U.S. military overseas medical research laboratories.

Many infectious disease threats to U.S. military operations are uncommon in the United States. The advanced development and testing of countermeasures, such as vaccines, drugs, or insect repellents, requires the capability to study militarily important infectious diseases where they occur. With formal agreements between the U.S. and each host country, the U.S. military operates seven overseas medical research laboratories (labs). Six labs conduct infectious disease research and are distributed over three continents: Africa (labs in Egypt and Kenya), Asia (labs in Indonesia and Thailand), and South America (labs in Brazil and Peru). One other lab is located in Germany and conducts psychosocial research related to military personnel and their families. In addition to product development, these labs play vital roles supporting overseas deployments, providing technical training, and promoting international relations. Also, these labs are well positioned to become part of a developing global surveillance and response system to help address the threat posed by emerging infectious diseases. This article will present an overview of this unique medical research capability, describe the history and some of the activities of each lab, and discuss the importance of maintaining these labs in the 21st century.

Experience with the use of an investigational F(ab')2 heptavalent botulism immune globulin of equine origin during an outbreak of type E botulism in Egypt.

During an outbreak of type E foodborne botulism in Cairo in 1991, an investigational equine F(ab')2 "despeciated" heptavalent botulism immune globulin (dBIG) was provided to the Egyptian Ministry of Health by the U.S. Army. Of 54 patients known to have been treated with antitoxins, 4 received commercially available trivalent antitoxins, 45 received dBIG, and 5 received both commercial antitoxin and dBIG. Physicians recorded side effects in 10 (22%) of 45 patients who received dBIG; in nine cases, reactions were considered "mild," and in one case they were believed to be serum sickness. In contrast, possible serum sickness during hospitalization was recorded for two of four patients who were receiving commercial antitoxins. No complications of therapy were noted for any patient who was receiving both antitoxin types. In a separate study, 31 patients were contacted about their reactions to the antitoxin by telephone after discharge from the hospital. Seven (54%) of 13 patients attributed symptoms that they experienced while they were hospitalized to receipt of dBIG, while four (44%) of nine patients who indicated that they had received commercial antitoxins and one (20%) of five who received both commercial antitoxin and dBIG reported side effects before discharge. Data on the efficacy of the antitoxins were not obtained. In our experience, equine dBIG was at least as safe as commercially available antitoxins in treating type E foodborne botulism.

Coxiella burnetii antibody prevalences among human populations in north-east Africa determined by enzyme immunoassay.

Retrospective serosurveys were conducted to determine the prevalence of antibody to phase-I Coxiella burnetii among humans in various locations of north-east Africa. Sera were tested by the enzyme immunoassay (EIA). Initially the EIA was compared with the standard indirect fluorescent antibody (IFA) method for the detection of antibody to C. burnetii. Results indicated that the EIA was slightly less sensitive (88%), but highly specific (94%) and less subjective than the IFA technique. EIA was subsequently adopted for estimating prevalences in the studied human populations. Data obtained by EIA indicated that the prevalence of C. burnetii antibody among adult Egyptian blood donors was 20% (n = 358) in the Suez Canal area, 16% (n = 501) in the Nile Valley and 10% (n = 427) in the Nile Delta. Among adult patients with acute, undifferentiated fever in Egypt, the prevalence was 28% (n = 50) of acute sera, with seroconversion in 12% of convalescent sera. Antibody to C. burnetii was detected by EIA in the sera of 25% (n = 71) of cattle workers in Egypt, 10% (n = 100) of housewives in Sudan, and 37% (n = 104) of adults in north-west Somalia. Following a fever outbreak affecting all ages in northern Sudan, IgG antibody to C. burnetii was present in 54% of the febrile persons (n = 185) and in 53% of afebrile persons (n = 186). IgM antibody to C. burnetii was demonstrated in 29% of the febrile persons and 15% of the afebrile persons. These results implicate C. burnetii as a possibly important and under-reported cause of human disease and undiagnosed fevers in north-east Africa.

