Infectious disease is a rapidly evolving field; new viral agents are continually being identified, and the geographic ranges of known viruses continue to evolve (Berger et al, 2003.) As recent experiences with West Nile virus, severe acute respiratory syndrome (SARS), and Avian flu dramatically illustrate, people in any setting may be called on to consider infectious entities from any part of the globe due to shifts in geographic disease distribution, travel-related imported infections, or even potentially intentional releases of exotic viruses. The recent crisis of avian flu shows the importance of knowledge of infectious diseases for anyone working in a wilderness setting.
Few diseases frequent a wilderness excursion. However, these ailments have common occurrences in the wilderness. They are Cryptosporidium, E. Coli, Rocky Mountain Spotted Fever, Giardia, Lyme’s Disease, and finally Tularemia. This list is by no means comprehensive. The outdoor enthusiast should research what diseases and vectors are prevalent in the area where they are hiking.
Cryptosporidiosis is a disease caused by microscopic parasites of the genus Cryptosporidium. Once a person is infected, the parasite lives in the intestine and passes in the stool. The parasite is protected by an outer shell that allows it to survive outside the body for long periods and makes it very resistant to chlorine- based disinfectants. During the past two decades, crypto has become recognized as one of the most common causes of waterborne disease within humans in the United States. The parasite may be found in drinking water and recreational water in every region of the United States and throughout the world (Guerrant, 1997.)
Cryptosporidium is passed from person to person by fecal-oral pathways. In a wilderness environment, it is imperative that everyone washed his or her hands before ingesting anything. This is often difficult with adolescent youth.
Cryptosporidium causes symptoms that could manifest as watery diarrhea, abdominal cramps, vomiting, and fever. In immune competent persons, symptoms last an average of six to ten days but can last up to several weeks. In persons with severely weakened immune systems, cryptosporidiosis can become chronic and can be fatal (Guerrant, 1997.)
Some people with Cryptosporidium will have no symptoms at all. While the small intestine is the site most commonly affected, Cryptosporidium infections could possibly affect other areas of the digestive or the respiratory tract. Treatment for Cryptosporidium is Nitazoxanide. The wilderness therapist should consult a physician before using this as is has ill effects on people in poor health (Morgan-Ryan, 2002.)
Escherichia coli is an emerging cause of food borne illness. An estimated seventy three thousand cases of infection and sixty-one deaths occur in the United States each year (Fischer et al, 2001.) Infection often leads to bloody diarrhea, and occasionally to kidney failure. Most illness has been associated with eating undercooked, contaminated ground beef. Person-to-person contact in families and childcare centers is also an important mode of transmission. Infection can also occur after drinking raw milk and after swimming in or drinking sewage-contaminated water.
Most persons recover without antibiotics or other specific treatment in two weeks. There is no evidence that antibiotics improve the course of disease, and it is thought that treatment with some antibiotics may precipitate kidney complications. Antidiarrheal agents, such as loperamide (Imodium), should also be avoided (Fischer et al, 2001.)
Like Cryptosporidium, E. Coli can stay in a client’s system without symptoms for extended periods. Prevention is the same as Cryptosporidium. The wilderness psychologist should maintain a rigid regiment of hand washing and person hygiene within their client community.
Giardia is a diarrhea causing illness. It is a one-celled, microscopic parasite. Once an animal or person has been infected with Giardia, the parasite lives in the intestine and is passed in the stool. Because the parasite is protected by an outer shell, it can survive outside the body and in the environment for long periods.
During the past two decades, Giardia infection has become recognized as one of the most common causes of waterborne disease in humans in the United States (Berger et al, 2003). Giardia is found worldwide and within every region of the United States.
The Giardia parasite lives in the intestine of infected humans or animals. Millions of germs can be released in a bowel movement from an infected human or animal. Giardia is found in soil, food, water, or surfaces that have been contaminated with the feces from infected humans or animals. Spread of this infectious disease is caused by fecal-oral pathways, unsanitary food preparation, or ingestion of untreated water.
The symptoms for Giardia are diarrhea, flatulence, greasy stools that tend to float, stomach cramps, and upset stomach or nausea. Treatment for Giardia is taking an antibiotic series. The symptoms will go away from two to six weeks after initial diagnosis.
