Category Archives: disease

Tick Talk Time

As we slide in to summer or as some call it “tick time,” it might be important to focus on the tick part. We’ve had a mild winter so at least in Bullfrog Valley we have had ticks active year round. There are five species of ticks found in Arkansas most of which are capable of carrying various pathogens and now the new risk of alpha-Gal. Stay tuned for more on tick induced problems.

Regardless of species all ticks go through four phases: Egg, larva, nymph, and adult. The total life cycle can range from one to three years depending on species and environmental conditions. Adult ticks have eight legs and are classified as arachnids, related to mites and spiders.

A tick, like every other form of life begins as an egg. Ticks hatch in the spring to become six-legged larvae. All stages of all species require blood meals from any of a variety of birds, small and large mammals including you and me, and North America’s only marsupial – the Opossum. For the larval tick, the blood meal is usually obtained from more accessible small mammals like mice. After the blood meal they morph into to the nymph stage. The larva will only eat one meal. This means that this stage of a tick cannot transmit disease, because it must eat first to be exposed.

The nymph of the deer tick more formally known as the black-legged tick, will then overwinter in a dormant stage. In the spring when the air temperature gets about 10 degrees Celsius the nymphs become active. If a deer tick larva fed on an alternate host which was infected, the nymph becomes capable of transmitting any of the several diseases: Lyme disease, Rocky Mountain Spotted Fever, Erlichiosis, and others. The nymph then molts and becomes an adult. Only the female adult will now take a blood meal and be capable of disease transmission. After feeding she mates, lays eggs and dies.

As an aside, you would be advised to not run over those possums on the road as they are a principal tick vacuum plus they are a poor reservoirs for disease. One study found the average possum carried around 200 ticks at any one time and were capable of killing 4000 ticks a week. Even if bitten, possums are unlikely to become infected with disease vectors, so larva or nymph which fed on a possum is unlikely to become a vector itself.

If you are not creeped out already to hear of all the tick born diseases, there is a new concern on the rise, alpha-Gal induced meat allergy spread by the lone star tick. Alpha-Gal is present in the meat of all mammals except primates thus humans. If a lone star tick nymph feeds on a deer or mouse, then the adult feeds on on a human, it can transmit enough alpha-Gal to induce a delayed immune reaction. Later consumption of meat by the inoculated individual can induce a range of symptoms including itching, hives, digestive upset and even life threatening anaphylaxis. In extreme cases even diary products can induce a reaction.

Only the lone star tick most common in the Southeast US causes this problem. It is a growing problem, possibly due to burgeoning populations of deer and/or global warming. The allergy is rather new to science, so it is not known whether the allergy becomes a static life long condition or waxes or wanes over time.