Nov 25, 2025 · Viruses that become resistant to antivirals have affected treatment, including for genital herpes, HIV and, in 2008, for influenza (flu). Treating and preventing bacterial and viral …

Mar 5, 2024 · Viruses are responsible for causing many diseases, including: Common cold. Influenza. Measles. Chickenpox and shingles. Coronavirus disease 2019, also called COVID …

Dec 19, 2025 · Influenza viruses are constantly changing, with new strains appearing often. A person's first flu infection gives some long-term protection against similar strains of flu. But the …

Apr 30, 2025 · Viral gastroenteritis is an intestinal infection that includes signs and symptoms such as watery diarrhea, stomach cramps, nausea or vomiting, and sometimes fever. The …

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Oct 22, 2025 · Coronavirus disease 2019 (COVID-19) and seasonal flu have many similarities and differences. Find out what to know and how to protect yourself from these diseases.

Dec 9, 2025 · HBV and HCV are viruses that cause liver disease. The symptoms may be the same. But they spread and are treated in different ways.

May 24, 2023 · Germs called viruses cause a common cold. Often, adults may have two or three colds each year. Infants and young children may have colds more often. Most people recover …

Jun 8, 2024 · Bird flu rarely infects humans. But health officials worry because influenza A viruses that infect birds can change, called mutate, to infect humans and spread from person to …

May 16, 2024 · Encephalitis (en-sef-uh-LIE-tis) is inflammation of the brain. It can be caused by viral or bacterial infections, or by immune cells mistakenly attacking the brain. Viruses that can …