Force health protection through laboratory analysis and health risk assessment.

INTRODUCTION

The US Army's 1st and 9th Area Medical Laboratories (AMLs) provide the Department of Defense (DoD) with a Force Health Protection (FHP) capability. FHP is a strategy using preventive health techniques and emerging technologies in environmental surveillance and combat medicine to protect all service members before, during and after deployment. (1) The mission of the AML:

   On order, deploy worldwide and conduct health hazard
   surveillance for biological, chemical, nuclear,
   radiological, occupational/environmental health, and
   endemic disease threats at the theater level to protect
   and sustain the health of the force across the full
   spectrum of military and domestic support operations.

Through the use of sophisticated analytical instrumentation combined with health risk assessment by medical and scientific professionals, the AML performs field confirmation of environmental exposures associated with the contemporary operating environment. The execution of this mission provides the warfighting commander with the critical information requirements needed to mitigate or eliminate health threats during the operational risk management process.

The 1st and 9th AMLs are the only deployable laboratories in the US Army's inventory capable of providing health hazard surveillance through a robust analytical capability. Both AMLs are an Echelon Above Corps level asset assigned to 44th Medical Command and XVIII Airborne Corps. This relationship exists primarily to provide command and control, however, both AMLs can provide FHP support to Army, joint, or combined forces. The AML is authorized 43 personnel, however, only 30 personnel are required by the Modified Table of Personnel and Equipment and are available at all times. The 13 personnel not permanently assigned to the unit are PROFIS (Professional Filler System) assigned to US Army Medical Command (MEDCOM) organizations. The organizational structure of the AML consists of the Headquarters, Occupational/Environmental Health, Nuclear/Biological/Chemical, and Endemic Disease Sections. The unit personnel represent a wide range of scientific military occupational specialties, therefore, both the 1st and 9th AMLs are capable of providing the comprehensive health hazard surveillance typically associated with MEDCOM's fixed facilities.

The home station of the AMLs is Edgewood Area, Aberdeen Proving Ground, Maryland. This location was chosen due to the reliance of the 1st and 9th AMLs on MEDCOM for sustaining Soldier technical proficiency. The AMLs draw upon the following organizations for the scientific expertise, technical training, assistance, and consultation:

* US Army Center for Health Promotion and Preventative Medicine (USACHPPM),

* US Army Medical Research Institute for Chemical Defense (USAMRICD)

* Walter Reed Army Institute for Research (WRAIR)

Due to the proximate location to these organizations, the AMLs can easily leverage and stay current with the emerging technologies necessary to perform their FHP mission.

HISTORY

The Army has activated and inactivated both the 1st and 9th AMLs several times. Both laboratories supported campaigns in World War II. The 1st AML participated in investigations in North Africa and the European Theaters of Operation. The 1st AML also participated in campaigns of the Korean War and the Vietnam War. The 9th AML participated in the China-Burma-India Theater during World War II and participated in 15 campaigns in the Vietnam War. The Army activated the current version of the 1st and 9th AMLs in September 2004. The Army based both AMLs on the structure of the 520th Theater Army Medical Laboratory (TAML) which was inactivated on the same day. The history of the 520th TAML is similar to the AMLs with participation credit for Vietnam, Bosnia, and Operation Iraqi Freedom.

Transformation of the 520th TAML to the 1st and 9th AMLs did little to change the mission. The Army expects both units to execute the same level of surveillance as the 520th TAML performed in support of Operation Iraqi Freedom. The chain of command for both the 1st and 9th AMLs runs through the 44th Medical Command, the XVIII Airborne Corps, and the US Army Forces Command. The Army preserved this chain of command during the conversion from the 520th TAML. The personnel of both units are largely enlisted Soldiers of the 91 (now changed to 68) military occupation specialty series and a sergeant major is the highest ranking noncommissioned officer. In addition to the commander, 5 officers provide leadership to the AML. The Army equips both AMLs with tactical equipment that enable the units to move and survive in a tactical environment. Each AML has organic transportation assets including 5-ton trucks, FMTVs (Family of Medium Tactical Vehicles), and HMMWVs (High Mobility Multipurpose Wheeled Vehicles). The AML conducts laboratory operations in TEMPERs (Tent, Extendable, Modular, Personnel), and Isolation Facilities. Each AML can supply all the power needed for its own continuous operations.

