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COVID Impacts on Lyme Disease Reporting

In a new study published by the CDC, Effects of COVID-19 Pandemic on Reported Lyme Disease, United States, 2020, authors describe how the impacts of COVID-19 might have influenced Lyme disease case reporting in 2020. Investigators explored 4 data sources to assess how the COVID-19 pandemic may have influenced reporting of Lyme disease cases in 2020. Surveys that were conducted indicate that residents in the United States spent more time in the outdoors in 2020 than in 2019, but that reports of tick bite–related ER visits and Lyme disease laboratory tests were fewer. Authors indicate that although outdoor exposures were higher, case reporting for Lyme disease in 2020 may have been “artificially reduced” due to changes in people’s medical care seeking behavior in response to the COVID-19 pandemic. Additionally, many health departments were limited in resources to investigate Lyme disease case reports in 2020 due to the increased workload created by the COVID-19 pandemic. 

Read the full text article here

Read more LDA articles on COVID here

 




Delayed CDC Lyme Final Lyme Case Numbers for 2019 Finally Released

Deer Tick Questing

Lyme Disease Association (LDA) Announces CDC’s 2019 Final Lyme Disease Reported Case Numbers:  The Centers for Disease Control & Prevention (CDC) has just released the 2019 final Lyme disease reported U.S. case numbers–34,945. CDC reported that cases were ~4% more than in 2018, and the geographic distribution of areas with a high incidence of Lyme appears to be expanding based on data reported to National Notifiable Disease Surveillance System (NNDSS). The number of counties with an incidence of ≥10 confirmed cases per 100,000 persons increased from 324 in 2008 to 432 in 2019. 

Reporting Delay Explained  Final Lyme disease case numbers are usually reported in the fall of the next year (for 2019, should have been reported in 2020). The CDC has responded to LDA inquiries over time that reporting was delayed due to the pandemic and thus to shortages of resources/personnel at many government levels, which was no surprise to anyone following the numbers’ delay.  CDC also had a note on the reporting page that “Due to the coronavirus disease 2019 (COVID-19) pandemic, data from some jurisdictions may be incomplete.” 

Past Estimates of Underreporting  In the past,  CDC has reported that only 10% of cases are actually reported─ that translates into 349,450 actual new Lyme cases in the US in 2019.  However, in 2021, the CDC announced that  “A recently released estimate based on insurance records suggests that each year ~ 476,000 Americans are diagnosed & treated for Lyme disease(1,2). ” Prior Lyme estimates based on claims data had indicated “~300,000 people get Lyme disease  each year.”  It appears clear from the number of patients culled from insurance data as being diagnosed and treated annually for Lyme disease in the U.S. that cases are vastly under-reported. 

  1. Schwartz AM, Kugeler KJ, Nelson CA, et al. Use of Commercial Claims Data for Evaluating Trends in Lyme Disease Diagnoses, United States, 2010-2018Emerg Infect Dis. 2021;27(2).
  2. Kugeler KJ, Schwartz AM, Delorey M, et al. Estimating the frequency of Lyme disease diagnoses —United States, 2010-2018Emerg Infect Dis. 2021;27(2).

LDA NOTE: The State of Hawaii does not require reporting of Lyme disease. The State of New York estimates the Lyme numbers in many counties and those numbers are not permitted to be entered into CDC reported case numbers. Massachusetts changed their reporting system and their numbers on paper have dramatically dropped in the past few years, moving them out of the top 15 states.  To see more states that have changed reporting of Lyme disease over time see  LDA Lyme Cases Map Page

Top 15 States  The LDA has ranked the top 15 states based on the CDC total reported Lyme case numbers for 2019 below. This ranking should not be construed to mean that other states do not have reported Lyme cases. They do have reported cases,  Click here for all states, but often patients cannot get diagnosed and/or treated in states that CDC considers “low incidence” states, because  doctors in low incidence states are often either afraid to diagnose Lyme or do not understand that surveillance criteria are not meant as diagnostic criteria.  Read about Diagnosis by Geography

