Clinic-based Surveillance Research Articles

A comparison of missing data procedures for addressing selection bias in HIV sentinel surveillance data

BackgroundSelection bias is common in clinic-based HIV surveillance. Clinics located in HIV hotspots are often the first to be chosen and monitored, while clinics in less prevalent areas are added to the surveillance system later on. Consequently, the estimated HIV prevalence based on clinic data is substantially distorted, with markedly higher HIV prevalence in the earlier periods and trends that reveal much more dramatic declines than actually occur.MethodsUsing simulations, we compare and contrast the performance of the various approaches and models for handling selection bias in clinic-based HIV surveillance. In particular, we compare the application of complete-case analysis and multiple imputation (MI). Several models are considered for each of the approaches. We demonstrate the application of the methods through sentinel surveillance data collected between 2002 and 2008 from India.ResultsSimulations suggested that selection bias, if not handled properly, can lead to biased estimates of HIV prevalence trends and inaccurate evaluation of program impact. Complete-case analysis and MI differed considerably in their ability to handle selection bias. In scenarios where HIV prevalence remained constant over time (i.e. β = 0), the estimated derived from MI tended to be biased downward. Depending on the imputation model used, the estimated bias ranged from −1.883 to −0.048 in logit prevalence. Furthermore, as the level of selection bias intensified, the extent of bias also increased. In contrast, the estimates yielded by complete-case analysis were relatively unbiased and stable across the various scenarios. The estimated bias ranged from −0.002 to 0.002 in logit prevalence.ConclusionsGiven that selection bias is common in clinic-based HIV surveillance, when analyzing data from such sources appropriate adjustment methods need to be applied. The results in this paper suggest that indiscriminant application of imputation models can lead to biased results.

Prevalence and Distribution of Human Papillomavirus Genotype in South Eastern Italy, in the Period 2006-2011: Implications for Intervention

Persistent infection of High Risk (HR) Human papillomavirus (HPV) infection can lead to cervical cancer. The HPV genotypes are found worldwide, but important regional variations have been found. For a population-based HPV type prevalence study to assess the effect of existing and new prevention methods, frequently updated information on the burden of cervical cancer is essential. We evaluated the prevalence of HPV genotypes in a volunteer population screened for cervical cancer at the Local Health Unit (LHU) of Lecce. A total of 9,720 women were studied. The tests were performed by INNO-Lipa HPV Genotyping and LINEAR ARRAY HPV Genotyping Test. The overall HPV prevalence was 29.7% (95% CI, 28.8-30.6) for any HPV DNA. The prevalent type for all age groups was HPV 16 (7.4%; CI, 6.9-7.9) followed by HPV 31 (3.4%; CI, 3.0-3.7), 51 (3.0%; CI, 2.6-3.3), 52 (2.7%; CI, 2.3-3.0) and 58 (2.4%; CI, 2.1-2.7). HPV 53 was the most common low-risk HPV type with prevalence rate of 3.5 (CI, 3.1-3.8), followed by HPV 66 (3.0; CI, 2.6-3.3), 6 (2.9; CI, 2.6-3.2) and 42 (2.5; CI, 2.2-2.8). Multiple infections were present in 13.6% of HPV-tested women (CI, 12.9-14.3). Among these, the most common combination was of HPV 16 and HPV 52 genotypes. This study reports high prevalence of HPV infection and may serve as a valuable reference for assessing the impact of HPV vaccination programs. Furthermore, it supports the need for new vaccines that contain the most common HPV genotypes present in the population.

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.

Monitoring HPV type-specific prevalence over time through clinic-based surveillance: A perspective on vaccine effectiveness

We investigated the feasibility of monitoring trends in prevalence of vaccine-preventable human papillomavirus (HPV) types in different clinic populations. We collected cervical specimens from women presenting to family planning, primary care, and sexually transmitted disease (STD) clinics for routine pap smears in five US cities during 2003-2005. We performed HPV genotyping and calculated annual type-specific prevalences; pre-vaccine era prevalence was highest for HPV 16 (6.0; 95% confidence interval [CI] 5.5-6.6%) and annual prevalences for vaccine-preventable types were stable, with few exceptions, after controlling for clinic type, age group, and city. With sufficient sample size and stable population characteristics, clinic-based surveillance systems can contribute to monitoring HPV vaccine impact in the cervical screening population.

