State’s 2018 Lyme rate likely to re­main steady

Connecticut Post (Sunday) - - News - By Ed Stan­nard ed­ward. stan­[email protected] hearst­media ct. com; 203- 680- 9382.

Last year will likely turn out to have been an av­er­age year for Lyme dis­ease in­fec­tions in Con­necti­cut, un­like in Maine, which ex­pe­ri­enced a dra­matic de­crease in 2018, pos­si­bly caused by a drought in that state.

“We have to be very care­ful to use pre­cip­i­ta­tion as a proxy for the num­ber of Lyme dis­ease cases in hu­mans,” said Goudarz Mo­laei, di­rec­tor of the tick- test­ing pro­gram at the Con­necti­cut Agri­cul­tural Ex­per­i­ment Sta­tion in New Haven and a pro­fes­sor at the Yale School of Pub­lic Health.

“I think that based on the trend that we have had … we are go­ing to have [ an] aver- age num­ber of Lyme dis­ease cases, not sub­stan­tially lower,” he said. Fi­nal to­tals won’t be in un­til April, how­ever, Mo­laei said.

Ac­cord­ing to the Port­land Press Her­ald, Maine’s re­ported Lyme dis­ease cases dropped by 29 per­cent in 2018, al­though fi­nal fig­ures were not yet in. Un­like Con­necti­cut, the orig­i­nal epi­cen­ter of Lyme dis­ease, where in­fec­tions have been grad­u­ally drop­ping through the years, the num­ber of cases has been ris­ing in Maine, from 175 in 2003 to 1,852 in 2017, a record, based on data from the Maine Cen­ter for Dis­ease Con­trol and Pre­ven­tion.

In fact, 2018 was only the fourth year since 2003 in which Lyme dis­ease cases in Maine didn’t set a record. There were 1,310 cases last year, lower even than 2016’ s 1,464, the Press Her­ald re­ported.

Con­necti­cut had a hot sum­mer, with an av­er­age tem­per­a­ture of 71.3 de­grees from June to Au­gust, more than 3 de­grees above the norm, and an av­er­age fall, ac­cord­ing to the North­east Re­gional Cli­mate Cen­ter, based at Cor­nell Uni­ver­sity. Bridge­port’s tem­per­a­tures rose above 90 a dozen times by Aug. 31.

But it was also a wet sum­mer and fall, with an av­er­age rain­fall of 14.81 inches, 117 per­cent of nor­mal, from June to Au­gust, and 21 inches, 159 per­cent higher than av­er­age, from Septem­ber to Novem­ber, ac­cord­ing to the cen­ter.

Mo­laei said hot, dry con­di­tions may lead to fewer deer ticks and, thus, fewer cases of Lyme dis­ease, which the tick passes on from deer and white- footed mice to hu­mans. “It de­creases tick ac­tiv­ity be­cause their sur­viv­abil­ity … is af­fected by the drought,” he said.

“We have not ex­pe­ri­enced such drought in re­cent years,” he said. “Last year, 2018 par­tic­u­larly, we had a hot sum­mer but higher pre­cip­i­ta­tion rate,” he said.

But rain­fall isn’t al­ways a good pre­dic­tor of tick ac­tiv­ity, he said. In 2013, “the pre­cip­i­ta­tion was not that high ( but) we had the high­est num­ber of Lyme dis­ease cases, nearly 3,000 cases.”

Ac­cord­ing to the state Depart­ment of Pub­lic Health, Con­necti­cut’s record for Lyme dis­ease in­fec­tion, first dis­cov­ered in 1975 in the town of Lyme, was 4,156 cases in 2009, shortly af­ter the state ex­panded its dat­a­col­lec­tion sys­tem. Since then the num­bers have de­clined to a re­cent low of 1,752 in 2016. In 2017, there were 2,022 cases.

Mo­laei said the cause of the fluc­tu­a­tion in re­ported cases is not easy to de­ter­mine and may be at­trib­uted to “a num­ber of fac­tors, in­clud­ing re­port­ing ir­reg­u­lar­ity.”

