Polio is a highly contagious, sometimes fatal, viral infection that can produce permanent muscle weakness, paralysis, and other symptoms. Polio is spread by swallowing material such as water contaminated by infected feces. The infection spreads from the intestine throughout the body, but the brain and the spinal cord are the most affected.

Symptoms and Diagnosis

Polio in young children is often mild. Symptoms, which begin 3 to 5 days after infection, include an overall feeling of illness (malaise), a slight fever, headache, a sore throat, and vomiting. The child usually recovers within 24 to 72 hours.

More significant illness is more likely in older children and adults. Symptoms usually appear 7 to 10 days after infection and include fever, severe headahce, a stiff neck and back, and deep muscle pain. Sometimes areas of skin develop odd sensations, such as pins and needles or unusually sensitivity to pain. Recovery occurs in 24 to 72 hours. Depending upon the which parts of the brain and spinal cord are affected, the disease may progress no further, or weakness or paralysis may develop in certain muscles. The person may have difficult in swallowing and may choke on saliva, food, or fluids. Sometimes fluids go up into the nose, and the voice may develop a nasal quality.

A doctor an diagnose polio from its symptoms. Diagnosis is conirmed by identifying poliovirus in a stool sample and deteciting high levels of antibodies to the virus in the blood.

Prevention and Treatment

The Polio vaccine is included among the routine childhood immunizations. Two types of vaccines are available: a) an inactivated poliovirus vaccine (Salk vaccine), which is given by injection, and b) a live polio-virus vaccine (Sabin vaccine) taken orally. The live oral vaccine provides better immunity and is usually preferred. It is important to note that, in very rare cases, those with an impaired immune system may actually get polio from the vaccine. A good assessment of those about to receive treatment should reveal whether or not people have an impaired immune system, as well as those who are in close contact with such people.

Hepatitis B is highly endemic in Africa south of the Sahara. Serological evidence of prior hepatitis B infection is present in 70%-90% of the population. The burden of the disease is enormous: mortality from primary cancer of the liver ranks either number one or two among cancer deaths in males in Africa. Primary cancer of the liver is 100% fatal and kills at an average age of 35-45 years, causing families to lose parents and wage earners at the most productive periods of their lives.

It is estimated that there are about 50,000 deaths from hepatitis B related cirrhosis and about 130,000 deaths from hepatitis B related primary liver cancer annually in sub-Saharan Africa.

Hepatitis B vaccine is more than 90% effective in preventing hepatitis B infection of children. Despite the high prevalence of infection and the enormous burden of disease, only a few African countries use hepatitis B vaccine routinely with other childhood diseases vaccines.

Tuberculosis (TB) is an infection caused by Mycobacterium tuberculosis, slow-growing bacteria that can thrive in areas of the body with plenty of oxygen and blood flow, such as the lungs.

About 85% of people in the United States with TB have the disease in the lungs (pulmonary TB). Tuberculosis also can spread to other parts of the body (extrapulmonary TB), but this is relatively uncommon.

Tuberculosis is classified as latent TB infection or active TB disease.

Latent TB infection

A latent TB infection occurs when TB-causing bacteria are in the body but there are no signs or symptoms of TB. When the bacteria enter the lungs, the body's immune system fights the infection by walling off the bacteria into tiny capsules called tubercles. In about 90% of people infected with TB, the immune system succeeds in encapsulating the bacteria, and there are no symptoms.

People who have a latent infection cannot spread the bacteria to other people but are at risk of developing active TB disease. Only a skin test can detect latent TB infection.

Active TB disease

Active TB disease occurs when Mycobacterium tuberculosis is found in the body and there are signs or symptoms of TB. About 10% of people infected with the bacteria will develop active TB disease. People who have active disease sometimes have few symptoms and may assume another, less serious problem is causing them. Symptoms of active TB include a persistent cough that brings up thick, cloudy, and sometimes bloody mucus (sputum) from the lungs. Other symptoms that may occur include weight loss, fatigue, night sweats, and fever.

People who have active TB disease can spread the bacteria to other people. If left untreated, active TB can damage the lungs or other organs and possibly cause death.

Doctors use a combination of antibiotics (multiple-drug therapy) to treat active TB, whether it occurs in the lungs or elsewhere. People who have a latent TB infection are treated with one or more antibiotics to prevent the infection from developing into active disease and to reduce the chances that complications will develop. Virtually all people who take their medications as prescribed are cured.

Meningitis

Topic Overview

Meningitis is an infection of the tissues (meninges) and sometimes the fluid (cerebral spinal fluid) that surrounds the brain and spinal cord. Meningitis results in swelling of the brain tissue and, in some cases, the spinal tissue (spinal meningitis). When brain tissue swells, less blood and oxygen reach brain cells, producing symptoms such as fever, severe headache, and stiff neck.

Meningitis usually is caused by viruses or bacteria. Rarely, organisms such as fungi or parasites or a reaction to a medication can cause meningitis. The infection also can develop as a complication of another illness, an injury, or brain surgery. Sometimes, the cause is not identified.

Meningitis occurs most often in infants, young adults between ages 15 and 24, older adults, and people who have long-standing health conditions. The illness can range from mild to life-threatening. The severity usually depends on the organism causing the infection and a person's age and overall health.

Treatment for meningitis depends on the cause of the infection:

The vast majority of malaria deaths occur among young children in Africa, especially in remote rural areas with poor access to health services. Approximately one million deaths among children under five years of age can be attributed to malaria alone or in combination with other diseases.

