parasitosis

Parasites are living things that use other living things - like your body - for food and a place to live. You can get them from contaminated food or water, a bug bite, or sexual contact. Some parasitic diseases are easily treated and some are not.

Parasites range in size from tiny, one-celled organisms called protozoa to worms that can be seen with the naked eye. Some parasitic diseases occur in the United States. Contaminated water supplies can lead to Giardia infections. Cats can transmit toxoplasmosis, which is dangerous for pregnant women. Others, like malaria, are common in other parts of the world.

If you are traveling, it's important to drink only water you know is safe. Prevention is especially important. There are no vaccines for parasitic diseases. Some medicines are available to treat parasitic infections.

Leishmaniasis is a parasitic disease spread by the bite of infected sand flies. There are several different forms of leishmaniasis. The most common are cutaneous and visceral. The cutaneous type causes skin sores. The visceral type affects internal organs such as the spleen, liver, and bone marrow. People with this form usually have fever, weight loss, and an enlarged spleen and liver.

Leishmaniasis is found in parts of about 88 countries. Most of these countries are in the tropics and subtropics. It is possible but very unlikely that you would get this disease in the United States. But you should be aware of it if you are traveling to the Middle East or parts of Central America, South America, Asia, Africa or southern Europe.

Treatment is with medicines that contain antimony, a type of metal, or with strong antibiotics. The best way to prevent the disease is to protect yourself from sand fly bites:

• Stay indoors from dusk to dawn, when sand flies are the most active
• Wear long pants and long-sleeved shirts when outside
• Use insect repellent and bed nets as needed

Centers for Disease Control and Prevention

Chagas disease, or American trypanosomiasis, is an illness that can cause serious heart and stomach problems. It is caused by a parasite. Chagas disease is common in Latin America, especially in poor, rural areas. It can also be found in the United States, most often in people who were infected before they moved to the U.S.

Chagas disease is caused by the Trypanosoma cruzi parasite. It is usually spread by infected blood-sucking bugs called triatomine bugs. They are also known as "kissing bugs" because they often bite people's faces. When one of these bugs bites you, it leaves behind infected waste. You can become infected if you rub the waste in your eyes or nose, the bite wound, or a cut.

Chagas disease can also spread through contaminated food, a blood transfusion, a donated organ, or from the pregnant parent to the baby during pregnancy.

Kissing bugs can be found throughout the Americas, but they are more common in certain areas. The people who are most at risk for Chagas disease:

• Live in rural areas of Latin America
• Have seen the bugs, especially in those areas
• Have stayed in a house with a thatched roof or with walls that have cracks or crevices

In the beginning, there may be no symptoms. Some people do get mild symptoms, such as:

• Fever
• Fatigue
• Body aches
• Headache
• Loss of appetite
• Diarrhea
• Vomiting
• A rash
• A swollen eyelid

These early symptoms usually go away. However, if you don't treat the infection, it stays in your body. Later, it can cause serious intestinal and heart problems such as:

• An serious arrhythmia (a problem with the rate or rhythm of your heartbeat) that can cause sudden death
• An enlarged heart that doesn't pump blood well
• Problems with digestion and bowel movements
• An increased chance of having a stroke

To find out if you have Chagas disease, your health care provider:

• Will do a physical exam
• Will take your medical history, including asking about your symptoms and where you have lived and traveled
• Will run a blood test for Chagas disease
• May run tests to see whether the disease has affected your intestines and heart

Medicines can kill the parasite, especially early on. You can also treat related problems. For example, a pacemaker can help with some heart complications.

There are no vaccines or medicines to prevent Chagas disease. If you travel to areas where it occurs, you are at higher risk if you sleep outdoors or are staying in poor housing conditions. It is important to use insecticides to prevent bites and practice food safety.

Centers for Disease Control and Prevention

Giardiasis is an illness caused by a parasite called Giardia intestinalis. It lives in soil, food, and water. It may also be on surfaces that have been contaminated with waste. You can become infected if you swallow the parasite. You can also get it if you're exposed to human feces (poop) through sexual contact.

The risk of getting giardia is higher for travelers to countries where it is common, people in child care settings, and those who drink untreated water.

Diarrhea is the main symptom of giardia infection. Others include:

• Passing gas
• Greasy stools
• Stomach cramps
• Upset stomach or nausea

These symptoms may lead to weight loss and loss of body fluids. Some people have no symptoms at all. Symptoms of infection often last two to six weeks. Stool sample tests can diagnose it. You often need to collect several samples to test. Doctors use several drugs to treat it.

