Rabies: transmission, prevention, and clinical management

Rabies Is the Oldest and Deadliest Disease Known to Mankind, Killing 55,000 Persons Worldwide Each Year

Oklahoma Department of Health

("World Rabies Day…," ¶ 2).

Transmission of a Deadly Disease

Each year, the disease known as canine rabies kills approximately 55,000 persons worldwide ("World Rabies Day…"; "Rabies Deaths from…"; McMaster University; "West Lafayette…"). In the news article, "World Rabies Day 2008: Awareness is Best Defense Against Rabies," the Oklahoma Department of Health explains that rabies, a viral disease, primarily transmitted by bite may be transmitted to animals and humans. Once neurological symptoms of rabies develop, it proves fatal to animals and humans. This paper, which focuses on rabies, reports ways it is transmitted, examines symptoms of the disease, notes organs/systems affected, relates the cure/treatment, and communicates prevention strategies. The researcher also presents means for educating individuals about rabies.

In the developing world, particularly in rural Africa, a person dies from a rabid dog bite every 10 minutes. McMaster University purports, albeit that "sustained, international commitment, global elimination of rabies from domestic dog populations, the most dangerous vector to humans, is a realistic goal" (McMaster University, p.1). Merriam-Webster's Online Medical Dictionary defines rabies, also called hydrophobia, as:

An acute virus disease of the nervous system of warm-blooded animals that is caused by a rhabdovirus (species Rabies virus of the genus Lyssavirus) transmitted in infected saliva usually through the bite of a rabid animal and that is characterized typically by increased salivation, abnormal behavior, and eventual paralysis and death when untreated

Ways Rabies Transmitted; System Affected

Exposure to rabies usually occurs from a bite from a rabid animal. Rabies "may also occur through contamination of broken skin or mucous membranes with saliva from an infected animal" ("World Rabies Day…," ¶ 2). Figure 1 depicts the primary way the rabies virus may be transmitted, by saliva spread to enter the victim's bloodstream through a bite or wound from a rabid animal.

Figure 1: Example of Bite from Rabid Animal (Lentnek, 2007).

Marilynn Marchione, an AP medical writer, notes a rare way rabies has been found to be spread, in the article, "Rodent Virus Now Linked to Six Deaths." Marchione reports that at least six organ transplant patients' deaths reportedly linked to a rodent virus. These confirmed deaths stimulate questions regarding whether others similar cases may have not been detected. Questions arise as to whether the rabies germ may also be spread through blood transfusions. Questions have also arisen regarding the rabies infection of two animals that had eaten infected animals; whether the rabies resulted from eating animals or from exposure to the virus during the butchering process ("Two Cases of Rabies…").

Symptoms of Rabies

Patricia Harris Pointing notes in the article, "Rabies: What you need to know," that rabies symptoms, generally depicted as causing violent aggression, do not always cause the animal to foam at the mouth and cringe away from water. Symptoms of the disease in animals and humans vary and at times may simulate a different disease or appear as an object stuck in the throat. The traditional "furious' form of rabies involves unusual excitement, fearlessness and aggression. 'Dumb' or 'paralytic' rabies involves depression, apparent tameness and gradual paralysis" (Pointing, ¶ 10). The Mayo Clinic staff reports that rabies does not display any signs or symptoms until the disease progresses to its later stages; often just days before the victim dies ("Symptoms"). Signs and symptoms of rabies may include:

Fever

Headache

Agitation

Anxiety

Confusion

Difficulty swallowing

Excessive salivation

Fear of water (hydrophobia) because of the difficulty in swallowing

Hallucinations

Insomnia

Partial paralysis. ("Symptoms")

As rabies attacks the person's brain, it causes them to become agitated, triggers terror and convulsions. "Victims suffer painful throat spasms when they try to drink or eat. Paralysis follows, yet people infected with rabies are intermittently alert until near death and can communicate their fear and suffering to family and caregivers" Rodney E. Willoughby, Jr. reports in "A Cure for Rabies?" (¶ 1). After rabies' symptoms appear, generally within two months of the person being bitten, death is traditionally inevitable and usually occurs in less than one week.

Figure 2 portrays the human central nervous system, along with the brain, also affected by rabies.

Figure 2: Human Central Nervous Center; Brain, Affected by Rabies (Lentnek, 2007).

The Cure/Treatment

Vaccines against the rabies virus may prevent the illness from developing, however, until 2004, doctors could relate hope for patients who neglected to obtain immunization soon after they had been bitten by a rabid animal (Willoughby, Jr.). Willoughby, Jr. reports that he worked as part of a team of physicians at Children's Hospital of Wisconsin in Milwaukee to treat Jeanna Giese, a 15-year-old girl, of Fond du Lac, Wisconsin. Giese who survived, is the first known unimmunized survivor of rabies. The experimental treatment stimulated controversy among medical specialists; with some claiming Giese's cure was a fluke. Following attempts to replicate this particular treatment had not been effective, however. Five other individuals, immunized who still consequently developed rabies also survived. Whether canine rabies can be cured, controlled, eliminated and if so, how can it best may be controlled/eliminated contribute to current research considerations (McMaster University).

The Handbook of Diseases reports that the rabies' patient wound requires treatment and immunization immediately after exposure. The bite wounds (or other) and scratches must be thoroughly washed soap and water. The individual's e patient's immunization status must be checked and, if needed, medical staff should administer tetanus-diphtheria prophylaxis. Medical personnel need to also take measures to control bacterial infection. Should the wound require suturing, the medical staff should utilize special treatment and suturing techniques to permit proper wound drainage. "If the wound is sutured, antiserum may be infiltrated locally" (Rabies: Treatment, ¶ 3).

Following rabies exposure, a person who has not previously been immunized must, as soon as possible, "receive passive immunization with rabies immune globulin and active immunization with human diploid cell vaccine" (Rabies: Treatment, ¶ 4). If the individual received the vaccine in the past, however and possess an adequate rabies antibody titer, he/she only needs a vaccine booster; not immune globulin immunization. Prevention Strategies

When one is bitten by an apparently healthy domestic animal, according to the Centers for Disease Control (CDC), the animal must be confined and observed for 10 days. If the animal develops any signs of illness during that time, a veterinarian should examine it. If the symptoms suggest rabies, the animal should be aeuthanized, and the animal's head then submitted for testing to determine whether the victim of the bite needs treatment. Apparently-healthy animals, however, are seldom rabid (Pointing, In case of human exposure section, ¶ 1).