We conducted a study to determine if use of a new flocculant-disinfectant home water treatment reduced diarrhea. We randomly assigned 492 rural Guatemalan households to five different water treatment groups: flocculantdisinfectant, flocculant-disinfectant plus a customized vessel, bleach, bleach plus a vessel, and control. During one year of observation, residents of control households had 4.31 episodes of diarrhea per 100 person-weeks, whereas the incidence of diarrhea was 24% lower among residents of households receiving flocculant-disinfectant, 29% lower among those receiving flocculant-disinfectant plus vessel, 25% lower among those receiving bleach, and 12% lower among households receiving bleach plus vessel. In unannounced evaluations of home drinking water, free chlorine was detected in samples from 27% of flocculant-disinfectant households, 35% of flocculant-disinfectant plus vessel households, 35% of bleach households, and 43% of bleach plus vessel households. In a setting where diarrhea was a leading cause of death, intermittent use of home water treatment with flocculant-disinfectant decreased the incidence of diarrhea.

We examined the incremental yield of stool culture (with toxin testing on isolates) versus our two-step algorithm for optimal detection of toxigenic Clostridium difficile. Per the two-step algorithm, stools were screened for C. difficile-associated glutamate dehydrogenase (GDH) antigen and, if positive, tested for toxin by a direct (stool) cell culture cytotoxicity neutralization assay (CCNA). In parallel, stools were cultured for C. difficile and tested for toxin by both indirect (isolate) CCNA and conventional PCR if the direct CCNA was negative. The "gold standard" for toxigenic C. difficile was detection of C. difficile by the GDH screen or by culture and toxin production by direct or indirect CCNA. We tested 439 specimens from 439 patients. GDH screening detected all culture-positive specimens. The sensitivity of the two-step algorithm was 77% (95% confidence interval [CI], 70 to 84%), and that of culture was 87% (95% CI, 80 to 92%). PCR results correlated completely with those of CCNA testing on isolates (29/29 positive and 32/32 negative, respectively). We conclude that GDH is an excellent screening test and that culture with isolate CCNA testing detects an additional 23% of toxigenic C. difficile missed by direct CCNA. Since culture is tedious and also detects nontoxigenic C. difficile, we conclude that culture is most useful (i) when the direct CCNA is negative but a high clinical suspicion of toxigenic C. difficile remains, (ii) in the evaluation of new diagnostic tests for toxigenic C. difficile (where the best reference standard is essential), and (iii) in epidemiologic studies (where the availability of an isolate allows for strain typing and antimicrobial susceptibility testing).Since its identification in 1978, Clostridium difficile has emerged as the predominant cause of antibiotic-associated colitis and the leading cause of diarrhea in hospitalized patients (4). Strains of C. difficile can be toxigenic or nontoxigenic; however, only toxigenic strains produce disease. The two main virulence factors are toxin A, a 308-kDa enterotoxin with some cytopathic effects (TcdA), and Toxin B (TcdB), a potent 270-kDa cytotoxin that affects various tissue cell lines in vitro and inhibits bowel motility in vivo (3, 12). The genes encoding both toxins, tcdA and tcdB, have been sequenced, and both are known to disrupt the actin cytoskeleton of intestinal epithelial cells by modifying Rho family proteins. Toxin A has long been considered more important (19,20), but an increasing number of reports of colitis due to TcdA-negative but TcdB-positive strains have now been made (5, 35). Furthermore, other virulence factors have now been identified. Recently, an increase in the frequency and severity of C. difficile-associated colitis, which is associated with a new strain that produces binary toxin (actin-specific ADP-ribosyltransferase) and is resistant to fluoroquinolones in vitro, has refocused attention on early, accurate diagnosis (2,9,23,29,36).Cell culture cytotoxicity neutralization assays (CCNA), which detect ...

SCHERICHIA COLI O157, SUCH AS E coli O157:H7, causes approximately 70000 illnesses and 60 deaths annually in the United States. 1 Illness is often characterized by severe bloody diarrhea; renal failure from hemolytic-uremic syndrome (HUS) may occur in 3% to 7% of cases. 2 Healthy cattle are believed to be the most important reservoir of E coli O157. 2 Humans usually become infected from contaminated food or water or from contact with infected animals, infected humans, or either's excreta. 3,4 Because E coli O157 has a low infectious dose and can survive in the environment, environmental contamination with E coli O157 may be an important public health problem. 5,6 Outbreaks have been linked to contamination of surfaces regularly touched by animals, such as the soil of pastures or railings in petting zoos. 7-9 County fairs are popular throughout the United States. 10 Because fairs bring animals and humans into close contact, they are increasingly recognized as a setting for E coli O157 outbreaks. 11 Such outbreaks often affect multiple communities because fairs attract large numbers of individuals, particularly children, and person-toperson transmission may occur after a fair has ended. We describe an investigation of a fair-associated E coli O157 outbreak in which epidemiological and microbiological studies document that infections can be Author Affiliations are listed at the end of this article.

