Bacteria abound in the environment, on the skin and in the human body. While most bacteria are harmless to humans, some species prove uniformly dangerous. Campylobacter jejuni, Rickettsia rickettsii and Salmonella typhi are examples of disease-causing bacteria that provoke different types of human illnesses, which range in severity from mild to potentially life-threatening.
Campylobacter Jejuni
The Centers for Disease Control and Prevention reports that the bacterium Campylobacter jejuni is one of the most frequent causes of acute diarrhea in the United States. Approximately 2.4 million Americans contract Campylobacter each year, with infants and young children disproportionately affected. The majority of cases of Campylobacter are contracted from eating raw or undercooked chicken or turkey. Other foods can be cross-contaminated from handling raw poultry or the packaging. Unpasteurized milk is another common source of Campylobacter. The Centers for Disease Control and Prevention notes that even a minute number of bacteria can cause illness. Most people recover from Campylobacter-induced diarrhea without treatment in roughly two to five days. Although uncommon, Campylobacter infection may trigger a neurological complication, Guillain-Barré syndrome. With this condition, the immune system reacts against the nerves of the body, leading to temporary paralysis. Recovery from Guillain-Barré syndrome may take many weeks to months. The Centers for Disease Control and Prevention estimates that up to 40 percent of cases of Guillain-Barré syndrome in the United States are triggered by a Campylobacter infection.
Rickettsia Rickettsii
Rickettsia rickettsii is the bacterium that causes Rocky Mountain spotted fever. The disease is carried by ticks and transmitted to humans through a bite. The bacteria migrate from the skin to the lymph nodes, and then enter the bloodstream. As Kenneth Todar, PhD, notes in the electronic reference book "Todar's Online Textbook of Bacteriology," Rickettsia rickettsii infect the cells that line the blood vessels of the body. Early symptoms of Rocky Mountain spotted fever include severe headache, fever, chills, muscle pains, loss of appetite, nausea and vomiting. A faint rash characteristically appears on the wrists, forearms and ankles approximately two to four days after the fever begins. People with Rocky Mountain spotted fever can deteriorate rapidly after the development of kidney failure, severe breathing difficulties and brain involvement. The Centers for Disease Control and Prevention urges prompt antibiotic therapy for any person suspected of having Rocky Mountain spotted fever.
Salmonella Typhi
Salmonella typhi is the bacterium that causes typhoid fever. While uncommon in the United States, the illness remains a life-threatening health problem worldwide. Typhoid fever is contracted via inadvertent ingestion of the bacteria due to contamination from the feces of someone with the illness or a carrier of the bacteria. The Centers for Disease Control and Prevention notes that while gastrointestinal symptoms vary, a persistent high fever of approximately 103 to 104 F occurs in nearly all people with typhoid fever. Abdominal pain, headache, loss of appetite and weakness may accompany the fever. Late intestinal complications of typhoid fever may prove life-threatening. Antibiotic treatment is typically required for people with laboratory-diagnosed typhoid fever.
References
- Centers for Disease Control and Prevention: Campylobacter
- "Todar's Online Textbook of Bacteriology"; Kenneth Todar, PhD; 2008
- Centers for Disease Control and Prevention: Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain Spotted Fever, Ehrlichioses, and Anaplasmosis--United States
- Centers for Disease Control and Prevention: What Are the Symptoms of Rocky Mountain Spotted Fever?
- Centers for Disease Control and Prevention: Typhoid Fever