The best way to prevent giardia infection is to practice good hygiene, including frequent hand washing. You should not drink water that may be contaminated. You should also peel or wash fresh fruit and vegetables before eating.

Centers for Disease Control and Prevention

Mosquitoes are insects that live all over the world. There are thousands of different species of mosquitoes; about 200 of those live in the United States.

Female mosquitoes bite animals and humans and drink a very small amount of their blood. They need protein and iron from blood to produce eggs. After drinking blood, they find some standing water and lay their eggs in it. The eggs hatch into larvae, then pupae, and then they become adult mosquitos. The males live for about a week to ten days, and the females can live up to several weeks. Some female mosquitoes can hibernate in the winter, and they can live for months.

Most mosquito bites are harmless, but there are times when they can be dangerous. The ways that mosquito bites can affect humans include:

• Causing itchy bumps, as an immune system response to the mosquito's saliva. This is the most common reaction. The bumps usually go away after a day or two.
• Causing allergic reactions, including blisters, large hives, and in rare cases, anaphylaxis. Anaphylaxis is a severe allergic reaction that affects the whole body. It is a medical emergency.
• Spreading diseases to humans. Some of these diseases can be serious. Many of them do not have any treatments, and only a few have vaccines to prevent them. These diseases are more of a problem in Africa and other tropical areas of the world, but more of them are spreading to the United States. One factor is climate change, which makes the conditions in some parts of the United States more favorable to certain types of mosquitoes. Other reasons include increased trade with, and travel to, tropical and subtropical areas.

Common diseases spread by mosquitoes include:

• Chikungunya, a viral infection that causes symptoms such as fever and severe joint pain. The symptoms usually last about a week, but for some, the joint pain may last for months. Most cases of chikungunya in the United States are in people who traveled to other countries. There have been a few cases where it has spread in the United States.
• Dengue, a viral infection that causes a high fever, headaches, joint and muscle pain, vomiting, and a rash. Most people get better within a few weeks. In some cases, it can become very severe, even life-threatening. Dengue is rare in the United States.
• Malaria, a parasitic disease that causes serious symptoms such as high fevers, shaking chills, and flu-like illness. It can be life-threatening, but there are drugs to treat it. Malaria is a major health problem in many tropical and subtropical areas of the world. Almost all cases of malaria in the United States are in people who traveled to other countries.
• West Nile Virus (WNV), a viral infection that often has no symptoms. In those that do have symptoms, they are usually mild, and include fever, headache, and nausea. In rare cases, the virus can enter the brain, and it can be life-threatening. WNV has spread across the continental United States.
• Zika Virus, a viral infection that often does not cause symptoms. One in five infected people do get symptoms, which are usually mild. They include a fever, rash, joint pain, and pink eye. Besides being spread by mosquitoes, Zika can spread from mother to baby during pregnancy and cause serious birth defects. It can also spread from one partner to another during sex. There have been a few outbreaks of Zika in the southern United States.

• Use an insect repellent when you go outdoors. Choose an Environmental Protection Agency (EPA)-registered insect repellent. They are evaluated to make sure they are safe and effective. Make sure that the repellant has one of these ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol. It is important to follow the instructions on the label.
• Cover up. Wear long sleeves, long pants, and socks when outdoors. Mosquitoes may bite through thin fabric, so spray thin clothes with an EPA-registered repellent like permethrin. Don't apply permethrin directly to skin.
• Mosquito-proof your home. Install or repair screens on windows and doors to keep mosquitoes out. Use air conditioning if you have it.
• Get rid of mosquito breeding sites. Regularly empty standing water from your house and yard. The water could be in flowerpots, gutters, buckets, pool covers, pet water dishes, discarded tires, or birdbaths.
• If you plan to travel, get information about the areas you will be going to. Find out whether there is a risk of diseases from mosquitoes, and if so, whether there is a vaccine or medicine to prevent those diseases. See a health care provider familiar with travel medicine, ideally 4 to 6 weeks before your trip.

