Story at a glance

  • Most of the infectious diseases that have high numbers of reported cases in the U.S. are caused by bacteria.
  • Several are becoming resistant to existing antibiotics, which does not bode well for us.
  • Many of them can be fought off by washing your hands regularly.

It’s cold and flu season, but there are plenty of other infectious diseases we should be aware of. Many of these are bacterial diseases, which can often be prevented by washing hands or cooking food thoroughly. Here’s a list of some of the most concerning infectious diseases in the U.S. right now.


If you’ve recently had to throw out food because of contamination, it was most likely because of this group of bacteria species. Generally when you talk about food poisoning, you are oftentimes talking about Salmonella and when it’s bad, it can cause diarrhea, fever, chills and abdominal pain. The Centers for Disease Control and Prevention (CDC) estimates that there are 1.35 million illnesses, 26,500 hospitalizations and 420 deaths caused by Salmonella in the U.S. every year. Many of the less serious cases don’t get reported, so it’s hard to know how much of a problem it is. While symptoms can last for up to four days, most people recover without any treatment.


Staphylococcus aureus

This bacterium is what causes a staph infection, and it can be found in your upper respiratory tract and on the skin. Most of the time it won’t cause any problems, and in fact about 30 percent of people already have this species living in their nose.

It can get fatal if the bacteria spread to the bloodstream. The really serious problems start when it gets to the heart valves or wound sites around the body. There are also several strains of the species that are resistant to existing antimicrobial drugs like methicillin and vancomycin. People with chronic conditions like diabetes or vascular disease and with compromised immune systems are more vulnerable.

Carbapenem-resistant Enterobacteriaceae

Enterobacteriaceae is a family of bacteria that includes the infamous Escherichia coli (E. coli). Other species are responsible for urinary tract infections and some types of pneumonia. Carbapenem is an antibiotic that is highly effective and generally reserved for the really bad bugs. So the fact that some Enterobacteriaceae are resistant to it could be a serious issue for health care.

Lyme disease


The reason why you should always check for ticks after a walk in the woods is that the ticks could be carrying the Borrelia bacteria that cause Lyme disease. Most commonly caused by the species Borrelia burgdorferi, the disease shows up in humans as aches, pains and dizziness, to name a few symptoms. It’s a chronic condition that is often overlooked.

The bacteria don’t cause disease in the ticks or mice, and even in humans it’s actually quite difficult to test for the presence of Borrelia and to definitively diagnose Lyme disease, which is why people may go undiagnosed. The life cycle of the ticks is closely tied to white-footed mice and deer. The ticks aren’t born with the bacteria but can become infected after their first blood meal on a mouse that is infected. On the tick’s second blood meal either on deer, humans or other mammals, the tick can pass on the bacteria. Lyme disease has spread throughout the geographical ranges of where the ticks and mice also live with other important hosts for ticks, including deer.

Meningococcal disease

Meningococcal disease is caused by the bacterium Neisseria meningitidis, also known as meningococcus. These bacteria can get into the bloodstream and infect the lining of the  brain and the spinal cord. Although there aren’t a lot of cases reported each year, if it’s missed, it could lead to serious health complications and could be fatal within hours.

The bacteria can spread through breath and mouth fluids, such as spending time in close quarters with someone or kissing. Hence the fact that the CDC highlights outbreaks on college campuses on their website. It can be treated with antibiotics, but a vaccine can help prevent against it. 


Tuberculosis, or TB, is an infection of the bacterium Mycobacterium tuberculosis that typically affects the lungs but can also affect the brain, kidney or spine. In 2018, about 10 million people had cases of TB, according to the World Health Organization. Of those 10 million people, 1.5 million people died from the illness. Most cases are in developing countries, but there were more than 9,000 cases reported in the U.S. in 2018, but potentially up to 13 million people with a latent infection, according to the CDC. Thankfully, the WHO reports that TB incidence is falling at a rate of 2 percent per year.

The bacteria can spread through the air, especially when someone with TB coughs or sneezes. The symptoms can be mild, making it more likely that it’ll go untreated and spread. It’s treatable by antibiotics, but resistance to drugs is a major concern in the medical world.


Syphilis is a sexually transmitted infection (STI) or sexually transmitted disease (STD). The CDC outlines the stages of the disease that range from sores on the body to skin rashes and lesions. There could be a latent stage with no symptoms even after the sores and rashes that if untreated could lead to damage to internal organs. 

The first case of syphilis was recorded in 1494 in Naples, Italy, and was the first to be recognized as an STI. In 2018, there were 115,045 new diagnoses of syphilis in the U.S. The treatment for it involves Benzathine penicillin administered by injection.



Chlamydia is another bacterial infection and the most common STI. It is a silent one, especially when compared to syphilis. There are very few symptoms of chlamydia and not everyone will experience them, so the only way to know if you have it is to get tested at your doctor’s office or an STI clinic. Because it’s less noticeable, it can get passed around unknowingly. In 2018, there were more than 1.7 million cases of chlamydia reported in the U.S., according to the CDC.

If left untreated, chlamydia can leave a person sterile, which means they are unable to reproduce. While using protection during sex should help protect from infection, it’s not perfect. The best course is to get tested regularly and take the necessary antibiotics if diagnosed.


Shigellosis is caused by bacteria from the genus Shigella. People infected with these species can develop diarrhea, fever and stomach cramps within a day or two of exposure and typically recover without treatment. On rare occasions, people may experience arthritis after their infection, but this typically only affects about 2 percent of cases.

Spread of Shigellosis can be prevented by washing hands. It’s another reminder to not skip the soap, Nature’s best solution to mischievous microbes.

Hepatitis C

The only virus on our list, hepatitis C is a liver infection that’s caused by the hepatitis C. It can lead to fatigue, a form of diabetes and non-Hodgkin’s lymphoma. People with hepatitis C should avoid alcohol and need to be careful with their medications.

People can get infected through sharing needles and other equipment for taking drugs, according to the CDC. In 2017, there were 3,186 cases of hepatitis C reported to the CDC. There are antiviral therapies available for hepatitis C, but there’s also a wide rage of types of the virus so the effectiveness of treatment will vary across people.

Published on Nov 22, 2019