Insects Carry Disease

1917

Our knowledge of the connection of insects with diseases is a very modern acquisition. In his presidential address to the Washington Academy of Sciences, Dr. L. O. Howard noted that standard medical works of a score of years ago made no mention of the subject, but recent literature records 226 different disease germs as known to have been carried by insects to man or animals, 87 organisms as known to be parasitic in insects but not known to be transmitted, and 282 species of insects as discovered causes or carriers of diseases of man or animals.

The transportation by wind of the body-louse, the carrier of typhus fever, is among late discoveries to which many writers have given attention. Tick paralysis is another novel subject, the disease occurring in Australia, Africa and North America, and 13 cases have been reported by a single Oregon physician.

Progressive paralysis of motor but not sensory nerves follows the attachment of the tick. The disease is not infectious, and it has not been decided whether it is due to a specific organism or to nerve shock. Infantile paralysis is believed to be one of the diseases not carried by insects.