A. Before the Gulf Crisis
When US troops deployed to Saudi Arabia in August 1990, military medicine was prepared for the unique health risks our troops faced in the Persian Gulf. The US military operates a network of six overseas infectious disease research laboratories, which serve as training sites for military medical personnel and scientists. These laboratories are regional centers of excellence for basic and applied research that benefit both the US military and host nations by identifying infectious disease risks and developing improved prevention, control, and treatment measures.
One of the oldest overseas laboratories is located in Cairo, Egyptthe US Naval Medical Research Unit No. 3 (NAMRU-3). NAMRU-3 has operated continuously since 1946, including the 7-year period (1967 to 1973) when there was a break in diplomatic relations between the USA and Egypt. NAMRU-3 has a long and distinguished record training US and foreign medical personnel, assisting local health ministries and the World Health Organization, and representing the United States abroad.
The research efforts at NAMRU-3 are extensive and include vaccine and drug development and disease surveillance. Research investigations frequently involve field studies in various Middle East countries where numerous temporary laboratories have been established over the last 40 years. Consequently, when Operation Desert Shield began, the Navy already had a sophisticated diagnostic laboratory and an active research and surveillance program in the Middle Eastplus medical personnel with extensive experience in this region. US Navy doctors and scientists knew what infectious diseases threatened our troops, what diagnostic tests were needed in Saudi Arabia, and, most critically, how to effectively operate in this region.
B. Navy Forward Laboratory
Beginning in August 1990, US Navy preventive-medicine personnel and scientists began evaluating disease risks among deployed troops. In September 1990, the Navy Forward Laboratory (NFL) was established at the "Marine Corps Hospital" in Al Jubayl, Saudi Arabia. The "Marine Corps Hospital" was an unoccupied civilian hospital that had all the requirements to accommodate a modern diagnostic laboratory: an unused clinical facility, running water, and climate control. Laboratory equipment and supplies were quickly flown into the theater by commercial airlines from Cairo, Egypt, the US Navy Environmental and Preventive Medicine Unit No. 7 (NEPMU-7) in Naples, Italy, and various medical facilities in the US.
The NFL eventually had a staff of eight personnel: four Medical Service Corps officers (microbiologists), two Medical Corps officers (infectious diseases specialists), and two Hospital Corpsmen (advanced laboratory technicians). The NFL was attached to the Naval Logistics Support Command and reported directly to the US Naval Forces Command (NAVCENT) Surgeon, whose leadership was critical in establishing and maintaining the laboratory. The NFL developed into a state-of-the-art infectious disease diagnostic laboratory that had the capabilities of a well-equipped laboratory in the USincluding DNA probes and polymerase chain reaction (PCR) analysis. When fully operational, the NFL served as the theater-wide, infectious diseases reference laboratory for coalition forces. The out of theater support for the NFL was provided by the Naval Medical Research Institute (NMRI), the Armed Forces Research Institute of Medical Sciences, the US Army Medical Research Institute of Infectious Diseases/Walter Reed Army Institute of Research, the National Institute of Health, the Naval Research Laboratory, the Chemical Biologic Defense Establishment in Porton Down, United Kingdom, as well as the US Naval Medical Research Unit No. 3 in Cairo, Egypt and the US Navy Environmental and Preventive Medicine Unit No. 7 in Naples, Italy. Figure 1 shows the location of the NFL and the satellite labs established by the NFL in Al Mishab, Al Khanjar, and Kuwait City.
Figure 1 - Location of NFL and Satellite Labs
II. NFLs FUNCTIONS AND RESPONSIBILITIES
A. Naturally Occurring Infections
During Operation Desert Shield, the NFLs main focus was to analyze blood and stool samples and to assist preventive medicine personnel. To carry out these duties, the NFL staff traveled extensively throughout northeastern Saudi Arabia, evaluating patients and assessing health risks. During these travels, staffers were often questioned about the numerous piles of dead animals scattered across the desert. Beginning in August 1990, US veterinary personnel evaluated these animals and determined that their deaths were due to natural causes among the large herds of sheep, goats, and camels kept by the Bedouin in this region. The local residents left the dead animals in specific locations for counting and compensation from the government. In the desert, these dead animals tended to dry out rather than decompose rapidly.
US troops camping near these locations were naturally concerned about the piles of dead animals. There was concern that the animals might be a breeding ground for insect-transmitted diseases. Consequently, military entomologists (experts in insect and pest control) thoroughly sprayed the piles of dead animals with insecticideswhich may in turn explain some subsequent reports of dead animals and insects, particularly among troops who arrived in Saudi Arabia in January and February 1991, at the start of the war. These newly arrived troops would not have known that dead animals had been in the desert for at least five months before hostilities began.
During the early stages of the deployment, the main infectious disease problems were acute diarrhea and the common cold. Epidemiological surveys show that approximately two-thirds of ground troops had acute diarrhea during both Operation Desert Shield and Desert Storm. Nearly all cases of diarrhea were due to the infectious agents NFL personnel had identified during prior US troop deployments to the Middle Eastmainly traveler's diarrhea ("tourista" or the "trots") and Shigella. Laboratory analysis identified no cases of typhoid fever, cholera, or amoebic dysentery.