Influenza causes excess morbidity in sickle cell disease (SCD). H1N1 pandemic influenza has been severe in children. To compare H1N1 with seasonal influenza in SCD (patients younger than 22), we reviewed medical records (1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)). We identified 123 cases of laboratory-confirmed influenza (94 seasonal, 29 H1N1). Those with seasonal influenza were younger (median 4.4 vs 8.7 years old, P ‫؍‬ .006) and had less asthma (24% vs 56%, P ‫؍‬ .002). Those with H1N1 influenza more often had acute chest syndrome (ACS; 34% vs 13%, P ‫؍‬ .01) and required intensive care (17% vs 3%, P ‫؍‬ .02), including mechanical ventilation (10% vs 0%, P ‫؍‬ .02). In multivariate analysis, older age (odds ratio [OR] 1.1 per year, P ‫؍‬ .04) and H1N1 influenza (OR 3.0, P ‫؍‬ .04) were associated with ACS, and older age (OR 1.1 per year, P ‫؍‬ .02) and prior ACS (OR 3.3 per episode in last year, P < .006) with intensive care. Influenza, especially H1N1, causes critical illness in SCD and should be prevented. IntroductionInfluenza causes disproportionate morbidity in sickle cell disease (SCD), an inherited hemoglobinopathy affecting 1 in 2500 children in the United States. 1 In one study, SCD was associated with a 56-fold increased risk of influenza-related hospitalization. 2 Yet, despite its effectiveness, 3,4 most children with SCD do not receive the influenza vaccine yearly. 5 Recognition of the influenza A virus of swine origin (H1N1) in March 2009 6 caused heightened concern. Case series of H1N1 influenza in SCD have reported severe illness, with 10 in 21 children and 2 in 2 adults developing acute chest syndrome (ACS). 7,8 To assess the relative severity of pandemic H1N1 versus seasonal influenza in SCD, we performed a comprehensive analysis at our institution. Methods Study populationWe identified patients aged Ͻ 22 years with SCD and influenza by searching for SCD and respiratory virus testing from September 1, 1993, to April 30, 2007, in the discharge and billing databases of Johns Hopkins Hospital (JHH). From May 1, 2007, to December 10, 2009, we also prospectively identified patients with SCD and influenza admitted to the pediatric hematology service or seen in the pediatric emergency department at JHH. We reviewed clinical records to identify influenza vaccination and administrative records to estimate the number of patients aged Ͻ 22 years with SCD seen at JHH. Additional information appears in supplemental data (available on the Blood Web site; see the Supplemental Materials link at the top of the online article). DefinitionsWe defined influenza as laboratory-confirmed influenza A or B and ACS as a new pulmonary infiltrate involving Ն 1 complete lung segment with fever (Ͼ 38.5°C), tachypnea, cough, wheezing, or chest pain. 9 We defined severe pain as pain requiring Ͼ 2 doses of opiates and asthma exacerbation as bronchodilator-treated wheezing. Diagnosis of influenzaInfluenza was detected by rapid antigen-based test (immunochromatograp...

