by Rabi Biswas. / Publication date from spine. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1995. / Includes bibliographical references (leaves 122-143). / PREFACE --- p.2 / ACKNOWLEDGEMENTS --- p.3 / CONTENTS --- p.4 / GLOSSARY --- p.9 / ABSTRACT --- p.11 / INTRODUCTION --- p.12 / Chapter 1.1. --- OVERVIEW --- p.12 / Chapter 1.2. --- OBJECTIVES OF THE STUDY --- p.14 / LITERATURE REVIEW --- p.15 / Chapter 2.1. --- BACKGROUND OF THE STUDY --- p.15 / Chapter 2.2. --- ESCHERICHIA COLI : OVERVIEW --- p.17 / Chapter 2.2.1. --- Morphology --- p.18 / Chapter 2.2.2. --- Cultural characteristics --- p.18 / Chapter 2.2.3. --- Biochemical reactions --- p.19 / Chapter 2.2.4. --- Antigenic Structure --- p.19 / Chapter 2.2.5. --- Identification --- p.20 / Chapter 2.2.6. --- Classification of coli --- p.20 / Chapter 2.3. --- HISTORY OF EPEC --- p.22 / Chapter 2.3.1. --- E. coli as a cause of diarrhoea --- p.22 / Chapter 2.3.2. --- The first use of the term EPEC --- p.23 / Chapter 2.3.3. --- EPEC as a separate category of E. coli --- p.24 / Chapter 2.4. --- PATHOGENESIS OF EPEC --- p.25 / Chapter 2.4.1. --- Plasmid encoded virulence properties --- p.25 / Chapter 2.4.2. --- Characteristic interaction with intestinal mucosa --- p.26 / Chapter 2.4.3. --- Production of toxins --- p.28 / Chapter 2.5. --- EPIDEMIOLOGY OF EPEC --- p.29 / Chapter 2.6. --- EPIDEMIOLOGY OF EPEC IN CHINA AND HONG KONG --- p.32 / Chapter 2.7. --- CLINICAL INFECTION BY EPEC AND MANAGEMENT --- p.33 / Chapter 2.7.1. --- Epidemiological syndromes --- p.33 / Chapter 2.7.2. --- Infective dose --- p.33 / Chapter 2.7.3. --- Incubation period --- p.33 / Chapter 2.7.4. --- Host factors --- p.33 / Chapter 2.7.5. --- Reservoirs of infection --- p.33 / Chapter 2.7.6. --- Routes of transmission --- p.34 / Chapter 2.7.7. --- Seasonal variation --- p.34 / Chapter 2.7.8. --- Mechanism of diarrhoea --- p.34 / Chapter 2.7.9. --- Histology --- p.35 / Chapter 2.7.10. --- Clinical features --- p.35 / Chapter 2.7.11. --- Treatment --- p.35 / Chapter 2.7.12. --- Prevention --- p.36 / Chapter 2.8. --- DETECTION OF EPEC: LABORATORY METHODS --- p.36 / Chapter 2.8.1. --- O/H Serotyping --- p.36 / Chapter 2.8.2. --- Adhesion assay --- p.37 / Chapter 2.8.3. --- EAF probe --- p.37 / Chapter 2.8.4. --- FAS (Fluorescein Actin Staining) test --- p.37 / Chapter 2.8.5. --- ELISA (Enzyme Linked Immunosorbent Assay) --- p.38 / Chapter 2.8.6. --- eaeA gene probe --- p.38 / Chapter 2.8.7. --- bfpA probe --- p.39 / Chapter 2.8.8. --- PCR (Polymerase Chain Reaction) --- p.39 / MATERIALS AND METHODS --- p.41 / Chapter 3.1. --- PATIENT RECRUITMENT AND DATA COLLECTION --- p.41 / Chapter 3.1.1. --- Study site --- p.41 / Chapter 3.1.2. --- Study design --- p.41 / Chapter 3.1.3. --- Study period --- p.42 / Chapter 3.1.4. --- Study population --- p.42 / Chapter 3.1.5. --- Selection of patients --- p.42 / Chapter 3.1.6. --- Inclusion criteria for cases --- p.43 / Chapter 3.1.7. --- Exclusion criteria --- p.43 / Chapter 3.1.8. --- Selection of control group --- p.43 / Chapter 3.1.9. --- Collection of stool specimens --- p.44 / Chapter 3.1.10. --- Treatment of the study-patients --- p.45 / Chapter 3.1.11. --- Collection of date --- p.45 / Chapter 3.1.12. --- Ethical approval --- p.46 / Chapter 3.2. --- LABORATORY METHODS --- p.47 / Chapter 3.2.1. --- IN PWHLABORATORY --- p.47 / Chapter 3.2.2. --- IN AFRIMS LABORATORY --- p.48 / Chapter 3.3. --- DATA MANAGEMENT AND STATISTICAL METHODS --- p.63 / RESULT --- p.64 / Chapter 4.1. --- DEMOGRAPHY OF THE PATIENTS --- p.64 / Chapter 4.1.1. --- Age distribution of the patients --- p.64 / Chapter 4.1.2. --- Sex distribution of the patients --- p.64 / Chapter 4.1.3. --- Ethnic origin of the patients --- p.65 / Chapter 