Health Topics

Infections

HIV/AIDS and Infections
National Library of Medicine
AIDS and Infections
Opportunistic Infections in AIDS
AIDS-related opportunistic infections
OIs

Having HIV/AIDS weakens your body's immune system. It destroys the white blood cells that fight infection. This puts you at risk for opportunistic infections (OIs). OIs are serious infections that take advantage of your weak immune system. These infections are less common and less severe in healthy people.

There are many types of OIs:

  • Bacterial infections, including tuberculosis and a serious related disease, Mycobacterium avium complex (MAC)
  • Viral infections, such as cytomegalovirus (CMV) and hepatitis C
  • Fungal infections, like yeast infections, cryptococcal meningitis, pneumocystis carinii pneumonia (PCP) and histoplasmosis
  • Parasitic infections, such as crypto (cryptosporidiosis) and toxo (toxoplasmosis)

Having HIV/AIDS can make infections harder to treat. People with HIV/AIDS are also more likely to have complications from common illnesses such as the flu.

You can help prevent infections by taking your HIV/AIDS medicines. Other things that can help include practicing safe sex, washing your hands well and often, and cooking your food thoroughly.


AIDS-Related Opportunistic Infections
Infections
Immune System
Having HIV/AIDS weakens your body's immune system. It destroys the white blood cells that fight infection. This puts you at risk for opportunistic infections ( ...
Urinary Tract Infections
National Library of Medicine
Bladder Infections
Infections, Bladder
Kidney Infections
Pyelonephritis
UTI

The urinary system is the body's drainage system for removing wastes and extra water. It includes two kidneys, two ureters, a bladder, and a urethra. Urinary tract infections (UTIs) are the second most common type of infection in the body.

You may have a UTI if you notice

  • Pain or burning when you urinate
  • Fever, tiredness, or shakiness
  • An urge to urinate often
  • Pressure in your lower belly
  • Urine that smells bad or looks cloudy or reddish
  • Pain in your back or side below the ribs

People of any age or sex can get UTIs. But about four times as many women get UTIs as men. You're also at higher risk if you have diabetes, need a tube to drain your bladder, or have a spinal cord injury.

If you think you have a UTI it is important to see your doctor. Your doctor can tell if you have a UTI with a urine test. Treatment is with antibiotics.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Urinary Tract Infections
Kidneys and Urinary System
Infections
The urinary system is the body's drainage system for removing wastes and extra water. It includes two kidneys, two ureters, a bladder, and a urethra. Urinary ...
Viral Infections
National Library of Medicine
Adenovirus Infections
Coxsackievirus Infections
Enterovirus
Hand, Foot, and Mouth Disease
Infections, Viral
Roseola

Viruses are very tiny germs. They are made of genetic material inside of a protein coating. Viruses cause familiar infectious diseases such as the common cold, flu and warts. They also cause severe illnesses such as HIV/AIDS, smallpox, and Ebola.

Viruses are like hijackers. They invade living, normal cells and use those cells to multiply and produce other viruses like themselves. This can kill, damage, or change the cells and make you sick. Different viruses attack certain cells in your body such as your liver, respiratory system, or blood.

When you get a virus, you may not always get sick from it. Your immune system may be able to fight it off.

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


Virus Diseases
Infections
Immune System
Viruses are very tiny germs. They are made of genetic material inside of a protein coating. Viruses cause familiar infectious diseases such as the common cold, ...
Bacterial Infections
National Library of Medicine
Flesh-Eating Bacteria
Infections, Bacterial
Necrotizing Fasciitis
Q Fever

Bacteria are living things that have only one cell. Under a microscope, they look like balls, rods, or spirals. They are so small that a line of 1,000 could fit across a pencil eraser. Most bacteria won't hurt you - less than 1 percent of the different types make people sick. Many are helpful. Some bacteria help to digest food, destroy disease-causing cells, and give the body needed vitamins. Bacteria are also used in making healthy foods like yogurt and cheese.

But infectious bacteria can make you ill. They reproduce quickly in your body. Many give off chemicals called toxins, which can damage tissue and make you sick. Examples of bacteria that cause infections include Streptococcus, Staphylococcus, and E. coli.

