Pertussis, or whooping cough, is a highly contagious upper respiratory infection caused by Bordetella pertussis or Bordetella parapertussis bacteria. It is a serious disease that can cause permanent disability in infants, and even death. The disease spreads from person to person when someone breathes in the tiny droplets that enter the air when an infected person sneezes or coughs. These droplets can also end up on surfaces like tabletops or door handles and when a person touches them and then touches their nose, mouth, or eyes, the bacteria enter their body. At first whooping cough may seem like an ordinary cold, but can become more serious. After a week or two, signs and symptoms worsen, and can include coughing fits so severe it makes it difficult to breathe. Severe and prolonged coughing attacks may: bring up thick phlegm, provoke vomiting, result in a red or blue face, cause extreme fatigue, or end with a high-pitched "whoop" sound during the next breath of air. For the best protection against whooping cough, children need five shots. Infants can be vaccinated starting at age 2 months, and again at 4 and 6 months. Until all three shots are completed, infants are at serious risk for severe illness and even death from whooping cough.
A fourth shot is recommended for children between age 15 and18 months, and a fifth shot is given when a child enters school, at age 4 to 6 years. Immunity wears off, so adults need a booster shot, particularly those who live with or care for an infant.
Plague is a disease that mostly affects rodents like rats and squirrels. It is caused by bacteria. People can get the disease if they are bitten by an infected rodent flea. Symptoms include fever and swollen lymph nodes. Plague is treatable with antibiotics, but can progress to severe and sometimes fatal illness if diagnosis and treatment are delayed. Squirrels, chipmunks, and other rodents in many areas of California can carry plague.
Psittacosis is caused by Chlamydophila psittaci bacteria. Humans get the infectious disease from infected birds. While it is usually transmitted from an infected pet bird of the parrot family, turkeys, chickens, pigeons, and almost any other bird can be carry the bacteria. The disease most commonly affects pet-store workers, farmers, and slaughterhouse workers, or people who have recently purchased an infected bird. The elderly and people with weakened immune systems are most at risk. People get the disease by breathing the dust from dried droppings in birdcages, or by handling infected birds in slaughterhouses. The bacteria are very resistant, so waste material in birdcages can be infectious for weeks. Symptoms usually occur four to 15 days after exposure and include fever, headache, chills, cough, and sometimes pneumonia. The signs of disease in birds are nonspecific and include poor appetite, ruffled appearance, discharge from the eyes or nose, and diarrhea. Birds can die of the disease.
Rabies is caused by a virus and affects the central nervous system. The virus is usually passed to humans when an infected animal bites them. Rabies can sometimes be transmitted if the saliva of an infected animal gets into a fresh scratch or break in the skin, or comes in contact with mucous membranes (eyes, mouth, nose). In California, most cases of rabies occur in skunks and bats. Domestic animals account for only 3 percent of animal rabies, and the rest occurs in a variety of wild animals, including foxes. If you are bitten or scratched by a rabid or possibly rabid animal, wash the wound thoroughly with soap and warm water and immediately consult a physician, who will decide if the series of rabies vaccinations is necessary to prevent serious illness.
Salmonellosis is caused by Salmonella bacteria. These bacteria live in the intestinal tracts of humans and other animals, including birds. Salmonella are usually transmitted to humans by eating foods contaminated with animal feces. Contaminated foods usually look and smell normal, and are of animal origin, such as beef, poultry, milk, or eggs. However, all foods, including vegetables, may become contaminated. While many raw foods of animal origin are frequently contaminated, thorough cooking kills Salmonella. Food may also become contaminated by the unwashed hands of an infected food handler who did not properly wash their hands after using the bathroom. Salmonella may also be found in the feces of some pets, especially those with diarrhea, and people can become infected if they do not wash their hands after contact with these feces. Reptiles are particularly likely to carry Salmonella. Symptoms usually occur within 12 to 72 hours after becoming infected and include diarrhea, fever, and abdominal cramps. The illness usually lasts four to seven days, and most people recover without treatment. However, in some people the diarrhea may be so severe that they need to be hospitalized. In these people, the Salmonella infection may spread from the intestines to the blood stream, and then to other areas in the body and can cause death unless the person is treated promptly with antibiotics. The elderly, infants, and those with impaired immune systems are more likely to have a severe illness.
Shigellosis is a gastrointestinal disease caused by a group of bacteria called Shigella. It is passed from person to person when an infected person’s stool comes in contact with another person’s mouth. The disease most often spreads during person-to-person contact, especially within families and childcare centers that do not have good hand-washing and hygiene habits. Shigella can also contaminate food and cause illness among those who eat the affected food. Common food sources include parsley, cilantro, lettuce, raw oysters, and commercially prepared bean dip. Shigellosis can also occur after drinking or swimming in contaminated water. Symptoms usually develop one to two days after exposure to Shigella, and last five to seven days. This disease can be severe and lead to hospitalization, especially in young children and the elderly. While some people with shigellosis have no symptoms, they can still pass it to others.
