Having recently talked about pigs from Jersey and trichinosis, I decided to see what other stories Berton Roueche had that might be of interest. Looking at the table of contents in his compendium called “The Medical Detectives” (1980), my eye was caught by “The Dead Mosquitoes.” Why did “dead mosquitoes” catch my eye? Therein lies a tale.
In August, 1957, having finished the course for the Epidemic Intelligence Service at the CDC in Atlanta, I headed down the road to Savannah and the Technical Development Laboratories, a branch of the CDC, on Oatland Island. (The drive, without air conditioning in those days, when the temp and humidity both hover around 90 is another story.)
TDL, as the lab was called, was set on a marshy island that bred mosquitoes in impressive battalions that found my blood especially delicious and inviting. I therefore found it ironic that inside the lab mosquitoes of several species were being raised by the millions. Why? To study their habits. Such as, how far do they range. Radioactively tagged mosquitoes of different species were released from a central spot and collection traps were spaced at a variety of distances. Turns out some species do not fly more than several feet high and have small ranges while others fly much higher and get caught by wind currents and travel much farther. (Thought you would like to know that.)
Mosquito larvae are so sensitive to insecticides that they were used for bioassays. Except when they weren’t. Also indigenous to the lab were great hordes of American cockroaches. (American cockroaches are up to 2 inches long vs the puny German variety at 1/2 inch). TDL was in a 240 foot long building. Someone at one end of the building decided to attack the roaches with a pyrethrum spray. The spray traveled 200 feet down the hall and wiped out the mosquito larvae in the bioassay lab. After that all insecticides were strictly verboten in the building which must have made the cockroaches deliriously delighted.
Anyway back to the Medical Detectives. It’s a complex story of poisoning by an organophophorus insecticide that was accidentally spilled on some blue jeans that were subsequently sold at discount in Fresno, CA. A pair of these were worn by a boy who then rapidly became violently ill. Another boy wore another pair of the blue jeans with the same result. (He was diagnosed by a classmate of mine, Merritt Warren, MD, who had heard about the first case.) Pinpoint pupils, low cholinesterase levels in blood and rapid response to atropine cemented the diagnosis. But which insecticide? While waiting for a chemical analysis in a research lab, the pants were left overnight in a room with some mosquito-laden cages. In the morning the mosquitoes were all stone cold dead, killed by insecticide vapors.
The insecticide was determined to be Phosdrin and it was later shown to have come from a leaking container being transported on the same truck as the package of blue jeans. One lesson to be drawn from this episode is that if the jeans had been laundered before being worn (they were not), the Phosdrin would have been washed out.