Prevalence of HIV among rural pregnant women attending antenatal clinics at Pravara Rural Hospital, Loni, Maharashtra, India

Background: Many antenatal clinics (ANC)-based HIV surveillance systems in India have limited coverage of remote rural sites, a weakness that compromises adequate estimation, monitoring, and development of effective preventive and care programs. To address this void in rural area of western Maharashtra, we conducted antenatal clinic-based sentinel surveillance to know the prevalence of HIV infection among rural pregnant women. Materials and Methods: A cross-sectional study was carried out at ANC clinic, Dept. of Obstetrics and Gynaecology of Pravara Rural Hospital, Loni, Maharashtra. A total of 12,171 pregnant women from rural area accepted HIV testing after counseling who attending ANC clinic in Pravara Rural Hospital, Loni, during January 2008 to December 2011 were included in the study. Data were entered in Microsoft excel and percentage and proportion was calculated. Results: In the present study, out of 12171 pregnant women from the rural area accepted HIV testing after counseling who attending ANC clinic, only 50 (0.41%) were HIV positive and remaining 12, 221 (99.59%) were HIV negative. The study showed that the prevalence of HIV among pregnant women was 0.41%. Out of the 50 HIV positive pregnant women studied majority, 32 (64.0%), were primigravidas and 18 (36.0%) were multigravidas. Conclusion: In our study all 12171 pregnant women from the rural area accepted HIV testing after counseling and prevalence of HIV was found to be 0.41%. The need of the hour is to provide universal access to these services by involving the NGO's and the private sector.

LBO-1.3 Syphilis infection and associated behaviours among transgender women, Chicago 2010

BackgroundTransgender women are an underserved and understudied population with unique medical and behavioural risk profiles. High rates of STIs and HIV in this population have been reported, although accurately quantifying...

Comparison of estimates of malnutrition in children aged 0–5 years between clinic-based nutrition surveillance and national surveys

This study documents a marked discrepancy between the nutritional status of children aged 0-5 years in Botswana when measured by national surveys compared to clinic-based surveillance. We compared the average prevalence of underweight (weight-for-age z-scores below 2 standard deviations of the mean of the Center for Disease Control (CDC)/WHO reference standards) in children 0-5 years of age. According to clinic surveillance, prevalence of underweight has fallen from 14.6 ± 0.03 to 3.5 ± 0.04 per cent between 1993 and 2010. In national surveys, it had fallen from 14.6 ± 0.01 to 11.5 ± 0.01 per cent between 1993 and 2007. We explored several possibilities to explain this discrepancy, and conclude that it is because of sampling bias in the clinic surveillance. This finding underlines the need for properly conducted surveys to ensure accurate information about the nutritional status of children.

Impact evaluation of a youth sexually transmissible infection awareness campaign using routinely collected data sources

Young people are at high risk of sexually transmissible infections (STI) and notifications of chlamydia are rising rapidly. In 2007, a Victorian multimedia campaign aimed to increase STI testing and condom use among 18-25-year-olds. We conducted a retrospective impact evaluation using multiple sources of routinely collected data. Population-level chlamydia testing data from general practice, chlamydia testing data from five government primary care clinics with a high caseload of young people, and behavioural data from an annual youth behavioural survey were analysed. Analyses included time-series regression to assess trends in testing levels, Kruskal-Wallis tests to assess changes in positivity, and χ(2)-tests to assess knowledge and behaviour change. There was no significant difference in the slope of monthly chlamydia testing in population-level or clinic-based surveillance during the campaign compared with before or after the campaign, and no changes in chlamydia positivity. Between 2007 and 2008, there was a significant increase in STI knowledge among females (P<0.01) and in the proportion of females reporting always using a condom with casual (P=0.04) and new sexual partners (P<0.01) in the annual behavioural survey. Our findings suggest the campaign had no impact on STI testing but may have contributed to an increase in knowledge and condom use among females; however, this increase could not be directly attributed to the campaign. Future campaigns targeting young people for STI testing should consider alternative messages and approaches, and include robust evaluation mechanisms to measure campaign impact prospectively.

