chikungunya

Chikungunya is a virus that spread by the same kinds of mosquitoes that spread dengue and Zika virus. Rarely, the virus can spread from the pregnant parent to their newborn around the time of birth. It may also spread through contact with infected blood. There have been outbreaks of chikungunya virus in Africa, Asia, Europe, the Indian and Pacific Oceans, the Caribbean, and Central and South America.

Most people who have chikungunya will have symptoms, which can be severe. They usually start 3-7 days after being bitten by an infected mosquito. The most common symptoms are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling, and rash.

Most people feel better within a week. In some cases, however, the joint pain may last for months. People at risk for more severe disease include newborns, older adults, and people with diseases such as high blood pressure, diabetes, or heart disease.

A blood test can show whether you have chikungunya virus. There are no medicines to treat it. Drinking lots of fluids, resting, and taking non-aspirin pain relievers might help you feel better.

In the U.S., there is a vaccine for adults who are at a higher risk of getting chikungunya. You can also help prevent getting or spreading chikungunya by avoiding mosquito bites:

• Use a U.S. Environmental Protection Agency (EPA)-registered insect repellent when you go outdoors. Make sure to follow the instructions for using the repellant.
• Wear clothes that cover your arms, legs, and feet.
• Stay in places that either have air conditioning (with the windows closed) or that use window and door screens.

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.

Dengue is a viral infection. It can be caused by four related viruses. You can get it if an infected mosquito bites you. It is common in warm, wet areas of the world. Although rare, it can be found in some parts of the United States. Outbreaks are more common during rainy seasons.

Dengue spreads to people through the bite of an infected mosquito. It does not spread directly from person to person. However, a pregnant person can pass the infection on to the baby. In rare cases, it can spread through a blood transfusion, organ transplant, or needle stick injury (an accidental injury from a used needle)..

About one in four people infected with dengue will get sick. For those who do get sick, the infection can be mild or severe. The symptoms of dengue include:

• A high fever
• Nausea and vomiting
• Rash
• Aches and pains (eye pain, usually behind the eyes, and pain in the muscles, joints, or bones)

The symptoms usually last two to seven days.

Severe dengue is a serious form of the illness. About 1 in 20 people who get sick with dengue will develop severe dengue. It can cause shock, internal bleeding, and even death. People are more likely to develop severe dengue if they have had dengue before, are pregnant, or are infants.

Watch for signs and symptoms of severe dengue. Warning signs usually begin about 24 - 48 hours after your fever has gone away. If you or your family member have these signs, get immediate medical care:

• Severe abdominal (belly) pain and tenderness
• Vomiting at least 3 times in 24 hours
• Bleeding from the nose or gums
• Vomiting blood, or blood in the stool (poop)
• Feeling tired, restless, or irritable

There is a blood test which can show if you have been infected with dengue.

There is no specific medicine to treat dengue. Most people will get better after about a week. But if you think you might have dengue:

• See a health care provider and mention any recent travel.
• Rest as much as possible.
• Take acetaminophen to control fever and relieve pain. But do not take aspirin or ibuprofen.
• Drink plenty of fluids to prevent dehydration.

Severe dengue often requires care at a hospital.

In the United States, a dengue vaccine is approved for children who are ages 9 - 16. They must also have previously had dengue and live in areas where dengue is common.

You can also help prevent dengue by avoiding mosquito bites:

• Wear insect repellent with DEET or another U.S. Environmental Protection Agency (EPA)-registered insect repellent. Make sure to follow the instructions for using the repellant.
• Wear clothes that cover your arms, legs and feet.
• Close unscreened doors and windows.

Centers for Disease Control and Prevention

Zika is a virus that is spread mostly by mosquitoes. A pregnant mother can pass it to her baby during pregnancy or around the time of birth. It can spread through sexual contact. There have also been reports that the virus has spread through blood transfusions. There have been outbreaks of Zika virus in the United States, Africa, Southeast Asia, the Pacific Islands, parts of the Caribbean, and Central and South America.

Most people who get the virus do not get sick. One in five people do get symptoms, which can include a fever, rash, joint pain, and conjunctivitis (pink eye). Symptoms are usually mild, and start 2 to 7 days after being bitten by an infected mosquito.

A blood test can tell whether you have the infection. There are no vaccines or medicines to treat it. Drinking lots of fluids, resting, and taking acetaminophen might help.

Zika can cause microcephaly (a serious birth defect of the brain) and other problems in babies whose mothers were infected while pregnant. The Centers for Disease Control and Prevention recommends that pregnant women do not travel to areas where there is a Zika virus outbreak. If you do decide to travel, first talk to your doctor. You should also be careful to prevent mosquito bites:

• Use insect repellent
• Wear clothes that cover your arms, legs, and feet
• Stay in places that have air conditioning or that use window and door screens

Centers for Disease Control and Prevention

Viruses are very tiny germs. They are made of genetic material (either DNA or RNA) inside of a protein coating. There are a huge number of viruses on earth. Only a small number of them can infect humans. Those viruses can infect our cells, which may cause disease. Some of the diseases that viruses can cause include the common cold, the flu, COVID-19, and HIV.

Viruses can be spread in different ways:

• Through droplets and particles that are breathed out by someone who has the infection. You might breathe in the droplets or particles, or they could land on your mouth, nose, or eyes.
• By touching surfaces or objects that have the virus on them and then touching your mouth, nose, or eyes.
• From the pregnant parent to the baby during pregnancy.
• Through contaminated food or water.
• By being bitten by an infected insect or animal.
• Through sexual contact (usually vaginal, anal and oral sex) with someone who has the infection.

Viruses are like hijackers. They invade living, normal cells. They then use those cells to multiply (make copies of themselves). This process is also called replication. The process can kill, damage, or change the infected cells. Sometimes this can make you sick. The symptoms can range from mild to very severe. Other times, your immune system may be able to fight it off and you may not have any symptoms.

Each different virus usually only infects one type of cell in your body. For example, hepatitis viruses affect the cells in the liver. HIV infects a certain type of immune system cell.

For most viral infections, treatments can only help with symptoms while you wait for your immune system to fight off the virus. There are antiviral medicines to treat some viral infections. Antibiotics do not work for viral infections.

Vaccines can help prevent you from getting many viral diseases. You may be able to prevent some viral infections by:

• Proper hand washing.
• Paying attention to food safety.
• Cleaning surfaces that may be infected with germs.
• Avoiding contact with wild animals.
• Preventing insect bites by using insect repellent when you go outdoors. If you travel to an area that has a high risk of diseases from insect bites, also wear long pants, shirts, and socks.
• Practicing safe sex (using a condom every time you have anal, vaginal, or oral sex).
• Avoiding close contact with people who are sick.