US troops also frequently had acute upper respiratory infections and complaints (cough, sore throat, sneezing, runny nose). These problems occur any time troops are crowded together and rapidly deployed overseas. Also, there was concern that the fine blowing sand in Saudi Arabia might be contributing to the respiratory problems. Epidemiological surveys determined, however, that respiratory symptoms were more common among the minority of troops who worked and slept in air-conditioned buildings than among personnel living in tents or open warehouses. Furthermore, troops living in tightly constructed buildings had more symptoms, because in closed and crowded spaces, they were more likely to pass respiratory infections among each other. NFLs analyses found that common viral and bacterial agents, like influenza, caused these respiratory infections.
Medical personnel were also worried about two infectious diseases that had caused problems for US and British troops during World War IIsand fly fever and cutaneous leishmaniasis (both transmitted by sand flies). Extensive surveillance and testing of US troops, however, did not identify a single case of sand fly fever; and after the war, researchers found only 12 cases of visceral leishmaniasis and 20 cases of cutaneous leishmaniasis in a population of over 750,000 US, British, and Canadian Gulf War veterans. In addition, sand fly vectors could not be found during and after the war in most locations where our troops deployed.[14, 15] The very low number of illnesses caused by sand flies and other insects may have been due to:
- Deployment of most troops to barren desert locations where sand flies and their animal hosts do not live
- Deployment of most US troops during the cooler winter months of December to February when insects are least active
- Use of insecticides and repellents
Among US troops, researchers identified only seven cases of malaria, three cases of Q-fever, and one case of West Nile fever. The infectious diseases diagnosed during this wartime deployment were the same ones diagnosed in peacetime when US troops are sent to the Middle East. Although preventive measures can reduce the risk of diarrhea and respiratory infections, these common ailments cannot be totally avoided during crowded deployments to tropical and developing countries. Only the development of effective vaccines and preventive measures will further reduce the incidence of diarrhea and respiratory infections under such conditions.
B. Biological Warfare Detection
During Operation Desert Storm, the NFL shifted its focus from routine infectious disease problems to the threat of biological warfare (BW). From the beginning of the deployment, it was clear that an in-theater laboratory capable of detecting BW agents was essential to protect US and coalition troops. Therefore, the NFLs diagnostic capabilities and staff were augmented during Operation Desert Shield to deal with the threat. By the start of Operation Desert Storm, the NFL was prepared to detect potential BW agents. Techniques used to identify potential BW agents included:
� Bacteriological identification and microscopy
� Immunologic-based assays for detecting bacterial viral antigens and antibodies
� Molecular techniques, like polymerase chain reaction
Using these techniques, the NFL could analyze both biological samples (like blood) and environmental samples from soil, water, and air collectors.
Based on the best intelligence at the time, the most likely Iraqi BW threats were shells loaded with either anthrax (Bacillus anthracis), or botulism (a toxin produced by the bacterium, Clostridium botulinum). The bacteria that cause anthrax and botulism both occur naturally in the environment. Anthrax affects livestock and causes disease among humans working closely with infected animals or their hides. Anthrax is a potentially effective BW agent because when inhaled, it causes rapid death from massive bleeding in the lungs.
Botulism is a highly lethal substance which causes disease in the United States when contaminated food is improperly canned or stored. Because minute amounts of this toxin cause very rapid paralysis and death, it is ideal for biological weapons production. The NFLs extensive number of assays could detect both these likely agents and other less likely bacterial, viral, and toxic agents that might potentially be used. After receiving and analyzing samples in-theater, the NFL also sent these samples to laboratories in the United States (US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland) and the United Kingdom (Chemical Biologic Defense Establishment, Porton Down) for further confirmatory analysis. Aflatoxin was considered a less likely BW threat than anthrax or botulinum toxinassays in this agent existed in the US, but not at the NFL.
During the course of the war, the Navy Forward Laboratory BW team also analyzed some of the dead animals discussed earlier. Using the NFLs array of detection techniques, the BW team analyzed samples from seven dead goats and found no BW agents. Further, water samples obtained after the war from the Royal Palace in Kuwait City were analyzed and no biological agents were found.
Because of the inherent limitations of any laboratory test, especially newly developed ones, the NFL subjected all samples analyzed for BW agents to repeated testing with dissimilar assay methods to confirm results. Even in the routine hospital and outpatient clinic setting, multiple tests are often required to diagnose a patient's condition because of the limitations of any test method. Because no test for biological or chemical agents is foolproof, multiple tests are even more necessarythe stakes are too high when chemical or biological agents are in question.
Although it required additional time and labor, the NFLs commitment to overlapping and different assay methods significantly enhanced the labs BW detection capability during the war. Infectious or chemical agents are sometimes sampled in such a form or amount that they cannot be detected by one method alone. By using multiple methods, the NFL ensured that these agents would not slip detection. This attitude also protected against false negatives and false positives, which are unavoidable problems with all assays. By using different tests to analyze samples, questionable test results could be identified and corrected.
During Operations Desert Shield and Desert Storm, the NFL detected no biological agents in clinical, environmental, and veterinary samples. Nevertheless, these results did not diminish the perceived need for an effective in-theater biological laboratory like the NFL. When large numbers of troops are deployed, they need an early-warning facility to detect hostile biological agents so that preventive and therapeutic measures may be taken.
The Gulf War demonstrated the need for more rapid BW assay methods. This has since been the focus of the military's biological defense research program (BDRP). The present number of detectable BW agents has expanded. New methods have also been designed to detect BW agents in a broader range of samplesincluding soil and sand samples, water samples, and even samples obtained by swabbing hard surfaces. A greatly improved rapid assay for biological agents has been developed at the NMRI in Bethesda, Maryland. Assays similar to standard pregnancy tests are now capable of detecting a growing list of BW agents in about 15 minutes.
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