Bacteria and Virus

Risk for Travelers:
The risk for international travelers is generally considered to be low. The viruses carried in rodent reservoirs are transmitted when humans have contact with urine, fecal matter, saliva, or other excreta of infected rodents. The viruses associated with arthropod vectors are usually spread when the vector mosquito or tick bites a human or when a human crushes an infected tick. Some of these vectors may spread the virus to animals, including livestock.

Shingles is a disease caused by the varicella-zoster virus, the same virus that causes chickenpox. After an attack of chickenpox, the virus lies dormant in the nerve tissue. As we get older, it is possible for the virus to reappear in the form of shingles. Shingles is estimated to affect 2 in every 10 people in their lifetime. This year, more than 500,000 people will develop shingles

Anthrax, notorious for its role in the fall 2001 bioterrorist attacks, is a disease caused by a microbe known as Bacillus anthracis. In the fall of 2001, lethal anthrax bacteria were spread deliberately through the U.S. mail. Twenty-two people became ill, and five died. The perpetrator has not been caught.

Syphilis is passed from person to person through direct contact with a syphilis sore. Sores occur mainly on the external genitals, vagina, anus, or in the rectum. Sores also can occur on the lips and in the mouth. Transmission of the organism occurs during vaginal, anal, or oral sex. Pregnant women with the disease can pass it to the babies they are carrying.

Fever blisters and canker sores are two of the most common disorders of the mouth, causing discomfort and annoyance to millions of Americans. Both cause small sores to develop in or around the mouth, and often are confused with each other. Canker sores, however, occur only inside the mouth--on the tongue and the inside linings of the cheeks, lips and throat. Fever blisters, also called cold sores, usually occur outside the mouth--on the lips, chin, and cheeks or in the nostrils.

Food borne illness results from eating food contaminated with bacteria or their toxins or other pathogens such as parasites or viruses. The illnesses range from upset stomach to more serious symptoms, including diarrhea, fever, vomiting, abdominal cramps, and dehydration. Although most food borne infections are undiagnosed and unreported, the Centers for Disease Control and Prevention estimates that every year about 76 million people in the United States become ill from pathogens in food. Of these, about 5,000 die.

Pinworm is the most common worm infection in the United States. School-age children, followed by preschoolers, have the highest rates of infection. In some groups nearly 50% of children are infected. Infection often occurs in more than one family member. Adults are less likely to have pinworm infection, except mothers of infected children. Childcare centers, and other institutional settings often have cases of pinworm infection.

Scabies spreads rapidly under crowded conditions where there is frequent skin-to-skin contact between people, such as in hospitals, institutions, child-care facilities, and nursing homes.

Plague is an infectious disease caused by bacteria called Yersinia pestis. These bacteria are found mainly in rodents, particularly rats, and in the fleas that feed on them. Other animals and humans usually contract the bacteria from rodent or fleabites.

Historically, plague destroyed entire civilizations. In the 1300s, the "Black Death," as it was called, killed approximately one-third (20 to 30 million) of Europe's population. In the mid-1800s, it killed 12 million people in China. Today, thanks to better living conditions, antibiotics, and improved sanitation, current World Health Organization statistics show there were 2,118 cases in 2003 worldwide.

Hand foot and mouth disease (HFMD) is a common viral illness that occurs worldwide, mostly during the summer and autumn months in temperate climates. A group of viruses called enteroviruses is usually the cause of the infection. HFMD mainly affects infants and children, although it can also occur in adults.

TB disease in the lungs or throat is infectious and can be spread from one person to another through the air. The bacteria are put into the air when a person with TB disease of the lungs or throat coughs or sneezes. People nearby may breathe in these bacteria and become infected. People with TB disease are most likely to spread it to people they spend time with every day.

Hepatitis A is a highly contagious disease that attacks the liver. It is the most common type of hepatitis reported in the United States.

Head lice are tiny insects. The crawling stages of this insect feed on human blood, which can result in severe itching. Head lice can be found anywhere on the scalp but are heaviest behind the ears and just above the hairline along the nape of the neck.

Botulism is a rare, but potentially deadly illness characterized by muscle paralysis. Botulism is caused by a nerve toxin that is produced by a bacterium called Clostridium botulinum. A toxin is a poison that is created by living organisms (plants, animals and certain bacteria).