Nancy D. Puhr

Cholera--a possible endemic focus in the United States.

In September and October 1978, after a case of cholera had been discovered in southwestern Louisiana, 10 more Vibrio cholerae O-Group 1 infections were detected in four additional clusters. All 11 infected persons had recently eaten cooked crabs from five widely separated sites in the coastal marsh, and a matched-triplet case-control study showed a significant relation between cholera and eating such crabs (P = 0.007). V. cholerae O1 was isolated from estuarine water, from fresh shrimp, from a leftover cooked crab from a patients refrigerator, and from sewage in six towns, including three without identified cases. All isolates in Louisiana and an isolate from a single unexplained case in Texas in 1973 were biotype El Tor and serotype inaba; they were hemolytic and of a phage type unique to the United States--suggesting that the organism persisted undetected along the Gulf Coast for at least five years.

Molecular, serological, and virulence characteristics of Vibrio parahaemolyticus isolated from environmental, food, and clinical sources in North America and Asia

ABSTRACT Potential virulence attributes, serotypes, and ribotypes were determined for 178 pathogenic Vibrio parahaemolyticus isolates from clinical, environmental, and food sources on the Pacific, Atlantic, and Gulf Coasts of the United States and from clinical sources in Asia. The food and environmental isolates were generally from oysters, and they were defined as being pathogenic by using DNA probes to detect the presence of the thermostable direct hemolysin (tdh) gene. The clinical isolates from the United States were generally associated with oyster consumption, and most were obtained from outbreaks in Washington, Texas, and New York. Multiplex PCR was used to confirm the species identification and the presence of tdh and to test for the tdh-related hemolysin trh. Most of the environmental, food, and clinical isolates from the United States were positive for tdh, trh, and urease production. Outbreak-associated isolates from Texas, New York, and Asia were predominantly serotype O3:K6 and possessed only tdh. A total of 27 serotypes and 28 ribogroups were identified among the isolates, but the patterns of strain distribution differed between the serotypes and ribogroups. All but one of the O3:K6 isolates from Texas were in a different ribogroup from the O3:K6 isolates from New York or Asia. The O3:K6 serotype was not detected in any of the environmental and food isolates from the United States, and none of the food or environmental isolates belonged to any of the three ribogroups that contained all of the O3:K6 and related clinical isolates. The combination of serotyping and ribotyping showed that the Pacific Coast V. parahaemolyticus population appeared to be distinct from that of either the Atlantic Coast or Gulf Coast. The fact that certain serotypes and ribotypes contained both clinical and environmental isolates while many others contained only environmental isolates implies that certain serotypes or ribotypes are more relevant for human disease.

Sporadic Cases of Hemorrhagic Colitis Associated with Escherichia coli 0157:H7

After two outbreaks of hemorrhagic colitis associated with a previously unrecognized pathogen, Escherichia coli O157:H7, a surveillance system was established to identify and study sporadic cases of this distinct clinical illness in the United States. Between August 1982 and April 1984, we identified 28 persons from 11 states who met our case definition and whose stool specimens yielded E. coli O157:H7. Patients ranged in age from 1 to 80 years. Seventeen patients required hospitalization. All patients recovered, although one developed hemolytic-uremic syndrome 7 days after the onset of bloody diarrhea. Detection of E. coli O157:H7 in stools from persons with hemorrhagic colitis was highly associated with collection of stool specimens within the first 6 days after onset of illness. All E. coli O157:H7 isolates produced a Vero cytotoxin. Hemorrhagic colitis caused by E. coli O157:H7 is widely distributed in the United States as a sporadic illness; clinicians should be aware of its distinctive clinical presentation, and should collect specimens promptly when the diagnosis is suspected.

