Less than one hundred years ago, one out of every 10 babies born in the United States died before its first birthday. Major advances in hygiene, and development of vaccines led to giant strides being taken in the prevention of disease. Doctors have always intuitively understood the value of disease prevention. When faced with the hard and often unsuccessful task of treating advancedstages of disease, the benefits of incorporating prevention into medical practice have become apparent.
One of the most obvious ways to prevent disease especially among children isthrough routine childhood immunizations. As a result of widespread vaccination among children over the past several decades, a number of diseases such asdiphtheria, pertussis, tetanus, poliomyelitis, measles, mumps, rubella, and congenital rubella syndrome have become remarkably less common. Several otherdiseases such as infection by Hemophilus influenzae type B have been shown tocause meningitis, pneumonia, arthritis, and epiglottitis in one out of every200 children in the USA before age 5. Similarly, children account for 20-30%of the chronic Hepatitis B infections in the USA. Hence, new childhood vaccines such as H. influenzae type b (Hib), hepatitis B, hepatitis A, and varicella (for chicken pox) have also been introduced. Although chicken pox is generally mild in healthy children, it accounts for missed school days for the children, missed work days for parents and visits to health care providers. Occasionally it leads to serious complications such as encephalitis, pneumonia, bacterial superinfections, which may require hospitalization and may eventually result in death.
Disease prevention has now become a very challenging medical specialty. The physicians or preventive medicine specialists are trained in epidemiology, biostatistics, environmental and occupational health services, administration, as well as clinical prevention. They are therefore uniquely qualified to workwith both individuals and the community to prevent disease. They initiate several programs in infectious disease prevention and control, sexually transmitted diseases and in the prevention of chronic diseases. They seek to identifyhealth hazards in the work place and the community. They are active in patient care and like to say that their patient is their community.
There are several steps in the disease prevention program. In order to prevent disease, the prevention technologies have to be first delivered to the patient, in this case the community at large. In the clinical prevention model, which is the traditional model for disease prevention, the health care provider and the patient have to interact. Early detection and treatment rely on that interaction. Screening for diseases, vaccination and early diagnosis all occur within this setup.
The second component of this preventive program is "behavioral prevention strategies". The preventive medicine specialists have to try and use a broad array of strategies to encourage lifestyle changes such as exercise, quitting smoking and adopting healthful diets. To accomplish these behavioral changes, the person's knowledge and attitudes may require changing.
Environmental prevention strategies form the third component of the preventive program. Providing safe drinking water, fluoridation, lead abatement, regulations on public smoking, seat-belt laws, and safer highways all come under this banner.
In order to incorporate these changes into the community, societal commitmentis required. However once these changes are made, they require very little effort from the individual and can have far-reaching effect.
Primary disease prevention is aimed at reducing risk factors or controlling the causative factors for a health problem. These include risk factors such assmoking in order to prevent lung cancer, environmental exposure to lead to prevent mental retardation in children, and sex education to reduce sexually transmitted diseases. Health services such as vaccinations, routine physical examinations and providing preventive therapy tools such as fluoridated wateralso fall under this category. Secondary disease prevention involves early detection and treatment such as mammography for detecting breast cancer or "contact tracing" for detecting and treating persons with AIDS and other sexuallytransmitted diseases.
Tertiary disease prevention involves providing appropriate supportive and rehabilitative services to prevent secondary complications, minimize morbidity and maximize quality of life such as rehabilitation from injuries.
According to the Center for Disease Control and prevention (CDC), contaminated food and drink are major sources of stomach or intestinal illness while traveling. Intestinal problems due to poor sanitation are found in greater numbers outside the United States and other industrialized nations. The CDC, therefore, advises travelers on how to select food and water and what procedures to follow while traveling outside of the United States. According to the CDC information sheets, in areas with poor sanitation, it is advisable to drink only boiled hot beverages such as coffee, tea, or canned and bottled carbonatedbeverages, beer and wine. Ice, should be avoided, since it may be made fromunsafe water. It is also safer to drink from a can or bottle of beverage thanfrom a container that was not known to be clean or dry. The area of a can orbottle that will touch the mouth should be wiped clean and dry. Where wateris contaminated, travelers should not brush their teeth with tap water.
CDC recommends that boiling water is the most reliable method to make water safe to drink. The water should be boiled vigorously, and then allowed to coolon its own. Chemical disinfection can be achieved with either iodine or chlorine. Disinfectant tablets can be purchased from a pharmacy and the manufacturer's directions should be followed. If water is cloudy, then it may be strained through a clean cloth and then double the number of disinfectants added.
