New test for Lyme dis­ease could sp ot it in 15 min­utes

Scottish Daily Mail - - Good Health - By PAT HA­GAN

When it comes to Lyme dis­ease — the potentiall­y deadly in­fec­tion spread by ticks — the med­i­cal com­mu­nity is in com­plete agree­ment that the sooner treat­ment starts, the bet­ter.

That’s be­cause, with­out prompt ad­min­is­tra­tion of an­tibi­otics, there is a greater chance that the bac­te­ria in­tro­duced by the tick bite will spread around the body and cause per­ma­nent — even fa­tal — dam­age to the heart or brain.

But there’s a prob­lem with that, be­cause the symp­toms typ­i­cally don’t de­velop un­til be­tween two and 30 days af­ter a pa­tient has been bit­ten. They usu­ally start with a bullseye­shaped rash, which sig­nals that the bac­te­ria from the tick are spread­ing around the site of the bite. how­ever, some peo­ple don’t de­velop this rash.

Fur­ther­more, cur­rent blood tests to de­tect the bac­te­ria that cause the con­di­tion can take sev­eral days to process.

But now comes new hope, with a blood test that gives re­sults in just 15 min­utes.

The test, which could be given in a GP’s surgery, could speed up di­ag­no­sis and im­prove pa­tients’ chances of mak­ing a full re­cov­ery — as an­tibi­otics can erad­i­cate the in­fec­tion if given soon enough.

Of­fi­cial fig­ures show that there are around 2,000 to 3,000 cases of Lyme dis­ease in the UK each year — in­clud­ing 190 in Scot­land. how­ever, re­cent re­search, pub­lished in the jour­nal BMJ Open, sug­gested the real fig­ure is closer to 8,000, as GPs, of­ten un­sure whether or not a pa­tient has Lyme dis­ease, are fail­ing to record it in their notes.

Public health ex­perts say that cases have tre­bled since 2011, and there is some spec­u­la­tion that this is due to milder win­ters and dam­per sum­mers — the per­fect breed­ing con­di­tions for ticks.

These tiny, spi­der­like bugs feed off sheep, foxes, deer, hedge­hogs and birds and carry a bac­terium called Bor­re­lia, the cause of Lyme dis­ease. The bac­te­ria then pass through the blood­stream, at­tack­ing the joints and ner­vous system, be­fore spread­ing to the brain or the heart.

With­out an­tibi­otics, in the first few days the bac­te­ria can trig­ger a pow­er­ful at­tack by the im­mune system, which leads to harm­ful in­flam­ma­tion that can dam­age the heart’s rhythm. how quickly this hap­pens varies, but it can oc­cur within a fort­night. For­mer eng­land rugby union star Matt Daw­son, 47, needed spe­cial­ist heart treat­ment af­ter be­ing bit­ten by a tick in a park in Chiswick, West Lon­don, in July 2015.

The bite led to a con­di­tion called Lyme cardi­tis, which made his heart beat an ex­tra 30,000 times a day, putting it un­der added stress. Doc­tors at the Royal Bromp­ton hos­pi­tal in Lon­don used tiny elec­trodes fed into his heart to de­stroy the car­diac tis­sue caus­ing the ex­tra beats.

In a small num­ber of cases, the in­fec­tion leads to ir­re­versible brain dam­age. Vic­tims lose con­trol over their bod­ies and be­come de­pen­dent on 24­hour care.

At present, doc­tors check for Lyme dis­ease with two blood tests, called elisa and Western blot. Both look for an­ti­bod­ies — in­fec­tion­fight­ing cells pumped out by the im­mune system — to the Lyme dis­ease bac­te­ria, but nei­ther is ac­cu­rate enough to give a de­fin­i­tive di­ag­no­sis on its own.

Us­ing two tests in­creases the chances of get­ting the di­ag­no­sis right, but slows down the process, be­cause they can take at least 48 hours to com­plete and re­sults must be an­a­lysed by highly skilled laboratory tech­ni­cians. The new, 15­minute check, be­ing de­vel­oped at Columbia Univer­sity in new York, har­nesses a tech­nol­ogy called mi­croflu­idics, where a tiny mi­crochip is used to an­a­lyse minute quan­ti­ties of blood in a matter of min­utes.

Once a drop of blood has been taken, it is fed into a mo­bile phone­sized de­vice.

As the blood flows through tiny chan­nels in­side the gad­get, the chip is able to de­tect the pres­ence of an­ti­bod­ies that con­firm Lyme dis­ease is present.

This is faster than cur­rent tests be­cause it needs only a frac­tion of the blood presently re­quired for a di­ag­no­sis, so the blood re­acts much more quickly to chem­i­cals de­signed to show if an­ti­bod­ies are present.

The re­sults of a re­cent trial, pub­lished in the Jour­nal Of Clin­i­cal Mi­cro­bi­ol­ogy, on 142 pa­tients who were ei­ther healthy or had Lyme dis­ease, showed that the new, un­named test was at least as ac­cu­rate as the cur­rent two­test method — and sig­nif­i­cantly faster.

Larger tri­als are now be­ing planned and, if they are suc­cess­ful, the high­speed test could be avail­able within the next two to three years.

The test would be given straight af­ter a tick bite, which would mean that peo­ple could start tak­ing an­tibi­otics im­me­di­ately. In some cases, de­lay­ing treat­ment by even a few days can make a big dif­fer­ence to the even­tual out­come.

Dr ed Mo­ran, a con­sul­tant in in­fec­tious dis­eases at South­mead hos­pi­tal in Bris­tol, wel­comes the new test, but warns: ‘It has only been eval­u­ated in 142 pa­tients and needs to be stud­ied in larger groups be­fore it can be in­tro­duced into rou­tine use.’

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