Infectious diseases

Infectious diseases happen when germs enter our bodies and cause infections. Germs include:

Some, but not all, infectious diseases are contagious. That means they spread person to person.

OHSU's lead data scientist, Peter Graven, Ph.D., provides regular updates on COVID-19, flu, RSV and other infectious diseases.

Graven's latest forecast came out April 13.

Media: Call 503-494-8231 or email [email protected].

Some infectious diseases are or have been common enough that we routinely vaccinate people against them, typically in infancy and childhood.

Chickenpox, a viral disease, causes an itchy and sometimes painful rash on the whole body. Chickenpox spreads easily to people who haven't had it or weren't vaccinated against it.

The virus that causes chickenpox also causes another painful rash called shingles. The shingles vaccine is recommended for:

This bacterial infection often damages tissues in the nose and throat. If it gets into the blood, it can damage the heart, nerves and kidneys. It can also infect the skin. Diphtheria spreads through droplets from coughing or sneezing.

This viral disease damages the liver. The most common types are called hepatitis A, hepatitis B and hepatitis C. Vaccines are available for hepatitis A and B. Hepatitis can spread through:

About 97,800 people get hepatitis each year in the U.S. Hepatitis B and C can become chronic (ongoing) conditions and can cause liver cancer.

This viral disease has symptoms that include:

The CDC warned Nov. 23 that measles vaccination rates are at their lowest since 2008 and that millions of children worldwide are at risk of infection.

This viral disease spreads through close contact, especially repeated contact. Symptoms include:

The U.S. last had a mumps outbreak in 2019, with 3,780 cases. Thirty-six states have reported at least one mumps case in 2022; Oregon has reported five.

This contagious viral disease has symptoms that vary from person to person:

A case of paralytic polio was reported in New York state in July 2022 in an unvaccinated young adult.

In most people, this viral disease causes mild symptoms. But in unvaccinated pregnant people, it can cause a miscarriage or serious birth defects.

This bacterial infection makes muscles tighten, especially in the jaw, which can cause breathing and swallowing problems. Tetanus does not spread from person to person. People usually get tetanus through broken skin.

More than 100 OHSU staffers helped care for an Oregon boy who got tetanus in 2019.

This bacterial infection starts like a cold. In children and adults, it moves to violent coughing fits that can last up to 10 weeks. These coughing fits can cause:

Babies may not cough. Instead, they may:

Unvaccinated pregnant people should get the whooping cough vaccine to protect their babies, who cannot get it until 2 months. A CDC study released in February 2023 found that vaccinations during pregnancy helped prevent whooping cough cases in newborns. The CDC recommends getting the vaccine between the 27th and 36th weeks of pregnancy.

OHSU experts say the best way to avoid infectious diseases is to keep up with vaccines. Children's doctors offer vaccines against certain infectious diseases on a standard schedule that starts at birth.

Many pharmacies offer vaccines for flu and COVID-19, two infectious diseases that have spread widely in recent months. It's safe to get both at the same time. OHSU pharmacies also offer the Jynneos vaccine for mpox.

Find a flu shot or COVID-19 vaccine or booster near you:

Researchers are working to create RSV vaccines.

You can limit the spread of infectious diseases by:

You can get more than one infectious disease at the same time (co-infections). People who get co-infections may:

Infectious diseases have similar symptoms and signs. Your provider can order lab tests to figure out what you have.

For respiratory viruses like RSV, flu and COVID-19, lab tests usually mean doing a nose or throat swab.

Lab tests may also use samples of:

For mild symptoms or if you think you need a test:

These symptoms need medical care right away, especially in babies and children:

Make an appointment for a:

The app gives you a symptom checker and other helpful guidance