LDA State Ranking by Reported CDC Lyme Cases

 State RankingReported CasesActual Cases (10x = actual cases)
1Pennsylvania899889980
2New York424342430
3New Jersey361936190
4Wisconsin217821780
5Maine216721670
6New Hampshire171017100
7Minnesota152815280
8Maryland141714170
9Connecticut123312330
10Virginia119911990
11Vermont106410640
12Rhode Island9719710
13West Virginia8858850
14Delaware6416410
15Ohio4674670




County-Level Distribution of Ixodes and Lyme Disease Spirochetes in US

This new summary article by employees of the CDC, presents the first county-level map of the distribution of Lyme disease spirochetes in host seeking Ixodes ticks between 2004-2019 in the contiguous United States. Data compiled for this summary was from literature searches; publicly available tick-borne pathogen surveillance databases (ArboNet Tick module); and internal CDC pathogen testing databases to map the county-level distribution of Lyme disease spirochetes reported in host-seeking Ixodes pacificus and Ixodes scapularis across the contiguous US. 

Investigators narrowed their search to include only host-seeking ticks, because ticks in this state are most likely to bite humans, and because host-seeking ticks provide enhanced spatial precision compared to ticks collected from mobile hosts. Data used was restricted to studies that collected ticks by flagging, dragging or CO2 Traps. Ticks that were collected from mobile hosts such as wildlife, pets, and livestock were excluded because county of exposure could not be confirmed. County level pathogen infection data was included from these sources when provided. 

Authors report B. burgdorferi s.s. infected I. scapularis from 384 counties in 26 eastern states of the Northeastern, North Central and Mid-Atlantic regions. B. burgdorferi s.s. infected I. pacificus were reported from 20 counties 2 western states, primarily from northern and north-coastal California. Borrelia mayonii was reported in I. scapularis in 10 counties in Minnesota and Wisconsin, where records of B. burgdorferi s.s. were also reported. 

Important caveats that the authors state in regard to this mapping effort:

  • The reported distribution of  B. burgdorferi s.s and B. mayonii in host seeking ticks is almost certainly an underestimate of the actual distribution of these disease agents.”
  •  “Though support for and participation in tick and tick-borne pathogen surveillance has increased in the US in recent years, collection and pathogen testing efforts have been limited with most efforts focused on US regions where Lyme disease cases are most commonly reported.” 
  • “In some instances, lack of records could represent lack of sampling effort or low prevalence of pathogens within sampled tick populations.” 

The authors were confident in the distribution of tick presence records, but for counties where Lyme disease spirochete has not been documented in ticks, they were unable to determine whether this represented a true absence of pathogen or a merely a failure to detect the pathogen. Lack of data is especially evident in the Rocky Mountain region, Western plains and Southwestern region in regard to both tick presence and pathogen detection; and in the Southeastern region and Western states for pathogen detection. Continued surveillance and reporting will likely result in additional counties to be added to the map, and reporting densities of infected host-seeking ticks for many jurisdictions may be possible in the future.

In comparison to a broad distribution of vector ticks, the resulting map shows a more limited distribution of Lyme disease spirochetes.

Reported distribution of Lyme disease spirochetes, B. burgdorferi s.s. and B. mayonii in host-seeking I. scapularis (eastern United States) or I. pacificus (western United States), relative to the previously reported distribution of these vector species. Ticks were considered present in a county if at least one tick was recorded (Eisen et al. [2016] or CDC [2020]). Counties where ticks have been reported without records of infection may be reported as such either if ticks were not tested or if the pathogen was not detected in tested samples.
LDA NOTE: Contained in the journal article: This work is written by (a) US Government employee(s) and is in the public domain in the US.