For food, the CDC recommendations are that food should be selected with care.Any raw food could be contaminated. Foods such as salads, uncooked vegetables and fruit, unpasteurized milk and milk products, raw meats, and shellfish are particularly to contamination. Foods that are cooked and still hot are generally safe. Some fish are not guaranteed to be safe even when cooked becauseof the toxins present in their flesh.
In the United States, although food supply is very safe, millions of people become sick every year from a food borne infection. Sometime these illnesses can be severe and deadly. These illnesses are caused by microorganisms presentin food. Many of the illnesses occur because of the way food is handled andprepared in the home. In order to handle food safely, it is important to follow a few simple rules:
- Wash hands with soap and water before and afterhandling food.
- Wash hands thoroughly after handling raw meat or poultry and before handling ready-to eat food.
- Keep raw meats and poultryseparate from other foods, do not allow juices to drip on other foods.
- Clean and disinfect cutting boards and kitchen surfaces after preparing foods.
- When barbecuing or cooking meat, use a different plate for cooked than the one that held the raw food, Use different utensils also.
- Cook food thoroughly. Meat and poultry should be cooked all the way until their juices run clear. Hamburgers should be cooked to a temperature of 160o andshould be brown inside, not pink.
- When eating out, order foods that are thoroughly cooked.
- Cook seafood until it is opaque and flaky. Do not eat raw shellfish, oysters, and clams even if marinated.
- Cook eggsthoroughly; they should be firm not runny.
- Refrigerate or freeze perishable foods right after coming home from the store.
- Thaw frozen food in the refrigerator not the microwave oven or kitchen counter.
- Keephot food shot and cold foods cold after they are prepared.
- Do not leave food out at room temperature outside for longer than two hours.
- Refrigerate or freeze leftovers promptly in shallow containers or tightly wrapped bags.
Typhoid fever, a life threatening illness caused by the bacterium Salmonella,is one of the food-borne diseases that can be acquired while traveling overseas. Persons with typhoid fever have a sustained fever as high as 103 to 104degrees. They may also feel weak, or have stomach pains, headache, or loss ofappetite. In some cases, the patients have a rash of flat, rose-colored spots. The disease is preventable and can be treated with antibiotics. Persons with typhoid fever carry the bacterium in their bloodstream and intestinal tract. In addition, a small number of persons, called carriers, recover from thedisease, but continue to carry the bacteria. Both these types shed the bacteria in their feces. A person can get typhoid fever if he or she eats food or drinks beverages that have been handled by a person who is shedding the bacteria. In addition, if the water that is used for handling and cooking food getscontaminated with sewage, it becomes a source of the disease.
Most food-borne diseases are more rampant in areas of the world with poor hygiene and sanitation. Therefore, if one is traveling to the developing world,one should consider taking precautions. Two basic actions can protect one from typhoid fever. They are avoiding risky foods and drinks, and being vaccinated against the fever. If one is traveling to a country where typhoid is common, one should definitely consider getting vaccinated against typhoid. However, watching what one eats and drinks is just as important, as the vaccines maynot be 100% effective. Avoiding risky foods will also help protect travelersfrom other illnesses, including traveler's diarrhea, cholera, dysentery, andhepatitis A.
Another disease that afflicts travelers is a mosquito-borne viral disease, Japanese encephalitis. It is prevalent in three areas, mainly, China and Korea;the Indian sub-continent, and the Southeast Asian countries of Burma, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia, and the Philippines. It isalso found in a low frequency in Japan. Transmission of the disease is seasonal, following the prevalence of mosquitoes. The disease begins clinically asa flu-like illness with headache, fever, and often gastro-intestinal symptoms. Confusion and disturbances in behaviors also may occur at an early stage. The illness may progress to a serious infection of the brain i.e. encephalitisand in one third of the cases, the disease may be fatal. Once the illness has set in, only supportive treatment is available. However, there is a vaccineavailable in the United States and the CDC recommends the vaccine to anyonewho works or travels for longer than four weeks or more to the above-mentioned areas during the transmission season. In addition, the travelers are advised to minimize outdoor exposure during the cooler hours at dusk and at dawn, when the mosquitoes feed outdoors. Mosquito-repellents containing DEET as theactive ingredient should be worn and staying in air-conditioned or well-screened rooms is advised. A bednet and aerosol room insecticides can also be used. Permethrin, a mosquito repellent/insecticide, can be applied to clothing.