One rea­son may be that “be­cause it is an en­demic re­gion, peo­ple in our state have de­vel­oped aware­ness and they are avoid­ing tick bites,” Mo­laei said. Oth­ers who have de­vel­oped Lyme dis­ease mul­ti­ple times may have “stopped pay­ing at­ten­tion to the ill­ness” and take un­used an­tibi­otics or get them from their doc­tor with­out re­port­ing their ill­ness as Lyme.

How­ever, the num­ber of ticks isn’t de­creas­ing.

“The av­er­age sub­mis­sion to our lab has been 3,000” by res­i­dents, health de­part­ments and doc­tors’ of­fices, al­though the num­ber rose to 4,458 in 2017. Ac­cord­ing to the ex­per­i­ment sta­tion, the per­cent­age of deer, or black­legged, ticks that tested pos­i­tive for Lyme dis­ease has ranged from 27 to 32 per­cent be­tween 2013 and 2017.

In 2018, “even though we had slightly less tick sub­mis­sion to our lab­o­ra­tory,” back to 3,000, “none­the­less, the in­fec­tion rate was at 38 per­cent,” Mo­laei said. “This in­crease in in­fec­tion rate for sure will have some in­flu­ence or some im­pact on the num­ber of Lyme dis­ease cases that will be re­ported in 2018.”

Jo­ce­lyn Mullins, the state pub­lic health vet­eri­nar­ian, said “sur­vey data is af­fected by many dif­fer­ent things. There’s ac­tual dis­ease changes and tick changes and how data is re­ported to us.

“I would pre­dict that we’re not go­ing to have a big change from last year, but it’s re­ally too early to say,” since fi­nal num­bers are not in un­til April, she said.

Mo­laei said a rea­son for a po­ten­tial in­crease in Lyme dis­ease in Con­necti­cut “is that the weather pat­tern has changed. We are see­ing shorter win­ters and warmer win­ters that al­lows ticks to sur­vive bet­ter.”

If ticks be­come ac­tive ear­lier, that will mean a larger gen­er­a­tion later in the year.

“We are not hav­ing bru­tally or sub­stan­tially cold win­ters that re­duce the tick pop­u­la­tion,” he said. Warmer weather also cre­ates fa­vor­able con­di­tions for deer and mice hosts, he said.

There are two peaks of tick ac­tiv­ity each year: AprilMay and Oc­to­ber- Novem­ber, Mo­laei said. There is also a peak in June, caused by nymphs, the stage be­tween larva and adult. “Quite of­ten they are over­looked be­cause of their size and peo­ple can­not see them as eas­ily as adult ticks,” he said.

Lyme dis­ease is caused by the bac­terium Bor­re­lia burgdor­feri. While Lyme- in­fected tick bites of­ten can be de­tected by a bull’s- eye rash, that is not al­ways the case. The dis­ease brings flu- like symp­toms, such as mus­cle aches, fa­tigue and fever, but can in­clude joint pain and swelling, menin­gi­tis and fa­cial palsy, ac­cord­ing to the state health depart­ment. It is usu­ally cured with an­tibi­otics.

Be­tween 10 and 20 per­cent of pa­tients re­port post- treat­ment Lyme dis­ease syn­drome, with on­go­ing symp­toms of fa­tigue and joint or mus­cle aches, ac­cord­ing to the depart­ment’s web­site. While its cause is un­known, many ex­perts be­lieve the syn­drome is the re­sult of dam­age to the suf­ferer’s im­mune sys­tem, ac­cord­ing to the health depart­ment.

The Cen­ters for Dis­ease Con­trol and Pre­ven­tion records about 30,000 cases of Lyme dis­ease na­tion­ally each year, most heav­ily in the North­east, but that may be only one- tenth the num­ber of ac­tual cases, ac­cord­ing to the CDC web­site.

“The take- home mes­sage is that Lyme dis­ease and other tick- borne dis­eases are a sig­nif­i­cant pub­lic health prob­lem in the United States and … par­tic­u­larly in New Eng­land and in our state,” Mo­laei said.

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