The impact of household hygiene on the risk of bacterial diarrhea among Egyptian children in rural areas, 2004-2007.

INTRODUCTION: The present study, conducted between January 2004 and April 2007, explored the impact of household hygiene on the risk of bacterial diarrhea, using data from a prospective birth cohort of 348 infants in five villages in the Nile Delta in Egypt. METHODOLOGY: Neonates were enrolled at birth and followed up until 24 months of age. Children were visited twice a week to survey them for acute diarrhea. A detailed observational household hygiene survey was completed in-house every six months. Adjusted relative risk (aRR) of developing bacterial diarrhea was calculated for exposure to different hygiene variables and examined for specific bacterial pathogens. RESULTS: Exclusive breastfeeding reduced the risk of bacterial diarrhea by 70%, while bacterial diarrhea cases were 2.6 times higher in the warm season. Risk of Campylobacter diarrhea increased with the absence of barriers to keep birds and animals out of the eating area, the presence of garbage containers and a bathing facility within the compound, and the presence of feces on the floor of the bathing facility. Use of municipal water for drinking and cooking was associated with a lower risk of Campylobacter diarrhea. Risk of enterotoxigenic Escherichia coli diarrhea increased with uncovered garbage containers and the presence of liquid materials in the garbage containers, but decreased with the use of tap water in the washing facility. CONCLUSION: The results highlight some potential targets for interventions, such as expanding municipal water supply to all houses and comprehensive mass-media awareness programs to change hygiene-promoting behaviors and practices.

The epidemiological and clinical characteristics of diarrhea associated with enteropathogenic, enteroaggregative and diffuse-adherent Escherichia coli in Egyptian children.

A total of 220 enteroadherent Escherichia coli were identified from 729 Egyptian children with diarrhea using the HEp-2 adherence assay. Enteropathogenic E.coli (EPEC = 38) was common among children <6 months old and provoked vomiting, while diffuse-adhering E.coli (DAEC = 109) induced diarrheal episodes of short duration, and enteroaggregative E.coli (EAEC = 73) induced mild non-persistent diarrhea. These results suggest that EPEC is associated with infantile diarrhea in Egyptian children.

Pathogenicity and phenotypic characterization of enterotoxigenic Escherichia coli isolates from a birth cohort of children in rural Egypt.

Enterotoxigenic Escherichia coli (ETEC) has consistently been the predominant bacterial cause of diarrhea in many birth cohort- and hospital-based studies conducted in Egypt. We evaluated the pathogenicity of ETEC isolates in a birth cohort of children living in a rural community in Egypt. Between 2004 and 2007, we enrolled and followed 348 children starting at birth until their second year of life. A stool sample and two rectal swabs were collected from children during twice-weekly visits when they presented with diarrhea and were collected every 2 weeks if no diarrhea was reported. From routine stool cultures, five E. coli-like colonies were screened for ETEC enterotoxins using a GM1 enzyme-linked immunosorbent assay (ELISA). The isolates were screened against a panel of 12 colonization factor antigens (CFAs) by a dot blot assay. A nested case-control study evaluated the association between initial or repeat excretion of ETEC and the occurrences of diarrhea. The pathogenicity of ETEC was estimated in symptomatic children compared to that in asymptomatic controls. ETEC was significantly associated with diarrhea (crude odds ratio, 1.37; 95% confidence interval [CI], 1.24 to 1.52). The distribution of ETEC enterotoxins varied between the symptomatic children (44.2% heat-labile toxin [LT], 38.5% heat-stable toxin [ST], and 17.3% LT/ST) and asymptomatic children (55.5% LT, 34.6% ST, and 9.9% LT/ST) (P < 0.001). The CFAs CFA/I (n = 61), CS3 (n = 8), CS1 plus CS3 (n = 24), CS2 plus CS3 (n = 18), CS6 (n = 45), CS5 plus CS6 (n = 11), CS7 (n = 25), and CS14 (n = 32) were frequently detected in symptomatic children, while CS6 (n = 66), CS12 (n = 51), CFA/I (n = 43), and CS14 (n = 20) were detected at higher frequencies among asymptomatic children. While all toxin phenotypes were associated with diarrheal disease after the initial exposure, only ST and LT/ST-expressing ETEC isolates (P < 0.0001) were associated with disease in repeat infections. The role of enterotoxins and pathogenicity during repeat ETEC infections appears to be variable and dependent on the coexpression of specific CFAs.

