pneumococcus

Pneumococcus, also called Streptococcus pneumoniae, is a common bacterium that often lives harmlessly in the back of the nose and throat. But in some situations, especially when the body's defenses are weaker, it can cause disease.

The illness most people connect with pneumococcus is pneumonia, an infection in the lungs that can cause coughing, fever, chest pain, and trouble breathing. But this bacterium does not only affect the lungs. It can also cause ear infections, sinus infections, meningitis, and infections in the blood. Some of these can become very serious, especially in babies, older adults, and people with certain health problems.

Because pneumococcal disease can spread easily and sometimes become dangerous, vaccines are used to protect against the most common types. These vaccines are especially important for young children, older adults, and people with certain medical conditions.

You will usually see the word pneumococcus in medical or health contexts, such as discussions of vaccines, pneumonia, or bacterial infections. Doctors, nurses, and public health workers use it when talking about how these infections start, who is most at risk, and how they can be prevented. It is a medical word, but the idea behind it is simple: it names a bacterium that can live quietly in the body or, at times, cause serious infection.