Rocky Mountain spotted fever
Rocky Mountain spotted fever is the most severe and most frequently reported tick-borne illness in the United States (Archibald & Sexton, 1995.) The disease is caused by a species of bacteria that is spread to humans by ticks. Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment, it can be fatal.
The characteristic rash can be spotted after the fifth or sixth day after the client displays the symptoms of Rocky Mountain spotted fever. The rash does not always show up. It often occurs in the palms and soles of the feet, but this is more of a late description of the disease.
Prompt removal of embedded ticks is the most effective way to reduce the possibility of contracting the disease. It may take extended attachment time before organisms are transmitted from the tick to the host. In persons exposed to tick-infested habitats, prompt careful inspection and removal of crawling or attached ticks is an important method of preventing disease.
Treatment is antibiotics that should be started immediately when there is even a suspicion of contracting the disease (Archibald & Sexton, 1995.)
Lyme disease is caused by bacteria that is transmitted to humans by the bite of infected ticks (Hayes & Piesman, 2003.) Typical symptoms include fever, headache, fatigue, and a skin rash. If left untreated, infection can spread to joints, the heart, and the nervous system. Lyme disease is diagnosed based on symptoms, physical findings, and the possibility of exposure to infected ticks; laboratory testing is helpful in the later stages of disease. Most cases of Lyme disease can be treated successfully with a few weeks of antibiotics.
During 2002, over twenty three thousand new cases of Lyme’s Disease were reported to Center for Disease Control, more than in any previous year (Hayes & Piesman, 2003.) Factors potentially contributing to the increase in reported cases include growing populations of deer that support the hard tick vector, increased residential development of wooded areas, and tick dispersal to new areas, improved disease recognition in areas where Lyme’s Disease is endemic, and enhanced reporting (Hayes & Piesman, 2003.)
Detection and removal are the two best methods for reducing all diseases caused by ticks. Tick checks should be conducted morning and night, especially before sleep. Ticks carrying Lyme’s Disease characteristically need more than twenty-four hours embedding within their host in order to pass on the disease (Hayes & Piesman, 2003.)
Tularemia is another disease passed on by ticks. It can also be passed by other infected insects such as deer flies or misquitoes (Schmid et al, 1983.) People can also become infected by handling infected sick or dead animals, by eating or drinking contaminated food or water, or by inhaling airborne bacteria.
Tularemia is a widespread disease in animals. About two hundred human cases of tularemia are reported each year in the United States. Most cases occur in the south-central and western states. Nearly all cases occur in rural areas, and are caused by the bites of ticks and biting flies or from handling infected rodents, rabbits, or hares. Cases also resulted from inhaling airborne bacteria and from laboratory accidents (Schmid et al, 1983.)
The signs and symptoms people develop depend on how they are exposed to tularemia. Possible symptoms include skin ulcers, swollen and painful lymph glands, inflamed eyes, sore throat, mouth sores, diarrhea or pneumonia. If the bacteria are inhaled, symptoms can include abrupt onset of fever, chills, headache, muscle aches, joint pain, dry cough, and progressive weakness. Tularemia can be fatal if the person is not treated with appropriate antibiotics. Francisella tularensis can remain alive for weeks in water and soil.
From 1990 to 2000, over one thousand new cases of tularemia were reported to CDC from forty-four states, averaging over one hundred new cases per year.
Rabies is a preventable viral disease of mammals most often transmitted through the bite of a rabid animal (Berger et al, 2003.) The vast majority of rabies cases reported each year occur in wild animals like raccoons, skunks, bats, and foxes. Domestic animals account for less than ten percent of the reported rabies cases, with cats, cattle, and dogs most often reported rabid.
Rabies virus infects the central nervous system, causing a person’s brain to swell possibly causing death. Early symptoms of rabies in humans are nonspecific, consisting of fever, headache, and general malaise. As the disease progresses, neurological symptoms appear and may include insomnia, anxiety, confusion, slight or partial paralysis, excitation, hallucinations, agitation, increased salivation, difficulty swallowing, and fear of water. Death usually occurs within days of the onset of symptoms (Berger et al, 2003.)
One of the most effective methods to decrease the chances for infection involves thorough washing of the wound with soap and water. Medical treatment should be administered immediately. Treatment consists of a regimen of one dose of immune globulin and five doses of rabies vaccine over a month long period.