Both AMLs retained headquarters at Aberdeen Proving Ground, the location of the former 520th TAML's headquarters. Since the endemic disease section has a close relationship with US Army Medical Research Institute for Infectious Disease (USAMRIID), both AMLs stationed this section of their units at Fort Detrick, Maryland. The AMLs retained the same close relationship that the 520th TAML established with USACHPPM, USAMRICD and USAMRIID. Combined, these centers provide most of the technical training needed by each AML. These centers also provide PROFIS personnel and controller/observers to evaluate the performance of each AML on field exercises.

CAPABILITIES

The personnel and equipment organizational structure of the AML places great challenges upon the AML to perform logistical and maintenance operations. Based upon the Modified Table of Organization and Equipment (MTOE), the AML is approximately 35% mobile. If and when called upon to provide support in a theater of operation, the AML would require transportation assets to move all assigned equipment and personnel. Under the new MTOE following the Medical Reengineering Initiative, the AML lost key support military occupational specialties (MOS) formerly available in the 520th TAML. The most significant losses were the Supply Sergeant (MOS 92Y20), Utilities Equipment Repairman (52C10), and the Medical Equipment Repairman (91A20).

The AML Headquarters provides command and control functions, operational planning, administrative and logistics support to the unit. The headquarters is staffed by the commander, executive officer, sergeant major, medical operations officer, medical supply sergeant, administrative specialist, wheeled vehicle mechanic, and a cook.

Occupational and Environmental Health Section

The Occupational and Environmental Health (OEH) Section of the AML provides comprehensive environmental health threat assessments by conducting air, water, soil, entomological, epidemiological, and radiological surveillance and laboratory analyses. In support of this mission, the OEH Section conducts analysis in 4 areas: environmental health, industrial hygiene, radiological assessment, and entomology. (2-4)

The OEH Section monitors air quality for particulate, inorganic, and organic contaminants. The Section employs high volume, mid volume and low volume air sampling equipment capable of collecting particulate samples PM-10 (Particulate Matter 10 [micro]m), PM-2.5 (2.5 [micro]m), TSP (Total Suspended Particulates), and inorganics (ie, heavy metals). Sorbent tubes and polyurethane foam sampling systems are utilized to collect ambient and breathing-zone samples of volatile and semivolatile organics. The OEH Section presumptively determines particulate samples and sends these and inorganic samples to a laboratory in the United States for confirmatory analysis. The NBC Section receives the sorbent tubes collected by OEH Soldiers and analyzes the tubes using gas chromatography coupled with either mass selective detector, electron capture detector (ECD) or flame photometric detector (FPD).

The OEH Section executes comprehensive water quality surveillance. The OEH Section conducts inorganic analysis using ultraviolet and visible light spectroscopy and measures most inorganic water contaminants absorbance readings taken after addition of applicable reagents or in conjunction with other isolation and extraction procedures and reagent kits. The OEH Section detects, identifies, and measures concentrations of lead and copper in potable water with an electrochemical device which utilizes anodic stripping voltammetry. The method is specific for lead and copper and is free from all known interferences typically found in potable water. Organic analysis is conducted using either a portable gas chromatograph/ mass spectrometer (GC/MS) or a benchtop GC/MS/ ECD/FPD. To detect bacteriological contamination in water, the OEH Section utilizes presence/absence techniques, membrane filtration, most probable number, and heterotrophic plate counts. To further identify nonfecal coliforms or other problematic bacteria, the Section can forward collected samples to the Endemic Disease Section for analysis.

