The Four Worst Infectious Diseases In The U.S.

Every country in the world is vulnerable to transmissible diseases, and the United States is no exception. Here's a look at a few of the most dangerous infections currently making the rounds in America—and information on how to protect yourself from them:

1. Bacterial Meningitis

This infection attacks the protective lining that covers the brain and spinal cord, and it can be deadly. About 4,100 people are diagnosed with bacterial meningitis each year, and about 500 die from it, according to the Centers for Disease Control and Prevention (CDC). Survivors may be left with complications such as brain damage, seizures, memory and hearing loss, balance problems, and kidney failure, says Kathryn Boling, MD, a primary care physician at Lutherville Personal Physicians in Lutherville, Maryland, a division of Baltimore’s Mercy Medical Center.

Symptoms: "The classic signs of a meningitis infection are acute onset of fever, headache, and stiff neck," Boling says. Symptoms typically develop anywhere from three to seven days after exposure.

What you can do: Treatment includes immediate infusion of intravenous antibiotics and cortisones (anti-inflammatory agents) to reduce brain swelling and other complications. Unfortunately, even with treatment, about 10 percent of victims will die. The disease often strikes people living in close quarters, such as college dorms, and is spread via saliva or other respiratory secretions, like mucus.

2. The Flu

You may not think the influenza is a big deal because it’s so common—anywhere from five to 20 percent of Americans contract it in any given year—but it can have serious complications. More than 200,000 flu sufferers are hospitalized every year after the flu leads to bacterial pneumonia (a lung infection), sinus and ear infections, or severe dehydration. Anywhere from 3,000 to 49,000 of those patients will die. While older people, pregnant women, and the very young are more susceptible to the flu’s ravages, the flu occasionally kills otherwise healthy individuals of all ages.

Symptoms: Initially, the flu may just seem like a more intense version of a cold, with sore throat, body aches, headaches, a cough, and a fever. However, fever frequently rises above 101 degrees and other symptoms may be equally severe.

What you can do: Your best protection? Get a yearly flu shot and stay vigilant about avoiding contact with sick people, as the flu is spread by respiratory secretions that become airborne when a sufferer coughs, sneezes, or even talks. If your efforts fail and you catch the flu anyway, talk to your doctor about taking an antiviral medication within the first few days of symptoms—it may shorten your illness by a few days. And don’t hesitate to seek help if your symptoms worsen.

3. HIV

The human immunodeficiency virus is typically transmitted sexually, but can also be acquired through non-sexual exposure to infected blood and other body fluids; it can be transmitted in hospital settings or through IV drug use.

HIV gained worldwide notoriety in the 1980s and 1990s as the infection which led to AIDS (acquired immunodeficiency syndrome), and eventually death. HIV was originally associated with gay men, drug users, and people who received blood transfusions, especially hemophiliacs. But anyone can get HIV—even infants, who are infected by their mothers during pregnancy or delivery. In the U.S., about 50,000 people contract HIV every year, and there are more than 1.2 million people living with the condition.

Symptoms: After exposure to HIV, the first sign of the disease may be swollen lymph nodes. An infected person may also have diarrhea, lose weight, and be feverish, fatigued, and coughing. The bad news is that it can take about a month to show symptoms. "Early in the disease, people with HIV don't know they are sick and infectious, and they [may] continue with behaviors that spread the disease," Boling says.

What you can do: The good news is that the disease no longer automatically leads to AIDS, thanks to the development of antiviral drugs that stop HIV’s progression. Untreated, however, HIV does progress to AIDS. AIDS patients have very damaged immune systems and typically succumb to conditions such as pneumonia, cancer, meningitis, tuberculosis, or dementia.

4. Naegieria fowleri

It’s exceedingly rare, but this disease is almost invariably fatal. Naegieria fowleri, also known as primary amebic meningoencephalitis, is an amoeba (a single-celled organism) found in bodies of warm, fresh water such as lakes in southern states, hot springs, or occasionally tap water. When a swimmer gets contaminated water in his or her nose, the amoeba travels up through the nasal passages and into the brain, destroying tissue.

Symptoms: A few days after exposure a person will have a headache, fever, nausea, and vomiting, which will quickly progress to confusion, seizures, and hallucinations. According to the CDC, since 1962, 132 people in the U.S. have contracted Naegieria fowleri, mostly in the south and west; 129 have died. A drug called miltefosine may have played a part in helping the handful of survivors recover.

What you can do: Avoid swimming in warm bodies of fresh water, or at least hold your nose or use nose plugs when swimming in them to help prevent infected water from traveling up the nasal passages into the brain. Also, if you use a neti pot to rinse your nasal passages, don’t use tap water; filtered water, or water that’s been boiled for at least one minute, is a better bet.

Kathryn Boling, MD, reviewed this article.


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