I am writing to alert readers to a recent development in our understanding of tick-borne illnesses. The good news is that as we enter August, the number of nymph deer ticks, and with them the threat of Lyme disease, is decreasing. However, larval deer ticks are now hatching and will be present in increasing numbers during August and part of September.

Recent research has confirmed that another tick-borne illness, Miyamotoi disease, is present in some larval deer ticks, apparently transferred directly to the larvae from the female. Miyamotoi disease is a close relative of Lyme disease; they are both caused by pathogens in the genus Borrelia. Symptoms of Miyamotoi disease include fever, severe headache, chills, fatigue and achy joints. Fortunately, doxycycline, the standard treatment for Lyme disease, also appears to be effective in treating Miyamotoi disease.

Larval deer ticks are even smaller than the nymphs — roughly the size of the period at the end of this sentence — and extremely difficult to find once they are on your body. Thus it is imperative that people continue to take precautions against ticks, even in August, which we once considered to be a relatively low risk time for deer tick-transmitted illnesses.

Keeping the larvae off is the best defense, so I urge you to continue practicing safe gardening and safe hiking: tuck your pants into your socks, wear permethrin-treated clothing, use insect repellent and of course do daily tick checks. Those of you who have spoken with me know that I am a big fan of Permethrin-treated socks. Since both the deer tick nymphs and larvae are found close to the ground, they have to crawl over your feet and ankles before they can climb up your legs in search of a warm, moist spot to attach. Thus treated socks are very effective at keeping deer tick nymphs and larvae off. You can buy the Permethrin-treated socks online, at Basics clothing store on Circuit avenue in Oak Bluffs and at Brickman’s in Vineyard Haven.

For more information on ticks, tick borne illnesses and how to prevent them, please refer to the MV Boards of Health website at mvboh.org.

Richard Johnson
Oak Bluffs

The writer is a biologist with the Martha’s Vineyard Tick-Borne Illness Prevention Program.