A high risk of hepatitis C infection among Egyptian blood donors: the role of parenteral drug abuse.

To determine the prevalence and risk factors of hepatitis C virus (HCV) infection among Egyptian blood donors, 188 consecutive adult blood donors from four hospitals and one temporary donor center located in Cairo, Egypt were evaluated. Sera were tested for HCV antibodies (anti-HCV) using second-generation enzyme-linked immunosorbent assay (ELISA) test kits. Sera that were repeatedly reactive by ELISA were further verified by a second-generation recombinant immunoblot assay (RIBA). Antibodies to HCV were detected by RIBA in 26.6% of the blood donors, which is higher than the 10-19% prevalence of antibody found in other studies of Egyptian blood donors. A history of selling blood (odds ratio [OR] = 12.1) and the use of illicit parenteral drugs (OR = 2.5) were significantly associated with anti-HCV seropositivity after controlling for age and gender. These data indicate that the use of illicit drugs may be one reason for high levels of reported HCV infection among Egyptian blood donors. These findings also indicate that Egyptian blood donors should be screened for anti-HCV and individuals who have a history of drug abuse should be deferred from donating blood.

Evaluation of a twice-a-week application of 1% niclosamide lotion in preventing Schistosoma haematobium reinfection.

A randomized double-blind trial was conducted to assess the efficacy of a twice-a-week application of 1% niclosamide lotion for prevention of Schistosoma haematobium reinfection. Six hundred farmers in Fayoum, Egypt, 18-40 years of age, were treated to cure their S. haematobium infection, then randomly assigned to self-apply niclosamide or placebo lotion to their limbs, neck, and torso. Subjects were exposed to schistosomal-infested water during routine irrigation activities from April to October 1992. Three hundred fifty subjects met the inclusion criteria and completed the trial, 169 (48.3%) in the niclosamide group and 181 (51.7%) in the placebo group. The subjects assigned to the niclosamide-treated group were comparable with those in the placebo group in age (27.2 versus 27.8 years), total water contact (101.9 versus 109.0 hr), lotion application compliance (93.5% versus 90.6%), and avoidance of whole body water contact (94.7% versus 96.7%). The reinfection rate with S. haematobium was 30.8% in the niclosamide-treated group and 28.2% in the placebo group. Niclosamide lotion applied to the limbs and trunk twice a week failed to prevent S. haematobium reinfection.

Short-course norfloxacin and trimethoprim-sulfamethoxazole treatment of shigellosis and salmonellosis in Egypt.

In a double-blind clinical study, 109 adult Egyptian patients infected with Shigella spp. and 45 infected with Salmonella spp. were randomly assigned to three treatment groups: 1) norfloxacin in a single 800-mg dose, 2) norfloxacin, 400 mg twice a day for three days, and 3) trimethoprim (160 mg)-sulfamethoxazole (800 mg) (TMP-SMX), twice a day for three days. Among Shigella-infected patients, diarrheal symptoms had resolved in 86-97% and bacteriologic failure (repeat positive stool culture) occurred in only two patients five days after the start of the three treatment regimens. Among Salmonella-infected patients, diarrheal symptoms had resolved in 76-82% of patients and bacteriologic failure was common (18-36%) five days after the start of therapy. These data indicate that short-course therapy with either norfloxacin or TMP-SMX can be effectively used to treat shigellosis in adults in developing countries. However, for uncomplicated Salmonella spp. infection, short-course therapy with norfloxacin and TMP-SMX may not lead to a rapid resolution of symptoms or consistently eliminate this enteropathogen.

Abdominal tuberculosis in Cairo, Egypt.

