Many devastating diseases in tropical areas of the world are the result of infection with parasites. In these regions, the combination of climate and poverty contribute to the transmission of parasitic infections. Some parasites, like malaria, are a common cause of death, while others, like parasitic nematodes can lead to disfigurement, blindness and severe economic hardship. A recent World Health Organization (WHO) report on the leading causes of death world-wide shows that one-third of all deaths are due to infectious and parasitic diseases. It is estimated that about 1.5–2.7 million people die from malaria each year which is about the same that die from HIV/AIDS (World Health Report 1998, WHO).
In many tropical and subtropical areas, the prevalence of parasitic infections is on the rise due to rapid and unplanned growth of cities, which creates additional breeding sites for the mosquitoes that transmit the parasites responsible for malaria and filariasis. Effective control of these diseases requires repeated administration of potent drugs and continuous efforts to reduce vector insect populations.
# Malaria is probably the most prevalent and debilitating parasitic disease afflicting humans. It is normally caused by one of four species of Plasmodium. Infection with Entamoeba histolytica, resulting in amoebic colitis and liver abscesses, is the second leading cause of death resulting from a parasitic infection. E. histolytica is estimated to infect one tenth of the worlds' population or 500 million people (WHO Weekly Epidemiologic Record [1997] 72, 97–100).
# Filariasis is caused by several different species of parasitic nematodes that are transmitted to humans by a variety of insect vectors. Collectively, the various species of filarial parasites are estimated to infect approximately 150 million people worldwide, and over 1 billion people live in areas where filariasis is common (WHO [2000] Fact Sheets 102, 95). While filarial infection is rarely life-threatening, it causes chronic suffering, social stigma and disability. The degree of disability resulting from infection greatly hinders the ability to work and the economic impact of this disease is considerable.
# Brugia malari is a filarial nematode with widespread distribution in South and South East Asia. It is transmitted via the bite of blood-feeding mosquitoes. The parasite resides in the lymphatic system and is a cause of lymphatic filariasis. In the later stages of infection, the disease is characterized by a disfiguring condition known as elephantiasis.
# Onchocerca volvulus is the causative agent of River Blindness and the second leading cause of blindness worldwide. This filarial parasite is transmitted by female blackflies that breed in fast flowing rivers. Over 20 million people are infected world-wide although approximately 99% of cases are found in Africa (WHO [2000] Fact Sheet 95).
# Typhoid fever, also known simply as typhoid, is a bacterial infection due to Salmonella Typhi that causes symptoms which may vary from mild to severe and usually begin six to thirty days after exposure. Often there is a gradual onset of a high fever over several days. Weakness, abdominal pain, constipation, and headaches also commonly occur. Diarrhea is uncommon and vomiting is not usually severe. Some people develop a skin rash with rose colored spots. In severe cases there may be confusion. Without treatment symptoms may last weeks or months. Other people may carry the bacterium without being affected; however, they are still able to spread the disease to others. Typhoid fever is a type of enteric fever along with paratyphoid fever.
The cause is the bacterium Salmonella Typhi, also known as Salmonella enterica serotype Typhi, growing in the intestines and blood. Typhoid is spread by eating or drinking food or water contaminated with the feces of an infected person. Risk factors include poor sanitation and poor hygiene. Those who travel to the developing world are also at risk[4] and only humans can be infected. Diagnosis is by either culturing the bacteria or detecting the bacterium's DNA in the blood, stool, or bone marrow. Culturing the bacterium can be difficult. Bone marrow testing is the most accurate.[6] Symptoms are similar to that of many other infectious diseases. Typhus is a different disease.
A typhoid vaccine can prevent about 30% to 70% of cases during the first two years. The vaccine may have some effect for up to seven years. It is recommended for those at high risk or people traveling to areas where the disease is common.[5] Other efforts to prevent the disease include providing clean drinking water, better sanitation, and better handwashing. Until it has been confirmed that an individual's infection is cleared, the individual should not prepare food for others. Treatment of disease is with antibiotics such as azithromycin, fluoroquinolones or third generation cephalosporins. Resistance to these antibiotics has been developing, which has made treatment of the disease more difficult.