Soil sampling and analysis for the detection of volatiles, semivolatiles, inorganics, metals, and biologicals is also possible. The OEH Section uses traditional soil sampling equipment and techniques to obtain surface and subsurface soil samples. The Section has the capability to conduct some limited, on-the-spot colorimetric and electrochemical testing for PCBs (polychlorinated biphenyls) and PAH (polycyclic aromatic hydrocarbons), but most chemical soil analysis is conducted by the NBC Section using head-space analysis with the portable GC/MS or solvent extraction with analysis on the benchtop GC/ MS/ECD/FPD.

The OEH Section deploys a robust radiological surveillance capability. The Section uses numerous high volume particulate samplers and collects filters for radiological analysis. The Soldiers analyze these samples and collected soil samples using multichannel scaling spectroscopy. The Section also has a handheld radiation spectrometer/identifier, dose-ratemeter, and nuclide finder in addition to multiple radiac meters with probes for measuring alpha, beta, and gamma radiation. The Section analyzes wipe samples and water samples using a liquid scintillation counter. The Soldiers also employ dosimeters to manage their own exposures as well as occupational exposures of those working in and around radiation hazards. Further, besides detecting, identifying, and measuring ionizing radiation, the Section also has the capability to detect and measure nonionizing radiation hazards.

The OEH Section conducts industrial hygiene surveys. Using multigas electrochemical analyzers, photoionization detectors, infrared gas analyzers, and sampling pumps with filters and/or sorbent tubes, the Section identifies potential chemical hazards in the workplace. Noise meters, noise dosimeters, thermal environment monitors, ventilation meters, and particle counters help to characterize the physical environment and indoor air quality. Utilizing portable GC/MS and portable Fourier Transform Infrared Spectroscopy technology, the OEH Section responds and qualitatively identifies many unknown solids, liquids and gases.

The OEH Section contributes expertise in medical entomology, another vital discipline. The Section collects and identifies arthropods, rodents, and poisonous plants of military importance, and also raises mosquito larvae for accurate species identification or potential insecticide resistance studies. The Section prepares and forwards specimens to the Endemic Disease Section for real-time or traditional polymerase chain reaction analysis to detect and identify medically relevant vector-borne diseases.

The OEH Section's strength is the ability to conduct complete worksite and ambient environment evaluations to detect and identify the hazards present in the full spectrum of media, air, soil, water, physical environment, arthropods and rodents. These comprehensive evaluations provide the data necessary to conduct accurate and thorough environmental health site assessments.

Nuclear Biological and Chemical Section

The capabilities of the Nuclear/Biological/Chemical (NBC) Section include cholinesterase activity measurement, microbial identification, GC/MS/ECD/ FPD, a mobile laboratory and telechemistry. These capabilities allow the Section to monitor for chemical weapons of mass destruction and a wide variety of toxic industrial chemicals, as well as to conduct microbial identification using an independent method that compliments the capabilities of the Endemic Disease Section. The NBC Section works closely with both the OEH and Endemic Disease Sections. The NBC Section analyzes many samples collected by the OEH Section. Similarly, the NBC Section analyzes microbes cultured and incubated by the Endemic Disease Section. The technicians of the NBC Section execute all of the capabilities in an isolation facility (ISOFAC). The Soldiers set up the ISOFAC using an expandable, 2-sided shelter attached to 2 sections of TEMPER. Some of the capabilities can be executed in the mobile laboratory mounted in a shelter unit on the back of a M1097 HMMWV.

