Tick-borne encephalitis cases remain high, despite vaccination push

The various stages of a tick: from left to right, an adult female, an adult male, a nymph and a larva. © Keystone / Gaetan Bally

Over 250 cases of the tick-borne early summer meningo-encephalitis (ESME) disease have been recorded in Switzerland so far in 2019, the second-highest number since the year 2000.

In its weekly bulletin published MondayExternal link, the Federal Office for Public Health (FOPH) wrote that 251 cases of the disease had been reported up to the end of October. The government urged a nationwide vaccination against the disease at the start of the year.

The figure is second-only to the record 353 of last year. The third-most cases reported in a single year came in 2017, with 250. Overall, since the year 2000, annual cases have fluctuated, with some years seeing less than 100 incidences, but with a steady rise in the past five years.

ESME, which attacks the nervous system and may result in paralysis, permanent sequelaeExternal link or death, according to the World Health Organisation (WHO), is transmitted by tick bites, and most cases are reported in the summer months. In 2019, the peak came in July.

However, the FOPH also noted that general consultations by patients suffering from tick bites, as well as patients showing signs of Lyme disease – another tick-borne disease – were both within the normal range in 2019, at 18,000 and 9,300 respectively.

The WHO says that the risk of contracting ESME is highest when hiking or camping in forested areas up to an altitude of about 1,500 metres.

Advice for avoiding tick-borne diseases are mainly practical precautions such as wearing long trousers and closed footwear when hiking or camping in nature. The WHO also says that “the whole body should be inspected daily and attached ticks removed as soon as possible”.

Ticks have to be properly removed with tweezers. If mouth parts of the tick remain under the skin for longer than around 36-48 hours, there is a risk of becoming ill.