In 2013 there were 11 million new cases reported worldwide. The disease is most common in India. Children are most commonly affected. Rates of disease decreased in the developed world in the 1940s as a result of improved sanitation and use of antibiotics to treat the disease. Each year in the United States about 400 cases are reported and it is estimated that the disease occurs in about 6,000 people. In 2013 it resulted in about 161,000 deaths worldwide – down from 181,000 in 1990 (about 0.3% of the global total). The risk of death may be as high as 20% without treatment. With treatment it is between 1 and 4%. The name typhoid means "resembling typhus" due to the similarity in symptoms.
# Pneumonia is a lung infection that can make you very sick. You may cough, run a fever, and have a hard time breathing. For most people, pneumonia can be treated at home. It often clears up in 2 to 3 weeks. But older adults, babies, and people with other diseases can become very ill. They may need to be in the hospital.
- You can get pneumonia in your daily life, such as at school or work. This is called community-associated pneumonia. You can also get it when you are in a hospital or nursing home. This is called healthcare-associated pneumonia. It may be more severe because you already are ill. This topic focuses on pneumonia you get in your daily life.
- Germs called bacteria or viruses usually cause pneumonia.
# Pneumonia usually starts when you breathe the germs into your lungs. You may be more likely to get the disease after having a cold or the flu. These illnesses make it hard for your lungs to fight infection, so it is easier to get pneumonia. Having a long-term, or chronic, disease like asthma, heart disease, cancer, or diabetes also makes you more likely to get pneumonia.
Symptoms of pneumonia caused by bacteria usually come on quickly. They may include :
- Cough. You will likely cough up mucus (sputum) from your lungs. Mucus may be rusty or green or tinged with blood.
Fever.
- Fast breathing and feeling short of breath.
- Shaking and "teeth-chattering" chills.
- Chest pain that often feels worse when you cough or breathe in.
- Fast heartbeat.
- Feeling very tired or very weak.
- Nausea and vomiting.
- Diarrhea.
# Older adults may have different, fewer, or milder symptoms. They may not have a fever. Or they may have a cough but not bring up mucus. The main sign of pneumonia in older adults may be a change in how well they think. Confusion or delirium is common. Or, if they already have a lung disease, that disease may get worse.
- Symptoms caused by viruses are the same as those caused by bacteria. But they may come on slowly and often are not as obvious or as bad.
Many devastating diseases in tropical areas of the world are the result of infection with parasites. In these regions, the combination of climate and poverty contribute to the transmission of parasitic infections. Some parasites, like malaria, are a common cause of death, while others, like parasitic nematodes can lead to disfigurement, blindness and severe economic hardship. A recent World Health Organization (WHO) report on the leading causes of death world-wide shows that one-third of all deaths are due to infectious and parasitic diseases. It is estimated that about 1.5–2.7 million people die from malaria each year which is about the same that die from HIV/AIDS (World Health Report 1998, WHO).
In many tropical and subtropical areas, the prevalence of parasitic infections is on the rise due to rapid and unplanned growth of cities, which creates additional breeding sites for the mosquitoes that transmit the parasites responsible for malaria and filariasis. Effective control of these diseases requires repeated administration of potent drugs and continuous efforts to reduce vector insect populations.
# Malaria is probably the most prevalent and debilitating parasitic disease afflicting humans. It is normally caused by one of four species of Plasmodium. Infection with Entamoeba histolytica, resulting in amoebic colitis and liver abscesses, is the second leading cause of death resulting from a parasitic infection. E. histolytica is estimated to infect one tenth of the worlds' population or 500 million people (WHO Weekly Epidemiologic Record [1997] 72, 97–100).
# Filariasis is caused by several different species of parasitic nematodes that are transmitted to humans by a variety of insect vectors. Collectively, the various species of filarial parasites are estimated to infect approximately 150 million people worldwide, and over 1 billion people live in areas where filariasis is common (WHO [2000] Fact Sheets 102, 95). While filarial infection is rarely life-threatening, it causes chronic suffering, social stigma and disability. The degree of disability resulting from infection greatly hinders the ability to work and the economic impact of this disease is considerable.
# Brugia malari is a filarial nematode with widespread distribution in South and South East Asia. It is transmitted via the bite of blood-feeding mosquitoes. The parasite resides in the lymphatic system and is a cause of lymphatic filariasis. In the later stages of infection, the disease is characterized by a disfiguring condition known as elephantiasis.