Antibiotics are the usual treatment. When you take antibiotics, follow the directions carefully. Each time you take antibiotics, you increase the chances that bacteria in your body will learn to resist them causing antibiotic resistance. Later, you could get or spread an infection that those antibiotics cannot cure.

NIH: National Institute of Allergy and Infectious Diseases


Bacterial Infections
Infections
Bacteria are living things that have only one cell. Under a microscope, they look like balls, rods, or spirals. They are so small that a line of 1,000 could fit ...
Cytomegalovirus Infections
National Library of Medicine
CMV Infections
CMV

Cytomegalovirus (CMV) is a virus found around the world. It is related to the viruses that cause chickenpox and infectious mononucleosis (mono). Between 50 percent and 80 percent of adults in the United States have had a CMV infection by age 40. Once CMV is in a person's body, it stays there for life.

CMV is spread through close contact with body fluids. Most people with CMV don't get sick and don't know that they've been infected. But infection with the virus can be serious in babies and people with weak immune systems. If a woman gets CMV when she is pregnant, she can pass it on to her baby. Usually the babies do not have health problems. But some babies can develop lifelong disabilities.

A blood test can tell whether a person has ever been infected with CMV. Most people with CMV don't need treatment. If you have a weakened immune system, your doctor may prescribe antiviral medicine. Good hygiene, including proper hand washing, may help prevent infections.

Centers for Disease Control and Prevention


Cytomegalovirus Infections
Infections
Cytomegalovirus (CMV) is a virus found around the world. It is related to the viruses that cause chickenpox and infectious mononucleosis (mono). Between 50 percent and ...
Fungal Infections
National Library of Medicine
Cryptococcosis
Infections, Fungal
Mycoses

If you have ever had athlete's foot or a yeast infection, you can blame a fungus. A fungus is a primitive organism. Mushrooms, mold and mildew are examples. Fungi live in air, in soil, on plants and in water. Some live in the human body. Only about half of all types of fungi are harmful.

Some fungi reproduce through tiny spores in the air. You can inhale the spores or they can land on you. As a result, fungal infections often start in the lungs or on the skin. You are more likely to get a fungal infection if you have a weakened immune system or take antibiotics.

Fungi can be difficult to kill. For skin and nail infections, you can apply medicine directly to the infected area. Oral antifungal medicines are also available for serious infections.

NIH: National Institute of Allergy and Infectious Diseases


Mycoses
Infections
Skin, Hair and Nails
If you have ever had athlete's foot or a yeast infection, you can blame a fungus. A fungus is a primitive organism. Mushrooms, mold and mildew are examples. ...
Helicobacter Pylori Infections
National Library of Medicine
H. Pylori Infections

Helicobacter pylori (H. pylori) is a type of bacteria that causes infection in the stomach. It is the main cause of peptic ulcers, and it can also cause gastritis and stomach cancer.

About 30 to 40 percent of people in the United States get an H. pylori infection. Most people get it as a child. H. pylori usually does not cause symptoms. But it can break down the inner protective coating in some people's stomachs and cause inflammation. This can lead to gastritis or a peptic ulcer.

Researchers aren't sure how H. pylori spreads. They think that it may spread by unclean food and water, or through contact with an infected person's saliva and other body fluids.

A peptic ulcer causes a dull or burning pain in your stomach, especially when you have an empty stomach. It lasts for minutes to hours, and it may come and go for several days or weeks. It may also cause other symptoms, such as bloating, nausea, and weight loss. If you have the symptoms of a peptic ulcer, your health care provider will check to see whether you have H. pylori. There are blood, breath, and stool tests to check for H. pylori. In some cases, you may need an upper endoscopy, often with a biopsy.

If you do have a peptic ulcer, the treatment is with a combination of antibiotics and acid-reducing medicines. You will need to be tested again after treatment to make sure the infection is gone.

