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This article provides information about three major diseases: Rheumatic Fever, Tularemia, and Anthrax. It covers their causes, symptoms, and treatments, as well as potential complications.
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Rheumatic Fever • Caused by Streptcoccus pyogenes • Generally starts out as sore throat caused by Strep. “bug” • Signs and symptoms: • First expressed as a period of arthritis and fever • Subcutaneous nodules at joints often accompany this stage • 50% afffected, experience inflammation of heart probably due to misdirected immune reaction against infection • Causes damage to heart valves
Treatment • Treatment of rheumatic fever involves a dual approach — antibiotics to rid your body of streptococcal infection and prevent recurrences, and other medications to ease the symptoms of the disease. • To eliminate any remaining strep bacteria once you have rheumatic fever, your doctor may prescribe penicillin or another antibiotic. Usually, you'll then need to be on some kind suppressive schedule of antibiotics for several to many years to prevent second attacks of rheumatic fever.
Tularemia • Francisella tularensis, the organism that causes tularemia, is one of the most infectious pathogenic bacteria known, requiring inoculation or inhalation of as few as 10 organisms to cause disease. It is considered to be a dangerous potential biological weapon because of its extreme infectivity, ease of dissemination, and substantial capacity to cause illness and death. • Francisella tularensis is a hardy non-spore forming organism that is capable of surviving for weeks at low temperatures in water, moist soil, hay, straw or decaying animal carcasses.
Tularemia is a zoonosis. Natural reservoirs include small mammals such as voles, mice, water rats, squirrels, rabbits and hares. Naturally acquired human infection occurs through a variety of mechanisms such as: bites of infected arthropods; handling infectious animal tissues or fluids; direct contact or ingestion of contaminated water, food, or soil; and inhalation of infective aerosols. F. tularensis is so infective that examining an open culture plate can cause infection. • Humans can contract tularemia in the following ways: • direct contact with an infected animal or carcass via broken skin • the bite of an infected flea or tick • ingesting infected meat (rare)
Symptoms • red spot on the skin, enlarging to an ulcer • enlarged lymph nodes of groin or armpits • headache • muscle pains • possible conjunctivitis • shortness of breath • fever • chills • sweating • weight loss • joint stiffness
Treatment • The goal of treatment is to eliminate the infection with antibiotic therapy. Streptomycin and tetracycline are commonly used in this infection. • Tularemia is fatal in about 5% of untreated cases and in less than 1% with treatment. • Complications • meningitis • pneumonia • pericarditis
Anthrax • Anthrax is an infectious disease caused by the spore-forming bacteria called Bacillus anthracis. • Infection in humans most often involves the skin (cutaneous anthrax), the gastrointestinal tract, or the lungs (inhalation anthrax). • Cutaneous anthrax is an infection of the skin with anthrax. • The disease occurs after the bacteria contact skin cuts or abrasions. • Usually within two weeks, an itchy skin lesion develops (similar to an insect bite). • This lesion may later blister and then break down, resulting in a black ulcer which is frequently painless. The skin lesion is usually surrounded by significant swelling. • Sometimes painful lymph nodes may develop. A scab is often formed which then dries and falls off within two weeks. • In 20% of UN-treated individuals, the infection may spread through the bloodstream and become fatal. However, in most individuals who receive appropriate treatment, death from cutaneous anthrax is extremely rare.
Inhalation anthrax develops when anthrax spores enter the lungs. • A person may have spores in the nasal passages (which indicates exposure), but that doesn't mean they will get the disease. In fact, antibiotic therapy following known or suspected exposure can help prevent the disease. • In order for a person to develop the actual disease, the spores must germinate -- a process which may take several days, or even up to 60 days to occur. • The spores move to the lymph nodes, and once they germinate, lead to the release of several toxic substances (toxins). • This results in hemorrhage, swelling, and tissue death. The main form of inhalation anthrax includes hemorrhagic infection of the lymph nodes in the chest (hemorrhagic mediastinitis). • Up to half of affected individuals may also have a hemorrhagic meningitis.
There are usually two stages of inhalation anthrax – • the first stage can last from hours to a few days and is similar to a flu-like illness with fever, headache, cough, shortness of breath, and chest pain. • The second stage often develops suddenly and is notable for shortness of breath, fever, and shock. This second stage is highly fatal in up to 90% of individuals because of the build-up of toxins.