# Onchocerca volvulus is the causative agent of River Blindness and the second leading cause of blindness worldwide. This filarial parasite is transmitted by female blackflies that breed in fast flowing rivers. Over 20 million people are infected world-wide although approximately 99% of cases are found in Africa (WHO [2000] Fact Sheet 95).
# Typhoid fever, also known simply as typhoid, is a bacterial infection due to Salmonella Typhi that causes symptoms which may vary from mild to severe and usually begin six to thirty days after exposure. Often there is a gradual onset of a high fever over several days. Weakness, abdominal pain, constipation, and headaches also commonly occur. Diarrhea is uncommon and vomiting is not usually severe. Some people develop a skin rash with rose colored spots. In severe cases there may be confusion. Without treatment symptoms may last weeks or months. Other people may carry the bacterium without being affected; however, they are still able to spread the disease to others. Typhoid fever is a type of enteric fever along with paratyphoid fever.
The cause is the bacterium Salmonella Typhi, also known as Salmonella enterica serotype Typhi, growing in the intestines and blood. Typhoid is spread by eating or drinking food or water contaminated with the feces of an infected person. Risk factors include poor sanitation and poor hygiene. Those who travel to the developing world are also at risk[4] and only humans can be infected. Diagnosis is by either culturing the bacteria or detecting the bacterium's DNA in the blood, stool, or bone marrow. Culturing the bacterium can be difficult. Bone marrow testing is the most accurate.[6] Symptoms are similar to that of many other infectious diseases. Typhus is a different disease.
A typhoid vaccine can prevent about 30% to 70% of cases during the first two years. The vaccine may have some effect for up to seven years. It is recommended for those at high risk or people traveling to areas where the disease is common.[5] Other efforts to prevent the disease include providing clean drinking water, better sanitation, and better handwashing. Until it has been confirmed that an individual's infection is cleared, the individual should not prepare food for others. Treatment of disease is with antibiotics such as azithromycin, fluoroquinolones or third generation cephalosporins. Resistance to these antibiotics has been developing, which has made treatment of the disease more difficult.
In 2013 there were 11 million new cases reported worldwide. The disease is most common in India. Children are most commonly affected. Rates of disease decreased in the developed world in the 1940s as a result of improved sanitation and use of antibiotics to treat the disease. Each year in the United States about 400 cases are reported and it is estimated that the disease occurs in about 6,000 people. In 2013 it resulted in about 161,000 deaths worldwide – down from 181,000 in 1990 (about 0.3% of the global total). The risk of death may be as high as 20% without treatment. With treatment it is between 1 and 4%. The name typhoid means "resembling typhus" due to the similarity in symptoms.
# Pneumonia is a lung infection that can make you very sick. You may cough, run a fever, and have a hard time breathing. For most people, pneumonia can be treated at home. It often clears up in 2 to 3 weeks. But older adults, babies, and people with other diseases can become very ill. They may need to be in the hospital.
- You can get pneumonia in your daily life, such as at school or work. This is called community-associated pneumonia. You can also get it when you are in a hospital or nursing home. This is called healthcare-associated pneumonia. It may be more severe because you already are ill. This topic focuses on pneumonia you get in your daily life.
- Germs called bacteria or viruses usually cause pneumonia.
# Pneumonia usually starts when you breathe the germs into your lungs. You may be more likely to get the disease after having a cold or the flu. These illnesses make it hard for your lungs to fight infection, so it is easier to get pneumonia. Having a long-term, or chronic, disease like asthma, heart disease, cancer, or diabetes also makes you more likely to get pneumonia.
Symptoms of pneumonia caused by bacteria usually come on quickly. They may include :
- Cough. You will likely cough up mucus (sputum) from your lungs. Mucus may be rusty or green or tinged with blood.
Fever.
- Fast breathing and feeling short of breath.
- Shaking and "teeth-chattering" chills.
- Chest pain that often feels worse when you cough or breathe in.
- Fast heartbeat.
- Feeling very tired or very weak.
- Nausea and vomiting.
- Diarrhea.
# Older adults may have different, fewer, or milder symptoms. They may not have a fever. Or they may have a cough but not bring up mucus. The main sign of pneumonia in older adults may be a change in how well they think. Confusion or delirium is common. Or, if they already have a lung disease, that disease may get worse.
- Symptoms caused by viruses are the same as those caused by bacteria. But they may come on slowly and often are not as obvious or as bad.