Infectious Diseases

Is polio making a comeback in the United States and, if so, are you at risk? We talk to a doctor, who says that vaccination is key.

By Jennifer Walker-Journey

Viruses can alter a person's body odor to make it more attractive to mosquitoes, leading to more bites, which, in turn, allow a virus to spread.

By Penghua Wang

Who gets long COVID and why still remains a mystery, but several new studies are showing it's much more widespread than we initially thought. So what is long COVID and how can it be treated?

By Joanna Thompson

The wildly contagious delta coronavirus variant now accounts for more than 80 percent of cases in the United States. Does it pose a threat to eliminating COVID-19 across the globe?

By Jennifer Walker-Journey

It's been a year since the World Health Organization officially declared the novel coronavirus a global pandemic. The last 12 months have been truly historic and life-changing in ways that we may not even yet recognize.

By John Donovan

Many health experts are gravely concerned about how the massive protest crowds, chanting and especially use of tear gas could accelerate the spread of coronavirus.

By Patty Rasmussen

Learn the steps of contact tracing, one critical way that public health officials stop viruses like COVID-19 from spreading, in this HowStuffWorks video.

Despite strict closing and mask orders, San Francisco was hit hard by the 1918-1919 influenza pandemic. But some residents balked at the rules and that meant more people died.

By John Donovan

As COVID-19 rages around the world, distilleries quickly ramp up the switch from booze to hand sanitizer in an all-out effort to curb the spread.

By Jeremy Glass

The World Health Organization just declared the coronavirus a full-blown pandemic. What does that even mean, and how is that different from an epidemic?

By Sarah Gleim

You've probably heard the word "quarantine" a lot in relation to the coronavirus. But how is it different from patient isolation?

By Patty Rasmussen

There's been a steady uptick in Lyme disease across the United States since 1997, but the news isn't all bad.

By John Donovan

Sometimes the nose knows. What advances are being made in detecting diseases by scent?

By Laurie L. Dove

Are jet air hand dryers the safest way to dry your hands after using the bathroom or are they blasting invisible microbes through the air with every use?

By Laurie L. Dove

With the rise of drug-resistant bacteria, scientists are taking a second look at infection treatments that were popular before antibiotics. Which ones might work today, and which ones are just quackery?

By Patrick J. Kiger

It might seem counterintuitive for labs to stock highly contagious diseases, but some researchers insist it's with good reason.

By Debra Ronca

Some people believe being Rh-negative type makes them immune to viruses like Ebola. Let's get to the bottom of this theory.

By Debra Ronca

Modern medicine may be here, but there are still plenty of infectious diseases to combat, and the CDC is really busy doing that. Get to know 10 of these public (health) enemies.

By Nicholas Gerbis

Leprosy was the AIDS of the first millennium - a disfiguring disease that struck terror since people thought it was easy to contract. Patients were banished to live in colonies. What was life like there?

By Patrick J. Kiger

Pneumonia and diarrhea used to be bigger killers, but nowadays, developed countries can successfully treat them. Which other diseases are no longer death sentences?

By Alia Hoyt

No one thinks public toilets are altars of tidiness, but are they actually dangerous? The odds of catching something from a public bathroom are low -- but it's possible.

By Maria Trimarchi

You may think you know Ebola. You probably don't. The infectious disease has killed thousands in West Africa and has reappeared on the continent once again. What have scientists learned since the last outbreak?

By Patrick J. Kiger & Meisa Salaita

Parasites are common, and many are harmless. But we're willing to bet that you'd go to almost any length to avoid spending time with the five on this list.

By Maria Trimarchi

In general, people are at their most contagious approximately three days after having been exposed to a virus. You can learn more about how a virus behaves in the body from this article.

By HowStuffWorks.com Contributors

Researchers developed a safe and effective SARS vaccine. Learn more about SARS vaccine from this article.

By HowStuffWorks.com Contributors