Phenotypic and genotypic characterization of enterotoxigenic Escherichia coli isolated from U.S. military personnel participating in Operation Bright Star, Egypt, from 2005 to 2009.

Enterotoxigenic Escherichia coli (ETEC) is a major health problem for travelers to the Middle East. During the autumn months of 2005, 2007, and 2009, U.S. military personnel participated in Operation Bright Star (OBS) exercises in Egypt. Out of 181 military personnel enrolled in a diarrheal surveillance study, E. coli-like colonies were isolated from 170 patients. Isolates were tested for the detection of ETEC enterotoxins and colonization factors (CFs) using phenotypic and genotypic methods. Additionally, we studied the secular trends of ETEC isolates obtained from OBS studies since 1999. ETEC was isolated from 51.2% and 60.0% of the patients based on enzyme-linked immunosorbent assay and polymerase chain reaction (PCR), respectively. Heat stable (ST) was the dominant enterotoxin detected followed by heat labile (LT) and LTST. Additionally, we detected a CF in 59.7% and 67.6% of the ETEC-positive isolates using dot blot and PCR assays, respectively. The predominant CF isolated was CS6 followed by CS3.

Genotypic characterization of Egypt enterotoxigenic Escherichia coli isolates expressing coli surface antigen 6.

INTRODUCTION: One approach to control enterotoxigenic Escherichia coli (ETEC) infections has been to develop vaccines focused on inducing protective immunity against surface expressed antigenic factors. One such factor is coli surface antigen 6 (CS6); ETEC isolates expressing CS6 may also simultaneously co-express surface antigens CS4 or CS5. However, there is little information regarding the inter-relationships of isolates expressing the CS6 antigen alone or in combination with CS4 or CS5. METHODOLOGY: A total of 62 CS6-associated ETEC isolates were evaluated for their antimicrobial susceptibility, mechanisms of resistance, toxin genes, colonization factor expression, and XbaI-pulsed-field gel electrophoretic profiles. RESULTS: We observed 46 XbaI profiles; 31 were exclusive to ETEC expressing CS6 alone and 15 among the ETEC co-expressing CS4 or CS5. Nearly half (47%) of these isolates were resistant to ampicillin, a third (37%) of the isolates were resistant to trimethoprim-sulfamethoxazole, and 24% of the isolates were tetracycline-resistant. A blaTEM gene was detected in 24 (83%) ampicillin-resistant isolates. Trimethoprim-sulfamethoxazole-resistant isolates (n = 23) carried either sulI (n = 1, 4%), sulII (n = 8, 35%) or both genes (n = 10, 43%); 4 had no detectable sul gene. CONCLUSIONS: Our results show a lack of clonality among Egypt CS6 E. coli isolates and supports the use and the further research on vaccines targeting this cell surface antigen.

Specific IgA antibodies in the diagnosis of acute brucellosis.

An Egyptian female with night sweats, headache, and back pain was diagnosed with acute brucellosis one week after returning from a North African country. Humoral immune responses to specific immunogenic proteins were investigated before and after treatment. ELISA was performed to detect levels of specific antibody (Ab) titers. Immunoblot analysis of Ab recognizing specific Brucella antigenic bands was also performed. IgA was detected on the day of disease onset. Specific agglutination titer was 1:160; it doubled three days later and treatment was implemented. Blood culture yielded Gram-negative coccobacilli after one month, confirmed as B. melitensis by AMOS-PCR. Immunoblotting revealed IgM Abs against two protein bands of 112 and 130-kDa observed only during the acute stage. On the other hand, the intensity of IgG Abs against 21 and 21.5-kDa protein bands positively correlated with the time of convalescence. Based on our observations we conclude that specific IgA levels may be used as an early diagnostic marker for Brucella and high molecular weight protein bands may be useful in the differentiation between acute and chronic brucellosis.

Burden of Aeromonas hydrophila-associated diarrhea among children younger than 2 years in rural Egyptian community.

INTRODUCTION: Between 2004 and 2007, a birth cohort of Egyptian children was analysed to evaluate the epidemiology of enteric diseases. METHODOLOGY: A stool sample was collected from the study children every two weeks as well as whenever they experienced diarrhea. Samples were tested for routine bacterial pathogens as well as enteropathogenic viruses and parasites. A secondary goal of the study was to evaluate the burden of less commonly reported pathogens including Aeromonas hydrophila. RESULTS: Of the 348 study subjects, 79 had A. hydrophila isolated from their stool at some point during the study.  Thirty-six children had exclusively symptomatic (S) infections while 33 had exclusively asymptomatic (AS) infections. However, 10 children had both S and AS infections. Among symptomatic cases, A. hydrophila was the sole pathogen isolated 36% of the time. An important aspect of A. hydrophila associated diarrhea was the high level of resistance to cephalosporins. CONCLUSION: Although relatively uncommon, A. hydrophila was found to be associated with diarrhea among children living in Egypt and was frequently multi-drug resistant.

