PEP).1 In October
2004, a previously healthy female aged 15 years in Fond du Lac County, Wisconsin,
received a diagnosis of rabies after being bitten by a bat approximately 1
month before symptom onset. This report summarizes the investigation conducted
by the Wisconsin Division of Public Health (WDPH), the public health response
in Fond du Lac County, and the patient’s clinical course through December
17. This is the first documented recovery from clinical rabies by a patient
who had not received either pre- or postexposure prophylaxis for rabies.
While attending a church service in September, the girl picked up a
bat after she saw it fall to the floor. She released the bat outside the building;
it was not captured for rabies testing, and no one else touched the bat. While
handling the bat, she was bitten on her left index finger. The wound was approximately
5 mm in length with some blood present at the margins; it was cleaned with
hydrogen peroxide. Medical attention was not sought, and rabies PEP was not
Approximately 1 month after the bat bite, the girl complained of fatigue
and tingling and numbness of the left hand. These symptoms persisted, and
2 days later she felt unsteady and developed diplopia (i.e., double vision).
On the third day of illness, with continued diplopia and onset of nausea and
vomiting, she was examined by her pediatrician and referred to a neurologist.
At that time, the patient continued to have blurred vision and also had partial
bilateral sixth-nerve palsy. Magnetic resonance imaging (MRI) with and without
contrast and magnetic resonance angiography (MRA) studies of her brain were
normal, and the patient was sent home.
On the fourth day of illness, the patient’s symptoms continued,
and she was admitted to a local hospital for lumbar puncture and supportive
care. On admission, she was afebrile, alert, and able to follow commands.
She had partial sixth-nerve palsy, blurred vision, and unsteady gait. Standard
precautions for infection control were observed. Lumbar puncture revealed
a white blood cell count of 23 cells/μL (normal: 0 cells/μL) with
93% lymphocytes, a red blood cell count of 3 cells/μL (normal: 0 cells/μL),
a protein concentration of 50 mg/dL (normal: 15-45 mg/dL), and a glucose concentration
of 58 mg/dL (normal: 40-70 mg/dL). During the next 36 hours, she had slurred
speech, nystagmus, tremors of the left arm, increased lethargy, and a temperature
of 102oF (38.9oC).
On the sixth day of illness, the bat-bite history was reported, and
rabies was considered in the differential diagnosis. The patient was transferred
to a tertiary care hospital. Because rabies was recognized as a possibility,
expanded infection-control measures, including droplet precautions and one-to-one
nursing, were instituted at time of transport. On arrival, the patient had
a temperature of 100.9oF (38.3oC), impaired muscular
coordination, difficulty speaking, double vision, muscular twitching, and
tremors in the left arm. She was somewhat obtunded but answered questions
appropriately and complied with commands.
Blood serum, cerebrospinal fluid (CSF), nuchal skin samples, and saliva
were submitted to CDC for rabies testing. MRI with and without contrast and
angiogram/venogram sequences were normal. She had hypersalivation and was
intubated. Rabies-virus–specific antibodies were detected in the patient’s
serum and CSF. Direct fluorescent antibody staining of nuchal skin biopsies
was negative for viral antigen, and rabies virus was not isolated from saliva
by cell culture. Rabies-virus RNA was not detectable by reverse transcriptase
polymerase chain reaction assay of either sample. Therefore, identification
of the virus variant responsible for this infection was not possible.
Clinical management of the patient consisted of supportive care and
neuroprotective measures, including a drug-induced coma and ventilator support.
Intravenous ribavirin was used under an investigational protocol. The patient
was kept comatose for 7 days; during that period, results from lumbar puncture
indicated an increase in antirabies IgG by immunofluorescent assay from 1:32
to 1:2,048. Her coma medications were tapered, and the patient became increasingly
alert. On the 33rd day of illness, she was extubated; 3 days later she was
transferred to a rehabilitation unit. At the time of transfer, she was unable
to speak after prolonged intubation. As of December 17, the patient remained
hospitalized with steady improvement. She was able to walk with assistance,
ride a stationary cycle for 8 minutes, and feed herself a soft, solid diet.
She solved math puzzles, used sign language, and was regaining the ability
to speak. The prognosis for her full recovery is unknown.
To provide community members accurate information about rabies and its
transmission, local and state health officials held a press conference on
October 21. Public health officials and community pediatricians visited the
patient’s school to assess the need for rabies prophylaxis among students.
WDPH distributed assessment tools to the local health department to screen
health-care workers and community contacts of the patient for exposure to
potentially infectious secretions. The patient’s five family members,
five of 35 health-care workers, and 27 of 55 community contacts received rabies
PEP, either because of exposure to the patient’s saliva during sharing
of beverages or food items or after contact with vomitus. No health-care workers
at the tertiary care hospital required PEP. Site inspection of the church
revealed no ongoing risk for exposure to bats.
