Escherichia coli (called E. coli) includes hundreds of strains of bacteria that live in the intestines of healthy humans and animals. Some of these bacteria can cause severe illness. Most illness occurs from eating undercooked ground beef. Other cases have been traced to drinking unpasteurized apple juice or cider, raw milk, eating produce contaminated by animal feces, and recreational exposure in contaminated water. It can also spread from person to person in families and childcare centers where there is poor personal hygiene. Symptoms include abdominal cramps and diarrhea, which is sometimes bloody. There is little or no fever present, and serious illness is generally gone in five to 10 days. In children under age 5 and the elderly, the infection can cause hemolytic uremic syndrome, which destroys the red blood cells and causes the kidneys to fail. This complication occurs in about 2 to 7 percent of infections. Most people infected with E. coli recover without antibiotics or other specific treatment.
Valley Fever usually affects the lungs and is caused by Coccidioides fungus, which lives in the dirt. It is spread through spores that enter the air when the dirt is disturbed by digging, construction work, or strong winds. People can get Valley Fever if they breathe in dust from dirt that contains the fungal spores. The fungus is found in some areas of the southwestern United States, and in parts of Mexico and Central and South America. In California, the fungus is found in many areas of the San Joaquin Valley.
Legionellosis is caused by Legionella bacteria, responsible for between 8,000 and 18,000 cases of community-acquired pneumonias requiring hospitalization each year. The most common way to become infected is by inhaling contaminated water droplets. The bacteria are found in manmade and fresh-water environments. Warm temperatures support bacterial growth and hot-water and air-circulation systems, hot tubs, and decorative fountains have been responsible for community-based outbreaks. Legionellosis is associated with two syndromes: Pontiac fever and Legionnaires’ disease. Pontiac fever causes flu-like symptoms while Legionnaires’ disease is a common cause of serious bacterial pneumonia. The vast majority of reported legionellosis cases are Legionnaires’ disease. Those most at risk from legionellosis are the elderly and people with compromised immune systems.
Q Fever is caused by Coxiella burnetii bacteria. Most people get Q fever by coming in contact with animals infected with the bacteria, their tissues, or fluids. Those who have frequent direct contact with animals, including veterinarians, meat workers, and sheep and dairy farmers are at higher risk. People can also become infected by breathing contaminated air or dust from an area with a large concentration of animals, by drinking contaminated raw milk, or indirectly through contaminated materials like wool, straw, and fertilizer. Transmission by tick bites can occur, but is rare in the United States. Sheep, cattle, goats, cats, dogs, some wild animals such as bobcats and rodents, birds, and ticks carry the bacteria. Most infected animals do not show signs of illness. About half of all people infected with C. burnetii have symptoms and Q fever is rarely fatal. Symptoms are similar to the flu and may include fever, chills, sweats, headache, and weakness. In rare cases, Q fever can progress to the liver, nervous system, or heart valve. Q fever is diagnosed by identifying the bacteria in tissues or through a blood test. No treatment is needed for mild cases of Q fever. Those with severe illness can take antibiotics for two to three weeks. Patients with heart valve deformities should see their doctor for treatment to prevent infection of their heart valve.
Tularemia (Rabbit, Deer-Fly Fever)
Tularemia is an infectious disease caused by Francisella tularensis bacteria. It is usually found in wild animals, but severe illness and death may also occur in humans. The bacteria are common in various kinds of ticks and in small and medium-sized mammals, especially rabbits, hares, beavers, muskrats, and voles. In the United States, the two main sources of infection for humans are bites by ticks or biting flies and contact with infected animals or their carcasses, especially the cottontail rabbit. People may also become infected from eating undercooked rabbit or hare meat or from contact with contaminated water, dust, hay, mud, or animal bites. The disease is not spread from human-to-human.
Typhoid fever is caused by Salmonella Typhi bacteria. While not common in the United States, typhoid fever is prevalent in developing countries in Africa, Asia (especially Southeast Asia and the Indian subcontinent), and Central and South America. Most cases in the U.S. are in people who have traveled to those countries. The most common source of exposure is food or water contaminated by the feces or urine of those infected with typhoid fever. Illness can occur anywhere from three to more than 60 days after exposure. Symptoms include diarrhea, headaches, fever, and loss of appetite. Typhoid fever is treated with antibiotics. Two typhoid vaccines are currently available in the U.S.
