Rabies: Overview & Management PDF

Rhabdovirus & RABIES JOSE L. FERNANDEZ, RN, MAN  Rabies : Overview 2  Rabies is a preventable viral disease commonly transferred through the bite of a rabid animal.  Dogs are the principal source of human rabies mortality, contributing up t...

Rhabdovirus & RABIES JOSE L. FERNANDEZ, RN, MAN  Rabies : Overview 2  Rabies is a preventable viral disease commonly transferred through the bite of a rabid animal.  Dogs are the principal source of human rabies mortality, contributing up to 99% of all rabies transmissions to humans.  The rabies virus infects the CNS system of mammals, eventually causing infection in the brain and death.  Pathophysiology 3 has been best characterized in canine rabies variants. An animal is bitten by a rabid animal. virus from the infected saliva enters the wound. virus travels through the nerves to the spinal cord and brain. This process can last approx 3 to 12 weeks. The animal has no signs of illness during this time. When it reaches the brain, the virus multiplies rapidly and passes to the salivary glands. The animal begins to show signs of the disease. Theinfected animal usually dies within 7 days of becoming sick. Pathophysiology 4 5  Etiology 6  CMO: a neurotropic virus of the family Rhabdoviridae, genus Lyssavirus, subgroup rabies virus.  Transmission. The virus is commonly transmitted via saliva that contaminates bites, scratches, and wounds, and, recently, via mucosal exposure  Animals. the highest transmission risk to humans include canines (dogs, foxes, coyotes), cats, raccoons, & bats;  in the case of bats, exposure may go unrecognized by a sleeping individual; thus, postexposure prophylaxis (PEP) is recommended whenever a bat is discovered in the room of a sleeping or incapacitated person.  Statistics and 7  Incidences Each year, rabies worldwide causes approx 59k deaths  Dog rabies remains the cause of over 90% of human exposures to rabies and of 99% of human deaths worldwide.  The largest number of human deaths annually was recorded during the first half of the 20th century, with an average of 50 documented cases per year.  Common in males, who may have greater contact in certain geographic areas.;  Of the infections acquired in the United States, 70% were attributed to bats.  Clinical Manifestations 8  After a bite, the rabies virus travel through the body to the brain before it can cause symptoms; this time between the exposure & the appearance of S/S is called incubation pd, and it may last for wks to mos.  Flu-like symptoms. may be very similar to those of flu inc general weakness or discomfort, fever, or headache; lasting for days.  Hydrophobia and aerophobia. are pathognomonic for and occur in 50% of patients; attempting to drink or having air blown in the face produces severe laryngeal or diaphragmatic spasms and a sensation of asphyxia; this may be related to a violent response of the airway irritant mechanisms;  Psychologic symptoms. delirium, abnormal behavior, hallucinations, insomnia, anxiety, confusion, & agitation.  Assessment and Dx 9  Direct fluorescent antibody test. observation that animals infected have rabies virus proteins (antigen) present in their tissues, ideally tested is brain tissue  Histologic examination. biopsy or autopsy occasionally done, esp those not tested by routine methods.  Immunohistochemistry. detection provide sensitive and specific in formalin-fixed tissues; sensitive than histologic staining methods  Electron microscopy. using this methodviewed with an electron microscope Rhabdoviruses are seen as bullet- shaped particles.  Amplification methods. Mouse neuroblastoma cells (MNA) cells provide an excellent environment for amplification of virus w/o the use of animals;  Medical Management 1  0 Inpatient care. needed if wounds are extensive or are on the face and hands, if sx repair or replacement of blood loss is required, or if infection occurs.  Preexposure prophylaxis. Preexposure, active prophy/ immunization for veterinarians, persons who regularly explore or hike in caves, laboratory workers who are exposed to rabies virus or who handle specimens considered high risk for rabies,  Postexposure approach to an animal bite. washing and wound debridement @ the time of bite is essential, with careful cleaning of wound for longer than 10 mins; generally, leave wounds to heal by 2ndary intention.  Medical Management 1  1 Postexposure prophylaxis. Before the onset of rabies symptoms, optimal results require immediate, vigorous wound cleansing; passive immunization with immunoglobulin; & active immunization w/rabies vaccine  Medical tx after symptom onset. Intensive CP supportive care is the only treatment available for patients with symptomatic rabies.  Pharmacologic 1 2  Before the Management onset of rabies symptoms, passive and active immunizations are effective in preventing progression to full-blown rabies.  Passive immunizing agents. Rabies immunoglobulin is recommended as part of the postexposure regimen for persons not previously immunized against rabies  Rabies vaccines. promote immunity by inducing an active immune response; two types of rabies vaccines have been produced: a) cell-cultured vaccines and b) nerve tissue vaccines.  Nursing Assessment 1  3 History. Identify the following in any suspected case the nature of the interaction with the animal (recall that “provocation” is not an indication of rabies risk, since humans may not understand what is provocative to a wild animal.) a) strange animal behavior (eg, nocturnal animal out during the daytime) b) vaccination status of the animal for rabies; & c) availability of animal for testing  Physical exam. With furious rabies, pts present with episodic delirium, psychosis, restlessness, thrashing, muscular fasciculations, seizures, and aphasia; autonomic instability is observed with furious rabies.  Nursing Interventions 1  4 Improve breathing pattern. a) Place pt with proper body alignment for maximum breathing pattern; b) maintain a clear airway by encouraging patient to mobilize own secretions with successful coughing; suction secretions, as necessary; and c) encourage frequent rest periods and teach patient to pace activity.  Improve nutritional intake.  Provide a pleasant environment; a) promote proper positioning; provide good oral hygiene and dentition; b) consider six small nutrient-dense meals instead of three larger meals daily to lessen feeling of fullness;  Nursing Interventions 1 5  (cont) impaired swallowing:, coordinate with a speech therapist for evaluation and instruction; determine time of day when the pt’s appetite is at peak and offer highest calorie meal at that time.  Maintain normal body temperature. a) Adjust and monitor environmental factors like room temperature and bed linens as indicated; b) eliminate excess clothing and covers; and give antipyretic medications as prescribed.  Reduce anxiety.  Use presence, touch (with permission), verbalization, and demeanor to remind pts that they are not alone  Nursing Interventions 1  Encourage expression or clarification of needs, (cont) concerns, unknowns, and questions; 6  interact with pt in a peaceful manner; accept pt’s defenses;  do not dare, argue, or debate; converse using a simple language and brief statements;  explain all activities, procedures, & issues that involve the pt; use nonmedical terms and calm, slow speech.  Prevent injury. a) Avoid use of restraints; obtain a physician’s order if restraints are needed; b) if pt has confusion (delirium), render reality orientation when interacting with him; ask family or significant others to be with the patient to prevent him or her from accidentally falling; c) eliminate or drop all possible hazards in the room  Nursing Interventions 1 7  Prevent infection. (cont)  Maintain or teach asepsis for dressing changes and wound care;  wash hands and teach patient and SO to wash hands before contact with patients and between procedures with the patient;  teach the patient, family, and caregivers, the purpose and proper technique for maintaining isolation;  if infx occurs, teach the pt to take antibiotics as presc  1 8 THANK YOU