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

2016 USCaseMapLDALyme Literacy: From the Desk of the LDA President

The Lyme Disease Association (LDA) reports that the total number of CDC reported 2016 Lyme cases are now available. Never saw them? Not surprising. In the past, the CDC consistently reported Lyme numbers on a weekly basis, as they do with the other reportable diseases in its MMWR Report, which is published weekly. The last weekly case numbers reported, however, were reported one year ago for 2016.

The CDC annual year end summary of reported Lyme case numbers in MMWR— confirmed, probable, and total–were consistently reported in the past about each 3rd week of August for the preceding calendar year. The past two years, that system has changed. In fact, the 2016 numbers came out in November 2017, and they are now very difficult to locate. Thinking I had missed them, LDA wrote and asked CDC at the end of October when/where they were to be published, as the CDC website message about new reporting was unclear about that issue. CDC sent LDA two links when they came out in November.

In the summer, the LDA had asked CDC informally in a phone call why the weekly numbers were missing. CDC indicated it no longer publishes the weekly numbers due to states saying it was too confusing, and they did not want them published, and The Council of State & Territorial Epidemiologists (CSTE) really had control over what is published in MMWR. None of that made sense to me at the time, and it still does not make sense, and no other diseases were affected by this change in practice.

Some questions about the new reported Lyme data include why is the state of Hawaii no longer listed as N, not reportable, as it has been in the past, but only as 0 cases? Big difference between the state not reporting a disease and the CDC indicating there were 0 cases, although there could be 0 cases. Why are New York City numbers broken out from New York State numbers in one area and combined in another? Why has the State of New York never had a note on the CDC report indicating that a huge % of its counties are not even included in CDC reported numbers, a question I have posed to CDC in the past. The LDA on its NY case map indicates “In 2015, 25 NY Counties used a sampling method to determine Lyme disease case numbers. The Council of State & Territorial Epidemiologists (CSTE), charged with surveillance, does not allow CDC to include those estimated numbers to be reported by CDC in the national counts. Thus, NY State had 8,272 Lyme cases including those 25 county numbers by State count, but CDC was only able to report nationally 4,314 Lyme cases for the State of New York.” CDC could use a short note to indicate that only xx counties are represented in its reported case numbers for New York. This omission of reporting at least 25 NY counties in a high incidence state affects the entire total case numbers for the US, plus it can influence policy in New York if those policy makers do not understand the system.

The CDC has a totally new system (new MMWR mechanism) in place for the final numbers, called CDC Wonder. That name seems appropriate as this whole issue leaves me wondering why we even have a Lyme surveillance system that is highly inaccurate, beginning with the surveillance criteria, which CDC disclaims responsibility for—CSTE is responsible. The CDC Lyme surveillance system has already had a huge impact on patients’ access to care, another issue for another discussion. Why did CDC change the reporting system to one that is user unfriendly, did not fix some of the issues the old one had which carried over, and perhaps created some new ones.

2016 Final CDC Numbers The 3 states with the highest Lyme case numbers are the same as in 2015, from the Mid-Atlantic region: Pennsylvania, New Jersey and New York, the latter clinging to 3rd place despite at least 25 of its counties not included in the reporting. Also note, Massachusetts, often in the top 5 states in the US in Lyme cases, is not in the top 15. The CDC told the LDA that MA has taken a new approach to surveillance and we would need to talk to MA for details.

The LDA has ranked the top 15 states based on the 2016 CDC Lyme case number summary. The chart below has the top 15 states ranked in order of highest to lowest case numbers, followed by the CDC reported Lyme case number, and then the number adjusted x10 for underreporting.

Links CDC gave to LDA: https://www.cdc.gov/lyme/stats/index.html or you can access them through the new MMWR mechanism (go to the to table 2i at the following link) https://wonder.cdc.gov/nndss/nndss_annual_tables_menu.asp


 

Lyme Total Cases 2016 US 36,429——————————————————364,290

2016 USCaseMap

 

 

 

 

 

 

RANK/ STATE/ CDC REPORTED # ADJUSTED FOR UNDERREPORTING

1. Pennsylvania 11,443——————————————–114,430

2. New Jersey 4,350————————————————- 43,500

3. New York 3,882 *————————————————– 38,820

4. Wisconsin 2,295 —————————————————-22,950

5. Minnesota 2,126—————————————————–21,260

6. Maryland 1,866—————————————————— 18,660

7. Connecticut 1,748—————————————————-17,480

8. Maine 1,487———————————————————– 14,870

9. Virginia 1,350———————————————————-13,500

10. Rhode Island 903—————————————————- 9,030

11. New Hampshire 891————————————————- 8,910

12. Vermont 761———————————————————– 7,610

13. Delaware 506———————————————————- 5,060

14. West Virginia 368—————————————————–3,680

15. N. Carolina 272——————————————————–2,720

LDA NOTE “In 2015, 25 NY Counties used a sampling method to determine Lyme disease case numbers. The Council of State & Territorial Epidemiologists (CSTE), charged with surveillance, does not allow CDC to include those estimated numbers to be reported by CDC in the national counts. Thus, NY State had 8,272 Lyme cases including those 25 county numbers by State count, but CDC was only able to report nationally 4,314 Lyme cases for the State of New York.”

In 2016, NYS reported a total of 7,543 cases, of which CDC was able to report 3,882. Twenty-seven (27) counties were unreported due to the sampling method being used.

LDA Chart of all states in alphabetical order for 2016 final reported case numbers

State 2016 Total 2016
Confirmed
2016
Probable
2016
Incidence
Alabama 38 17 21 0.3
Alaska 15 6 9 0.8
Arizona 13 8 5 0.1
Arkansas 2 0 2 0.0
California 134 90 44 0.2
Colorado 0 0 0 0.0
Connecticut 1748 1238 510 34.6
Delaware 506 391 115 41.1
DC 103 66 37 9.7
Florida 216 132 84 0.6
Georgia 4 4 0 0.0
Hawaii 0 0 0 0.0
Idaho 17 9 8 0.5
Illinois 237 233 4 1.8
Indiana 152 127 25 1.9
Iowa 232 76 156 2.4
Kansas 39 16 23 0.6
Kentucky 33 16 17 0.4
Louisiana 7 4 3 0.1
Maine 1487 1151 336 86.4
Maryland 1866 1274 592 21.2
Massachusetts 198 146 52 2.1
Michigan 221 159 62 1.6
Minnesota 2126 1304 822 23.6
Mississippi 1 1 0 0.0
Missouri 10 1 9 0.0
Montana 17 12 5 1.2
Nebraska 14 10 4 0.5
Nevada 15 4 11 0.1
New Hampshire 891 691 200 51.8
New Jersey 4350 3332 1018 37.3
New Mexico 1 0 1 0.0
New York 3882 2623 1259 13.3
North Carolina 272 32 240 0.3
North Dakota 32 9 23 1.2
Ohio 160 122 38 1.1
Oklahoma 0 0 0 0.0
Oregon 61 13 48 0.3
Pennsylvania 11,443 8988 2455 70.3
Rhode Island 903 535 368 50.6
South Carolina 51 25 26 0.5
South Dakota 11 8 3 0.9
Tennessee 25 7 18 0.1
Texas 71 31 40 0.1
Utah 19 12 7 0.4
Vermont 761 488 273 78.1
Virginia 1350 976 374 11.6
Washington 31 14 17 0.2
West Virginia 368 297 71 16.2
Wisconsin 2295 1504 791 26.0
Wyoming 1 1 0 0.2
U.S. TOTAL 36,429 26,203 10,226 8.1