Increase in the detection rate of viral and parasitic enteric pathogens among Egyptian children with acute diarrhea.

INTRODUCTION: Acute diarrhea continues to be a major cause of morbidity and mortality in children from developing countries. Determination of the frequency of diarrhea in an area, along with the proportion of disease caused by specific enteric agents of different origins, is considered the first step in controlling diarrheal diseases. METHODOLOGY: From 2005 to 2007, a hospital-based surveillance was conducted in two locations in Egypt to determine the causes of acute diarrhea in children younger than 5-years seeking treatment. Five additional enteric viral and parasitic pathogens were tested using commercially-available enzyme immunoassays (EIA) to re-evaluate the prevalence of diarrheal pathogens in undiagnosed cases. RESULTS: Adenovirus, astrovirus, norovirus and G. lamblia were detected as the sole pathogen in 2% (n=34), 3% (n=56), 9% (n=191) and 7% (n=146) of the cases, respectively. E. histolytica was never detected as the sole pathogen. The percentage of diarrheal cases with a known cause increased significantly, from 48% (n=1,006) to 74% (n=1,568) (P < 0.0001). CONCLUSION: In our study, the incorporation of immunoassays yielded useful data in identifying pathogens in previously pathogen-negative diarrhea cases.

Increase in the Detection Rate of Viral and Parasitic Enteric Pathogens among Egyptian Children with Acute Diarrhea

Introduction: Acute diarrhea continues to be a major cause of morbidity and mortality in children from developing countries. Determination of the frequency of diarrhea in an area; along with the proportion of disease caused by specific enteric agents of different origins; is considered the first step in controlling diarrheal diseases. Methodology: From 2005 to 2007; a hospital-based surveillance was conducted in two locations in Egypt to determine the causes of acute diarrhea in children younger than 5-years seeking treatment. Five additional enteric viral and parasitic pathogens were tested using commercially-available enzyme immunoassays (EIA) to re-evaluate the prevalence of diarrheal pathogens in undiagnosed cases.Results: Adenovirus; astrovirus; norovirus and G. lamblia were detected as the sole pathogen in 2 (n=34); 3 (n=56); 9 (n=191) and 7 (n=146) of the cases; respectively. E. histolytica was never detected as the sole pathogen. The percentage of diarrheal cases with a known cause increased significantly; from 48 (n=1;006) to 74 (n=1;568) (P0.0001). Conclusion: In our study; the incorporation of immunoassays yielded useful data in identifying pathogens in previously pathogen-negative diarrhea cases

Burden of Aeromonas Hydrophila Associated Diarrhea among Children Younger than 2 Years in Rural Egyptian Community

Introduction: Between 2004 and 2007; a birth cohort of Egyptian children was analysed to evaluate the epidemiology of enteric diseases. Methodology: A stool sample was collected from the study children every two weeks as well as whenever they experienced diarrhea. Samples were tested for routine bacterial pathogens as well as enteropathogenic viruses and parasites. A secondary goal of the study was to evaluate the burden of less commonly reported pathogens including Aeromonas hydrophila. Results: Of the 348 study subjects; 79 had A. hydrophila isolated from their stool at some point during the study. Thirty-six children had exclusively symptomatic (S) infections while 33 had exclusively asymptomatic (AS) infections. However; 10 children had both S and AS infections. Among symptomatic cases; A. hydrophila was the sole pathogen isolated 36of the time. An important aspect of A. hydrophila associated diarrhea was the high level of resistance to cephalosporins. Conclusion: Although relatively uncommon; A. hydrophila was found to be associated with diarrhea among children living in Egypt and was frequently multi-drug resistant

Enteric pathogens associated with childhood diarrhea in Tripoli-Libya.

