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US officials report a record number of tick diseases

US health officials say a record number of tick-borne diseases were reported last year.

The 2017 tally of more than 59,000 cases is a 22 percent increase from the previous year, according to numbers the Centers for Disease Control and Prevention released on Wednesday.

Lyme disease accounted for nearly three-quarters of the illnesses. That’s about 43,000 cases.

Traditionally about 30,000 cases of Lyme disease were reported to the government each year, but experts believed there was underreporting and thought the actual number was more like 300,000.

The Centers for Disease Control and Prevention said a record number of tick-borne diseases – more than 59,000 – were reported in 2017. It’s a 22 percent increase from the number reported the year before

Experts say better reporting may be a reason for recent increases, but scientists have also discovered more diseases transmitted by ticks. 

Researchers also note that disease-spreading ticks have been seen over a wide range of states.

The new figures come six months after another CDC report showed the rate of tick-borne diseases reported in the US had tripled between 2004 and 2016. 

More than 642,000 cases of these illnesses were reported during the 13 years studied in the Vital Signs report from the US Centers for Disease Control and Prevention.

Cases of Lyme disease, Rocky Mountain spotted fever, West Nile and Zika numbered more than 27,000 in 2004, and soared to over 96,000 in 2016, it said, warning that since many cases go unreported, these numbers are likely ‘substantially’ lower than the true amount.

These diseases pose ‘an increasing risk’ and the ‘nation needs to be better prepared to face this public health threat,’ said the report.

‘Zika, West Nile, Lyme, and chikungunya – a growing list of diseases caused by the bite of an infected mosquito, tick, or flea – have confronted the US in recent years, making a lot of people sick,’ said CDC director Robert Redfield.

The most common mosquito-borne viruses are Lyme, West Nile, dengue, and Zika, while the most common disease resulting from the bite of an infected flea is the plague.

Lyle Petersen, director of the CDC division of vector-borne diseases, said increasing temperatures can help such diseases spread, though he declined to say specifically if climate change is the cause.

‘Many of these diseases are sensitive to increasing temperatures,’ he told reporters on a conference call.

‘Increasing temperatures will tend to expand the ranges of these ticks further north as well as increasing the length of tick season.’

Other factors leading to the spread of mosquito-borne diseases like Zika include international travel, the CDC said.

‘Nine new germs — seven of them spread by ticks — have been newly introduced or discovered in the United States since 2004,’ said Redfield.

Commenting on the CDC report, Paul Auwaerter, president of the Infectious Diseases Society of America, called for more research money for diagnostics, vaccines and treatments for Zika, Lyme disease, and other serious vector-borne diseases.

‘Vector-borne diseases such as Lyme disease and Zika virus disease can devastate patients and their families, causing significant suffering,’ he said.

‘We are also investigating how climate change may impact the spread of vector-borne diseases so that we can take appropriate actions to protect public health.’