Evaluation of an influenza-like illness case definition in the diagnosis of influenza among patients with acute febrile illness in cambodia

BackgroundInfluenza-like illness (ILI) is often defined as fever (>38.0°C) with cough or sore throat. In this study, we tested the sensitivity, specificity, and positive and negative predictive values of this case definition in a Cambodia patient population.MethodsPassive clinic-based surveillance was established at nine healthcare centers to identify the causes of acute undifferentiated fever in patients aged two years and older seeking treatment. Fever was defined as tympanic membrane temperature >38°C lasting more than 24 hours and less than 10 days. Influenza virus infections were identified by polymerase chain reaction.ResultsFrom July 2008 to December 2008, 2,639 patients were enrolled. From 884 (33%) patients positive for influenza, 652 presented with ILI and 232 acute fever patients presented without ILI. Analysis by age group identified no significant differences between influenza positive patients from the two groups. Positive predictive values (PPVs) varied during the course of the influenza season and among age groups.ConclusionThe ILI case definition can be used to identify a significant percentage of patients with influenza infection during the influenza season in Cambodia, assisting healthcare providers in its diagnosis and treatment. However, testing samples based on the criteria of fever alone increased our case detection by 34%.

Arboviral Etiologies of Acute Febrile Illnesses in Western South America, 2000–2007

BackgroundArthropod-borne viruses (arboviruses) are among the most common agents of human febrile illness worldwide and the most important emerging pathogens, causing multiple notable epidemics of human disease over recent decades. Despite the public health relevance, little is know about the geographic distribution, relative impact, and risk factors for arbovirus infection in many regions of the world. Our objectives were to describe the arboviruses associated with acute undifferentiated febrile illness in participating clinics in four countries in South America and to provide detailed epidemiological analysis of arbovirus infection in Iquitos, Peru, where more extensive monitoring was conducted.Methodology/FindingsA clinic-based syndromic surveillance system was implemented in 13 locations in Ecuador, Peru, Bolivia, and Paraguay. Serum samples and demographic information were collected from febrile participants reporting to local health clinics or hospitals. Acute-phase sera were tested for viral infection by immunofluorescence assay or RT-PCR, while acute- and convalescent-phase sera were tested for pathogen-specific IgM by ELISA. Between May 2000 and December 2007, 20,880 participants were included in the study, with evidence for recent arbovirus infection detected for 6,793 (32.5%). Dengue viruses (Flavivirus) were the most common arbovirus infections, totaling 26.0% of febrile episodes, with DENV-3 as the most common serotype. Alphavirus (Venezuelan equine encephalitis virus [VEEV] and Mayaro virus [MAYV]) and Orthobunyavirus (Oropouche virus [OROV], Group C viruses, and Guaroa virus) infections were both observed in approximately 3% of febrile episodes. In Iquitos, risk factors for VEEV and MAYV infection included being male and reporting to a rural (vs urban) clinic. In contrast, OROV infection was similar between sexes and type of clinic.Conclusions/SignificanceOur data provide a better understanding of the geographic range of arboviruses in South America and highlight the diversity of pathogens in circulation. These arboviruses are currently significant causes of human illness in endemic regions but also have potential for further expansion. Our data provide a basis for analyzing changes in their ecology and epidemiology.

