Posted by Tilapia on 6/10/2010 at 02:35
Below is an excerpt of a case that was posted on the Center for Disease Control and Prevention in the US. It was circulated to all Public Health agencies in North America. This might be of interest to those wondering about rabies and how it manifests itself, whether-or-not pre-exposure vaccine is worth the cost, whether-or-not they should let that cute puppy lick their faces, etc. It also illustrates several important aspects of the disease that are not well known outside of the realm of public health and veterinary medicine.
Some of these points include,
1) An animal can be infectious, but asymptomatic (meaning that an animal ... mammals only ... can be sick and can transmit the rabies virus without showing any symptoms of the disease), a period that usually lasts several days
2) Once symptoms begin, the end result is almost always a long and painful death ... it is a one-way ticket
3) Contact with saliva, and not blood, is the most common mode of transmission
4) Post-exposure prophylaxis (PEP) is effective in preventing the virus from manifesting itself (developing into the disease) should transmission occur
5) Early symptoms can be easily misdiagnosed without a thorough patient history (the guy never mentioned that he'd had exposure to a dog in India, but it would have been too late anyway)
For the record, if someone acquires the virus, disease symptoms will not develop until the virus reaches the brain via neural pathways. The further exposure occurs from the brain, the longer the exposed person has to receive PEP. For example, if someone is bitten by a dog on the leg or foot, the virus will have a greater distance to travel to reach the brain than it would had the person been bitten on the hand, neck or head.
Where I work, head, neck and shoulder bites (mostly from bats) demand immediate PEP. When there are bites to the appendages, PEP might be deferred for up to 2 or 3 weeks, but only if the suspect animal can be held for observation. If it is healthy after 10 days, no PEP is required.
PEP = 4-6 shots of Rabies Immunoglobulin, aka RIG (to boost the immune system ... the number of shots depends on the person's weight) given all at once (on Day 0), plus 5 shots of Rabies Vaccine given over the period of one month (on Days 0, 1, 3, 7, 14 & 28).
The virus can also cross mucus membranes (the eye, mouth, and other "wet" parts of the body).
Once infected, people can become as infectious as any other animal, and can transmit rabies through saliva.
This person would have survived if he had received PEP up until several days before the onset of the first symptoms.
According to the WHO, the places with the highest numbers of human rabies cases are,
#1 - India
#2 - Vietnam
#3 - Thailand
This is a long read, and you may have to look up a definition or two, but it is a relevant example of what can go wrong if the right measures aren't taken after exposure to a suspect animal while abroad.
On October 28, 2009, CDC notified the Virginia Department of Health (VDH) of suspected rabies in a Virginia man aged 42 years.
This report summarizes the patient's exposure history, clinical course, and treatment, and describes efforts to identify close contacts requiring post exposure prophylaxis(PEP).
According to family members, the patient had reported an encounter with a dog while in India approximately 3 months before symptom onset. On October 29, infection with a rabies virus was confirmed by direct fluorescent antibody testing of a nuchal skin biopsy, and reverse transcription--polymerase chain reaction (RT-PCR) typed the virus as a variant associated with dogs in India.The patient died on November 20.
This is the seventh case of rabies reported in the United States acquired abroad since 2000. This case highlights the importance of raising public awareness of rabies, particularly the risk for rabies exposures in association with travel to rabies-endemic countries, and the importance of initiating PEP promptly after a potential exposure.
On October 23, 2009, a male physician aged 42 years in Virginia experienced the onset of chills and "hot flashes." The next morning, he began experiencing discomfort in his legs, and that evening he developed spontaneous ejaculation occurring up to once per hour, urinary incontinence, and back pain radiating to the left lower extremity. Two days later, on October 26, he visited an ED for assessment. The patient was awake, oriented, and afebrile during this visit. Magnetic resonance imaging of his lumbar spine revealed degenerative disease at L4--L5, and he was discharged with a diagnosis of lumbar back pain, given pain medications, and instructed to follow up with his primary-care physician. That evening he began to gag while drinking and showering. On October 27, the patient contacted his primary-care physician and raised concern about the possibility of rabies. He was referred back to the same ED for evaluation of neurologic disorders, including rabies.
On October 27, the patient returned to the ED and, in addition to the previously noted symptoms, exhibited anxiety and erratic behavior and had involuntary dystonic movements of his upper extremities.
The patient reported travel to India approximately 3 months before symptom onset but gave no clear history of animal exposure occurring while in India or in the United States. Physical examination showed tachycardia (134 beats per minute) and elevated blood pressure (153/93 mm Hg) but no fever.The patient began displaying loud involuntary vocalizations. Sensation and motor strength were normal. The patient demonstrated aversion to water when offered.