The NBC Section provides confirmatory analysis of exposure to nerve agents and toxic industrial compounds (organophosphorus pesticides) by measuring acetylcholinesterase (AChE) activity in Soldier blood samples. Technicians use the Test-mate ChE Test System (EQM Research, Inc, 2814 Urwiler Ave, Cincinnati, Ohio, 513-661-0560) to perform the tests for AChE. The ability of the Test-mate ChE Test System to determine AChE activity under field conditions was evaluated several years ago by the 520th TAML in conjunction with USAMRICD. To mimic nerve agent exposure, USAMRICD spiked blood samples with variable amounts of soman. Blinded to the identity of the samples, the 520th TAML tested the samples during a field training exercise. The technicians accurately identified all of the samples and quantified the AChE activity. (5)

The NBC Section provides confirmatory analysis of microorganisms including aerobic bacteria anaerobic bacteria and yeasts using the MIDI Sherlock Microbial Identification System (MIDI, Inc, 125 Sandy Drive Newark, Delaware, 800-276-8068). The MIDI analysis system is based on fatty acid profiles and contains reference profiles for thousands of microorganisms. This technique provides an identification that is independent from other techniques used by the Endemic Disease Section.

The NBC Section provides confirmatory analysis of air, water, wipe, and soil samples using an Agilent 6890N GC (Agilent Technologies, Inc, 395 Page Mill Road, Palo Alto, California, 650 752 5303). The technicians extract water, wipe, and soil samples. Mass spectra frequently provide a unique fingerprint identification of chemicals. Using the retention time and the mass spectrum, technicians can often identify a chemical based solely on the results of GC-MS. The other detectors, the ECD and FPD, provide analysis for much lower concentrations of threat chemicals. The ECD detects compounds containing halogens and other electrons withdrawing groups at levels much lower than the mass selective detector (MSD). The FPD provides much greater sensitivity for compounds containing sulfur and phosphorous than the MSD. Soldiers of the NBC Section also conduct GC-MS with a portable instrument called HAPSITE (Inficon, Inc, Two Technology Place, East Syracuse, New York, 315-434-1100). Using the HAPSITE, Soldiers can commence analysis with less than an hour setup time

The 520th TAML constructed a mobile NBC laboratory from a shelter unit mounted on a M1097 HMMWV, equipped with a GC-MS, glovebox and Ruggedized Advanced Pathogen Identification Device[R] (Idaho Technology Inc, 390 Wakara Way, Salt Lake City, Utah, 801 736-6354) thermal cycler. (6) The M1097 HMMWV pulls a trailer with a mounted generator that supplies all the power needed to conduct sample preparation and GC-MS analysis. A full tank of fuel is sufficient to power the generator in nearly a week of continuous use. The mobile laboratory platform gives the commander of the AML more flexibility in responding to a volatile environment. The AML mobile lab can conduct sample analysis more rapidly upon arrival in an area of operations, usually within 3 hours of arrival, and can perform initial analysis at a remote location instead of waiting for collected samples to arrive at the ISOFAC. The mobile laboratory provides the commander of the AML with the ability to test for chemical and biological agents, endemic diseases and to monitor cholinesterase activity in Soldiers with potential field exposures.

Through a joint venture with USAMRICD, the AMLs have developed the capability to conduct telechemistry. Through a satellite link, senior scientists at USAMRICD can control the computers that run the AMLs gas chromatographs, conduct data analysis, tune the MSD, troubleshoot, and even run samples. Through a video link, USAMRICD scientists can inspect sample preparation and identify other problems that require visual inspection. Telechemistry provides the AMLs in a deployed environment with unprecedented access to scientists with years of experience in analytical chemistry. (7)

Endemic Disease Section

Upon request, the Endemic Disease Section deploys worldwide to conduct health threat surveillance for biological warfare agents and endemic disease threats at the theater level and provides and sustains FHP. The Endemic Disease Section is composed of an officer-in-charge (captain or major, microbiologist [MOS 71A]), a noncommissioned officer-in-charge (staff sergeant [91K30]), and 4 medical laboratory technicians (MOS 91K). The Section sets up its laboratory in an ISOFAC that is nearly identical to that used by the NBC Section. The Section is self-supporting, with the capacity to transport tactical and technical equipment, provide environmental control and power generation equipment in order to complete any assigned mission. The Endemic Disease Section relies primarily on nucleic acid and antigen detection based technologies, along with basic microbiological techniques in order to detect, identify, and analyze naturally occurring infections and biological warfare (BW) agents that may be encountered during deployments. The Section can also conduct laboratory diagnosis of military relevant infectious diseases which are endemic within the theater. However, in order to enhance the capabilities of the section, PROFIS personnel are assigned, including a veterinary pathologist, veterinary microbiologist, preventative medicine physician, and an infectious disease physician. With the PROFIS personnel, the Section serves as the local joint task force commander's subject matter experts on matters regarding infectious disease and BW agents, providing laboratory support for in-theater infectious disease outbreak investigations, and processing and analyzing potentially dangerous infectious specimens.