There is no vaccine for H. pylori. Since H. pylori might spread through unclean food and water, you might be able to prevent it if you

  • Wash your hands after using the bathroom and before eating
  • Eat properly prepared food
  • Drink water from a clean, safe source

NIH: National Institute of Diabetes and Digestive and Kidney Diseases


Helicobacter Infections
Digestive System
Infections
Helicobacter pylori (H. pylori) is a type of bacteria that causes infection in the stomach. It is the main cause of peptic ulcers, and it can also cause gastritis ...
Infections and Pregnancy
National Library of Medicine
Pregnancy, Infections in

During pregnancy, some common infections like the common cold or a skin infection do not usually cause serious problems. But other infections can be dangerous to you, your baby, or both. Some infections may lead to preterm birth and low birth weight babies. Others can cause serious illness, birth defects, and lifelong disabilities, such as hearing loss or learning problems.

Some of the infections that can be dangerous during pregnancy include

  • Bacterial vaginosis (BV)
  • Group B strep (GBS)
  • Hepatitis
  • Sexually transmitted diseases
  • Toxoplasmosis
  • Urinary tract infections
  • Yeast infections
  • Zika virus

To try to prevent infections,

  • Don't eat raw or undercooked meat
  • Don't share food or drinks with other people
  • Wash your hands frequently
  • Don't empty cat litter. Cats can transmit toxoplasmosis.

If you do get an infection during pregnancy, contact your health care provider about how best to protect you and your baby. Only some medicines are safe during pregnancy.


Pregnancy Complications, Infectious
Infections
Pregnancy and Reproduction
Female Reproductive System
During pregnancy, some common infections like the common cold or a skin infection do not usually cause serious problems. But other infections can be dangerous ...
Pinworms
National Library of Medicine
Enterobiasis
Oxyuriasis
Seatworm infection
Threadworm infection

Pinworms are small parasites that can live in the colon and rectum. You get them when you swallow their eggs. The eggs hatch inside your intestines. While you sleep, the female pinworms leave the intestines through the anus and lay eggs on nearby skin.

Pinworms spread easily. When people who are infected touch their anus, the eggs attach to their fingertips. They can spread the eggs to others directly through their hands, or through contaminated clothing, bedding, food, or other articles. The eggs can live on household surfaces for up to 2 weeks.

The infection is more common in children. Many people have no symptoms at all. Some people feel itching around the anus or vagina. The itching may become intense, interfere with sleep, and make you irritable.

Your health care provider can diagnose pinworm infection by finding the eggs. A common way to collect the eggs is with a sticky piece of clear tape. Mild infections may not need treatment. If you do need medicine, everyone in the household should take it.

To prevent becoming infected or reinfected with pinworms,

  • Bathe after waking up
  • Wash your pajamas and bed sheets often
  • Wash your hands regularly, especially after using the bathroom or changing diapers
  • Change your underwear every day
  • Avoid nail biting
  • Avoid scratching the anal area

NIH: National Institute of Allergy and Infectious Diseases


Enterobiasis
Children and Teenagers
Infections
Pinworms are small parasites that can live in the colon and rectum. You get them when you swallow their eggs. The eggs hatch inside your intestines. While you ...
Pneumococcal Infections
National Library of Medicine
Streptococcus Pneumoniae Infections

Pneumococci are a type of streptococcus bacteria. The bacteria spread through contact with people who are ill or by healthy people who carry the bacteria in the back of their nose. Pneumococcal infections can be mild or severe. The most common types of infections are

  • Ear infections
  • Sinus infections
  • Pneumonia
  • Sepsis
  • Meningitis

How the diagnosis is made depends upon where the infection is. Your doctor will do a physical exam and health history. Possible tests may include blood, imaging, or lab tests. Treatment is with antibiotics. Vaccines can prevent pneumococcal infections. There are two vaccines. One is for infants and young children. The other is for people at high risk, including those who are over 65 years old, have chronic illnesses or weak immune systems, smoke, have asthma, or live in long-term care facilities.

Centers for Disease Control and Prevention


Pneumococcal Infections
Infections
Pneumococci are a type of streptococcus bacteria. The bacteria spread through contact with people who are ill or by healthy people who carry the bacteria in the ...