 

Read full article here
Amy C Fleshman, Christine B Graham, Sarah E Maes, Erik Foster, Rebecca J Eisen, Reported County-Level Distribution of Lyme Disease Spirochetes, Borrelia burgdorferi sensu stricto and Borrelia mayonii (Spirochaetales: Spirochaetaceae), in Host-Seeking Ixodes scapularis and Ixodes pacificus Ticks (Acari:Ixodidae) in the Contiguous United States, Journal of Medical Entomology, 2021;tjaa283, https://doi.org/10.1093/jme/tjaa283

Read Entomology Today Press Release here

 

 




New Estimates of People Diagnosed/Treated for Lyme: 476,000 Annually

Fig. 1: Prepared by LDA, Jan. 2021

476,000 People Diagnosed & Treated for Lyme Annually: The Centers for Disease Control and Prevention (CDC) published in the February edition of its Emerging Infectious Diseases two new papers pertaining to Lyme disease.

CDC states on its How Many People Get Lyme Disease? webpage (reviewed Jan 13, 2021), “A recently released estimate based on insurance records suggests that each year ~ 476,000 Americans are diagnosed & treated for Lyme disease.1,2  This number is likely an over-estimate of actual infections because patients are sometimes treated presumptively in medical practice. Regardless, this number indicates a large burden on the health care system and the need for more effective prevention measures.”

The researchers found ~ 476,000 people are diagnosed with and treated for Lyme disease each year in the U.S.  The prior Lyme estimates by CDC from 2005 to 2010 indicated “~300,000 people get Lyme disease  each year.”  Both estimates are based in part on insurance claim data.  Based on CDC’s estimates the LDA calculated a 59% increase in the estimated number of people diagnosed & treated for Lyme disease annually. (See Fig. 1)  

The CDC clearly states on its website, “It’s important to emphasize that 476,000 is the estimated number of people treated for Lyme disease and likely includes some patients who were not actually infected.”  Read the two papers below for their discussion on this new estimated number. 

The two 2021 research papers on which the new 476,000 estimate is based are:

  1. Schwartz AM, Kugeler KJ, Nelson CA, et al. Use of Commercial Claims Data for Evaluating Trends in Lyme Disease Diagnoses, United States, 2010-2018. Emerg Infect Dis. 2021;27(2).
  2. Kugeler KJ, Schwartz AM, Delorey M, et al. Estimating the frequency of Lyme disease diagnoses —United States, 2010-2018. Emerg Infect Dis. 2021;27(2).

The two research papers on which the prior 300,000 estimate was based are:


 

Fig. 2: New CDC Data Dashboard

CDC Creates New Tick-Bite Data Dashboard:  The CDC posted a new page, syndromic surveillance of emergency department visits for tick bites, to its website, last reviewed on January 4, 2021, showing tick bites by time, age/sex and region. (See Fig. 2)  

According to a CDC official, “Unlike some tickborne disease surveillance data, the data shown in the charts [on the above webpage] are updated weekly, rather than annually. These data can indicate when people in different parts of the country might be at highest risk for tick bites. We think this is the closest we have come to providing real-time risk data for tickborne diseases ….”  CDC also indicated they are working with data providers to make this type of data state-specific verse region-specific.

Syndromic surveillance is a term unfamiliar to the general public. In its September 2004 MMWR CDC describes syndromic surveillance, “Although syndromic surveillance was developed for early detection of a large-scale release of a biologic agent, current surveillance goals reach beyond terrorism preparedness. Medical-provider reporting remains critical for identifying unusual disease clusters or sentinel cases. Nevertheless, syndromic surveillance might help determine the size, spread, and tempo of an outbreak after it is detected (5), or provide reassurance that a large-scale outbreak is not occurring, particularly in times of enhanced surveillance (e.g., during a high-profile event). Finally, syndromic surveillance is beginning to be used to monitor disease trends, which is increasingly possible as longitudinal data are obtained and syndrome definitions refined. The fundamental objective of syndromic surveillance is to identify illness clusters early, before diagnoses are confirmed and reported to public health agencies, and to mobilize a rapid response, thereby reducing morbidity and mortality. Epidemic curves for persons with earliest symptom onset and those with severe illness can be depicted graphically …

Stakeholders need to understand the advantages and limitations of syndromic surveillance systems. Syndromic surveillance systems might enhance collaboration among public health agencies, health-care providers, information-system professionals, academic investigators, and industry. However, syndromic surveillance does not replace traditional public health surveillance, nor does it substitute for direct physician reporting of unusual or suspect cases of public health importance.”