Currently, the nucleic acid identification capabilities/ technology relies on the Ruggedized Advanced Pathogen Identification Device (R.A.P.I.D[R]). The system utilizes quantitative real-time polymerase chain reaction technology and provides both presumptive and confirmatory analysis of potential BW and endemic disease agents. The system consists of the R.A.P.I.D. analyzer, a laptop computer for programming the analyzer, and backpack for efficient storage and ease of transport. Associated durable equipment consists of the nucleic acid extraction kits, a microcentrifuge for centrifugation of 1.5 ml snap-cap tubes, and a standard color printer. The technology is based on the detection of a fluorescent reporter fluorochrome attached to an internal primer that hybridizes to the target sequence between traditional forward and reverse primers. Presently, our BW nucleic acid confirmatory detection capabilities are limited to approximately 8 to 10 agents. Reagents are selected based on the disease causing agents endemic to a particular region and what is available through supporting research institutions, such as USAMRIID.

For antigen detection based capabilities, the Endemic Disease Section employs the M-Series[R] M1M analyzer (BioVeris(TM) Corp, 16020 Industrial Drive, Gaithersburg, Maryland 20877, 800-336-4436), an antibody-antigen based identification system (sandwich immunoassay) developed for the detection of a variety of antigens/analytes from small molecules, proteins, and microorganisms. The system is capable of analyzing raw liquid samples such as blood, serum, and liquid buffers from a joint biological point detection system or biological integrated detection system unit. The technology is based on electrochemiluminescence. Sample preparation tags the target to emit light when electrochemically stimulated. Presently, BW antigen confirmatory detection capabilities are limited to approximately 9 agents using the M1M analyzer, with expanded capabilities using an Enzyme Linked Immunosorbent Assay (ELISA).

The Endemic Disease Section is also capable of providing basic laboratory support for weaponized and endemic bacterial agents and parasitic organisms. Limited culture capabilities include the ability to generate ambient air, microaerophilic, and anaerobic culture environments. Basic biochemical identification of many human pathogens and environmental organisms can be performed. To enhance this capability the Dade Behring Microscan[R] autoSCAN[R] system (Dade Behring, Inc, 1717 Deerfield Road, Deerfield, Illinois 60015, 847-267-5300) is employed to provide definitive identification of gram positive and gram negative organisms. The antimicrobial susceptibilities of these organisms can also be determined with the autoSCAN[R]. Endemic parasite identification can be performed on fixed sample unknowns and other sample types, such as malarial smears and arthropod vectors. Fluorescent and light microscopy is available for pathogen analysis through variable staining methodologies, ie, Gram stain, Wright/Giemsa stain, and specialized fluorochrome stains for specific pathogens.

While in garrison and aside from technical and tactical training exercises, the Endemic Disease Section has had the opportunity to assist DoD as well as the local community with the present capabilities. During April-May of 2005, both the 1st and 9th AMLs were tasked by DoD to represent the Army in a multi-Service joint exercise during the initial operational test and evaluation of the Joint Biological Agent Identification and Diagnostic System (JBAIDS), at Brooks Air Base in San Antonio, Texas. The JBAIDS is a nucleic acid based laboratory instrument system that provides commanders with rapid and specific identification of biological threat agents. Following a 10 day training course, the AMLs were involved in a 10 day record test that evaluated 4 of 8 JBAIDS systems for network performance, survivability, interoperability, and logistical support. In August 2005, the 9th AML provided 5 Soldiers to assist USACHPPM for 2 weeks at Fort AP Hill, Virginia. The Soldiers assisted in the identification of Lone Star, Black-Legged (Deer), and American Dog ticks and used nucleic acid based technologies to screen for such arthropod-borne diseases as human monocytic ehrlichia, Lyme disease, human granulocytic ehrlichia, and Rocky Mountain spotted fever.

