Long Island Ticks Carry Lyme, Babesia and Other Pathogens

Long Island ticks carried five disease-causing pathogens
Lyme bacteria and Babesia were detected most frequently
Some individual ticks carried multiple infectious agents

A study of Long Island ticks found five pathogens associated with human illness. Researchers collected blacklegged ticks at five sites in Suffolk County, New York, and compared them with ticks collected at three sites in Connecticut.

The pathogens detected were associated with Lyme disease, babesiosis, anaplasmosis, Borrelia miyamotoi disease and Powassan virus infection. Some individual ticks carried two or three infectious agents.

Ticks collected in Suffolk County and Connecticut

Researchers collected Ixodes scapularis, or blacklegged ticks, during 2015 and 2016 by dragging cloth through vegetation.

The five Suffolk County sites were Southampton, Manorville, Southold, Islip and Huntington. The three Connecticut sites were Mansfield in Tolland County and Stamford and Greenwich in Fairfield County.

The study included 115 nymphs and 89 adult ticks from New York, along with 28 nymphs and 86 adult ticks from Connecticut.

Every tick sample was tested twice on different days. The researchers confirmed positive results using alternate PCR primers and sequencing.

Lyme bacteria were found most frequently

As expected, Borrelia burgdorferi, the primary bacterium responsible for Lyme disease in the United States, was the most frequently detected pathogen.

Among the Long Island ticks collected in Suffolk County, B. burgdorferi was detected in:

• 21% of nymphal ticks
• 67% of adult ticks

The prevalence was similar in Connecticut, where B. burgdorferi was found in 25% of nymphs and 62% of adult ticks.

These percentages describe the ticks collected at the study sites. They do not mean that every tick bite on Long Island or in Connecticut carries the same risk.

Babesia was common in Long Island ticks

The most notable finding was the high prevalence of Babesia microti, the parasite responsible for most cases of babesiosis in the northeastern United States.

Among the ticks collected in Suffolk County, B. microti was detected in:

• 17% of nymphal ticks
• 30% of adult ticks

In earlier studies of blacklegged tick nymphs throughout New York, the prevalence of B. microti ranged from 3% to 12%. The 17% prevalence found in Suffolk County nymphs was higher than that earlier range and approached the 21% prevalence of B. burgdorferi in the same group.

The 30% prevalence of B. microti in adult Suffolk County ticks was among the highest reported in adult blacklegged ticks at that time.

The prevalence was lower in Connecticut. B. microti was found in 7% of nymphs and 13 of 86 adult ticks, or approximately 15%.

The difference in B. microti prevalence between adult ticks from Suffolk County and Connecticut was statistically significant. The difference between the nymphal groups was not statistically significant.

“Our finding of a high frequency of ticks infected with Babesia microti in Suffolk County, NY, implicates this agent as a probable frequent cause of non-Lyme tick-borne disease in this area,” Tokarz and colleagues wrote.

Suffolk County reported 197 cases of babesiosis in 2014. The investigators noted that the high frequency of B. microti in local ticks was consistent with the number of human cases reported in the region.

Other pathogens found in New York and Connecticut ticks

The researchers also detected Anaplasma phagocytophilum, Borrelia miyamotoi and Powassan virus.

Anaplasma phagocytophilum

Anaplasma phagocytophilum, the bacterium responsible for anaplasmosis, was found in 7% of nymphs and 11% of adult ticks from Suffolk County. In Connecticut, it was detected in 7% of nymphs and 8% of adults.

Borrelia miyamotoi

Borrelia miyamotoi was less common. It was detected in 3% of both nymphal and adult ticks from Suffolk County. Three adult ticks collected in Connecticut were positive.

Powassan virus

Powassan virus was detected in 2% of adult ticks from Suffolk County and in one adult tick from Connecticut.

Although Powassan virus was uncommon in this study, its detection remains important because the virus can cause severe neurological disease, including life-threatening encephalitis.

Some Long Island ticks carried multiple pathogens

The researchers also identified ticks infected with more than one organism. Coinfections were detected in 11% of nymphs and 45% of adult ticks collected in Suffolk County.

Multiple-pathogen findings in Suffolk County included:

• One nymph and seven adult ticks carrying A. phagocytophilum, B. burgdorferi and B. microti
• One adult tick carrying A. phagocytophilum, B. burgdorferi and B. miyamotoi
• One adult tick carrying B. burgdorferi, B. microti and B. miyamotoi

In Connecticut, one adult tick carried three agents: B. burgdorferi, B. microti and B. miyamotoi.