Stool samples from children < 5 years of age with diarrhea (N = 239) were examined for enteric pathogens using a combination of culture, enzyme-immunoassay, and polymerase chain reaction methods. Pathogens were detected in 122 (51%) stool samples; single pathogens were detected in 37.2% and co-pathogens in 13.8% of samples. Norovirus, rotavirus, and diarrheagenic Escherichia coli (DEC) were the most frequently detected pathogens (15.5%, 13.4%, and 11.2%, respectively); Salmonella, adenovirus, and Aeromonas were detected less frequently (7.9%, 7.1%, and 4.2%). The most commonly detected DEC was enteroaggregative E. coli (5.4%). Resistance to ≥ 3 antimicrobials was observed in 60% (18/30) of the bacterial pathogens. Salmonella resistance to ciprofloxacin (63.1%) has become a concern. Enteric viral pathogens were the most significant causative agents of childhood diarrhea in Tripoli. Bacterial pathogens were also important contributors to pediatric diarrhea. The emergence of ciprofloxacin-resistant Salmonella represents a serious health problem that must be addressed by Libyan health authorities.

Enteric disease surveillance under the AFHSC-GEIS: current efforts, landscape analysis and vision forward.

The mission of the Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) is to support global public health and to counter infectious disease threats to the United States Armed Forces, including newly identified agents or those increasing in incidence. Enteric diseases are a growing threat to U.S. forces, which must be ready to deploy to austere environments where the risk of exposure to enteropathogens may be significant and where routine prevention efforts may be impractical. In this report, the authors review the recent activities of AFHSC-GEIS partner laboratories in regards to enteric disease surveillance, prevention and response. Each partner identified recent accomplishments, including support for regional networks. AFHSC/GEIS partners also completed a Strengths, Weaknesses, Opportunities and Threats (SWOT) survey as part of a landscape analysis of global enteric surveillance efforts. The current strengths of this network include excellent laboratory infrastructure, equipment and personnel that provide the opportunity for high-quality epidemiological studies and test platforms for point-of-care diagnostics. Weaknesses include inconsistent guidance and a splintered reporting system that hampers the comparison of data across regions or longitudinally. The newly chartered Enterics Surveillance Steering Committee (ESSC) is intended to provide clear mission guidance, a structured project review process, and central data management and analysis in support of rationally directed enteric disease surveillance efforts.

Discovery and phylogenetic analysis of novel members of class b enterotoxigenic Escherichia coli adhesive fimbriae.

Enterotoxigenic Escherichia coli (ETEC) is recognized to be a common cause of acute watery diarrhea in children from developing countries. Colonization factors (CFAs) have been identified predominantly in ETEC isolates secreting heat-stable enterotoxin (ST) or cosecreting ST with a heat-labile toxin (LT). We hypothesized that LT-only-secreting ETEC produces unique colonization factors not previously described in ST and LTST-secreting ETEC. A set of degenerate primers based on nucleotide sequence similarities between the major structural genes of CS20 (csnA), CS18 (fotA), CS12 (cswA), and porcine antigen 987 (fasA) was developed and used to screen a collection of 266 LT-secreting ETEC isolates in which no known CFA was detected. PCR-amplified products of different molecular masses were obtained from 49 (18.4%) isolates. Nucleotide sequence analysis of the PCR amplicons followed by GenBank nucleotide BLASTn analysis revealed five novel DNA sequences; translated amino acid BLASTx analysis confirmed sequence similarity to class 1b major structural proteins encoded by csnA, fotA, and fasA. Strains expressing the novel CFAs were phylotyped and analyzed using multilocus sequence typing (MLST; Achtman scheme), and the types detected were compared to those of a collection of archived global E. coli strains. In conclusion, application of the degenerate primer sets to ETEC isolates from surveillance studies increased the total number of ETEC isolates with detectable CFAs by almost 20%. Additionally, MLST analysis suggests that for many CFAs, there may be a requirement for certain genetic backgrounds to acquire and maintain plasmids carrying genes encoding CFAs.

A randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of rifaximin for the prevention of travelers' diarrhea in US military personnel deployed to Incirlik Air Base, Incirlik, Turkey.

BACKGROUND: Infectious diarrhea is an important problem among travelers and deployed US military overseas causing substantial morbidity due to acute illness and may result in burdensome postinfectious sequelae. METHODS: The nonsystemic antibiotic rifaximin was evaluated for prevention of travelers' diarrhea (TD) in a US military and civilian adult beneficiary population in a randomized, double-blind, placebo-controlled clinical trial. In all, 100 volunteers deployed to Incirlik Air Base, Turkey, received rifaximin 1,100 mg once daily or placebo for 2 weeks, and participants were followed daily for 2 weeks. RESULTS: In an intention to treat analysis (n = 95), TD (based on subjects meeting case definition or early treatment) developed in 6.3% (3 of 48) of the rifaximin group compared with 19.2% (9 of 47) in the placebo group (Fisher's exact test p = 0.07). Rifaximin provided 67% (95% confidence interval, -13% to 91%, p = 0.07) protection against TD. Rifaximin 1,100 mg once daily was well tolerated with no observed differences in adverse events, whether solicited or unsolicited among the two treatment groups. CONCLUSIONS: Rifaximin may represent an option among military personnel on deployment for prevention of TD with supportive future studies that consider deployment length, settings, and operational situations where widespread use of chemoprophylaxis may increase force health protection without undue risk during critical deployments.

