a. General
"Scrub typhus" is an important typhus-like fever encountered in the Southwest Pacific
area and in the Chinese-Burma-India Theater. Formerly regarded
as a curiosity in the United States, it has now assumed military importance
because of its deadliness and prevalence in areas where our forces are now engaged. This
disease is transmitted by the bite of the larval of mites, known popularly
as chiggers, red bugs, or harvest mites. These mites are only about 0.01 inch in
length. While the disease-carrying larval form feeds on rats and bandicoots (a small
marsupial), the adult form feeds on plants and is not, like the larval mite, a
human parasite. The mite infests the high "kunai grass" of New Guinea fig. 1 and
adjacent islands. The infection may be passed through several generations of
mites, thus obviating the need of an animal reservoir over short periods of time.
b. Precautions
Based on present knowledge, the following measures are effective in controlling
the incidence of the disease:
(1) Locations which are to be used as new camp sites should be prepared
as fully as possible before the arrival of a new unit and as far as possible, employing
native labor. All kunai grass should be cut level with the ground, and after drying
for several days (if the weather permits) collected and burned or hauled away. It is
highly desirable to burn over the area with a power oil sprayer (figure 2).
(2) Sleeping on the ground should be avoided, and cots provided wherever
possible. Floors for tents, preferably raised two or three feet off the ground, are
desirable.
(3) Individual control methods apply particularly to personnel in combat
areas or to those working in areas where the disease is known to exist. At the
earliest possible time after exposure, men should be instructed to take a bath with
thorough soaping and scrubbing of the skin with a rough cloth. Antimite
repellents (dimethyl phthalate, dibutyl phthalate) should be employed according to
instructions given in W.D. Technical Bulletin, TB MED 31, dated 11 April 1944.