The researchers also found that 25% of the B. burgdorferi-positive nymphs from Suffolk County carried B. microti.

A tick carrying several pathogens does not necessarily transmit every organism during a bite. Nevertheless, these findings demonstrate that multiple tick-borne pathogens can circulate in the same geographic area—and sometimes within the same tick.

A broader test for tick-borne pathogens

Multiplex real-time PCR assays have traditionally focused on B. burgdorferi, B. microti and A. phagocytophilum. According to the authors, these assays have not always included B. miyamotoi or Powassan virus.

To broaden tick surveillance, Tokarz and colleagues developed a multiplex one-step real-time reverse transcription-PCR assay capable of detecting five agents in a single reaction:

• Anaplasma phagocytophilum
• Babesia microti
• Borrelia burgdorferi
• Borrelia miyamotoi
• Powassan virus

This type of surveillance can provide a more complete picture of the pathogens circulating in blacklegged ticks.

Why Babesia coinfection matters

In a separate study, Curcio and colleagues found that 29% of serum samples from individuals who tested positive for Lyme disease also had antibodies to B. microti. However, the investigators could not determine whether the infections occurred at the same time.

The distinction remains clinically important. Lyme disease is caused by bacteria, while babesiosis is caused by a parasite that infects red blood cells. Standard Lyme disease regimens such as doxycycline, amoxicillin or cefuroxime do not treat babesiosis. Babesiosis requires different medications, although some drugs, such as azithromycin, may be used as part of treatment for either infection.

For more information about overlapping tick-borne infections, see Lyme disease coinfections.

Frequently Asked Questions

What I see in my New York practice

I practice medicine in New York, and many of my patients live in areas where several tick-borne pathogens circulate. In my practice, I have treated patients with Lyme disease who also had evidence of another tick-borne infection, including babesiosis. This clinical experience does not establish how frequently coinfections occur, but it reinforces the importance of considering more than Lyme disease when symptoms and exposure history raise that possibility.

What pathogens were found in Long Island ticks?

Researchers detected Borrelia burgdorferi, Babesia microti, Anaplasma phagocytophilum, Borrelia miyamotoi and Powassan virus in ticks collected in Suffolk County.

How frequently was Lyme disease bacteria found in the ticks?

In this 2015–2016 study, Borrelia burgdorferi was detected in 21% of nymphal ticks and 67% of adult ticks collected at the Suffolk County sites.

Can one tick carry Lyme disease and Babesia?

Yes. Some ticks in the study carried both B. burgdorferi and B. microti. A smaller number carried three pathogens. Detection in a tick does not establish that every organism will be transmitted during a bite.

Do these percentages apply to every tick on Long Island?

No. The percentages apply to ticks collected at five Suffolk County sites during 2015 and 2016. Pathogen prevalence can vary by location, year, tick species and life stage.

Do standard Lyme disease antibiotics treat babesiosis?

No. Common Lyme disease regimens such as doxycycline, amoxicillin or cefuroxime do not treat Babesia microti. Babesiosis requires a different treatment approach.

Clinical Takeaway

This surveillance study found that blacklegged ticks from Long Island carried more than Lyme disease bacteria. Researchers also detected the agents associated with babesiosis, anaplasmosis, Borrelia miyamotoi disease and Powassan virus infection.

Tick surveillance cannot diagnose an infection in an individual patient. However, knowing which pathogens circulate locally may help clinicians consider illnesses beyond Lyme disease when evaluating symptoms following a tick bite.

A tick bite on Long Island may involve exposure to more than one tick-borne pathogen.

Related Articles

Lyme disease symptoms guide
Understanding Lyme disease test accuracy
Why Lyme disease testing and diagnosis remain challenging

References

1. Tokarz R, Tagliafierro T, Cucura DM, Rochlin I, Sameroff S, Lipkin WI. Detection of Anaplasma phagocytophilum, Babesia microti, Borrelia burgdorferi, Borrelia miyamotoi, and Powassan virus in ticks by a multiplex real-time reverse transcription-PCR assay. mSphere. 2017;2(2):e00151-17.
2. Curcio SR, Tria LP, Gucwa AL. Seroprevalence of Babesia microti in individuals with Lyme disease. Vector Borne Zoonotic Dis. 2016;16(12):737–743.

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Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention