b. Selection of humans for control sampling is somewhat more complicated than selection of environmental control samples. This is because ethnic diets, racial differences, physiological makeup, and actual living conditions of persons who are outwardly similar may introduce potentially large deviations. Each of these factors must be accurately considered before selecting subjects as controls.

c. Consideration of ethnic diets is important because of unique foods or methods of food preparation that may exist. As an example, individuals in settled areas may purchase beer that has been carefully filtered and sterilized, while individuals in a nearby unsettled area may ferment their own beer by burying home crafted jugs in the ground and extracting the product little by little over several months.

d. Racial differences can account for differences in mortality and morbidity rates in specific populations. One example of this could be the high rate of hemophilia in a population versus the rarity of the disease in another.

e. Physiological makeup is critical because of the differences in hormone balance and tissue composition in males, females, adults, and juveniles. For this reason, medical control specimens should be drawn from individuals of the same gender and approximate age as specimens from exposed personnel, if possible.

f. Differences in the actual living conditions of people also require a close look. The point here is that conditions in remote, semicivilized camps are seldom the same as those in a well-established camp that has access to modern amenities.

g. The bottom line in selecting subjects for medical control sampling is that they be as similar in all aspects as possible.

B-13. Collection of Medical Specimens

a. Trained medical technicians or physicians should collect medical specimens (human or animal); however, Special Forces NBC Reconnaissance team personnel are trained to do this procedure. Remember, the collector must have express permission (authority) to collect medical specimens from the dead, because of religious beliefs in many cultures. To obtain such specimens without permission may result in unnecessary mission complications. Ensure all personnel handling or collecting medical specimens have received proper immunizations for their own protection. They must be inoculated IAW The Surgeon General's guidance.

b. Medical specimens collected during an investigation include blood, urine, sputum, nasal swabs, and tissue specimens from living victims and blood and urine specimens from unexposed persons (background control specimens).