The burden of inherited leukodystrophies in children

Leukodystrophies are diseases of the white matter for which data concerning clinical characteristics, incidence, disease burden, and description of outcomes are sparse. The purpose of our study was to determine the incidence and most common types of inherited leukodystrophies in a population, the mortality and time course of deaths, common neurologic features in patients, and health care costs associated with leukodystrophies. We conducted a retrospective, hospital- and clinic-based surveillance of inherited leukodystrophies among children younger than 18 years presenting to a regional children's hospital. We enrolled children evaluated from January 1, 1999, through December 31, 2007; clinical information was obtained from medical records. We calculated incidence based on state birth rates. A total of 122 children with an inherited leukodystrophy were identified; 542 patients were excluded. A total of 49% had epilepsy, 43% required a gastrostomy tube, and 32% had a history of developmental regression. Mortality was 34%; average age at death was 8.2 years. No final diagnosis was reported in 51% of patients. The most common diagnoses were metachromatic leukodystrophy (8.2%), Pelizaeus-Merzbacher disease (7.4%), mitochondrial diseases (4.9%), and adrenoleukodystrophy (4.1%). Endocrine abnormalities and hypoplastic cerebellum were noted in significant portions of patients (15% and 14%). Average yearly per-patient medical costs were $22,579. Population incidence was 1 in 7,663 live births. Inherited leukodystrophies are associated with substantial morbidity and mortality in children. Overall population incidence is higher than generally appreciated (1 in 7,663 live births). Most leukodystrophies remain undiagnosed, but a logical algorithm based on prevalence could aid testing.

Venezuelan Equine Encephalitis Virus in Iquitos, Peru: Urban Transmission of a Sylvatic Strain

Enzootic strains of Venezuelan equine encephalitis virus (VEEV) have been isolated from febrile patients in the Peruvian Amazon Basin at low but consistent levels since the early 1990s. Through a clinic-based febrile surveillance program, we detected an outbreak of VEEV infections in Iquitos, Peru, in the first half of 2006. The majority of these patients resided within urban areas of Iquitos, with no report of recent travel outside the city. To characterize the risk factors for VEEV infection within the city, an antibody prevalence study was carried out in a geographically stratified sample of urban areas of Iquitos. Additionally, entomological surveys were conducted to determine if previously incriminated vectors of enzootic VEEV were present within the city. We found that greater than 23% of Iquitos residents carried neutralizing antibodies against VEEV, with significant associations between increased antibody prevalence and age, occupation, mosquito net use, and overnight travel. Furthermore, potential vector mosquitoes were widely distributed across the city. Our results suggest that while VEEV infection is more common in rural areas, transmission also occurs within urban areas of Iquitos, and that further studies are warranted to identify the precise vectors and reservoirs involved in urban VEEV transmission.

Haemoglobin adjustments to define anaemia

To provide researchers with an unambiguous definition of anaemia using haemoglobin. Review of recommendations by expert groups and review of the literature. This report provides an unambiguous approach to haemoglobin adjustments to define anaemia using international criteria. When determining anaemia using haemoglobin, it is important to account for pregnancy, altitude, cigarette smoking, and possibly ethnicity after removing unlikely values. These haemoglobin adjustments are presented. Recommendations for defining extreme haemoglobin values and for reporting anaemia and haemoglobin results are provided, and software programs to determine anaemia are described.

Epidemiological and Clinical Observations on Patients with Dengue in Puerto Rico: Results from the First Year of Enhanced Surveillance—June 2005–May 2006

From June 2005 to May 2006, a clinic-based enhanced surveillance system for dengue was implemented in a Puerto Rican municipality to provide a population-based measure of disease incidence and clinical outcomes. We obtained demographic and clinical information from suspected cases and performed serologic and virologic testing. We used World Health Organization (WHO) criteria to classify cases and applied a simplified case definition for severe dengue illness. There were 7.7 laboratory-positive cases of dengue per 1,000 population. The highest incidence, 13.4 per 1,000, was among 10 to 19 year olds. Of the 156 laboratory-positive cases, three patients (1.9%) met WHO criteria for dengue hemorrhagic fever, and 30 patients (19.2%) had at least one severe clinical manifestation of dengue infection. Our data suggest that in a community with endemic dengue, enhanced surveillance is useful for detecting symptomatic infections. Furthermore, the simplified case definition for severe dengue may be useful in clinic-based surveillance.