Design and validation of a multiplex polymerase chain reaction for the identification of enterotoxigenic Escherichia coli and associated colonization factor antigens.

Development of a genetic tool for the detection of genes encoding enterotoxins and colonization factors would greatly enhance enterotoxigenic Escherichia coli (ETEC) surveillance. Oligonucleotide primers were designed to amplify genes encoding human ST, porcine ST, LT and the structural genes of colonization factor antigen (CFA)/I, CS1 to CS8, CS12 to CS15, CS17 to CS22, and PCFO71. Screening 89 ETEC isolates phenotypically expressing a known CFA showed that, without exception, the multiplex polymerase chain reaction (mPCR) detected the structural gene of the expressed CFA, in addition to CS21 in 22.5% of isolates. Silent genes such as cssB (CS6) were also detected in 9.0%. Additionally, we screened 71 CFA phenotypically negative isolates and detected a CFA in more than 50% of tested isolates. In conclusion, we have designed a simple 4-step mPCR for the rapid detection of ETEC virulence factors. The assay is rapid, reproducible, relatively inexpensive, and has the potential to be field applicable.

Fractionation of organ extracts of Culex pipiens mosquitoes for the isolation of active components that impair biological parameters of the insect.

The previous phase of the present study revealed that when crude extracts of Culex pipiens midgut, ovaries, and salivary glands are injected into New Zealand White (NZW) rabbits (Oryctolagus cuniculus), rabbits immunized with midgut extract exert the greatest negative impact on adult Cx. pipiens survival and fecundity. This study was conducted to further our understanding of the immunogenic nature of the aforementioned antigenic preparations, thus providing data for the ultimate goal of developing a vaccine against the numerous Cx. pipiens-vectored diseases that affect human populations throughout the world. Extracts of Cx. pipiens midgut, ovaries, and salivary glands were fractionated using Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE). The high (> 80.0 to >106.0 kDa) and low (< 18.5 kDa) molecular weight (MW) fractions of midgut extract, high MW fractions (75.0 - <106.0 kDa) of salivary gland extract, and low MW fraction (27.5 kDa) of ovary extract were excised, and used to immunize rabbits. Following immunization, anti-sera from all immunized rabbits were assayed for antibody response using Enzyme-Linked Immunosorbent Assay (ELISA), Enzyme Immunoblot transfer (EIB), and Indirect Fluorescent Antibody Techniques (IFAT). These assays resulted in both high and low MW fractions of midgut extract, with special reference to the midgut extract low MW fraction (18.0 kDa), eliciting the strongest humoral responses in immunized hosts. When Cx. pipiens were fed on rabbits immunized with the low MW fractions of midgut extract, the fecundity and survival rates were significantly less than those of mosquitoes fed on rabbits immunized with the high MW fractions of midgut extract and control rabbits (P < 0.001). It is concluded that, the low MW fraction of midgut extract is highly immunogenic, and the antibody response of immunized rabbits contributes to a significant disturbance in the life cycle of Cx. pipiens and their progeny. This impairment of feeding behavior and reproduction, in turn, could interfere with pathogen transmission.

Acute gastrointestinal infection, respiratory illness, and noncombat injury among US military personnel during Operation Bright Star 2005, in Northern Egypt.

BACKGROUND: In the fall 2005, approximately 7,500 US military personnel participated in an exercise in the Egyptian desert. The epidemiology of disease and noncombat injury among deployed troops is important in the context of assessing current mitigation strategies and the development of future ones. METHODS: To assess the prevalence and impact of diarrhea and enteropathogen distribution, we conducted a case series study. To assess the relative impact of diarrhea compared to respiratory infection and injury, we conducted a post-deployment survey and compared these data to clinic-based syndromic surveillance data. RESULTS: We enrolled 43 patients with acute diarrhea, 21 (49%) having one or more pathogens isolated. Enterotoxigenic Escherichia coli (n= 16), enteroaggregative E coli (n= 3), and Shigella spp. (n= 3) were the most common pathogens identified. Respiratory illness had the highest incidence (73 episodes/100 person-months) compared to diarrhea (35 episodes/100 person-months) and noncombat injury (17 episodes/100 person-months), though noncombat injury more frequently resulted in lost duty days and health-care utilization. CONCLUSIONS: Noncombat injuries and illnesses have had a significant impact on military missions and continue to result in force health protection challenges today. Future studies are needed to test and evaluate countermeasures to mitigate these illnesses and injuries to increase the health of the individuals and optimize mission readiness.