4.1.4. --- Distribution of area of abode in Hong Kong --- p.66 / Chapter 4.1.5. --- School attendance of the patients --- p.66 / Chapter 4.2. --- PREDISPOSING FACTORS FOR DIARRHOEA --- p.67 / Chapter 4.2.1. --- History of breast feeding of the patients --- p.67 / Chapter 4.2.2. --- History of contact with diarrhoea --- p.68 / Chapter 4.2.3. --- Travel history within last two weeks preceding onset of diarrhoea --- p.68 / Chapter 4.2.4. --- Source of drinking water --- p.69 / Chapter 4.3. --- CLINICAL FEATURES --- p.70 / Chapter 4.3.1. --- Duration of diarrhoea at the time of admission --- p.70 / Chapter 4.3.2. --- Frequency of stool --- p.71 / Chapter 4.3.3. --- Nature and contents of stool --- p.72 / Chapter 4.3.4. --- Condition of the perineum --- p.72 / Chapter 4.3.5. --- Duration of vomiting at the time of admission --- p.73 / Chapter 4.3.6. --- Frequency of vomiting --- p.73 / Chapter 4.3.7. --- Level of dehydration in cases --- p.74 / Chapter 4.3.8. --- Urine output during illness --- p.74 / Chapter 4.3.9. --- Fever associated with illness --- p.75 / Chapter 4.4. --- HISTORY OF HOME- MANAGEMENT --- p.77 / Chapter 4.4.1. --- Main food taken at home during illness --- p.77 / Chapter 4.4.2. --- Supplementary fluid taken at home during illness --- p.77 / Chapter 4.4.3. --- Duration of hospital stay --- p.78 / Chapter 4.4.4. --- Recruitment of patients in different months --- p.79 / Chapter 4.5. --- RESULTS OF GENE PROBING FOR E. COLI --- p.80 / Chapter 4.6. --- DETAILS OF THE EAF+ EPEC CASES --- p.82 / Chapter 4.6.1. --- Associated infections in EAF+ cases --- p.83 / Chapter 4.7. --- AETIOLOGY OF DIARRHOEA --- p.84 / Chapter 4.7.1. --- Age distribution --- p.85 / Chapter 4.7.2. --- Seasonal distribution --- p.86 / Chapter 4.7.3. --- Clinical features --- p.87 / Chapter 4.7.4. --- Different groups of Salmonella --- p.88 / Chapter 4.7.5. --- Dual infection among enteropathogens isolated --- p.89 / DISCUSSION --- p.90 / Chapter 5.1. --- RISK FACTORS ASSOCIATED WITH DIARRHOEA --- p.91 / Chapter 5.1.1. --- Age and sex of the patients --- p.91 / Chapter 5.1.2. --- Nutritional status --- p.91 / Chapter 5.1.3. --- Breast feeding --- p.92 / Chapter 5.1.4. --- Travelling --- p.93 / Chapter 5.2. --- SEVERITY OF DIARRHOEA IN HONG KONG --- p.93 / Chapter 5.3. --- MOLECULAR EPIDEMIOLOGY OF EPEC IN HONG KONG --- p.94 / Chapter 5.3.1. --- EAF probe --- p.94 / Chapter 5.3.2. --- EAF and EPEC virulence --- p.95 / Chapter 5.3.3. --- eaeA probe --- p.96 / Chapter 5.3.4. --- FAS test --- p.97 / Chapter 5.3.5. --- bfpA probe --- p.97 / Chapter 5.3.6. --- Comparison and contrast among the probes --- p.97 / Chapter 5.3.7. --- Probes in the present study --- p.99 / Chapter 5.3.8. --- Role of serogrouping at present --- p.100 / Chapter 5.3.9. --- EPEC in Hong Kong --- p.100 / Chapter 5.4. --- PREVALENCE OF OTHER CATEGORIES OF E. COLI --- p.101 / Chapter 5.5. --- COMMON AETIOLOGY OF DIARRHOEA IN HONG KONG --- p.102 / Chapter 5.5.1. --- Rotavirus as the most common cause --- p.102 / Chapter 5.5.2. --- Non-typhoid Salmonella as the major bacterial pathogen --- p.102 / Chapter 5.5.3. --- Campylobacter and Shigella as cause of diarrhoea --- p.103 / Chapter 5.5.4. --- Role of parasites in childhood diarrhoea in Hong Kong --- p.104 / Chapter 5.6. --- CONTROL MEASURES FOR DIARRHOEAL DISEASES --- p.105 / Chapter 5.6.1. --- Prevention of diarrhoea through improved nutrition --- p.105 / Chapter 5.6.2. --- Fluid supplementation in diarrhoea --- p.106 / Chapter 5.6.3. --- Strategies to control diarrhoea --- p.106 / Chapter 5.6.4. --- Health education --- p.107 / CONCLUSION --- p.108 / APPENDIX --- p.109 / Chapter 7.1. --- QUESTIONNAIRE --- p.109 / Chapter 7.2. --- LABORATORY METHODS --- p.111 / Chapter 7.2.1. --- Routine culture of stool specimens for bacteria --- p.111 / Chapter 7.2.2. --- "Serotyping of Salmonella, Shigella and Vibrio cholerae" --- p.114 / Chapter 7.2.3. --- Microscopic examination of ova and cysts --- p.117 / Chapter 7.2.4. --- Laboratory diagnosis of rotavirus --- p.118 / Chapter 7.3. --- INVESTIGATION REQUISITION FORM --- p.121 / REFERENCES --- p.122 / GRADUATE SEMINARS & PUBLICATIONS --- p.144 / Chapter a. --- Graduate seminars --- p.144 / Chapter b. --- Publications --- p.144