Acute Gastrointestinal Infection, Respiratory Illness, and Noncombat Injury Among US Military Personnel During Operation Bright Star 2005, in Northern Egypt

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. 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. 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. 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.

Surveillance for Bacterial Diarrhea and Antimicrobial Resistance in Rural Western Kenya, 1997-2003

Diarrhea is a major cause of preventable illness in sub-Saharan Africa. Although most cases of bacterial gastroenteritis do not require antimicrobial treatment, antimicrobial use is widespread. We examined the bacterial causes of diarrhea and monitored antimicrobial susceptibilities of isolates through clinic-based surveillance in a rural Kenyan community. From May 1997 through April 2003, diarrheal stool samples from persons presenting to 4 sentinel health centers were cultured by standard techniques for routine bacterial enteric pathogens, for which antimicrobial susceptibilities were determined. A random subset of specimens was also evaluated for diarrheagenic Escherichia coli. Among stool specimens from 3445 persons, 1092 (32%) yielded at least 1 bacterial pathogen. Shigella species was most commonly isolated (responsible for 16% of all illnesses; 54% of isolates were Shigella flexneri). Campylobacter species and diarrheagenic E. coli predominated among children aged <5 years and were progressively replaced by Shigella species with increasing age. With the exception of Campylobacter species, susceptibility to the antimicrobials used most widely in the community was low: <40% for all isolates tested and <25% for Shigella species. Most persons were treated with an antimicrobial to which their isolate was resistant. Susceptibility to specific antimicrobials was inversely proportional to the frequency with which they were prescribed. The utility of available antimicrobials for treating bacterial diarrhea in rural western Kenya is substantially limited by reduced susceptibility. More judicious use of appropriate antimicrobials is warranted. Efforts to prevent illness through provision of clean water, improved hygiene, and vaccine development should be strengthened.

Molecular Epidemiology of Recently Emergent Ciprofloxacin-Resistant Neisseria gonorrhoeae in South Africa

Syndromic management guidelines for male urethritis syndrome and female discharge syndrome (nonpregnant) in South Africa advocate the use of ciprofloxacin for potential infection with Neisseria gonorrhoeae. In 2003, reports of clinical failure of gonorrhea following ciprofloxacin treatment prompted a clinic-based surveillance to detect the presence of resistant isolates. Urethral samples for the isolation of N gonorrhoeae were obtained from consecutive male patients with urethral discharge attending the largest sexually transmitted disease clinic in KwaZuluNatal. Molecular typing of isolates was performed by means of N gonorrhoeae multiantigen sequence typing (NG-MAST). Of 139 isolates, 31 (22%) were resistant to ciprofloxacin (minimum inhibitory concentration >or=1 mg/l). NG-MAST revealed novel, as well as previously described, sequence types (ST). The largest cluster of our isolates belonged to ST 217. This ST has been reported among ciprofloxacin-resistant isolates from Europe. : The results underscore the urgency of review of the current treatment guidelines for discharge disease in KwaZuluNatal.

The silent HIV epidemic among pregnant women within rural Northern Tanzania

BackgroundMany national antenatal clinics (ANC) based HIV surveillance systems in sub-Saharan Africa have limited coverage of remote rural sites, a weakness that compromises adequate estimation, monitoring and development of effective preventive and care programmes. To address this void in rural Manyara and Singida within Northern Tanzania, we conducted antenatal clinic-based sentinel surveillance.MethodsWe consecutively enrolled 1377 counselled and consenting pregnant women attending ANC clinics for the first time during the current pregnancy. The study was conducted in six antenatal clinics, within three divisions of rural Manyara and Singida regions in 2003/2004. Interviews were conducted and blood samples for routine purposes were collected and tested for anti-HIV IgG antibody anonymously, using Bionor HIV-1 & 2 assay ®.ResultsAmong enrolees, 94% (1296/1377) participated fully. The overall prevalence of HIV was 2.0% (95%CI: 1.34–2.97). The highest HIV prevalence was among women aged between 15–19 years in both rural and remote rural populations. The odds of HIV infection was 4.3 (95%CI: 1.42–12.77) times among women reporting more than one lifetime sexual partners compared with those with one partner. HIV infection was associated with history of genital sores or foul smelling discharge, OR 6.8 (95%CI: 2.78–16.66) and age at first pregnancy (2.5 times higher likelihood of infection if before the age of 18 years versus at a later age).ConclusionIncluding rural remote sites, as part of the national ANC routine surveillance, is crucial in order to discover imminent silent epidemics such as the one described in this paper. Scaling up HIV prevention efforts is mandatory to prevent the imminent escalation of the HIV epidemic highly associated with a history of sexually transmitted infections (STIs), multiple sexual partners and pregnancies at a younger age. Ignorance of relevant knowledge and low utilisation of condoms underscores the urgency for large-scale preventive efforts. Research to capture a wider representation of the risk factors in the general population should be a priority to enable further customised HIV prevention efforts.