Symptoms • Cutaneous anthrax: papule, blister, ulcer with black scar with extensive surrounding swelling • Inhalation anthrax: Initial stage -- fever, malaise, headache, cough, shortness of breath, and chest pain; Second stage -- fever, severe shortness of breath, and shock
Treatment • The mainstay of treatment is early antibiotic therapy. Several antibiotics are effective, including penicillin, doxycycline, and ciprofloxacin (Cipro). • If an outbreak of anthrax is suspected, the antibiotic of choice is ciprofloxacin, until it is known whether the anthrax strain is resistant to any of the other usual antibiotics. • Because spores may take up to 60 days to germinate, the length of treatment is usually 60 days. • For inhalation anthrax, people with known or suspected exposure would be given oral antibiotics (pills). • If a person develops symptoms of the disease or has a positive test for the disease itself (not just a test for "exposure"), antibiotics would be given intravenously (IV) for 14 days, then orally for the rest of the 60 days. • Cutaneous anthrax is treated with oral antibiotics (pills).
The prognosis of cutaneous anthrax treated with antibiotics is excellent. However, in the absence of antibiotics, up to 20% of individuals may die as anthrax may spread into the bloodstream. • The prognosis of inhalation anthrax once it reaches the second stage is poor, even with antibiotic therapy. Up to 90% of cases in the second stage are fatal.
Cat-scratch Disease • Cat scratch disease is an infectious illness caused by the bacteria Bartonella, believed to be transmitted by cat scratches, bites, or exposure to cat saliva. • More than 40,000 cases occur annually in the US • Symptoms • A history of contact with a cat • Common • Papule or pustule at site of injury (inoculation), usually the first sign • Swelling of the lymph nodes (adenopathy) occurs in the area near where the skin was infected (bitten, scratched, etc.)
Fever in approximately one third of patients • Fatigue • Malaise • Headache • Treatment • Generally, cat scratch disease is not serious. Treatment, other than reassurance, is not usually recommended. However, in severe cases treatment with antibiotics can be helpful.
Plague • Plague is transmitted among rodents and to humans by flea bite or ingestion of the feces of fleas. It can also be transmitted human to human when a plague victim develops pneumonia and spreads infected droplets by coughing. An epidemic may be started this way.
Symptoms • Sudden onset of high fever • Chills • General discomfort, uneasiness, or ill feeling (malaise) • Muscular pains • Severe headache • Smooth, oval, reddened, painful swellings of swollen lymph glands called buboes in the groin, armpits, neck, or elsewhere in the body. Pain may occur in the area before the swelling; the most common area is in the groin • Seizures
Treatment • Immediate treatment with antibiotics such as streptomycin, chloramphenicol, or tetracycline is indicated. • Oxygen, intravenous fluids, and respiratory support are additional treatments. • Patients with pneumonic plague are strictly isolated from other patients. • People who have had contact with anyone infected by pneumonic plague are observed closely and are given antibiotics as a preventive measure. • Prognosis • Half of bubonic plague victims die if not treated, and almost all victims of pneumonic plague die if not treated. Treatment reduces the death rate to 5%
Typhus • Typhus is a rickettsial disease caused by one of two organisms, Rickettsia prowazekii (epidemic typhus and Brill disease) and Rickettsia typhi (murine or endemic typhus). Epidemic typhus and Brill disease are uncommon in the United States. • Murine typhus occurs in the southeastern and southern states. There are less than 100 cases per year. Murine typhus is a milder form and is seldom fatal (less than 2%). • It is frequently seen in the summer and fall and typically lasts two to three weeks. Risk factors for murine typhus include exposure to rat fleas or rat feces, or exposure to other animals (such as cats, opossums, raccoons, skunks, and rats). • Epidemic typhus occurs in poor hygienic conditions (which is why it is sometimes called "jail fever"), usually when the temperature is cold. It is spread by lice. Although very rare in the United States, it has sometimes been spread by the lice and fleas of flying squirrels.