BackgroundDengue is a leading cause of fever and mimics other acute febrile illnesses (AFI). In 2009, the World Health Organization (WHO) revised criteria for clinical diagnosis of dengue.Methodology/Principal findingsThe new WHO 2009 classification of dengue divides suspected cases into three categories: dengue without warning signs, dengue with warning signs and severe dengue. We evaluated the WHO 2009 classification vs physicians’ subjective clinical diagnosis (gestalt clinical impression) in a large cohort of patients presenting to a tertiary care center in southern Sri Lanka hospitalized with acute febrile illness. We confirmed acute dengue in 388 patients (305 adults ≥ 18 years and 83 children), including 103 primary and 245 secondary cases, of 976 patients prospectively enrolled with AFI. At presentation, both adults and children with acute dengue were more likely than those with other AFI to have leukopenia and thrombocytopenia. Additionally, adults were more likely than those with other AFI to have joint pain, higher temperatures, and absence of crackles on examination whereas children with dengue were more likely than others to have sore throat, fatigue, oliguria, and elevated hematocrit and transaminases. Similarly, presence of joint pain, thrombocytopenia, and absence of cough were independently associated with secondary vs primary dengue in adults whereas no variables were different in children. The 2009 WHO dengue classification was more sensitive than physicians’ clinical diagnosis for identification of acute dengue (71.5% vs 67.1%), but was less specific. However, despite the absence of on-site diagnostic confirmation of dengue, clinical diagnosis was more sensitive on discharge (75.2%). The 2009 WHO criteria classified almost 75% as having warning signs, even though only 9 (2.3%) patients had evidence of plasma leakage and 16 (4.1%) had evidence of bleedingConclusions/SignificanceIn a large cohort with AFI, we identified features predictive of dengue vs other AFI and secondary vs primary dengue in adults versus children. The 2009 WHO dengue classification criteria had high sensitivity but low specificity compared to physicians’ gestaldt diagnosis. Large cohort studies will be needed to validate the diagnostic yield of clinical impression and specific features for dengue relative to the 2009 WHO classification criteria.

Molecular diagnosis of malaria offers many potential advantages over microscopy, including identification of malaria to the species level in an era with few experienced microscopists. We developed high-throughput multiplex 5= nuclease quantitative PCR (qPCR) assays, with the potential to support large studies, to specifically identify Plasmodium falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi. We compared qPCR to microscopy and confirmed discordant results with an alternative target PCR assay. The assays specifically detected 1 to 6 parasites/l of blood. The clinical sensitivities (95% confidence intervals [CIs]) of the 4-plex assay to detect microscopically confirmed malaria were 95.8% (88.3 to 99.1%) for P. falciparum, 89.5% (75.2 to 97.1%) for P. vivax, 94.1% (71.3 to 99.9%) for P. ovale, and 100% (66.4 to 100%) for P. malariae. The specificities (95% CIs) were 98.6% (92.4 to 100%) for P. falciparum, 99% (84.8 to 100%) for P. vivax, 98.4% (94.4 to 99.8%) for P. ovale, and 99.3% (95.9 to 100%) for P. malariae. The clinical specificity for samples without malaria was 100%. The clinical sensitivity of the 5-plex assay for confirmed P. knowlesi malaria was 100% (95% CI, 69.2 to 100%), and the clinical specificity was 100% (95% CI, 87.2 to 100%). Coded retesting and testing with an alternative target PCR assay showed improved sensitivity and specificity of multiplex qPCR versus microscopy. Additionally, 91.7% (11/12) of the samples with uncertain species by microscopy were identified to the species level identically by both our multiplex qPCR assay and the alternative target PCR assay, including 9 P. falciparum infections. Multiplex qPCR can rapidly and simultaneously identify all 5 Plasmodium species known to cause malaria in humans, and it offers an alternative or adjunct to microscopy for clinical diagnosis as well as a needed high-throughput tool for research.

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Abstract. Acute respiratory tract infections (ARTIs) are a common reason for unnecessary antibiotic prescriptions worldwide. Our objective was to determine if providing access to rapid influenza test results could reduce antibiotic prescriptions for ARTIs in a resource-limited setting. We conducted a prospective, pre-post study from March 2013 to October 2014. Outpatients presenting to a hospital in Sri Lanka were surveyed for influenza-like illness-onset of fever ≥ 38.0°C and cough in prior 7 days. Enrolled patients were administered a structured questionnaire, physical examination, and nasal/nasopharyngeal sampling for rapid influenza A/B testing. Influenza test results were released only during phase 2 (January-October 2014). We enrolled 571 patients with ILI-316 in phase 1 and 241 in phase 2. The proportion positive for influenza was 46.5% in phase 1 and 28.6% in phase 2, P < 0.001. Between phases, antibiotic prescriptions decreased from 81.3% to 69.3% (P = 0.001) among all patients and from 83.7% to 62.3% (P = 0.001) among influenza-positive patients. On multivariable analysis, a positive influenza result during phase 2 was associated with lower odds of antibiotic prescriptions (OR = 0.50, 95% CI = 0.26-0.95). This prospective study suggests that providing access to rapid influenza testing may reduce unnecessary antibiotic prescriptions in resource-limited settings.