 

Lyme Disease Association, Inc. (LDA) Response:  It is important that data surrounding Lyme and other tick-borne diseases be continuously collected and distributed to safeguard the health of the public.  Since the above material has just been released by the CDC, the LDA will review the material and comment further if necessary in the near future.


 

Click on Image to Watch CDC Video Tweet: The burden of Lyme disease in the U.S.

 

 

 

 

 

 

 


Other Links:

2016 Final Lyme Case Numbers: Wondering If Surveillance Can Get More Confusing?

LDA Maps for Lyme Cases

CDC Surveillance for Lyme Disease – US




Reported Lyme Disease Cases in the U.S. by County

The Lyme Disease Association Inc. is providing you with information from the Centers for Disease Control & Prevention (CDC) on the U.S reported Lyme disease case numbers by county in each state for the years 2000-2018.

  • 2000-2007 data reflect surveillance case definition at that time and reflect confirmed cases.
  • 2008-present data reflect that surveillance case definition which allows for reporting of confirmed & probable cases.
  • County codes of 999 represent unknown county of residence in each state.
  • Annual cases are generally published in the fall of the following year.
  • CDC has indicated Lyme Disease is under-reported by a factor of 10.

Click here for Excel Document – U.S. Lyme Disease Case Counts by County 2000- 2018




2018 US Reported Lyme Disease Cases Featuring Top 15 States

Lyme Disease Association Announces 2018 Final Lyme Cases Reported by CDC.

The Centers for Disease Control & Prevention (CDC) has just released the 2018 final Lyme disease reported cases numbers. Total US reported cases was 33,666 ─ CDC has reported that only 10% of cases are actually reported─ that translates into 336,660 actual new Lyme cases in the US in 2018.

Lyme Disease Association, Inc. (LDA) has ranked the top 15 states based on those CDC reported Lyme case numbers below.

 

 

 

 

*

 

 

 

 

 

 

 

 

 

 

 

*In recent years, an increasing number of NY Counties have used estimating to determine Lyme case numbers. The Council of State & Territorial Epidemiologists, in charge of surveillance, doesn’t permit estimation to be reported by CDC in the national counts. In 2018, NY State reported it had 7,320 Lyme cases including those 30 estimated county numbers. CDC reported 3,638 Lyme cases for NY State, which excluded the 30 counties’ estimated numbers.
https://www.health.ny.gov/statistics/diseases/communicable/2018/docs/cases.pdf

Note: In 2016, MA changed reporting requirements and very few MA cases are now able to be included in the CDC reported Lyme cases (in 2018 CDC reported 16 cases in Massachusetts)

Click here for Ranking of all US states/DC

Click here for pie chart of 2018 Reported Lyme Cases – Top 15 States

Click here to go to LDA’s Interactive Lyme Disease Case Maps




2018 Reported Lyme Cases – Top 15 States

The LDA has used CDC total reported Lyme case numbers (includes “confirmed” and “probable”) to create a pie graph of the 15 states in the US with the highest case numbers for 2018. 

Click here for pdf version of pie graph




LDA Analysis of Lyme Disease Data by Age from 2001-2017

Click here for pdf of pie graph




Now Available – Lyme Case Map: Total Lyme Cases from 1990-2017

Click US map to go to all LDA’s Interactive Lyme Disease Case Maps

2017 US Lyme Case Map




2017 Reported Lyme Cases – Top 15 States

The LDA has used CDC total reported Lyme case numbers (includes “confirmed” and “probable”) to create a pie graph of the 15 states in the US with the highest case numbers for 2017. 

2017 case numbers