Lyme disease is an increasingly common threat to public health. Incidences of Lyme disease in the United States reportedly doubled between 1991 and 2014, and this statistic doesn’t take into account the numerous undiagnosed/misdiagnosed cases of this insidious disease.
The good news about the rise of Lyme disease is that many more practitioners (and people in general) are beginning to get a better understanding of it. Patients are learning to spot signs of Lyme disease, and physicians are becoming more adept at diagnosing and treating it.
Unfortunately, Lyme disease is a complex condition, and we still have a lot to learn. One of the areas of Lyme research causing confusion revolves around the other types of infections that frequently affect patients with Lyme disease.
It’s widely understood that Lyme disease itself is caused by the bacterium Borrelia burgdorferi, which is transmitted through the bite of a black-legged tick (also known as an Ixodes tick or deer tick). What many people don’t know is that disease vectors like ticks may carry many different strains of bacteria as well as viruses, protozoans, and fungi, all of which can be transmitted in a single bite. As a result, many people with Lyme disease also have co-infections – diseases they acquired at the same time they were infected with Lyme.
To make matters even more complicated, Lyme patients frequently experience opportunistic infections, which are diseases that take advantage of a weakened immune system to infect a host. A subset of these illnesses, called re-activated opportunistic infections, consists of latent infections already present in the host, which lie in wait for a weakened immune system to re-activate themselves and re-infect the host.
Even among people who are aware of the co-infections that often accompany Lyme disease, “co-infection” is often misused as an umbrella term that also includes opportunistic infections and re-activated opportunistic infections. While these types of infections are similar in that they can all occur along with Lyme disease, they are not the same. Let’s take a closer look at the difference between co-infections and opportunistic infections.
Co-infections: transmitted along with Lyme
In a single tick bite, a person can be infected with Lyme disease and a host of other illnesses at the same time. These co-infections are quite common; one recently-published survey of people with chronic Lyme disease showed that over 50% had co-infections, with 30% reporting two or more of them.
Some of the co-infections that often occur in people with Lyme disease are:
- Babesiosis, caused by a malaria-like parasite called Babesia
- Bartonellosis, caused by Bartonella bacteria
- Rocky Mountain spotted fever, caused by Rickettsia bacteria
- Ehrlichiosis/anaplasmosis, caused by Ehrlichia parasites
Because even Lyme-savvy physicians aren’t always aware of their existence, these co-infections can be difficult to diagnose and treat. But a Lyme patient with one or more co-infections can’t be truly healthy unless these illnesses are also addressed.
Opportunistic infections: taking advantage of weak defenses
Unlike co-infections, opportunistic infections aren’t transmitted by ticks. Instead, these diseases take hold after a person has been infected with Lyme disease. Since many people with chronic Lyme disease experience weakened or suppressed immunity, opportunistic infections are able to move in. These illnesses bring their own symptoms, adding to and exacerbating the challenge of treating a Lyme patient. Opportunistic organisms that commonly prey on people with compromised immune systems include:
- Candida albicans, which can cause thrush, yeast infections, and invasive candidiasis
- Chlamydia pneumoniae, which can cause severe community-acquired pneumonia
- Mycoplasma pneumoniae, which can cause respiratory infections
Another type of opportunistic infection that can affect people with Lyme disease is known as re-activated opportunistic infection. These illnesses are already present in the body of a person with Lyme disease, but they remain latent until lowered immune function allows them the opportunity to re-activate. Like opportunistic infections, re-activated opportunistic infections aren’t the result of a tick bite; rather, they’re caused by the same types of organisms that cause opportunistic infections. They are dormant in the body of people before they’re bitten, and are able to re-infect the host once immunity is weakened by Lyme disease.
One category of re-activated opportunistic infection that sometimes affects people with Lyme disease is those from the Herpes family. These include:
- Cytomegalovirus (CMV) infection
- Epstein-Barr virus (EBV)
- Human herpesvirus 6 (HHV-6)
Most people will become infected with one or more of these viruses at some point in their lives. Healthy individuals don’t usually experience symptoms, but these infections may re-activate in patients with weakened immune systems.
Treating co-infections and opportunistic infections: understanding is key
The general public is becoming increasingly alert to the threat of Lyme disease, and health care professionals are doing a better job of diagnosing and treating it. However, much education is still needed when it comes to understanding co-infections and opportunistic infections – and this starts with recognizing the differences between the two.
Once practitioners and patients understand that co-infections and opportunistic infections often accompany Lyme disease, and that they need to be diagnosed and treated separately, people with chronic Lyme will have a better chance of recovering from all types of infection and regaining their health.