Para determinar a prevalência e epidemiologia dos enteropatógenos bacterianos e parasitários na diarréia aguda infantil, foram estudadas 290 crianças menores de 24 meses com diarréia e 290 crianças controles, que procuraram o serviço de emergência do Hospital Infantil Arlinda Marques em João Pessoa, Nordeste do Brasil. Enteropatógenos foram identificados em 78,2% dos casos e em 12,4% dos controles; Escherichia coli enteroagregativa (EAEC) foi o patógeno mais freqüente sendo detectada em 25% dos casos e em 8,3% dos controles; seguida por E. coli enteropatogênica (EPEC) em 11% dos casos (dos quais 9,3% foram cepas atípicas) e em 0,3% dos controles; E. coli Enterotoxigência (ETEC) em 10% dos casos e 2,8% dos controles; Salmonella sp em 7,9% dos casos; Shigella sp em 4,1% dos casos; E. coli enteroinvasora (EIEC) em 1,7% dos casos; Campylobacter sp em 2,4% dos casos e enteroparasitas foram detectados em 15,5% dos casos e 1,0% dos controles. Infecções mistas foram verificadas em 32 (11%) casos e em apenas 1 (0,3%) controle. A faixa etária mais atingida foi a dos menores de um ano e as associações mais frequentes ocorreram entre EAEC + Salmonella e EAEC + EPEC atípica. Neste estudo foram identificados fatores de risco associados com episódios de diarréia em crianças de acordo com o agente etiológico bacteriano. As análises estatísticas demonstram uma importante associação de EAEC com diarreia aguda infantil em João Pessoa, Brasil, sendo a ingestão de leite de vaca em pó e a exposição a aglomerados e creche os fatores de risco mais associados a diarreia causada por EAEC. / In order to determine the prevalence and epidemiology of enteropathogens in acute infantile diarrhoea, 290 infants younger than 24 months of age with diarrhoea and 290 age-matched control subjects who came to ER of the Hospital Infantil Arlinda Marques in João Pessoa, Northeastern of Brazil were studied. Enteropathogens were identified in 78,2% of case infants and 12,4% of controls. Enteroagregative Escherichia coli (EAEC) was the most frequently found pathogen and was detected in 25,0% of cases and 8,3% of controls. The second most frequent pathogen was Enteropathogenic E. coli (EPEC), in 11,0% of cases and 0,3% of controls, followed by Enterotoxigenic E. coli (ETEC) in 10% of cases and 2,7% of controls; Salmonella sp was found in 7,9% of cases, Shigella sp in 4,1% of cases, Enteroinvasive E. coli (EIEC) in 1,7% of cases and Campylobacter sp in 2,4% of cases. Enteroparasites were detected in 15,5% of cases and 1,0% of controls. Mixed infections (more than one pathogen) were found in 32 (11%) of cases and in only 1 (0,3%) control. The most affected age group was of those smaller than 1 year of age and the most frequent associations were of EAEC + Salmonella e EAEC + atypical EPEC. In this study risk factors associated with episodes of diarrhoea among infants by bacterial etiological pathogens were identified. Statistical analysis demonstrated a significant association of Enteroagregative E. coli (EAEC) with acute infantile diarrhoea in João Pessoa, Brazil. The risk factors most strongly associated diarrhoea caused by EAEC were the ingestion of powdered cow milk and exposure to crowds and day care centres.

