(2) What droplets carry. Droplets easily carry a multitude of disease agents
from the respiratory tract of the infected person.
Droplet or direct contact transmission is effected when the
susceptible person comes in close association or direct contact with the infected
person, his exhalations, or with personal articles, clothing, bedding, or similar fomites
moistened by respiratory discharges from the infected person.
Members of a family or members of a military unit housed in the
same tent or bay are easily subject to such contact. These contacts are sometimes
called familial contacts.
b. Droplet Nuclei. Droplet nuclei are the residue of dried-out respiratory
discharge droplets. Approximately 1 to 5 microns in size (although some may be
smaller), they consist of infectious agents plus organic matter remaining after the
saliva and moisture originally in the droplet have evaporated.
(1) Travels of droplet nuclei. These nuclei do not fall rapidly but remain in
the air for long periods of time and travel with the air currents. Those that settle out on
floors, clothing, bedding, or other fomites can be resuspended in the air as dust on any
movement such as shaking, dusting, or sweeping.
(2) Transmission of droplet nuclei. When disease agents in the droplet
nuclei are drawn into the respiratory tract of a susceptible, there is disease agent
transmission without direct contact with the disease source. Respiratory disease
transmission of the type mentioned in paragraph 3-1b includes droplet nuclei
transmission, in that the disease agents may be suspended in the air and inhaled by the
FACTORS IN TRANSMISSION: MILITARY FACTORS
a. Crowding. In the military, the population tends to be crowded.
(1) The situation
As members of a military unit, people are housed, fed, drilled, and
trained as a group.
They march together and go into combat together.
In-group activities---crowding in washrooms, eating in dining halls,
and waiting in line for various activities--opportunities are increased for direct contact
between military personnel.
(2) The result. The transmission of respiratory disease agents is aided by
these conditions of crowding and increased direct or indirect contact.