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.

Prospective analysis of psychiatric risk factors in marines sent to war.

The objective of this longitudinal study was to identify risk factors for combat-related psychiatric disorders. The sample consisted of 6442 enlisted U.S. Marines who completed a questionnaire during basic training, deployed to a combat zone with no prior psychiatric diagnoses, and completed a postdeployment assessment form. Cox proportional hazards regression was used to determine associations between predeployment and postdeployment self-reports and subsequent mental health outcomes. During the observation period, 6.8% of the sample were diagnosed with a psychiatric disorder. The strongest predictors of postdeployment psychiatric disorders were, in order of importance, low paygrade, hospitalization during deployment, low education, preservice smoking, and post-traumatic stress disorder symptoms at deployment's end. The impact of war zone variables was smaller than expected. It was recommended that the combat experience section of the military's postdeployment assessment form be expanded to enhance the military's ability to identify and refer personnel who may be at risk for psychiatric disorders.

Pyridostigmine, diethyltoluamide, permethrin, and stress: a double-blind, randomized, placebo-controlled trial to assess safety.

OBJECTIVE: To determine whether short-term human exposure to pyridostigmine bromide, diethyltoluamide, and permethrin, at rest or under stress, adversely affects short-term physical or neurocognitive performance. PARTICIPANTS AND METHODS: A multicenter, prospective, double-blind, placebo-controlled crossover trial exposing 64 volunteers to permethrin-impregnated uniforms, diethyltoluamide-containing skin cream, oral pyridostigmine, and corresponding placebos was performed. Each participant had 4 separate sessions, ensuring exposure to all treatments and placebos under both stress and rest conditions in random order. Outcomes Included physical performance (handgrip strength and duration, stair climbing, and pull-ups [males] or push-ups [females]), neurocognitive performance (computerized tests), and self-reported adverse effects. RESULTS: Permethrin was undetectable in the serum of all participants; pyridostigmine levels were higher Immediately after stress (41.6 ng/mL; 95% confidence Interval, 35.1-48.1 ng/mL) than rest (23.0 ng/mL; 95% confidence Interval, 19.2-26.9 ng/mL), whereas diethyltoluamide levels did not significantly differ by stress condition. Heart rate and systolic blood pressure increased significantly with stress compared with rest but did not vary with treatment vs placebo. Physical and neurocognitive outcome measures and self-reported adverse effects did not significantly differ by exposure group. CONCLUSION: Combined, correct use of pyridostigmine, diethyltoluamide, and permethrin is well tolerated and without evidence of short-term physical or neurocognitive impairment.

Risky alcohol use, age at onset of drinking, and adverse childhood experiences in young men entering the US Marine Corps.

OBJECTIVE: To examine how childhood experiences relate to risky underage drinking. DESIGN: A survey study of men starting military training between June 11, 2002, and April 5, 2006. Multivariate logistic regression models compared risky drinkers with "all others" or with nonrisky drinkers; excluding nondrinkers. SETTING: Marine Corps Recruit Depot, San Diego, Calif. PARTICIPANTS: Forty-one thousand four hundred eighty-two men aged 18 to 20 years. Main Exposures Age at drinking onset; childhood emotional, physical, and sexual abuse; childhood emotional and physical neglect; and household alcohol abuse, mental illness, domestic violence, or divorce. MAIN OUTCOME MEASURES: Risky drinking identified by scoring responses to 3 questions about alcohol consumption. RESULTS: Of 41,482 young men, 6128 (14.8%) were identified as risky drinkers, 18,693 (45.1%) as nonrisky drinkers, and 16 661 (40.2%) as nondrinkers. Among drinkers, early initiation of alcohol use was strongly associated with risky drinking, with a 5.5-fold risk if age at onset of drinking was 13 years or younger. Other associated factors included tobacco use, rural or small hometown, higher education, motivation to join the military for travel or adventure or to leave problems at home, numerous close friends and relatives, household alcohol abuse or mental illness, and childhood sexual or emotional abuse. When the comparison group included nondrinkers, additional associated factors included childhood physical abuse and domestic violence. CONCLUSIONS: These analyses confirm previous findings on risks for alcohol misuse in young adults and quantify these risks in new, large, multivariable models, adding unique perspective from a population of young Marines. Public health efforts to decrease alcohol misuse may be effectively targeted by prevention of underage alcohol use, tobacco use, and childhood abuse.

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.

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.

Enteric viral infections as potential risk factors for intussusception.

INTRODUCTION: We aimed to identify potential risk factors for intussusception (ISS) among children presenting to two pediatric hospitals in Egypt. METHODOLOGY: In this case-control study,  enrolled children < 3 years old with ISS (confirmed radiologically and/or surgically) were  matched by age and gender to controls admitted with acute non-abdominal surgical illnesses. Stool samples were collected and tested for various enteric bacteria, rotavirus, enteric adenoviruses (EA, 40 and 41) and astroviruses using commercially available ELISA diagnostic kits. RESULTS: From December 2004 to May 2009, 158 cases and 425 matched controls were enrolled. A history of diarrhoea and cough over the preceding four weeks of interview were more common in cases than controls, respectively. Children with mothers who had secondary education and above were 2.2 times more likely to have ISS than those whose mothers had a lower level of education. In spite of the low detection rate of EA infection (regardless of diarrhoea history) and asymptomatic rotavirus infection, they were detected in higher frequencies in cases than controls; however, infection with astrovirus and bacterial pathogens did not appear to be associated with increased risk of ISS. CONCLUSIONS: History of diarrhoea and cough over the four weeks preceding the study and maternal education above secondary level were potential risk factors for ISS. EA and asymptomatic rotavirus infection were detected in higher frequencies among cases than controls; however, association with ISS cannot be confirmed. Additional research is needed to confirm these findings and evaluate the pathogenesis which may link such infections with ISS.

Hotel clinic-based diarrheal and respiratory disease surveillance in U.S. service members participating in Operation Bright Star in Egypt, 2009.

We conducted clinic-based, influenza-like illness and diarrheal disease surveillance among U.S. service members participating in Operation Bright Star 2009. Epidemiologic data and samples were collected. Nasopharyngeal swab specimens were tested for viruses, and feces was tested for microbiologic, immunologic, and molecular diagnostics. A survey was used to collect self-reported data. From 1,529 surveys, 41% reported diarrheal disease and 25% reported respiratory illness (incidence rate = 62 of 100 versus 37 of 100 person-months; incidence rate ratio = 1.7, 95% confidence interval = 1.5-1.9). Enterotoxigenic Escherichia coli was identified in 74% (69 of 93) of fecal samples. In the influenza-like illness case series, 17% (9 of 52) were positive for influenza A; all were positive for pandemic (pH1N1) 2009 virus. Rates of decreased work performance reported by patients with diarrhea and influenza-like illness were similar (46% versus 48%; P = 0.8). Diarrheal diseases and respiratory illness remain common among deployed military personnel, with important operational impact. Despite an ongoing influenza pandemic, diarrheal disease incidence was higher than that of respiratory illness.

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.

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

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