Para determinar a prevalência e epidemiologia dos enteropatógenos bacterianos e parasitários na diarréia aguda infantil, foram estudadas 290 crianças menores de 24 meses com diarréia e 290 crianças controles, que procuraram o serviço de emergência do Hospital Infantil Arlinda Marques em João Pessoa, Nordeste do Brasil. Enteropatógenos foram identificados em 78,2% dos casos e em 12,4% dos controles; Escherichia coli enteroagregativa (EAEC) foi o patógeno mais freqüente sendo detectada em 25% dos casos e em 8,3% dos controles; seguida por E. coli enteropatogênica (EPEC) em 11% dos casos (dos quais 9,3% foram cepas atípicas) e em 0,3% dos controles; E. coli Enterotoxigência (ETEC) em 10% dos casos e 2,8% dos controles; Salmonella sp em 7,9% dos casos; Shigella sp em 4,1% dos casos; E. coli enteroinvasora (EIEC) em 1,7% dos casos; Campylobacter sp em 2,4% dos casos e enteroparasitas foram detectados em 15,5% dos casos e 1,0% dos controles. Infecções mistas foram verificadas em 32 (11%) casos e em apenas 1 (0,3%) controle. A faixa etária mais atingida foi a dos menores de um ano e as associações mais frequentes ocorreram entre EAEC + Salmonella e EAEC + EPEC atípica. Neste estudo foram identificados fatores de risco associados com episódios de diarréia em crianças de acordo com o agente etiológico bacteriano. As análises estatísticas demonstram uma importante associação de EAEC com diarreia aguda infantil em João Pessoa, Brasil, sendo a ingestão de leite de vaca em pó e a exposição a aglomerados e creche os fatores de risco mais associados a diarreia causada por EAEC. / In order to determine the prevalence and epidemiology of enteropathogens in acute infantile diarrhoea, 290 infants younger than 24 months of age with diarrhoea and 290 age-matched control subjects who came to ER of the Hospital Infantil Arlinda Marques in João Pessoa, Northeastern of Brazil were studied. Enteropathogens were identified in 78,2% of case infants and 12,4% of controls. Enteroagregative Escherichia coli (EAEC) was the most frequently found pathogen and was detected in 25,0% of cases and 8,3% of controls. The second most frequent pathogen was Enteropathogenic E. coli (EPEC), in 11,0% of cases and 0,3% of controls, followed by Enterotoxigenic E. coli (ETEC) in 10% of cases and 2,7% of controls; Salmonella sp was found in 7,9% of cases, Shigella sp in 4,1% of cases, Enteroinvasive E. coli (EIEC) in 1,7% of cases and Campylobacter sp in 2,4% of cases. Enteroparasites were detected in 15,5% of cases and 1,0% of controls. Mixed infections (more than one pathogen) were found in 32 (11%) of cases and in only 1 (0,3%) control. The most affected age group was of those smaller than 1 year of age and the most frequent associations were of EAEC + Salmonella e EAEC + atypical EPEC. In this study risk factors associated with episodes of diarrhoea among infants by bacterial etiological pathogens were identified. Statistical analysis demonstrated a significant association of Enteroagregative E. coli (EAEC) with acute infantile diarrhoea in João Pessoa, Brazil. The risk factors most strongly associated diarrhoea caused by EAEC were the ingestion of powdered cow milk and exposure to crowds and day care centres.