Identification of Vibrio Isolates by a Multiplex PCR Assay and rpoB Sequence Determination

ABSTRACT Vibrio, a diverse genus of aquatic bacteria, currently includes 72 species, 12 of which occur in human clinical samples. Of these 12, three species—Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus—account for the majority of Vibrio infections in humans. Rapid and accurate identification of Vibrio species has been problematic because phenotypic characteristics are variable within species and biochemical identification requires 2 or more days to complete. To facilitate the identification of human-pathogenic species, we developed a multiplex PCR that uses species-specific primers to amplify gene regions in four species (V. cholerae, V. parahaemolyticus, V. vulnificus, and V. mimicus). The assay was tested on a sample of 309 Vibrio isolates representing 26 named species (including 12 human pathogens) that had been characterized by biochemical methods. A total of 190 isolates that had been identified as one of the four target species all yielded results consistent with the previous classification. The assay identified an additional four V. parahaemolyticus isolates among the other 119 isolates. Sequence analysis based on rpoB was used to validate the multiplex results for these four isolates, and all clustered with other V. parahaemolyticus sequences. The rpoB sequences for 12 of 15 previously unidentified isolates clustered with other Vibrio species in a phylogenetic analysis, and three isolates appeared to represent unnamed Vibrio species. The PCR assay provides a simple, rapid, and reliable tool for identification of the major Vibrio pathogens in clinical samples, and rpoB sequencing provides an additional identification tool for other species in the genus Vibrio.

Hospitalization and Mortality Among Primarily Nonbreastfed Children During a Large Outbreak of Diarrhea and Malnutrition in Botswana, 2006

Background:In 2006, a pediatric diarrhea outbreak occurred in Botswana, coinciding with heavy rains. Surveillance recorded a 3 times increase in cases and a 25 fold increase in deaths between January and March. Botswana has high HIV prevalence among pregnant women (33.4% in 2005), and an estimated 35% of all infants under the age of 6 months are not breastfed. Methods:We followed all children <5 years old with diarrhea in the countrys second largest referral hospital at the peak of the outbreak by chart review, interviewed mothers, and conducted laboratory testing for HIV and enteric pathogens. Results:Of 153 hospitalized children with diarrhea, 97% were <2 years old; 88% of these were not breastfeeding. HIV was diagnosed in 18% of children and 64% of mothers. Cryptosporidium and enteropathogenic Escherichia coli were common; many children had multiple pathogens. Severe acute malnutrition (kwashiorkor or marasmus) developed in 38 (25%) patients, and 33 (22%) died. Kwashiorkor increased risk for death (relative risk 2.0; P = 0.05); only one breastfeeding child died. Many children who died had been undersupplied with formula. Conclusions:Most of the severe morbidity and mortality in this outbreak occurred in children who were HIV negative and not breastfed. Feeding and nutritional factors were the most important determinants of severe illness and death. Breastfeeding is critical to infant survival in the developing world, and support for breastfeeding among HIV-negative women, and HIV-positive women who cannot formula feed safely, may prevent further high-mortality outbreaks.

Rotavirus Antigenemia in Patients with Acute Gastroenteritis

Although rotavirus infections are generally considered to be confined to the intestine, recent reports suggest that extraintestinal disease occurs. We studied whether rotavirus infection was associated with antigenemia during a major outbreak of gastroenteritis in the Kingston metropolitan area, during July-August 2003. Rotavirus antigen was identified in 30 of 70 acute-phase serum samples (including from 2 deceased individuals) but in only 1 of 53 control samples. Serum antigen levels were inversely associated with time since symptom onset and were directly associated with antigen levels in stool (P = .02). Serum antigen levels were significantly elevated during primary infections (acute-phase serum immunoglobulin G [IgG] titers, <25), compared with those in subsequent infections (acute-phase serum IgG titers, > or = 25) (P = .02). Antigenemia was common in this outbreak and might provide a mechanism to help explain rare but well-documented reports of findings of extraintestinal rotavirus. In situations in which stool samples are not readily available (i.e., patients with severe dehydration or those recently recovered or deceased), serum testing by enzyme immunoassay offers a new and practical diagnostic tool.

Colonic epithelial lymphocytosis associated with an epidemic of chronic diarrhea.