Ciguatera fish poisoning can occur when people eat fish contaminated with toxins that are produced by sea plants. These fish include large subtropical and tropical finfish, such as king mackerel; barracuda; black and yellowfin grouper; blackfin, cubera, and dog snapper; greater amberjack; hogfish; and horse-eye jack. These fish are typically caught by sport fishermen on reefs in Hawaii, Guam, and other South Pacific islands, the Virgin Islands, and Puerto Rico. Because there are no specific tests for ciguatera fish poisoning in humans, diagnosis is based on symptoms and recent dietary history. Ciguatera fish poisoning usually involves a combination of gastrointestinal, neurological, and cardiovascular disorders. Symptoms can vary with the geographic origin of toxic fish. Gastrointestinal symptoms such as diarrhea, vomiting, and abdominal pain occur first, usually within 24 hours of eating the contaminated fish. Neurologic symptoms may occur at the same time or may follow one to two days later and include pain and weakness in the lower extremities. Other frequent symptoms include temperature reversal (e.g., hot food tastes cold, cold food tastes hot) and “aching teeth.” Most patients recover completely within a few weeks, but severe cases may progress to coma and respiratory arrest within the first 24 hours of illness, while other patients may have intermittent reoccurrence of symptoms over a period of months to years.
Scombroid fish poisoning can occur after eating fish contaminated with histamine. Because there are no specific tests for Scombroid fish poisoning in humans, diagnosis is based on symptoms and recent dietary history. Illness typically begins minutes to hours after eating the toxic fish and looks like an allergic reaction. Symptoms include tingling and burning sensations around the mouth, facial flushing and sweating, nausea, vomiting, headache, palpitations, dizziness, and rash. Some patients report that the toxic fish has a peppery or a metallic taste. Fish in the Scombridae family (tuna, mackerel, skipjack and bonito) are the most common source of scombroid fish poisoning. Other fish, however, have been implicated in scombroid fish poisoning, including mahi mahi, bluefish, marlin, and escolar. When susceptible fish are not promptly and continuously refrigerated, bacteria can metabolize naturally occurring histamine to produce scombrotoxin. Histamine is heat resistant and can cause illness even when fish are properly canned or cooked thoroughly. Scombroid fish poisoning is usually mild and does not last long, making treatment unnecessary. For more severe cases or in those with underlying medical conditions, oral antihistamines may be beneficial.
Influenza, also called the flu, is a contagious respiratory illness caused by influenza viruses. Types of flu include seasonal, avian, H1N1, and haemophilus. The flu can cause mild to severe illness, and at times can lead to death. The best way to prevent influenza is by getting a flu vaccination each year. There are two main types of influenza virus: Types A and B. Influenza A and B viruses that routinely spread in people are responsible for seasonal flu epidemics each year. The emergence of a new influenza virus like H1N1 can result in a flu pandemic as occurred in the spring of 2009. Over the course of a flu season, different types (A and B) and subtypes of influenza A viruses can circulate and cause illness. The flu is different from a cold. The flu usually comes on suddenly and symptoms can include fever, chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headache, fatigue, vomiting, and diarrhea. Most people who get the flu will recover in a few days to two weeks, but some people will develop complications that can be life-threatening and result in death. Flu complications include pneumonia, bronchitis, and sinus and ear infections. The flu can also make chronic health problems like asthma and congestive heart failure worse. Anyone can get the flu (even healthy people), and serious problems from influenza can happen at any age. However, those most at risk from serious complications include people over age 65, people certain chronic medical conditions (such as asthma, diabetes, or heart disease), pregnant women, and young children.
Gonorrhea is a common sexually transmitted infection caused by Neisseria gonorrhoeae bacteria. These bacteria can grow and multiply easily in the warm, moist areas of the reproductive tract, including the cervix (opening to the womb), uterus (womb), and fallopian tubes (egg canals) in women, and in the urethra (urine canal) in women and men. The bacteria can also grow in the mouth, throat, eyes, and anus. Gonorrhea is spread through contact with the penis, vagina, mouth, or anus. Ejaculation does not have to occur for gonorrhea to be transmitted or acquired. Gonorrhea can also be spread from mother to baby during delivery. Infection can cause serious reproductive health problems, such as pelvic inflammatory disease (PID) and infertility. Gonorrhea also can cause infections in newborn babies. Tests and effective treatments are available.