SYMPTOMS OF MURINE TYPHUS: • headache • backache • arthralgia • fever, extremely high (105 to 106 degrees Fahrenheit) and may last up to two weeks • rash that begins on the trunk and spreads peripherally (The rash is made up of dull red macules that may become slightly papular after the initial appearance may last only a few hours.) • nausea and vomiting in most patients • hacking, dry cough • abdominal pain
SYMPTOMS OF EPIDEMIC TYPHUS: • severe headache • fever, high (104 degrees Fahrenheit) • cough in 70% of patients • arthralgia and myalgia, (muscle pain) severe • chills • falling blood pressure • stupor • delirium • rash that begins on chest and spreads to rest of trunk and extremities, but not to palms and soles • early rash is faint and rose colored and fades with pressure (Later the lesions become dull, red, and do not fade. People with severe typhus may also develop petechiae.) • lights appear very bright, and exposure to light may hurt the eyes
Treatment • The goal of treatment is to eliminate the infection and to treat the symptoms with antibiotics (such as tetracycline, doxycycline, or chloramphenicol). For epidemic typhus, intravenous fluids and oxygen may be necessary to help stabilize the patient. • Prognosis • Without treatment death may occur in 10 to 60% of patients with epidemic typhus. Patients over the age of 60 have the highest risk of death. With timely antibiotic therapy, the affected person is expected to recover completely. • Less than 2% of untreated patients with murine typhus may die, and appropriate antibiotic therapy will cure virtually all patients.
Rocky Mountain Spotted Fever • An infectious disease caused by Rickettsia rickettsii transmitted to humans by the bite of ticks. • Symptoms • fever • chills • incubation period of 2 to 14 days • severe headache • muscle pain • mental confusion • rash, first appearing on wrists and ankles, then spreading to most of the body, usually starts a few days after fever starts; up to 20% of people do not get a rash
Treatment • The objective of treatment is careful removal of the tick from the skin and antibiotics to eliminate the infection. Doxycycline or tetracycline are frequently used. Chloramphenicol may be used in pregnant women. • Prognosis • Treatment usually cures the infection. Complications are rare but can include paralysis, hearing loss, and nerve damage. The death rate is 5 to 7% and usually reflects a delay in seeking treatment.
Gangrene • A severe form of gangrene (tissue death) usually caused by Clostridium perfringens (see also necrotizing subcutaneous infection). It can also be from Group A Streptococcus. Staphlococcus aureus and Vibrio vulnificus can also cause similar infections. • Gas gangrene occurs as a result of infection by Clostridium bacteria that, under anaerobic (low oxygen) conditions, produce toxins that cause the tissue death and associated symptoms.
Gas gangrene generally occurs at the site of trauma or a recent surgical wound. • Symptoms • moderate to severe pain around a skin injury • progressive swelling around a skin injury • moderate to high fever • skin color initially pale, later dusky progressing to dark red or purple • vesicle (blister) formation, coalescent (combine into large blisters) • blisters filled with brown-red fluid • drainage from the tissues, foul-smelling brown-red or bloody fluid (serosanguineous discharge) • increased heart rate (tachycardia) • sweating • subcutaneous emphysema (air under the skin)
Treatment • Prompt surgical removal of dead, damaged, and infected tissue (debridement) is necessary. Amputation of an arm or leg may be indicated to control the spread of infection. • Antibiotics, preferably penicillin-type, should be given. Initially, this is given intravenously (through a vein). Analgesics may be required to control pain. Hyperbaric oxygen has been tried with varying degrees of success. • Prognosis • Gas gangrene is progressive and often lethal. Immediate medical attention is required.
Lyme Disease • Borrelia burgdorferi • Transmitted by bite of tick • One of the most common tickborne diseases in the US • Field mice most important reservoir • Prevalent in atlantic ticks
Symptoms: • Bull's-eye rash at site of bite • Flulike symptoms appear on couple of weeks as rash fades • During 2nd phase, irregular hearbeat • Neurological symp. • Facial paralysis • Meningitis, • Encephalitis
Early treatment with antibiotics seem to be effective • Lyme arthritis resolves in most patients within a few weeks or months following antibiotic therapy, although it can take years to disappear completely in some people. • If the disease has persisted long enough, however, it may irreversibly damage the structure of the joints. Following treatment for Lyme disease, some people still have muscle achiness, neurologic symptoms such as problems with memory and concentration, and persistent fatigue. NIH-sponsored researchers are conducting studies to determine the cause of these symptoms and how to best treat them.