Twenty-two abdominal tuberculosis patients seen at Abbassia Fever Hospital in Cairo, Egypt from January 1990 to August 1992 are described; their mean age was 21.5 years, range 9-54 years; 17 were female. Common symptoms were fever, malaise, abdominal pain (64%) and weight loss (82%). Chest X-rays were normal in 14 patients (64%), but ultrasonography/computerized tomography of the abdomen was abnormal in 20 patients (91%), with adenopathy the usual finding. Anaemia and a raised erythrocyte sedimentation rate were present in all patients, and purified protein derivative skin test (5 Tu) was positive in 82%. Predominant abnormal physical findings were abdominal (86%), including hepatomegaly/splenomegaly and abdominal mass. Diagnosis was made from biopsy material (caseating granulomas) in 6 patients by laparotomy, 1 by laparoscopy, and 3 by cervical or supraclavicular node biopsy; and from laboratory examination of excretions in only 4 patients (acid-fast bacilli in stools of 2, mycobacteria in urine and menstrual fluid). Eight patients required presumptive diagnosis after response to specific isoniazid (+ethambutol) antituberculous therapy.

Recurrence of Rift Valley fever in Egypt.

Rift Valley fever (RVF) has been recorded in man and in domestic animals in Egypt after a 12-year absence. Human infections were first noted in the Aswan Governorate in late May, 1993. Only cases of ocular disease, an infrequent and late manifestation, were reported. Of 41 cases, 35 were tested serologically and 27 (77%) had RVF virus-specific IgM antibodies. An estimated 600-1500 infections occurred in the region. Abortions in cattle and buffalo were seen concurrently and antibodies to RVFV were present in 39% of domestic livestock, presumably unvaccinated. RVFV was isolated from an aborted water buffalo fetus.

Prevalence of hepatitis C viral antibody in transfused and nontransfused Egyptian children.

Hepatitis C (HCV) virus is recognized as the major cause of what was previously referred to as parenterally acquired (blood-mediated) non-A, non-B hepatitis. A study involving 252 transfused and nontransfused Egyptian children was conducted from November 1990 through February 1991 to determine the prevalence of HCV and the role of blood and blood and blood product transfusions in the spread of the virus. Serum specimens were assayed by a second generation enzyme immunoassay and were considered reactive only after supplemental testing using the second generation recombinant immunoblot assay. Prevalence among 84 young study subjects with hematologic disorders was 55% (46 of 84), while no HCV antibodies were detected among the two nonhematologic pediatric populations studied: 84 hospital admissions and 84 acutely ill but otherwise healthy outpatients (seeking treatment for symptoms associated with a new condition less than three weeks old in the absence of any chronic health problem). Ninety-two percent (77 of 84) of the hematology-related cases had medical histories of multiple transfusions. Positive antibody responses (46) were significantly associated with increased duration of illness (P < 0.001) and the volume and number of transfusions (P < 0.01) when compared with negative ones (38). However, prior hospitalization and/or surgery were not related to HCV antibody status. The high prevalence of HCV antibody among multiply transfused infants and children suggests that blood and blood product supplies should be regularly screened for HCV antibody.

NAMRU-3: forty-six years of infectious disease research.

The United States Naval Medical Research Unit No. 3 (NAMRU-3), Cairo, Egypt, has been in continuous operation studying infectious diseases of military importance since its establishment in 1946, even during the lapse in diplomatic relations from 1967-1974. Other overseas research laboratories of the Naval Medical Research and Development Command include NAMRU-2 in Jakarta, Indonesia, with a detachment in Manila, and the Naval Medical Research Institute Detachment Lima, Peru. Comparable U.S. Army overseas research laboratories are located in Thailand, Brazil, Korea, and Kenya. Department of Defense overseas laboratories conduct research on infectious diseases endemic to their respective geographic regions which could adversely impact on the health of deployed military forces. This article describes the history of one such laboratory, NAMRU-3, and the important infectious disease research it conducts to enhance the health of military forces deployed to its strategic geographical region of the world.

A massive outbreak of type E botulism associated with traditional salted fish in Cairo.