Your skin is your body's largest organ. It covers the entire outside of your body. There are many ways that your skin protects your body and helps keep you healthy. For example, it:

• Holds body fluids in, which helps prevent you from getting dehydrated
• Keeps out harmful germs, which helps prevent infections
• Helps you feel things like heat, cold, and pain
• Helps control your body temperature
• Makes vitamin D when the sun shines on it
• Shields your body against heat and light

There are many different problems and conditions which can affect your skin. Some of them can cause uncomfortable symptoms, such as itching, burning, redness, and rashes. They might also affect your appearance. Some of the more common skin conditions include:

• Acne, which causes pimples when hair follicles under your skin get clogged up
• Burns
• Cuts and scrapes
• Dandruff, flaking of the skin on your scalp (the top of your head)
• Eczema (atopic dermatitis), which causes inflammation, redness, and irritation of the skin
• Hives, which are red and sometimes itchy bumps on your skin
• Insect bites
• Psoriasis, which causes itchy, scaly red patches
• Skin cancer
• Skin infections

Since your skin protects your body in many ways, it's important to try to keep your skin healthy. For example, you can:

• Wear the right protective equipment, like gloves, long sleeves, knee and elbow pads, or helmets to protect against cuts, bumps and scrapes.
• If you do get a cut or scrape, clean it right away with soap and warm water. Put on a bandage to protect it while it heals.
• When you are spending time outdoors, wear long sleeves and pants and use insect repellant to prevent insect bites.
• Prevent sunburn by covering up and using sunscreen when outdoors.
• Wash your hands often with soap and water.
• When you take a shower or bath, use warm (not hot) water. Use mild cleansers and wash gently (don't scrub).
• Use moisturizers, like lotions, creams, or ointments, to prevent dry skin.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

Traveling can increase your chances of getting sick. A long flight can increase your risk for deep vein thrombosis. Once you arrive, it takes time to adjust to the water, food, and air in another place. Water in developing countries can contain viruses, bacteria, and parasites that cause stomach upset and diarrhea. Be safe by using only bottled or purified water for drinking, making ice cubes, and brushing your teeth. If you use tap water, boil it or use iodine tablets. Food poisoning can also be a risk. Eat only food that is fully cooked and served hot. Avoid unwashed or unpeeled raw fruits and vegetables.

If you are traveling out of the country, you might also need vaccinations or medicines to prevent specific illnesses. Which ones you need will depend on what part of the world you're visiting, the time of year, your age, overall health status, and previous vaccinations. See your doctor 4 to 6 weeks before your trip. Most vaccines take time to become effective.

Centers for Disease Control and Prevention

Cryptosporidiosis is a contagious disease that causes watery diarrhea. It is caused by parasites called Cryptosporidium, or Crypto . These parasites live in soil, food, and water. They are found in every region of the United States and throughout the world. Crypto can also be found on surfaces or dirty hands that have been contaminated with the stool (poop) of humans or animals that have the infection.

You can become infected with Crypto by swallowing the parasite if it is in your food, drinking water, or water that you swim in. You can also get infected when you touch something that has been contaminated, and then you touch your eyes, mouth, or nose. Another way that Crypto can spread is through sexual contact.

Certain people are more likely to get Crypto; they include:

• Children and workers at childcare centers
• Older adults (ages 75 years and older)
• People who take care of other people with Crypto
• International travelers
• Backpackers, hikers, and campers who drink unfiltered, untreated water
• People, including swimmers, who swallow water from contaminated sources
• People who touch infected animals, often cows or sheep

The most common symptom of cryptosporidiosis is watery diarrhea. Other symptoms include:

• Dehydration
• Weight loss
• Stomach cramps or pain
• Fever
• Nausea and vomiting

The symptoms generally begin 2 to 10 days after becoming infected with the parasite. In people with healthy immune systems, the symptoms can last about 1 to 2 weeks. Occasionally, the symptoms can last longer or come and go for up to 30 days.

People with weakened immune systems may develop a serious, chronic illness. Some reasons why you might have a weakened immune system could include:

• Having HIV
• Having cancer
• Having a genetic condition that affects the immune system
• Taking certain medicines, such as chemotherapy and medicines needed after an organ transplant

Some people may not have any symptoms at all.

Contact your health care provider if you have watery diarrhea that lasts more than a few days, especially if you have a weakened immune system.

Cryptosporidiosis is diagnosed by examining stool samples, usually under a microscope. People with Crypto can have many parasites in their stool one day but not as many the next day. So you may need to give the lab three stool samples collected on three different days. This helps make sure that your diagnosis is correct.

Most people with cryptosporidiosis get better without treatment. It usually takes about one to two weeks. It's important to drink plenty of fluids to prevent dehydration. Infants, young children, and pregnant people are more likely to get dehydration. They should get extra fluids. If you are pregnant or if you think that you or your child are severely dehydrated, contact your provider about how to get enough fluids. Some people who are dehydrated may need to get intravenous (IV) fluids in a hospital.