Water is essential for life, and access to sources of safe water and sanitation facilities is a first-order concern for economic welfare and general well-being. While the majority of residents in developing countries have access to improved water and sanitation services, many parts of the developing world lag significantly behind in this vital infrastructure. This dissertation studies policies aimed at increasing access, quality, and efficiency of improved water and sanitation (WS) services in developing countries. In the following three chapters, I focus on non-technological methods for improving service by eliminating the economic, political, and institutional barriers to safe water and sanitation provision. Chapter 1, “The Buck Stops Where? Federalism and Investment in the Brazilian Water and Sanitation Sector”, shows how weak institutions can undermine public goods service when multiple levels of government share responsibility of provision. In particular, I study how legal ambiguities regarding degrees of governmental authority can lead to systematic underinvestment in public utilities. I examine the Brazilian water and sanitation (WS) sector, which presents an natural experiment of shared provision between state and municipality entities. I look at a legal reform that clarified the relationship between municipalities and states in a quasi-experimental, difference-in-differences framework, using an administrative, municipality-level panel dataset from 2001-2012. I find that when expropriation risk by state companies diminished - self-run municipalities almost doubled their WS network investment. This increase in investment led to a significant increase in access to the WS system in these municipalities. The analysis provides strong evidence that reforms that strengthen residual control rights and eliminate the threat of intra-governmental expropriation can lead to large increases in public goods investment. Chapter 2, “The Role of Basic Sanitation Plans on Service Provision: Evidence from Brazil”, investigates non-technological methods of increasing access to improved water and sanitation (WS) in developing countries. In particular, it presents evidence of the efficiency gains that can be achieved in municipal water provision through the act of formulating and carrying out basic sanitation plans. I exploit the staggered roll-out in implementation of basic sanitation plans throughout municipalities in southern Brazil from 2007-2013. I find that, in the three years after the enactment of sanitation plans, municipalities increased the efficiency of their respective water systems through the tightening up of “leakages" in the system, both in terms of water distribution and bill payment. However, I find no significant increases in the degree of individual access to the systems, suggesting that in the relatively short-run, providers focus on improving the existing system as opposed to building out new infrastructure. Chapter 3, “(Not So) Gently Down The Stream: River Pollution and Health in Indonesia”, addresses the fact that waterborne diseases are the leading cause of mortality in developing countries. We emphasize a previously ignored cause of diarrhea - upstream river bathing. Using newly constructed data on upstream-downstream hydrological linkages along with village census panel data in Indonesia, we find that upstream river bathing can explain as many as 7.5% of all diarrheal deaths. Our results, which are net of avoidance behavior, show no effect of trash disposal on diarrheal infections. Furthermore we find that individuals engage in avoidance behavior in response to trash disposal (visible pollutants) but not river bathing (invisible pollutants). We conduct policy simulations to show that targeting upstream individuals could generate substantial environmental and health savings relative to targeting downstream individuals. This provides a potential road map for low- and middle-income countries with limited resources for enforcement of water pollution.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-18T18:17:25Z No. of bitstreams: 1 servuloluizborges.pdf: 497208 bytes, checksum: 0cdbea63a9c3a9debc06799fb62e1820 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-10-25T12:11:43Z (GMT) No. of bitstreams: 1 servuloluizborges.pdf: 497208 bytes, checksum: 0cdbea63a9c3a9debc06799fb62e1820 (MD5) / Made available in DSpace on 2016-10-25T12:11:43Z (GMT). No. of bitstreams: 1 servuloluizborges.pdf: 497208 bytes, checksum: 0cdbea63a9c3a9debc06799fb62e1820 (MD5) Previous issue date: 2007-07-30 / Racional - A diarréia nosocomial é uma das infecções mais comuns entre pacientes internados em Unidades de Terapia Intensiva (UTI), embora sua epidemiologia, bem como causas e conseqüências sejam raramente documentadas em estudos de vigilância de infecções hospitalares. Objetivo - Estudar a incidência e os fatores risco entre os pacientes adultos acometidos com diarréia em uma UTI clínico cirúrgica, no período de 12 meses. Pacientes e métodos – Foram estudados prospectivamente, após exclusão, 457 pacientes quanto ao desfecho de diarréia e os fatores de risco, no período de outubro de 2005 a outubro de 2006. Considerou