Smallpox is a serious, contagious, and sometimes fatal infectious disease that is caused by the variola virus. There is no specific treatment for smallpox disease, and the only prevention is vaccination. The name smallpox is derived from the Latin word for "spotted" and refers to the raised bumps that appear on the face and body of an infected person. There are two types of smallpox. Variola major is the most severe and common form of smallpox, with a more extensive rash and higher fever. Variola minor is a less common form and much less severe. Smallpox outbreaks have occurred from time to time for thousands of years, but the disease is now eradicated after a successful worldwide vaccination program. The last case of smallpox in the United States was in 1949. The last naturally occurring case in the world was in Somalia in 1977. Generally, direct and fairly prolonged face-to-face contact is required to spread smallpox from one person to another. Smallpox can also be spread through direct contact with infected bodily fluids or contaminated objects such as bedding or clothing. While a person is sometimes contagious when a fever starts, they are most contagious when a rash first appears and remain contagious until the last scab falls off. Symptoms occur seven to 17 days after exposure. Smallpox begins with a high fever, head and body aches, and sometimes vomiting. A rash follows that spreads and progresses to raised pus-filled bumps that scab and fall off after about three weeks, and may leave a pitted scar. The majority of smallpox patients recover, but as many three out of every 10 infected with the disease die.
Syphilis is a sexually transmitted disease (STD) caused by Treponema pallidum bacteria. It is passed from person to person through direct contact with a syphilis sore. Sores occur mainly on the penis, scrotum, vagina, anus, or in the rectum. Sores also can occur on the lips and in the mouth. The bacteria are passed from the sore of an infected person to another person during vaginal, anal, or oral sex. Pregnant women with the disease can pass it to the babies they are carrying. While many people infected with syphilis do not experience symptoms for years, they remain at risk if they are not treated. The primary stage of syphilis is usually marked by the appearance of a single sore (called a chancre), but there may be multiple sores. The time between infection with syphilis and the start of the first symptom can range from 10 to 90 days (average 21 days). The chancre is usually firm, round, small, and painless. It appears at the spot where syphilis entered the body. The chancre lasts three to six weeks, and it heals without treatment. However, without adequate treatment, the infection moves to the secondary stage. Symptoms associated with the secondary stage include a rash on one or more areas of the body. The rash usually does not cause itching. Rashes associated with secondary syphilis can appear as the chancre is healing or several weeks after the chancre has healed. The characteristic rash of secondary syphilis may appear as rough, red, or reddish brown spots both on the palms of the hands and the bottoms of the feet. However, rashes with a different appearance may occur on other parts of the body, sometimes resembling rashes caused by other diseases. The latent (hidden) stage of syphilis begins when primary and secondary symptoms disappear. Without treatment, the infected person will continue to have syphilis even though there are no signs or symptoms. This latent stage can last for years. Syphilis is treated with antibiotics.
Tetanus, commonly called lockjaw, is caused by Clostridium tetani bacteria and affects the nervous system. People get the diseases when a wound becomes infected with the bacteria. The bacteria can get in through even a tiny cut or scratch, but deep puncture wounds or cuts like those made by nails or knives are especially susceptible to infection with tetanus. Tetanus bacteria are present worldwide and are commonly found in soil, dust and manure. Infection with tetanus can cause severe muscle spasms and "locking" of the jaw, which keeps people with tetanus from opening their mouths or swallowing. Tetanus is not passed from person to person. The DTaP, Td, and Tdap vaccines all protect against tetanus. Children need four doses of DTaP by age 15 months and a Tdap booster at age 11 or 12. Adults need a booster every 10 years after the primary series has been completed. For adults, ages 18 to 64 years, Tdap (tetanus, diphtheria and pertussis) vaccine is recommended.
Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis bacteria. The bacteria usually attack the lungs, but can also affect other parts of the body, including the kidney, spine, and brain. If not treated properly, TB can be fatal. TB is spread from person to person through the air when someone with active TB coughs or sneezes. People nearby breathe in the bacteria and become infected. However, not everyone infected with the bacteria becomes sick. Those who are infected with the bacteria but do not get sick have what is called latent TB infection. People who have latent TB do not feel sick, do not have any symptoms, and cannot spread TB to others. However, latent TB can turn into active TB. Symptoms include weakness, weight loss, fever, night sweats, chest pain, coughing, and coughing up blood. Active TB can be treated with medications, however, however there are drug-resistant strains. People with latent TB infection can take medicine so that they will not develop active TB disease.
West Nile Virus
West Nile virus is an infection that spreads to humans and animals by infected mosquitoes. Mosquitoes get the virus when they feed on infected birds. Most West Nile virus infections occur during warm weather, when mosquito populations are active. Symptoms can range from mild to severe and occur from three to 14 days after being infected. Mild symptoms include fever and a mild headache. Some people who become infected with West Nile virus develop a life-threatening illness that includes inflammation of the brain. Mild signs and symptoms of West Nile virus generally go away on their own. But severe signs and symptoms — such as a severe headache, disorientation or sudden weakness — require immediate attention and possibly hospitalization.