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Unexplained Illness Among Persian Gulf War Veterans in an Air National Guard Unit: Preliminary Report -- August 1990-March 1995

In November 1994, the U.S. Department of Veterans' Affairs (VA), the Department of Defense (DoD), and the Pennsylvania Department of Health requested that CDC investigate a report of unexplained illnesses among members of an Air National Guard (ANG) unit in south-central Pennsylvania (Unit A) who were veterans of the Persian Gulf War (PGW) (August 1990-June 1991). These veterans had been evaluated at a local VA medical center for symptoms that included recurrent rash, diarrhea, and fatigue. A three-stage investigation was planned to 1) verify and characterize signs and symptoms in PGW veterans attending the VA medical center; 2) determine whether the prevalence of symptoms was higher among members of Unit A than among members of other units deployed to the PGW and, if so, whether the increased prevalence was associated with PGW deployment; and 3) characterize the illness and identify associated risk factors. This report presents preliminary findings from stages 1 and 2 (stage 3 is in progress). Stage 1

In December 1994, a team of CDC medical epidemiologists visited the VA medical center, conducted standardized interviews and performed standardized physical examinations of 59 PGW veterans reported to be symptomatic, and reviewed medical records. Of the 59 veterans, 26 were selected from the health registry that had been established for PGW veterans who reported symptoms believed to be related to service in the Persian Gulf, and 14 were selected as typical cases by the physician who reported the illnesses to VA; the remaining 19 were listed on the registry but had not yet been evaluated at the VA medical center to determine whether they were eligible to be on the registry. In addition, 40 primary-care physicians and 16 regional hospitals in south-central Pennsylvania were surveyed; the survey did not identify additional PGW veterans with any health complaints.

The median age of the 59 persons was 39 years (range: 23-59 years), and 53 (90%) were male. All were enlisted personnel: 30 (51%) had been assigned to Unit A during the PGW and the remainder were in other Air Force units and military branches; 48 (81%) had been in the military for greater than or equal to 10 years; 16 (27%) had served greater than or equal to 5 years on active duty; and 19 (32%) had been deployed for greater than or equal to 2 tours to the PGW theater. At the time of the survey, 89% were employed in addition to their ANG work.

The most frequently reported symptoms considered "moderate" or "severe" were fatigue (61%), joint pain (51%), nasal or sinus congestion (51%), diarrhea (44%), joint stiffness (44%), unrefreshing sleep (42%), excessive gas (i.e., flatulence, bloating, and gastrointestinal distress) (41%), "difficulty remembering" (41%), muscle pains (41%), headaches (39%), abdominal pain (36%), general weakness (34%), and impaired concentration (34%). The two symptoms identified as "most bothersome" were fatigue (27%) and diarrhea (14%). Patients reported that their symptoms began during or 2-3 months after departure from the Persian Gulf, and all reported that several symptoms persisted greater than or equal to 6 months. No consistent abnormalities were identified among the participants on standardized physical examination or by review of medical records and accompanying laboratory tests performed at the VA medical center. After the war, one participant had viscerotropic leishmaniasis diagnosed and treated. Stage 2

From January through March 1995, members of Unit A and three comparison units (units B, C, and D) were surveyed to determine the prevalence of selected symptoms identified in stage 1 and to examine the relation between reported symptoms and PGW service. Comparison units were chosen for similarity in mission responsibility to Unit A and were located in Pennsylvania and another state. Units B and C (both reserve units) were surveyed during routine monthly training sessions, and Unit D (an active duty unit) was surveyed immediately after the Unit C survey. All personnel on each base at the time of the survey were asked to participate, regardless of health status or participation in the PGW, by anonymously completing a questionnaire describing the frequency, duration, and severity of 35 symptoms most commonly mentioned during the stage 1 investigation and a general health history. In addition, personnel who had been deployed to the Persian Gulf were asked about possible exposures (e.g., geography {location of service}, duties {combat or support}, medical and other procedures {e.g., vaccinations, dental work}, outdoor activities {sports, recreation, mission-related}, and food and water sources).

A total of 3927 personnel participated in the survey. Response rates varied by unit: 63% (677 of 1083) in Unit A, 36% (540 of 1520) in Unit B, 74% (843 of 1141) in Unit C, and 78% (1867 of 2407) in Unit D. The distribution of demographic characteristics and deployment status of the study participants was similar to the distribution of these variables in the population of each unit.

In all units, the prevalence of each of 13 chronic (lasting greater than or equal to 6 months) symptoms was significantly greater (p less than 0.05) among persons deployed to the PGW than among those not deployed Table_1. The prevalences of five symptom categories--chronic diarrhea, other gastrointestinal complaints (gas, bloating, cramps, or abdominal pain), difficulty remembering or concentrating, "trouble finding words," and fatigue--were significantly greater (p less than 0.03) among deployed personnel from Unit A than among deployed personnel from each of the other units. Symptom prevalences among nondeployed personnel were similar in all units. Reported by: KW Kizer, MD, Dept of Veterans' Affairs. S Joseph, MD, Dept of Defense. M Moll, MD, JT Rankin, DVM, State Epidemiologist, Pennsylvania Dept of Health. Div of Viral and Rickettsial Diseases, National Center for Infectious Diseases; National Center for Environmental Health, CDC.

Editorial Note

Editorial Note: Approximately 700,000 U.S. troops (active duty, reserve, and National Guard) were deployed to the Persian Gulf region during operations Desert Shield and Desert Storm from August 1990 through June 1991. Previous assessments of the health status of PGW veterans have been based on analysis of health registries established by VA and DoD to rapidly identify and report illnesses among PGW veterans (1). Through March 1995, approximately 43,000 and 16,000 PGW veterans had enrolled in the VA and the DoD registries, respectively. Efforts have not identified a specific etiology or biologic explanation for these illnesses, nor have specific diseases or syndromes been identified.