The term Brainerd diarrhea has been applied to outbreaks of chronic watery diarrhea of unknown etiology characterized by acute onset and prolonged duration. Our aim was to describe the histologic changes in gastrointestinal biopsy specimens from patients with Brainerd diarrhea. We examined 52 colonic and 12 small bowel biopsy specimens from 22 patients who were involved in an outbreak of Brainerd diarrhea that was linked to the water supply of a cruise ship visiting the Galapagos Islands. Small bowel biopsy specimens from seven patients were histologically normal. One patient had a duodenal biopsy specimen that resembled celiac sprue. Colonic biopsy specimens from 20 patients revealed surface epithelial lymphocytosis without distortion of mucosal architecture, surface degenerative changes, or thickened subepithelial collagen plates. The degree of surface epithelial lymphocytosis was greater than that seen in control groups of persons with normal colons, acute colitis, and ulcerative colitis (p < 0.001), similar to that seen with collagenous colitis, and less than that seen with lymphocytic colitis (p < 0.001). Three patients showed focal active colitis similar to that described in acute infectious-type colitis in addition to the epithelial lymphocytosis. Two patients had colonic biopsy specimens that were histologically normal. In summary, histologic abnormalities in the small bowel are generally absent in Brainerd diarrhea. Colonic biopsy specimens in Brainerd diarrhea frequently show epithelial lymphocytosis similar to that seen in collagenous and lymphocytic colitis. Although currently Brainerd diarrhea can be diagnosed only with epidemiologic data indicating an epidemic and a point source, the lack of surface degenerative changes and the relatively lower lymphocyte counts seen in our cases of Brainerd diarrhea may serve to distinguish it from lymphocytic colitis, and the lack of a thickened subepithelial collagen plate distinguishes it from collagenous colitis.

Diarrhea among African children born to human immunodeficiency virus 1-infected mothers: clinical, microbiologic and epidemiologic features.

Diarrhea and weight loss are common features of pediatric and adult human immunodeficiency type 1 (HIV-1) infection, particularly in developing countries. We studied prospectively episodes of diarrhea in 559 children, ages 10 to 15 months, participating in a longitudinal study of perinatal HIV-1 infection in Kinshasa, Zaire. Children with HIV-1 infection had more frequent episodes of diarrhea and were more likely to present with fever or moderate or severe dehydration and to have persistent or fatal diarrhea. Of 9 HIV-1-positive infants with diarrhea, 3 had enteroadherence factor-positive Escherichia coli, compared with 5 of 74 HIV-1-negative children with diarrhea (P = 0.04); no other pathogen was associated with HIV-1 infection. In a logistic regression model diarrhea was significantly associated with HIV-1 infection in the child, moderate or severe malnutrition and symptoms of acquired immunodeficiency syndrome in the mother. Diarrhea among children with perinatal HIV infection in Zaire is more severe than among uninfected children and is associated with malnutrition and advanced disease in the mother.

Enterotoxin-producing Escherichia coli O169:H41, United States

From 1996 to 2003, 16 outbreaks of enterotoxigenic Escherichia coli (ETEC) infections in the United States and on cruise ships were confirmed. E. coli serotype O169:H41 was identified in 10 outbreaks and was the only serotype in 6. This serotype was identified in 1 of 21 confirmed ETEC outbreaks before 1996.

An Outbreak of Brainerd Diarrhea among Travelers to the Galapagos Islands

In 1992, an outbreak of chronic diarrhea occurred among passengers on a cruise ship visiting the Galapagos Islands, Ecuador. Passengers (548) were surveyed, and stool and biopsy specimens from a sample who reported chronic diarrhea were examined. On completed questionnaires, returned by 394 passengers (72%), 58 (15%) reported having chronic diarrhea associated with urgency (84%), weight loss (77%), fatigue (71%), and fecal incontinence (62%). Illness began 11 days (median) after boarding the ship and lasted 7 to >42 months. Macroscopic and histologic abnormalities of the colon were common, but extensive laboratory examination revealed no etiologic agent. No one responded to antimicrobial therapy. Patients were more likely than well passengers to have drunk the ships unbottled water or ice before onset of illness and to have eaten raw sliced fruits and vegetables washed in unbottled water. Water handling and chlorination on the ship were deficient. Outbreaks of a similar illness, Brainerd diarrhea, have been reported in the United States. Although its etiology remains unknown, Brainerd diarrhea may also occur among travelers.