Mortality is concentrated in the younger age groups. Among children referred to hospitals with severe malaria, case-fatality rates of 10%-30% have been reported. In rural areas with little access to adequate treatment these rates might be even higher. Even in non-fatal cases malaria produces considerable impact on the health of young African children, increasing susceptibility to other infections and hampering development.

Symptoms

In regions where malaria is present, people may be immune (not susceptible to the disease) or semi-immune and be infected with malaria but have few or no symptoms.3 The symptoms of two people with malaria can vary greatly, depending on each person's immunity: one person may be very healthy, the other person may be extremely ill.

Symptoms in the early stages of malaria can be similar to those of many other illnesses caused by bacterial, viral, or parasitic infections. If a person has been in an area where malaria is present (especially in the past 2 months) and the person has symptoms of malaria, then he or she should be suspected of having the disease until tests prove otherwise. Symptoms may include the following:

Symptoms may appear in cycles. The symptoms may come and go at different intensities and for different lengths of time. However, especially at the beginning of the illness, the symptoms may not follow this typical cyclic pattern.

The cyclic pattern of malaria symptoms is due to the life cycle of malaria parasites and their development as they reproduce and are released from the red blood cells in the human body. This cycle of symptoms is also one of the major indicators that a person is infected with malaria.

Other common signs and symptoms of malaria

Other common signs and symptoms of malaria include:

Infection with the Plasmodium falciparum parasite is usually more serious and may become life-threatening. Symptoms in addition to those listed above include:

In the WHO African region, diarrhoeal diseases are still a leading cause of mortality and morbidity in children under five years of age. It is estimated that each child in the Region has five episodes of diarrhoea per year and that 800,000 die each year from diarrhoea and dehydration. Undernutrition and measles are very commonly associated with this mortality.

The prevention of diarrhoea ultimately depends on the improvement of water supplies and sanitation, which are very expensive but will eventually occur. The prevention of death from dehydration arising from diarrhoea is straightforward, using cheap oral rehydration salts or simple home-made fluids. The skills required by workers in health facilities and by mothers at home are easily learned.

Measles is a highly contagious viral infection that causes severe coldlike symptoms, high fever, and a distinct red rash.

Many people have been alarmed by a report published on the Internet that falsely linked the measles, mumps, and rubella (MMR) immunization with autism. Recently, researchers conducted several comprehensive studies and found no connection between the MMR immunization and autism.1

How is it spread?

Measles is transmitted when an infected person coughs or sneezes. The virus is most often spread when people first become ill, before the rash develops, and before they know they have the disease. Measles can be spread from 5 days before the rash breaks out to 4 days after the rash disappears.

Once you have had measles, you cannot get the disease again. Immunizations also protect you from the virus.

Complications of measles

Measles causes more severe symptoms in adults than in children. People usually recover from measles within 2 weeks, although complications can develop. These include ear infection (otitis media) and, in rare cases, pneumonia, strep throat, chronic diarrhea, encephalitis, and optic neuritis. In extremely rare cases, encephalitis can result in permanent brain damage and death.

If a woman gets measles while she is pregnant, the risk of miscarriage or premature birth is increased. However, measles infection does not cause birth defects

People who have impaired immune systems or who have poor nutrition are at a higher risk for complications.

How is it treated, and can it be prevented?

In most cases, people recover from measles with rest and care at home. In complicated cases, hospitalization may be required. The measles vaccine prevents the disease symptoms.

Pertussis is a highly contagious infection caused by bacteria that results in fits of coughing that usually end in a prolonged, high-pitched, deeply indrawn breath (the whoop).

Pertussis remains a major problem throughout the world and half the cases occur in children under age 4. An infected person spreads pertussis organisms into the air in droplets of moisture produced by coughing. Anyone nearby may inhale these droplets and become infected. A person with pertussis usually isn't contagious after the third week of the illness.

Symptoms begin, on the average, 7 to 10 days after explsure to pertussis bacteria. The infect lasts about 6 weeks, prodgressing through three stages:

Doctors have to distinguish between brochitis, influenza, and other viral infections, and perhaps tuberculosis, which have similar symptoms. The doctor takes samples of mucus from teh nose and trhoat with a small swab. The sample is then cultured.

Complications have to do with the airway. Infants are particularly at risk for damage that occurs from lack of oxygen after pauses in breathing (apnea) or coughing fits. Children may develop pneumonia, which can be fatal. During coughing fits, air may be driven out of the lings into the surrounding tissue, or the lungs may rupture and collapse. Severe coughing may result in bleeding in the eyes. A sore may develop under the tongue if the tongue is pushed against the lower teeth during coughing fits. Coughing may cuase an outpouching of the rectum. Bleeding, swelling, or inflammation of the brain may cuase brain damage and mental retardation, paralysis, or other neurologica problems. Ear infections also develop frequently as a result of pertussis.

Treatment

Severely ill infants are hospitalized because they need nursing care and oxygen. They are kept in a darkened, quiet room and are disturbed as little as possible. Cough medicines do not seem to be effective. Intravenous fluids may be given to replace fluids lost during vomiting and because coughing may prevent infants from being able to feed.

Prevention

Immunization is the best prevention against pertussis. The pertussis vacine is usually combined with vaccines for diptheria and tetanus as the DTP (diphtheria-tetanus-pertussis) vaccine.