Lyme disease has been receiving a lot of media attention lately. Now that spring has arrived in the northern half of the world, people are coming out of the isolation of the cold weather months and venturing into the great outdoors. But people aren’t the only things that come out in droves once warm weather arrives. Ticks have also emerged, and their populations are exploding.
While some ticks are relatively harmless, others carry bacteria that can cause serious health problems. The black-legged tick, also known as an Ixodes or deer tick, is particularly dangerous, as it can transmit Lyme disease and other infections to humans.
What is Lyme disease and how is it transmitted?
Lyme disease is a bacterial infection caused by a spirochete (corkscrew-shaped) bacterium called Borrelia burgdorferi. Black-legged ticks, which are typically found in wooded areas or long grass, become infected with Borrelia burgdorferi when they feed on deer, rodents or other small mammals, as well as certain birds. When a tick carrying Borrelia burgdorferi bites a human, the bacterium spreads from the tick to the bitten human, leading to Lyme disease.
What are the symptoms of Lyme disease?
There are two phases of Lyme disease: early (also known as acute) and late (also known as chronic). Both early and late Lyme disease share many of the same symptoms, but each presents its own unique characteristics as well. Here are some of the symptoms of early Lyme disease:
- An expanding red rash called “erythema migrans” that sometimes resembles a bullseye
- Headaches and neck stiffness
- Fever
- Fatigue
- Joint pain and swelling
- Weakness or paralysis of facial muscles
- Fainting or feeling lightheaded
- Chest pain or heart palpitations
When Lyme disease is diagnosed and treated within the first few weeks of infection, the illness may successfully be eradicated. Unfortunately, many Lyme patients don’t realize they’re infected or receive the wrong diagnosis, and even those who receive treatment may not respond to it. In these cases, Lyme disease can progress to the late phase. Symptoms of chronic Lyme disease, some of which can be debilitating, include:
- Fatigue
- Muscle aches and stiffness
- Joint pain and inflammation
- Headaches
- Cognitive problems like memory loss, trouble concentrating or “brain fog”
- Neuropathy (including nerve pain, numbness, or tingling)
- Sleep disturbances
- Changes in mood
- Digestive issues

The difficulty associated with diagnosing and treating Lyme disease is compounded by the frequent presence of Lyme co-infections, particularly when clinicians aren’t trained to look for these illnesses when working with Lyme patients.
What are Lyme co-infections?
While it’s widely known that Lyme disease itself is transmitted through the bite of a black-legged tick, many people don’t realize that disease vectors like ticks may carry many different strains of bacteria along with viruses, protozoans, and fungi. All of these organisms can be transmitted in a single tick bite. This means that people with Lyme disease often have co-infections – diseases they acquired through the same tick bite that infected them with Lyme disease.
The word “co-infection” is often used as an umbrella term that includes not only co-infections transmitted along with Lyme, but also opportunistic infections that prey on the weakened immunity of Lyme patients. A subset of opportunistic infections called “re-activated opportunistic infections” consists of latent infections already present in the host, which wait for a chance to re-activate. Most people will become infected with one or more of these at some point in their lives, and they often go unnoticed in healthy individuals. But in Lyme patients with compromised immunity, re-activated opportunistic infections can be serious. Such is the case with cytomegalovirus (CMV).
What is cytomegalovirus (CMV)?
Cytomegalovirus is a virus that is very common and can infect people of all ages. The Centers for Disease Control report that one in three children will be infected with CMV by the time they turn three, and over half of adults will be infected with the virus by age 40.
Because the immune system of a healthy person is able to fight CMV, most people will never experience any symptoms. Occasionally, though, healthy people with CMV may develop a mild illness, signs of which include:
- Fatigue
- Muscle aches
- Fever
- Swollen glands

Is cytomegalovirus a Lyme co-infection?
Although most people who are infected with CMV won’t get sick from it, Lyme disease patients may experience a re-activation of this opportunistic infection. The negative effects Lyme disease has on a patient’s immune system increase vulnerability to the development of illness from CMV co-infection. CMV in Lyme patients and others with weakened immune systems may cause serious symptoms of the eyes, lungs, liver, intestines, stomach, and esophagus.
How do you test for and treat CMV?
CMV can be detected with an ELISpot. This test has been used for years to detect Lyme and its co-infections on a cellular level.
In healthy people, CMV doesn’t usually require any sort of treatment, since it rarely causes illness. Patients with Lyme disease or those who are otherwise immunocompromised can treat CMV with antiviral medication.
When deciding on a treatment plan, Lyme disease patients and their providers need to be aware of the possibility of co-infections like CMV and treat them along with Lyme. It is only when co-infections are addressed along with Lyme disease that a patient can make a full recovery.