RE Willoughby, MD, MM Rotar, Children’s Hospital of Wisconsin,
Milwaukee; HL Dhonau, MD, KM Ericksen, Agnesian HealthCare, Fond du Lac; DL
Cappozzo, Fond du Lac County Health Dept; JJ Kazmierczak, DVM, JP Davis, MD,
Wisconsin Div of Public Health. CE Rupprecht, VMD, Div of Viral and Rickettsial
Diseases; AP Newman, DVM, AS Chapman, DVM, EIS officers, CDC.
This case represents the sixth known occurrence of human recovery after
rabies infection; however, the case is unique because the patient received
no rabies prophylaxis either before or after illness onset. Historically,
the mortality rate among previously unvaccinated rabies patients has been
100%.2 The five previous patients who survived
were either previously vaccinated3 or received
some form of PEP before the onset of illness.4- 7 As
in this case, viral antigen was not detected nor was virus isolated from those
patients; increased antibody titers detected in serum and CSF (inconsistent
with vaccination alone) confirmed the diagnosis of clinical rabies. Only one
of the five patients recovered without neurologic sequelae.4 No
specific course of treatment for rabies in humans has been demonstrated to
be effective, but a combination of treatments, which might include rabies
vaccine, rabies immune globulin, monoclonal antibodies, ribavirin, interferon-alpha,
or ketamine, has been proposed.2 Given the
lack of therapeutic utility observed to date, and because the patient had
rabies-virus–neutralizing antibodies on diagnosis, a decision was made
to avoid use of immune-modulators (e.g., rabies vaccine, rabies immune globulin,
or interferon). However, the particular benefits of the regimen received by
this patient remain to be determined.
The history of a bat bite 1 month before this patient’s illness
suggests an etiology of bat-associated rabies-virus variant. This is consistent
with the epidemiologic pattern of rabies in humans in the United States during
the preceding 2 decades. During 1980-2000, a total of 26 (74%) of rabies-virus
variants obtained from patients in the United States were associated with
insectivorous bats, most commonly silver-haired and eastern pipistrelle bats,8,9 including a variant from a fatal case
of rabies reported in Wisconsin in 2000.10
In this case, only five health-care workers received PEP. Previous reports
of rabies cases have noted large numbers of contacts being treated8; however, delivery of health care to a patient with
rabies is not an indication for PEP unless the mucuous membranes or open wound
of a health-care worker are contaminated by infectious material (e.g., saliva,
tears, CSF, or neurologic tissue). Adherence to standard precautions for infection
control will minimize the risk for exposure.1
Rabies in humans is preventable with proper wound care and timely and
appropriate administration of PEP before onset of clinical disease.1 PEP is recommended for all persons with a bite, scratch,
or mucous-membrane exposure to a bat, unless the bat tests negative for rabies.
When direct contact between a human and a bat has occurred and the animal
is not available for testing, PEP should be administered when a strong probability
of exposure exists. However, if a bat bite is unrecognized or if the significance
of exposure is underestimated, medical intervention might not be sought and
appropriate treatment not administered. Once clinical signs of rabies are
evident, a progressive and usually fatal encephalitis ensues.
This report underscores the need for increasing public awareness to
minimize the risk for rabies following contact with bats and other wildlife.
Persons bitten by a potentially rabid animal should immediately (1) wash the
wound thoroughly with soap and water, (2) capture the animal (if this can
be done safely by avoiding direct contact) and submit it for testing or quarantine,
(3) contact local or state public health officials, and (4) visit a physician
for treatment and evaluation regarding the need for PEP. Persons should not
handle or keep bats as pets and should keep bats away from living quarters
and public places. Despite the recovery of this patient, no proven therapy
for clinical rabies has been established, and the reasons for recovery in
this case are unknown. Clinicians and the public should recognize the risk
for contracting rabies from any direct contact with bats and not regard it
as a curable disease on the basis of the outcome of this case.
The findings in this report are based on data reported by L Fitzpatrick,
PharmD, Agnesian HealthCare, Fond du Lac, Wisconsin. C Hanlon, VMD, I Kuzmin,
PhD, P Morrill, M Niezgoda, MS, L Orciari, MS, P Yager, Div of Viral and Rickettsial
Diseases, National Center for Infectious Diseases, CDC.
Recovery of a Patient From Clinical Rabies—Wisconsin, 2004. JAMA. 2005;293(6):669-670. doi:10.1001/jama.293.6.669