The purpose of the Flight Crew Health Stabilization Program was, therefore, to minimize the possibility of adverse alterations in the health of flight crewmen during the preflight, in-flight, and postflight periods.
1) Establishing a primary work area for the crewmen during isolation periods
2) Establishing isolated crew housing at both the Kennedy and Johnson Space Centers (KSC and JSC) with methods to prevent crew exposure to infectious disease agents
3) Establishing a medical program for those persons who were required to work with the crewmen during the isolation periods, and
4) Establishing a Medical Surveillance Office as a coordination center for the operational aspects of the program.
Personnel who would come into direct contact (within 2 meters) of the crew were known as class A primary contacts; these persons were required to wear surgical masks when in the presence of the crew. Persons who worked in primary work areas, but were not in direct contact with crewmembers were called class B primary contacts.
For each primary work area identified, the area was inspected and procedures were established to minimize the possibility of crew exposure to pathogenic microorganisms. Positive air pressures and 80 percent ASHRAM (American Society of Heating, Refrigeration, and Air-Conditioning Engineers) air filters were used in the principal training area. A security guard and a nurse were stationed at the door of the primary work areas on the days that crewmen would be in the area. Only properly badged primary contacts were allowed to enter the area on these days.
Crew housing at JSC consisted of four mobile homes. Two were placed inside a large building; a third mobile home adjacent to the building served as the food service center. All food and drink consumed by the crew during the isolation period was specially prepared Skylab food (quality control had been designed into the food program, so no additional controls were needed). A fourth mobile home was available for isolation should any crewman become ill. Housing at KSC was provided in existing crew quarters and high efficiency particulate air (HEPA) filters were used in these living quarters to reduce airborne pathogens. Measures were taken to prevent crew exposure to illness while traveling between primary work areas. Non-primary contacts were kept at least 100 feet away from the crew. Biorespirators were kept near the crew at all times in the event of an emergency.
All primary contacts were given thorough examinations to ascertain their freedom from infectious diseases. Immunizations were given to those persons who were not immune to certain infectious diseases. Based on the results of the medical examinations, these persons were either approved or disapproved as primary contacts. Class A primary contacts (such as food handlers or personnel needing close direct or indirect contact with the crews) underwent further examinations later in the program. All primary contacts were instructed to report any illness or contact to an infectious illness to the Medical Surveillance Office. A primary contact found to have an infectious illness was temporarily withdrawn from the program and the primary work area. Re-admittance to the program occurred only after a medical examination indicated the infection was no longer present.
A report form was completed by the clinical staff for each occurrence of illness and forwarded to the Medical Surveillance Office. The report was coded for the type of illness using predetermined operational definitions of infectious illness. Medical surveillance continued throughout each mission to provide epidemiological support data for any crew illness occurring during the mission.
The list of approved primary contacts changed throughout the Skylab program, as names were added or deleted as required; the total number of primary contacts ranged from 620 to 709 throughout the program. The majority of the primary contacts were located at JSC. During the Skylab preflight phase, a modified Flight Crew Health Stabilization Program was initiated at the Marshall Space Flight Center, where additional training was being conducted. The primary contacts reported both illnesses and contact with sick persons to the Medical Surveillance Office.
The majority of illness reports and reports of contacts with illness originated from JSC. A total of 197 illnesses were reported to the Medical Surveillance Office during the Skylab program; 88 percent were reported from JSC. A total of 73 contacts with illness were reported during Skylab 2 and 4; Skylab 3 contacts with illness were not reported because of an error in the recording of the reports.
The rate of illness reported by the primary contacts declined from Skylab 2 to Skylab 4. During Skylab 2, the rate of illness reporting was 10.7 illnesses per 1000 primary contacts per week. During Skylab 3 the rate declined to 8.4, and during Skylab 4 to 6.7. The drop in illness rate is especially dramatic since the lowest rates occurred during the winter season when most respiratory infections were expected.
Active surveillance of class A primary contacts produced only 23 referrals to the clinic from a total of 3483 examinations. The small number of possible illnesses that were discovered suggests that active surveillance indirectly influenced the primary contacts to report their illnesses voluntarily. In addition, the presence of a nurse at the entrance of the primary work area may have indirectly protected the crew from infectious agents.
The most frequently reported illness by primary contacts was the upper respiratory infection. Syndromes other than the upper respiratory infection were relatively low and equally distributed in number. All of the percentages were below 10 percent with the exception of the reported presence of fever, which reached 14 percent during Skylab 3 and 11 percent during Skylab 4.
Exposure to persons with upper respiratory infections was the most frequently reported contact with illness. Fifty-seven percent were reported for Skylab 2 and 67 percent for Skylab 4. Skylab 3 contacts with illness were not reported due to an error in recording reports. However, the reporting trend appeared to decrease in rate in the same manner as illness reporting. A greater percentage of contacts with upper and lower enteric illness were reported for Skylab 4 than for Skylab 2. None of the Skylab 4 reports involved skin infections, while 18 percent of the Skylab 2 reports involved contact with skin infections. During the Skylab 3 and 4 missions, a minor skin infection, or rash, occurred on two of the crewmen of each mission. It is doubtful that either of the latter could have been prevented by measures taken in the health stabilization program, since each problem appears to have occurred for reasons other than preflight exposure.
The results indicate that the Flight Crew Health Stabilization Program successfully accomplished the goal of reducing the number of illness exposures to flight crewmen.