Over-the-counter anti-diarrheal medicine might help slow down diarrhea, but do not take it without first asking your provider. There is a medicine to treat diarrhea caused by Crypto in people with healthy immune systems. You and your provider can talk about whether that medicine is right for you.

To lower your chance of getting or spreading Crypto:

• Wash your hands often with soap and water, especially after using the toilet, changing diapers, or touching animals. You also need to wash your hands before eating or preparing food. Alcohol-based hand sanitizers are not effective against Crypto.
• Only drink water that you know is safe.
• Only drink milk and apple cider that have been pasteurized.
• Don't eat uncooked foods when traveling in countries where the food supply might be unsafe.
• Never go swimming when you have diarrhea.
• Don't swallow water when you go swimming.
• Use condoms or dental dams every time you have sex. This will also help prevent other sexually transmitted infections.

Centers for Disease Control and Prevention

We all need to drink water. How much you need depends on your size, activity level, and the weather where you live.

The water you drink is a combination of surface water and groundwater. Surface water includes rivers, lakes and reservoirs. Groundwater comes from underground. The United States has one of the safest water supplies in the world, but drinking water quality can vary from place to place. It depends on the condition of the source water and the treatment it receives. Treatment may include adding fluoride to prevent cavities and chlorine to kill germs.

Your water supplier must give you annual reports on drinking water. The reports include where your water came from and what contaminants are in it.

Centers for Disease Control and Prevention

Head lice are tiny insects that live on people's heads. Adult lice are about the size of sesame seeds. The eggs, called nits, are even smaller - about the size of a dandruff flake. Lice and nits are found on or near the scalp, most often at the neckline and behind the ears.

Head lice are parasites, and they need to feed on human blood to survive. They are one of the three types of lice that live on humans. The other two types are body lice and pubic lice. Each type of lice is different, and getting one type does not mean that you will get another type.

Lice move by crawling, because they cannot hop or fly. They spread by close person-to-person contact. Rarely, they can spread through sharing personal belongings such as hats or hairbrushes. Personal hygiene and cleanliness have nothing to do with getting head lice. You also cannot get pubic lice from animals. Head lice do not spread disease.

Children ages 3-11 and their families get head lice most often. This is because young children often have head-to-head contact while playing together.

The symptoms of head lice include:

• Tickling feeling in the hair
• Frequent itching, which is caused by an allergic reaction to the bites
• Sores from scratching. Sometimes the sores can become infected with bacteria.
• Trouble sleeping, because head lice are most active in the dark

A diagnosis of head lice usually comes from seeing a louse or nit. Because they are very small and move quickly, you may need to use a magnifying lens and a fine-toothed comb to find lice or nits.

Treatments for head lice include both over-the-counter and prescription shampoos, creams, and lotions. If you want to use an over-the-counter treatment and you aren't sure which one to use or how to use one, ask your health care provider or pharmacist. You should also check with your health care provider first if you are pregnant or nursing, or if you want to use a treatment on a young child.

Follow these steps when using a head lice treatment:

• Apply the product according to the instructions. Only apply it to the scalp and the hair attached to the scalp. You should not use it on other body hair.
• Use only one product at a time, unless your health care provider tells you to use two different kinds at once
• Pay attention to what the instructions say about how long you should leave the medicine on the hair and on how you should rinse it out
• After rinsing, use a fine-toothed comb or special "nit comb" to remove dead lice and nits
• After each treatment, check your hair for lice and nits. You should comb your hair to remove nits and lice every 2-3 days. Do this for 2-3 weeks to be sure that all lice and nits are gone.

All household members and other close contacts should be checked and treated if necessary. If an over-the-counter treatment does not work for you, you can ask your health care provider for a prescription product.

There are steps you can take to prevent the spread of lice. If you already have lice, besides treatment, you should:

• Wash your clothes, bedding, and towels with hot water, and dry them using the hot cycle of the dryer
• Soak your combs and brushes in hot water for 5-10 minutes
• Vacuum the floor and furniture, particularly where you sat or lay
• If there are items that you cannot wash, seal them in a plastic bag for two weeks

To prevent your children from spreading lice:

• Teach children to avoid head-to-head contact during play and other activities
• Teach children not to share clothing and other items that they put on their head, such as headphones, hair ties, and helmets
• If your child has lice, be sure to check the policies at school and/or daycare. Your child may not be able to go back until the lice have been completely treated.

There is no clear scientific evidence that lice can be suffocated by home remedies, such as mayonnaise, olive oil, or similar substances. You also should not use kerosene or gasoline; they are dangerous and flammable.

Centers for Disease Control and Prevention