The patient was admitted to the hospital with a differential diagnosis that included rabies and other neurologic diagnoses of unknown etiology.
Within 24 hours of admission, the patient was noted to be shouting, gagging on copious salivary secretions, and unable to follow commands. His tachycardia and hypertension worsened and, soon after he was transferred to the intensive-care unit, he developed seizures, sustained a cardiac arrest, and required ventilator support. At this time, the patient developed a low-grade fever (99.4°F[37.4°C]). Complete blood count showed mild leukocytosis, mild hyperglycemia, and a creatine kinase of >16,000 U/mL (normal: 12--70 U/mL).
On October 28, the second hospital day, a lumbar puncture showed an elevated cerebrospinal fluid. The treating physician initiated the Milwaukee protocol, including ketamine infusion, but in keeping with this protocol, the patient was not given rabies immune globulin, vaccine, or antivirals. Serum, CSF, nuchal skin biopsy, and saliva were collected and submitted to CDC for rabies testing. The next day, October 29, CDC detected rabies virus antigen in the skin biopsy by direct fluorescent antibody testing. Rabies viral RNA amplified by RT-PCR was typed as a variant common to dogs in India.
Serial assessments of serum, CSF, and saliva were conducted to monitor for viral clearance. A ventriculostomy drain was placed for continuous monitoring and management of intracranial fluid pressures. With turning and suctioning, the patient experienced asystole. Increasing episodes of asystole resulted in placement of a transvenous pacemaker by hospital day 8. By hospital day 12, the patient developed inappropriate antidiuretic hormone secretion followed by severe central diabetes insipidus treated with desmopressin and continuous vasopressin infusion. By hospital day 15, the patient developed late and marginal antibody response in saliva but never developed neutralizing antibody in CSF, which is necessary for viral clearance and cure. Sedation was tapered over 1 week with clinical evidence of denervation indicated by loss of brain stem reflexes and diminished autonomic dysfunction. The patient died on November 20 (hospital day 25).
Public Health Investigation
VDH and the Fairfax CountyHealth Department (FCHD) were notified of a suspected rabies case on October 28, the patient's second hospital day. FCHD began working with hospital A'sepidemiology and occupational health staff to generate a list of potentially exposed hospital employees. In addition, FCHD initiated interviews with family and friends to clarify the patient's exposure history and gather information about persons who had contact with the patient since October 8, the date after which he was considered potentially infectious.
A total of 32 (18%) of 174 persons evaluated for potential exposure initiated PEP. No adverse reactions to PEP or additional cases of rabies were reported to public health authorities.
FCHD interviewed all 70 health-care providers who had administered care to the patient in hospital A,and 17 met the criteria for a non-bite exposure to rabies (because of exposure to the patient's saliva). An additional seven assessed persons initiated rabies PEP despite no indication; two had already initiated PEP before the exposure assessment by FCHD. Among the 34 coworkers assessed at hospital B by DCDOH,only one, who identified himself as a close friend of the patient, met the criteria for non bite exposure and received rabies PEP. MDHMH assessed 37 coworkers and 26 patients associated with facilities A and B. No coworkers or patients at either facility met the criteria for exposure, and none pursued rabies PEP. All six family members and one assessed friend were identified who might have been exposed to saliva from the patient, and all received rabies PEP.
The case described in this report underscores two important aspects of human rabies prevention:
1) the importance of awareness about rabies risks when traveling abroad and
2) the need to seek prompt medical evaluation after an animal exposure (3).
Since 2000, seven of the 31 human rabies cases reported in the United States were acquired from exposure abroad; two were acquired in the Philippines (California, 2001 and 2006), and one each were acquired in Ghana (New York,2000), El Salvador (California, 2004), Haiti (Florida, 2004), Mexico(California, 2008), and India (the 2009 case described in this report) (4).
An attempt to treat the patient after the onset of clinical symptoms of rabies using an experimental treatment (the Milwaukee protocol) failed. Prompt administration of rabies PEP after an exposure remains the only documented method for preventing death after an exposure to rabies (http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5703a1.htm).
Dogs represent the most frequent risk for bite exposures to travelers and should be avoided. Travelers to rabies-endemic countries should be warned about the risk for acquiring rabies and educated about animal bite prevention and appropriate actions to take if an exposure does occur (i.e., wound washing and medical attention to determine if PEP is necessary). Relative rabies risk and recommendations for travelers by region and country can be found in CDC's Health Information forInternational Travel 2010 ).
What is already known on this topic?
If not prevented by administration of post exposure prophylaxis (PEP), the rabies virus causes acute progressive viral encephalitis that is almost always fatal.
#1 Tilapia has been a member since 21/4/2006. Location: Canada. Posts: 1,524