Unprotected People #71: Wisconsin teen survives clinical

[Guest guest]

Dec 30, 2004 4:44 PM

IAC EXPRESS: Extra Edition

Immunization news from the Immunization Action Coalition

*** Combined Federal Campaign #0233 ***

Federal employees, including military, may contribute

to IAC by using code #0233 on their pledge cards.

===============================================================

Issue Number 500: Unprotected People December 30, 2004

CONTENTS OF THIS ISSUE

1. Unprotected People #71: Wisconsin teen survives clinical

rabies without pre- or postexposure prophylaxis

---------------------------------------------------------------

(1 of 1)

December 30, 2004

UNPROTECTED PEOPLE #71: WISCONSIN TEEN SURVIVES CLINICAL RABIES

WITHOUT PRE- OR POSTEXPOSURE PROPHYLAXIS

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 71st in our series.

Bitten by a bat in September 2004, a 15-year-old Wisconsin girl was

hospitalized in October. Subsequently, the patient's bat-bite

history was reported, and rabies was diagnosed. Clinical management

included intubation, drug-induced coma, ventilator support, and

intravenous administration of ribavirin. The patient survived,

making her the only person documented to have recovered from

clinically diagnosed rabies without pre- or postexposure

prophylaxis. As of December 17, the patient remained hospitalized,

undergoing rehabilitation. Prognosis for her full recovery was

unknown.

Though the patient survived, no proven therapy for clinical rabies

has been established, and the reasons for recovery in this case are

unknown. It remains important for clinicians and the public to be

aware of the risk of contracting rabies from direct contact with

bats and other wildlife and to follow the steps outlined in the

concluding paragraph of the report reprinted below.

Titled " Recovery of a Patient from Clinical Rabies--Wisconsin,

2004, " the report initially appeared in MMWR on December 24, 2004.

It was reported by the following from Wisconsin: RE Willoughby, MD,

and MM Rotar of Children's Hospital of Wisconsin, Milwaukee;

HL Dhonau, MD, and KM ksen of Agnesian HealthCare, Fond du Lac;

DL Cappozzo of Fond du Lac County Health Dept.; JJ Kazmierczak,

DVM, and JP , MD, of Wisconsin Div. of Public Health.

Contributors from CDC include CE Rupprecht, VMD, of Div. of Viral

and Rickettsial Diseases; AP Newman, DVM, and AS Chapman, DVM,

Epidemic Intelligence Service officers.

***************************

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). 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 administered.

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/microliter (normal: 0 cells/microliter) with 93%

lymphocytes, a red blood cell count of 3 cells/microliter (normal:

0 cells/microliter), 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 102 degrees F (38.9 degrees C).

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 100.9 degrees F (38.3 degrees C), 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 [immunoglobulin G] 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 healthcare workers

and community contacts of the patient for exposure to potentially

infectious secretions. The patient's five family members, five of

35 healthcare 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 healthcare workers at the tertiary-care hospital

required PEP. Site inspection of the church revealed no ongoing

risk for exposure to bats.

Editorial Note:

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%. The five previous

patients who survived were either previously vaccinated or received

some form of PEP before the onset of illness. 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. 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. 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, including a

variant from a fatal case of rabies reported in Wisconsin in 2000.

In this case, only five healthcare workers received PEP. Previous

reports of rabies cases have noted large numbers of contacts being

treated; 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 healthcare 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.

Rabies in humans is preventable with proper wound care and timely

and appropriate administration of PEP before onset of clinical

disease. 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.

***************************

To access a web-text (HTML) version of the complete article, go to:

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5350a1.htm

To access a ready-to-copy (PDF) version of this issue of MMWR, go

to: http://www.cdc.gov/mmwr/PDF/wk/mm5350.pdf

To read more IAC Unprotected People Reports, go to:

http://www.immunize.org/stories