In April 1991, 91 hospitalized patients in Cairo were reported to the Egyptian Ministry of Health with botulism intoxication. To define the spectrum of illness and identify a food vehicle, 45 patients were interviewed and a case-control investigation was conducted among families of 5 hospitalized patients. Clinical specimens and specimens of implicated food were tested for toxin and cultured for Clostridium botulinum. Hospitalized patients had symptoms consistent with botulism; 18 (20%) of 91 reported patients died. Illness was associated with eating faseikh (uneviscerated, salted mullet fish; lower 95% confidence limit of odds ratio = 6.6, P < .001). All 5 case-families purchased faseikh from one shop. Very high levels of type E botulinal toxin were detected in faseikh reported to be purchased from the implicated shop; C. botulinum type E was isolated from cultures of clinical specimens and from the faseikh. This is the first documented outbreak of botulism in Egypt and the largest type E outbreak ever reported.

A light and electron microscopic study of the innervation of pulmonary arteries in the cat.

Nerve terminal-smooth muscle relationships were studied in pulmonary arteries of the cat using 5-hydroxydopamine to help differentiate adrenergic and nonadrenergic terminals. There was a periarterial plexus of nerves in the walls of pulmonary arteries that extended into the lung to innervate even small arteries having a single layer of smooth muscle cells. Adrenergic nerves surrounded all arteries and extended into the tunica media of the large arteries. There were also apparent cholinergic nerves around the pulmonary arteries, although this was confirmed by electron microscopy for medium- and small-sized arteries only. The relationships of nerve terminals to smooth muscle cells in pulmonary arteries suggest that release of norepinephrine by adrenergic terminals can produce both decreased compliance and increased resistance in the pulmonary vascular bed, and that acetylcholine released by cholinergic terminals may act directly on vascular smooth muscle or on adrenergic terminals to modulate release of norepinephrine. These results suggest that both sympathetic and parasympathetic nerves may have a regulatory role in the pulmonary circulation.

Influence of 5- and 6-hydroxydopamine on adrenergic transmission and nerve terminal morphology in the canine pulmonary vascular bed.

We studied the effects of 5- and 6-hydroxydopamine on adrenergic neurotransmission, fluorescence histochemistry, and nerve terminal ultrastructure in the canine pulmonary vascular bed. Fluorescence histochemistry on stretched preparations and sections of intrapulmonary artery and vein demonstrated that these vessels are well supplied with adrenergic nerves electron microscopy revealed adrenergic terminals in the adventitia and outer third of the media in the artery, but only in the adventitia in the vein. Adrenergic terminals in artery and vein contained many small and a few large dense-core vesicles. At least 20% of the terminals in the artery contained many small agranular vesicles and a few large opaque vesicles; this suggests that they were of the cholinergic type; Such terminals were not found in intrapulmonary veins. Under conditions of controlled blood flow, stimulation of the sympathetic nerves to the lung and intralobar injection of norepinephrine increased pressure in the perfused lobar artery and small intrapulmonary vein in a stimulus-related manner. The rise in pressure in the lobar artery and vein in response to nerve stimulation was blocked after administration of either 5- and 6-hydroxydopamine; Neither agent modified the response of the pulmonary vascular bed to norepinephrine; In contrast, the rise in pressure in the lobar artery and vein in response to both norepinephrine and to nerve stimulation was blocked by phenoxybenzamine, an alpha-receptor blocking agent. The attenuated neurogenic vasoconstrictor response in dogs treated with 5- and 6-hydroxydopamine was associated with a marked decrease in intensity of fluorescence of the abundant adrenergic innervation in both intrapulmonary artery and vein, and with the appearance of an osmiophilic material in dense-core vesicles of adrenergic terminals in artery and vein. We believe that these data suggest that 5- and 6-hydroxydopamine interfere with adrenergic transmission in intrapulmonary vessels by depleting norepinephrine from adrenergic terminals. Furthermore, we conclude from hemodynamic, histochemical, and ultrastructural studies that vasomotor tone in the pulmonary vascular bed can be regulated by the sympathetic nervous system.