Urban lymphatic filariasis in central Nigeria

Wuchereria bancrofti and the other mosquito-borne parasites that cause human lymphatic filariasis (LF) infect over 120 million people world-wide. Global efforts are underway to stop transmission of the parasites, using annual, single-dose mass drug administrations (MDA) to all at-risk populations. Although most MDA to date have been in rural settings, they are also recommended in urban areas of transmission. It remains unclear whether there is significant urban transmission in West Africa, however, and the need for urban MDA in this region therefore remains a matter of debate.Clinic-based surveillance, for the clinical manifestations of LF, has now been used to identify areas of urban transmission of W. bancrofti in Jos, the major urban population centre of Plateau state, Nigeria. The eight clinics investigated were all located in slum areas, close to vector breeding sites, and were therefore considered to serve at-risk populations. Over a 1-month period, selected providers in these clinics sought hydrocele, lymphoedema, elephantiasis, or acute adenolymphangitis among the patients seeking treatment. The consenting patients who were suspected clinical cases of LF, and a cohort of patients suspected to be cases of onchocerciasis, were tested for W. bancrofti antigenaemia. All the patients were asked a series of questions in an attempt to determine if those found antigenaemic could only have been infected in an urban area. During the study, 30 suspected clinical cases of LF were detected and 18 of these (including two patients who were found to be antigenaemic) lived in urban areas. Of the 98 patients with exclusively urban exposure who were tested for filarial antigenaemia, six (6.1%) were found antigenaemic. Clinic-based surveillance appears to be a useful tool for determining if there is W. bancrofti transmission in an urban setting.

CLINIC-BASED SURVEILLANCE FOR BACTERIAL- AND ROTAVIRUS-ASSOCIATED DIARRHEA IN EGYPTIAN CHILDREN

To identify enteropathogens for vaccine development, we implemented clinic-based surveillance for severe pediatric diarrhea in Egypt's Nile River Delta. Over 2 years, a physician clinically evaluated and obtained stool samples for microbiology from patients with diarrhea and less than 6 years of age. In the first (N = 714) and second clinic (N = 561), respectively, 36% (N = 254) and 46% (N = 260) of children were infected with rotavirus, enterotoxigenic Escherichia coli (ETEC), Campylobacter, or Shigella. When excluding mixed rotavirus-bacterial infections, for the first and second clinic, 23% and 10% had rotavirus-associated diarrhea, and 14% and 17% had ETEC-associated diarrhea, respectively. Campylobacter-associated diarrhea was 1% and 3%, and Shigella-associated diarrhea was 2% and 1%, respectively, for the two clinics. Rotavirus-associated diarrhea peaked in late summer to early winter, while bacterial agents were prevalent during summer. Rotavirus-associated cases presented with dehydration, vomiting, and were often hospitalized. Children with Shigella- or Campylobacter-associated diarrhea reported as watery diarrhea and rarely dysentery. ETEC did not have any clinically distinct characteristics. For vaccine development and/or deployment, our study suggests that rotavirus is of principle concern, followed by ETEC, Shigella, and Campylobacter.