The preliminary findings of this investigation are subject to at least two limitations. First, the stage 2 data on symptom prevalence reflect self-reported information that was not evaluated by physical examination and laboratory tests. However, standardized physical examinations and review of VA laboratory test results from patients in stage 1 did not reveal consistent abnormalities. Second, participation rates for the stage 2 survey varied widely; because persons with symptoms may have been more likely to participate, the prevalence of reported health conditions may have been overestimated.

The preliminary findings presented in this report indicate that some chronic symptoms were reported more commonly by PGW veterans than by nondeployed PGW-era service personnel. Potential explanations for the higher prevalence of symptoms among deployed personnel--and the increased prevalence among deployed personnel from Unit A--may include factors specific to the Persian Gulf region (e.g., environmental, toxic, and infectious exposures); factors related to military service and combat (e.g., exposure to toxic agents and combat-related stress); characteristics associated with the general population (e.g., stress-related disorders, age-related effects, or other poorly defined chronic illnesses); and factors especially specific to Unit A (e.g., increased local concern and media attention about illnesses related to PGW service when compared with other units). The stage 3 case-control study, which is in progress, will assess risk factors in ill and healthy PGW veterans from Unit A.

Mechanisms have been established to rapidly identify and treat PGW veterans with health problems. All PGW veterans with health problems are encouraged to obtain an evaluation at their local VA medical center or military treatment facility. Veterans can be referred for further evaluation at specialized referral centers established by VA and DoD.

PGW veterans and their eligible family members can register for medical examination and treatment by calling toll-free telephone numbers (VA: {800} 749-9387; DoD: {800} 796-9699). DoD has established a separate toll-free number ({800} 472-6719) for PGW veterans to report details of incidents they believe may be associated with a medical problem experienced since returning from the Persian Gulf and for health-care providers with questions about illnesses possibly related to service in the PGW.


  1. Institute of Medicine. Health consequences of service during the Persian Gulf War: initial findings and recommendations for immediate action. Washington, DC: National Academy Press, 1995.

+------------------------------------------------------------------- ------+ |             | | Erratum: Volume 44, No. 23 | |             | | SOURCE: MMWR 45(03);72 DATE: Jan 26, 1996 | |             | | In the article "Unexplained Illness Among Persian Gulf War Veterans | | in an Air National Guard Unit: Preliminary Report -- August | | 1990-March 1995," on page 447, the telephone number for the | | Department of Veterans Affairs' Persian Gulf War Veterans Registry | | was cited incorrectly. The correct telephone number is (800) | | 749-8387.  | |             | +------------------------------------------------------------------- ------+

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TABLE 1. Prevalence rates and ratios * for 13 chronic (i.e., >=6 months' duration) symptoms reported by >=25% of surveyed
personnel in Unit A who were deployed to the Persian Gulf War theater, by unit + -- January-March, 1995
                       Unit A                    Unit B                    Unit C                   Unit D
              ------------------------   ------------------------    ----------------------    -----------------------
                           Not                         Not                        Not                        Not
               Deployed  Deployed        Deployed    Deployed        Deployed   Deployed       Deployed    Deployed
Symptom        (n=313)    (n=364)   PR &  (n=119)   (n=421)    PR    (n=262 )  (n=581)   PR    (n=470)   (n=1397)   PR
Diarrhea@        27%        2%     12.5     15%       3%      5.3      10%       3%     3.6      13%       3%      4.1
Memory @ **      46%        9%      5.2     23%       5%      4.5      26%       8%     3.4      28%       8%      3.6
Rash             25%        5%      5.3     15%       3%      4.5      20%       6%     3.7      19%       4%      4.4
"Trouble finding
 Words" @        31%        9%      3.5     10%       5%      2.2      22%       8%     2.7      24%       8%      3.1
Joint Pain       38%       10%      4.0     35%       9%      4.1      29%      13%     2.2      30%      10%      3.0
Fatigue @        54%       16%      3.4     42%      12%      3.4      36%      14%     2.7      33%      12%      2.9
Joint stiffness  33%       11%      3.0     26%       6%      4.4      26%      11%     2.4      26%       8%      3.4
Irritability or
 moodiness       29%       10%      2.9     20%       4%      5.3      24%       7%     3.4      23%       7%      3.3
Depression       25%        9%      2.8     13%       6%      2.4      13%       8%     1.6      13%       8%      1.8
 intestinal @,++ 38%       14%      2.7     18%      11%      1.7      18%      10%     1.9      20%      10%      2.0
 sleep           29%       12%      2.5     29%       6%      4.6      23%      10%     2.3      22%       9%      2.5
Sinus congestion 51%       31%      1.6     45%      29%      1.6      44%      38%     1.2      44%      27%      1.6
Headache         43%       32%      1.4     41%      30%      1.4      42%      32%     1.3      46%      29%      1.6
 * All prevalence ratios were significant at p<0.05 except for sinus congestion in unit C.
 + Comparison units were chosen for similarity in mission responsibility to Unit A; units B and C were reserve units, and
   Unit D was an active duty unit.
 & Prevalence ratio.
 @ Significantly greater (p<=0.03) among deployed personnel from unit A than among deployed personnel from all of the other
** Difficulty remembering or concentrating.
++ Gas, bloating, cramps, or abdominal pain.

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