Dengue fever and Malaria are two other mosquito-transmitted diseases. The Aedes mosquito that transmits the Dengue virus is most active during the day. They are often found near human dwellings and often are present indoors. Thereis no vaccine for dengue fever, therefore the traveler should avoid mosquitobites by using insect repellent on skin and clothing. Malaria is a preventable infection that can be fatal if left untreated. Prescription antimalaria drugs can be taken as a prophylactic measure to prevent infection.
Influenza is a common infection among travelers. The risk for exposure to influenza during travel to foreign countries varies depending on the time of theyear and the destination. In the tropics, influenza can occur throughout theyear, while in the temperate zones and the Southern Hemisphere, the incidence is most during the months of April through September. In the Northern Hemisphere (i.e. United States and Canada), the occurrence is mainly November through March. It is not a very serious illness, but can lead to severe illness,especially for people at increased risk for complications. Influenza vaccinesare recommended for persons who are at high risk for complications and alsofor any person who would like to decrease their chances of developing influenza.
Acquired Immunodeficiency syndrome (AIDS) is a severe, often life-threatening, illness caused by the human immunodeficiency virus (HIV). The incubation period for the disease is very long, ranging from a few months to many years. Cases of HIV infection and AIDS have been reported worldwide. Hence, several issues have been raised regarding HIV infection and international travel. HIVinfection is preventable. The virus is transmitted through sexual intercourse, needle or syringe sharing, by medical use of contaminated blood or blood products, and perinatally from an infected woman to her baby. The disease is not transmitted through casual contact; air, food, water, contact with inanimate objects, or through mosquito or arthropod vectors.
In order to protect oneself from being infected with the virus, all sexual encounters with a person who is infected with HIV or whose infection status isunknown should be avoided. Sexual activity with intravenous drug users, and persons with multiple sexual partners, such as male or female prostitutes should be avoided. Condoms, when used consistently and correctly, prevent transmission of HIV. Intravenous drugs and needles should not be used for any purpose. In the developed countries of the world, the risk of infection of HIV through blood transfusion has been virtually eliminated through required testingof all donated blood for antibodies to HIV. However, in the less developed nations, a formal program for testing blood and biological products for antibody to HIV may not exist. If transfusion becomes necessary, the blood should betested, if at all possible, for HIV antibodies by appropriately trained laboratory technicians using a reliable test. Insulin-dependent diabetics, hemophiliacs, and other persons who require routine or frequent injections should carry a supply of syringes, needles, and disinfectant swabs (e.g. alcohol swabs) sufficient to last their entire stay abroad.
Yet another disease that can be prevented by reversing some risk factors is Heart Disease. Smoking is the most important risk factor and should be given up immediately. Dietary modifications, trying to achieve a proper weight, stress management, and regular exercise are also factors that help in preventingheart disease. The average U.S. Diet contains 37% fat. The American Heart Association recommends that the proportion be reduced to 30%. Increasing intakeof fruits and vegetables, which are rich in phytochemicals seem to decrease the risk of heart disease and some cancers. Exercise has also been shown to have a strong correlation with a decreased incidence of heart disease and hypertension.
Having a safe environment and a hazard-free workplace, all the appropriate vaccinations, and regular physical examinations are all very important towardspreventing disease. In addition, many diseases such as heart disease (which is the number one killer in the United States), hypertension, stroke, and manycancers can be prevented by adopting a healthful diet, incorporating physical exercise as a part of everyday routine, ceasing unhealthy habits such as smoking, drug use, overuse of alcohol, reducing stress, and maintaining a positive outlook on life.
In order to protect oneself from infectious diseases, which are most likely,when traveling overseas, the CDC has several recommendations. No matter whatthe destination is, the CDC suggests that travelers follow certain precautions such as washing hands with soap and water, choosing food and drinks wisely,and avoiding all dangerous activity such as unprotected sex, sharing needlesor syringes. Because motor vehicle crashes are leading cause of injury amongtravelers, it is advisable to walk and drive defensively. Seat belts shouldbe used at all times. To protect oneself from insect bites, long-sleeved shirts and pants should be worn outside and insect repellents should be used whennecessary. Travelers can always consult the CDC for more specific information about how to protect oneself against communicable diseases.