Now if you've been paying attention you may have found an inconsistency with my logic from the previous paragraph. Earlier I stated that increased precipitation leads to more fleas and thus more flea-borne diseases...but according to this graph, last year during the worst drought in Texas history, murine typhus cases sky rocketed! My hypothesis is that the normal animal hosts of the fleas probably suffered huge population losses forcing fleas to bite pets instead of their normal diet of raccoon, possum, hare, and rodent. Additionally, wildlife is attracted to urban center water sources and if the wildlife are more stressed due to drought, their immune systems may not be fighting off the infection as well leading to higher parasitemias in the blood. While droughts can be good for killing disease vectors, they can also cause them to look for other blood meal sources such as pets and humans. So again, what does this mean? This means that now that we're entering summer after a wet spring...those increased wildlife populations may move into urban centers again looking for water. I would guess we are entering the higher risk months RIGHT NOW.
So what can you do? Here are some tips taken from the Statesman article referenced in the above graph:
■ Keep homes, yards and pets flea-free.
■ Eliminate outdoor pet food that can attract animals with infected ticks or fleas.
■ Avoid places that may be infested with ticks or fleas.
■ Wear long sleeves, slacks, socks and shoes and use insect repellent containing DEET.
Report typhus cases to the health department at 972-5555.
Contact Mary Ann Roser at 445-3619
Personally, I've found fleas to be bad both this year and last year. Also, ticks can transmit another closely related rickettsial species causing sylvatic typhus so avoid ticks too! Ticks spread a lot of nasty and poorly understood parasites.
Stavana Strutz is a doctoral candidate in the Parmesan lab who studies disease ecology and evolution.