Chagas’ Disease • Chagas disease is caused by Trypanosoma cruzi, a parasite related to the African trypanosome that causes sleeping sickness. It is spread by reduvid bugs and is one of the major health problems in South America, where 20 million people are infected. Due to immigration, approximately 500,000 people in the United States are believed to be infected.
Chagas disease has two phases -- acute and chronic. • The acute phase may have no symptoms or have very mild symptoms. • Symptoms of the acute phase include swelling and reddening at the site of infection (where the blood-sucking insect caused the initial infection). • This may be followed by swelling of one eye. • Lymph nodes that drain the area of the insect bite may become swollen. • As the parasite spreads from the bite site, the patient develops fever, malaise, and generalized swelling of the lymph nodes. • The liver and spleen may become enlarged. • The disease goes into remission after the acute phase and may become chronic with no further symptoms for many years. • When symptoms finally develop, they appear as cardiac disease (cardiomyopathy) and digestive abnormalities.
Patients may develop congestive heart failure. Swallowing difficulties may be the first symptom of digestive disturbances and may lead to malnutrition. Patients who have parasitic infection of the colon may experience abdominal pain and constipation. Death is usually caused by heart disease.
Symptoms • history of exposure in an area where Chagas disease is known to occur • swollen red area at site of previous insect bite • enlarged lymph nodes • swelling of one eye • fever • irregular heartbeat (arrhythmia) • rapid heartbeat (tachycardia) • swallowing difficulties
Treatment • The acute phase should be treated. Benznidazole has been shown to be effective. Experimental treatment may include nifurtimox. Treating the chronic phase with antibiotics is not helpful. Instead, the symptoms of heart and intestinal disease should be treated. • Prognosis • Approximately 30% of infected and untreated people will develop chronic or symptomatic Chagas disease. It may take more than twenty years from the time of the original infection to develop heart or digestive problems. • Abnormal heart rhythms (arrythmias, ventricular tachycardia) may cause sudden death. Once congestive heart failure develops, death usually occurs within several years.
Leishmaniasis • Leishmania are tiny protozoa. Their parasitic life cycle includes the sandfly and an appropriate host. Humans are one of those hosts. Leishmania infection can cause skin disease (called cutaneous leishmaniasis). It can affect the mucous membranes with a wide range of appearance, most frequently ulcers. It may cause skin lesions that resemble those of other diseases including cutaneous tuberculosis, syphilis, leprosy, skin cancer (basal cell carcinoma), and fungus infections.
Leishmania can also cause systemic disease (visceral leishmaniasis) with fatal complications. • When introduced into the body by the bite of a sandfly, the parasite migrates to the bone marrow, spleen, and lymph nodes. • Systemic infection in children usually begins suddenly with vomiting, diarrhea, fever, and cough. • In adults, fever for 2 weeks to 2 months is accompanied by nonspecific symptoms such as fatigue, weakness, and loss of appetite. • Weakness increases as the disease progresses. The skin may become grayish, dark, dry and flaky. • The parasites damage the immune system by decreasing the numbers of disease-fighting cells so death usually results from complications such as other infections rather than from the disease itself. • Death often occurs within 2 years.
Symptoms • history of exposure to the bite of sandflies • history in being in an area known for leishmaniasis • Systemic illness (visceral leishmaniasis) • fever, persistent, long duration (weeks), may cycle irregularly • night sweats • fatigue • weakness • appetite loss (anorexia) • weight loss
abdominal discomfort, vague • vomiting (children) • diarrhea (children) • cough (children) • skin, scaly • skin, gray, dark, ashen • hair, thinning
Skin disease (cutaneous leishmaniasis) • Symptoms on the skin include: • macule or papule, erythematous • skin ulcer, forms at site of original lesion • ulcer heals very slowly over a matter of months • smaller lesions may form around the ulcer (satellite lesions)
Treatment • Antimony-containing compounds are the principal medications used to treat leishmaniasis. These include: • meglumine antimonate • sodium stibogluconate • Other drugs that may be used include: • pentamidine • amphotericin B • Miltefosine
Plastic surgery may be required to correct disfigurement by destructive facial lesions (mucocutaneous leishmaniasis). Removal of the spleen (splenectomy) may be required in drug-resistant cases (visceral leishmaniasis).