se como diarréia nosocomial o quadro clínico de diarréia com início após 72 h da admissão hospitalar, com pelo menos duas evacuações líquidas ou pastosas por mais de dois dias consecutivos. A coleta de dados foi realizada diariamente na UTI até a alta ou óbito do paciente no setor. As variáveis analisadas foram: idade, sexo, tempo de internação hospitalar antes da admissão na UTI, tempo de internação na UTI, o escore APACHE II, comorbidades, insuficiência orgânica, história cirúrgica nos últimos 30 dias, uso corrente de antimicrobianos (incluindo o número de dias e número total de antibióticos), antisecretores, nutrição enteral, parenteral, fleet enemas, duração total da diarréia (em dias), tempo do início da diarréia em relação à internação, presença de caso similar de diarréia na UTI na última semana ou na mesma ocasião, albumina sérica e taxa de hemoglobina em pelo menos uma ocasião durante a internação. Para análise dos dados, os pacientes foram divididos em grupos com e sem diarréia nosocomial. O nível de significância foi de 5% (P < 0,05). As variáveis significativas na análise univariada foram analisadas, de forma multivariada, através da estimação de um modelo de regressão logística. Resultados - Diarréia ocorreu em 135 (29,5%) pacientes, durando em média 5,4 dias. O tempo do seu início em relação à internação foi de 17,8 dias e casos similares no período foram registrados em 113 (83,7%) pacientes. Na análise multivariada através de modelo de regressão logística, apenas o número de antibióticos (OR 1,65; I.C. 95% = 1,39 – 1,95) e o número de dias de antibioticoterapia (OR 1,16; I.C. 95% = 1,12 – 1,20) associaram-se estatisticamente com a ocorrência de diarréia (P = 0.000). Cada dia de acréscimo a mais da 8 antibioticoterapia aumentou em 16% o risco de diarréia (I.C. 12% a 20%), enquanto a adição de um antibiótico a mais ao esquema antimicrobiano aumentou as chances de ocorrência de diarréia em 65% (I.C. 39% a 95%). Conclusão – A incidência de diarréia nosocomial na UTI é elevada (29,5%). Os principais fatores de risco para sua ocorrência foram número de antibióticos prescritos e duração da antibioticoterapia. Além das precauções entéricas, a prescrição judiciosa e limitada de antimicrobianos, provavelmente reduzirá a ocorrência de diarréia neste setor. / Background - Nosocomial diarrhea is one of the most common infection diseases among patients admitted at Intensive Care Units (ICUs), although its epidemiology as well as its causes and consequences are rarely documented in hospital infections surveillance studies. Objective - To study the incidence and the risk factors for diarrhea among adult patients admitted at a clinical-surgical ICU for a 12-months period. Patient and methods – Four-hundred-fifty-seven patients were studied prospectively, after application of exclusion criteria, to determine diarrhea incidence and risk factors from October 2005 to October 2006. Nosocomial diarrhea was defined as clinical picture of diarrhea beginning 72 hours from hospital admission, with at least two watery or pasty bowel movements for more than two consecutive days. Data acquisition was done on a daily basis at ICU until patient discharge or death in the unit. Variables analyzed were the following: age, sex, days of hospitalization before admission at the ICU, days of hospitalization at the ICU, APACHE II score, comorbidities, organic insufficiency, surgical history for the last 30 days, current use of antimicrobials (including number of days and total number of antibiotics), antisecretories, enteral nutrition, parenteral, fleet enemas, total duration of diarrhea (in days), period of time between patient admission and beginning of diarrhea, presence of similar case of diarrhea in ICU during the last week or at the same time, serum albumin and hemoglobin levels in at least one occasion during admission. For data analysis, the patients were divided into groups with and without nosocomial diarrhea. The level of significance was 5% (P <0.05). The significant variables in univariate analysis were analyzed, in a multivariate form, through estimation of a logistic regression model. Results - Diarrhea occurred in 135 (29.5%) patients and lasted for a mean of 5.4 days. The period of time between patient admission and beginning of diarrhea was 17.8 days and similar cases during the period were recorded in 113 (83.7%) patients. In multivariate analysis using logistic regression model only the number of antibiotics (OR 1.65; C.I. 95% = 1.39 – 1.95) and the number of days of antibiotic therapy (OR 1.16; C.I. 95% = 1.12 – 1.20) were statistically associated with the occurrence of diarrhea (P <0.05). Each day added of antibiotic therapy increased in 16% the risk of diarrhea (C.I. 12% to 20%), while the 10 addition of one more antibiotic to the scheme increased the chances of occurring diarrhea in 65% (C.I. 39% to 95%). Conclusion - The incidence of nosocomial diarrhea in ICU is high (29.5%). The main risk factors were number of prescribed antibiotics and duration of antibiotic therapy. Besides the enteric precautions, judicious and limited prescription of antimicrobials will probably decrease the incidence of diarrhea at this unit.