DISCUSSION

Although neither AML has been deployed since activation in September 2004, both units maintain a high state of readiness by conducting realistic field training exercises and maintaining a robust intramural training program. One of the largest challenges in the current operating environment is the maintenance of a core of Soldiers highly trained with the requisite skills to operate and maintain the advanced technologies fielded by the AMLs. To this end, the AMLs invest considerable effort in arranging mission-specific technical training programs for individual Soldiers in cooperation with their fixed facility partners. Through participation in strategic working groups and scientific conferences, AML personnel stay abreast of current issues in Force Health Protection. Every effort is made to update unit equipment to reflect the latest developments in technology and provide a better product to their customers. They also work to establish relationships and investigate joint training opportunities with the Army National Guard and organizations of the other armed services that perform similar missions. In addition to the doctrinal theater support mission, the AMLs provide an untapped resource of essential capabilities to support civil authorities in homeland defense missions, consequence management, and disaster relief operations. Ready, relevant, and reliable, the 1st and 9th AMLs stand prepared to assist whenever and wherever they are needed.

REFERENCES

(1.) US Dept of Defense resources page. Force Health Protection website. Available at: http://www.ha.osd.mil/forcehealth/about/main.html.

(2.) Field Manual 4-02.12: Health Service Support in Corps and Echelon Above Corps. Washington, DC: US Dept of the Army; 2 February 2004.

(3.) Field Manual 4-02.17: Preventive Medicine Services. Washington, DC: US Dept of the Army; 28 August 2000.

(4.) Army Training and Evaluation Program. ARTEP 8-668(MRI)-30-MTP: Mission Training Plan for the Area Medical Laboratory. Washington, DC: US Dept of the Army; 3 December 2002.

(5.) Taylor P, Lukey B, Clark C, Lee R, Roussel R. Field verification of Test-mate ChE. Mil Med. 2003;168:314-319.

(6.) Shippee RL. The TAML/AML concept; lessons learned/prescription for change. Army Med Dept J. 2004;Jul-Sep:65-68.

(7.) Slife H, Winston J. Telechemistry, projecting laboratory expertise to a deployed area medical laboratory. Mil Med Tech. 2005;9.3:3-42.

AUTHORS

MAJ Taylor is the Chief, Nuclear Biological and Chemical Threat Assessment Section, 9th Area Medical Laboratory, Edgewood Area-Aberdeen Proving Ground, Maryland.

COL Gordon is Commander, 1st Area Medical Laboratory, Edgewood Area-Aberdeen Proving Ground, Maryland.

MAJ Kimm is the Executive Officer, 1st Area Medical Laboratory, Edgewood Area-Aberdeen Proving Ground, Maryland.

MAJ Hall is the Chief, Occupational/Environmental Health Threat Assessment Section, 9th Area Medical Laboratory,

Edgewood Area-Aberdeen Proving Ground, Maryland. CPT Van Horn is the Chief, Endemic Disease Section, 9th Area Medical Laboratory, Fort Detrick, Maryland.

CPT Tyner is the Chief, Endemic Disease Section, 1st Area Medical Laboratory, Fort Detrick, Maryland.

MAJ Patterson W. Taylor, MS, USA COL Scott W. Gordon, MS, USA MAJ Tara L. Hall, MS, USA MAJ Gregory L. Kimm, MS, USA CPT Stuart D. Tyner, MS, USA CPT Gerald T. Van Horn, MS, USA