Identification of Culex pipiens Linnaeus (Diptera: Culicidae) immunogens recognized by host humoral immunity and their impact on survival and fecundity.

Insecticide use continues to be the primary control strategy to reduce insect vector populations. Concerns about insecticide resistance in target organisms, environmental degradation, and possible deleterious impact on human health have led researchers to seek a variety of alternative control strategies. We tested a relatively new method for controlling mosquitoes using host immune response. New Zealand White (NZW) rabbits (Oryctolagus cuniculus) were immunized with salivary gland (SGE), midgut (MGE), or ovary (OVE) extracts from female Culex pipiens L. Immunized rabbits were then exposed to unfed adult mosquitoes which were subsequently observed for changes in survival, fecundity, and hatch success. Parents that fed upon MGE- (P<0.001), SGE- (P<0.018) and OVE- (P<0.018) immunized rabbits experienced significantly higher mortality within 48 hours than parents fed on control rabbits. Midgut extract elicited the strongest effects upon survival (P<0.001), oviposition activity (P<0.001), and hatch success (P<0.001) in the parent generation. Survival (P<0.018), oviposition activity (P<0.001), and hatch success (P<0.001) were likewise strongly reduced in parents fed on SGE-immunized rabbits. Ovary extract-fed parents experienced less pronounced, but significant reductions, in survival (P<0.018) and hatch success (P<0.034). Surviving progeny were most strongly impacted by feeding upon MGE-immunized rabbits. Our study suggests that manipulating host immune response may be a suitable technique for reducing Cx. pipiens mosquito survival and fecundity, and subsequently the potential risk of disease transmission by this species.

Enteric pathogens associated with diarrhea in children in Fayoum, Egypt.

In a cross-sectional study of children <60 months old from Fayoum, Egypt, presenting with diarrhea, 46% (162/356) had detectable enteric pathogens. Bacterial pathogens were identified in 25% (89/356), whereas rotavirus and Cryptosporidium were detected in 21% (54/253) and 15% (39/253), respectively. Cryptosporidium is an important pathogen in this region.

Enterotoxigenic Escherichia coli colonization factor types collected from 1997 to 2001 in US military personnel during operation Bright Star in northern Egypt.

Operation Bright Star (OBS) is a biennial, multinational exercise in Egypt involving 15000 US troops. Consistent with past observations in deployed troops, diarrhea is the most significant cause of morbidity. Focused efforts are ongoing to develop vaccines against the most common pathogens affecting our troops. As part of these efforts, diarrhea surveillance was conducted during OBS to monitor pathogens associated with illness and to identify new vaccine targets. A retrospective review was conducted of prior studies with similar methods. Soldiers with diarrhea presenting to the OBS clinic provided a stool sample that was inoculated into Carey-Blair transport media. Within 3 days, the Cary-Blair tubes were transported to the Naval Medical Research Unit no. 3 in Cairo where bacterial culture was performed. As part of the evaluation, 5 Escherichia coli-like colonies were collected and tested for toxin production using the GM1-ELISA. Toxin-positive isolates were further tested for colonization factors (CF) by a dot-blot assay using a standardized panel of monoclonal antibodies against CFA/I, CS1-CS7, CS17, CS8 (CFA/III), CS12 (PCFO159), and CS14 (PCFO166). Enterotoxigenic E. coli (ETEC) was the most frequently isolated pathogen during each OBS from which data were collected. The rate of ETEC-associated diarrhea ranged from 22% to 58%. Over time, there were dramatic shifts in the frequency and distribution of CFs. Over the 5 years of study, an increasing number of ETEC isolates had no known CF identified, and in 2001, only 40% of ETEC was associated with known CFs. The most commonly identified CF was CS6. Diarrheal disease, particularly ETEC, continues to be a common malady among US military personnel deployed to Egypt. We have identified ETEC CF types, especially CS6, which should be considered potential vaccine candidates. However, despite intensive testing, CFs could not be identified in most of the ETEC isolated, highlighting the need for further studies to identify novel CFs and alternative vaccine targets.