A multistate outbreak of Salmonella enterica Serotype Newport infection linked to mango consumption: impact of water-dip disinfestation technology.

Fresh produce increasingly is recognized as an important source of salmonellosis in the United States. In December 1999, the Centers for Disease Control and Prevention detected a nationwide increase in Salmonella serotype Newport (SN) infections that had occurred during the previous month. SN isolates recovered from patients in this cluster had indistinguishable pulsed-field gel electrophoresis (PFGE) patterns (which identified the outbreak strain), suggesting a common source. Seventy-eight patients from 13 states were infected with the outbreak strain. Fifteen patients were hospitalized; 2 died. Among 28 patients enrolled in the matched case-control study, 14 (50%) reported they ate mangoes in the 5 days before illness onset, compared with 4 (10%) of the control subjects during the same period (matched odds ratio, 21.6; 95% confidence interval, 3.53- infinity; P=.0001). Traceback of the implicated mangoes led to a single Brazilian farm, where we identified hot water treatment as a possible point of contamination; this is a relatively new process to prevent importation of an agricultural pest, the Mediterranean fruit fly. This is the first reported outbreak of salmonellosis implicating mangoes. PFGE was critical to the timely recognition of this nationwide outbreak. This outbreak highlights the potential global health impact of foodborne diseases and newly implemented food processes.

Salmonella Typhimurium infections transmitted by chlorine-pretreated clover sprout seeds.

Raw seed sprouts have caused numerous outbreaks of enteric infections. Presoaking seeds in a 20,000 mg/liter (ppm) calcium hypochlorite solution before sprouting is recommended to reduce bacterial contamination and infection risk. In 1999, the authors investigated an outbreak of Salmonella serotype Typhimurium infections in Colorado. In a case-control study, they matched 20 cases with 58 controls by age, sex, and telephone prefix; 10 (52%) of 19 cases and no controls recalled eating raw alfalfa-style sprouts in the 5 days before the patient's illness (p < 0.00001). Traceback implicated clover sprouts grown from seeds shared by two sprouters. The time period and region over which these sprouts were sold matched the occurrences of 112 culture-confirmed illnesses. Only one of the sprouters presoaked seeds as recommended, and fewer infections were attributable to this sprouter (0.29 vs. 1.13 culture-confirmed infections/50-pound (110.1-kg) bag of seed). After recall of the implicated sprouts and seed, S. Typhimurium illnesses declined. Contaminated raw clover sprouts can cause outbreaks of enteric illness. Presoaking contaminated seeds in a 20,000 mg/liter calcium hypochlorite solution reduces, but does not eliminate, the risk of infection. Until safer production methods are developed, persons eating raw sprouts continue to risk developing potentially serious gastrointestinal illness.

Emergence of domestically acquired ceftriaxone-resistant Salmonella infections associated with AmpC beta-lactamase.

CONTEXT: Ceftriaxone, an expanded-spectrum cephalosporin, is an antimicrobial agent commonly used to treat severe Salmonella infections, especially in children. Ceftriaxone-resistant Salmonella infections have recently been reported in the United States, but the extent of the problem is unknown. OBJECTIVES: To summarize national surveillance data for ceftriaxone-resistant Salmonella infections in the United States and to describe mechanisms of resistance. DESIGN AND SETTING: Case series and laboratory evaluation of human isolates submitted to the Centers for Disease Control and Prevention from 17 state and community health departments participating in the National Antimicrobial Resistance Monitoring System (NARMS) for enteric bacteria between 1996 and 1998. PATIENTS: Patients with ceftriaxone-resistant Salmonella infections between 1996 and 1998 were interviewed and isolates with decreased ceftriaxone susceptibility were further characterized. MAIN OUTCOME MEASURES: Exposures and illness outcomes, mechanisms of resistance. RESULTS: The prevalence of ceftriaxone-resistant Salmonella was 0.1% (1 of 1326) in 1996, 0.4% (5 of 1301) in 1997, and 0.5% (7 of 1466) in 1998. Ten (77%) of the 13 patients with ceftriaxone-resistant infections were aged 18 years or younger. The patients lived in 8 states (California, Colorado, Kansas, Massachusetts, Maryland, Minnesota, New York, and Oregon). Nine (82%) of 11 patients interviewed did not take antimicrobial agents and 10 (91%) did not travel outside the United States before illness onset. Twelve of the 15 Salmonella isolates with ceftriaxone minimum inhibitory concentrations of 16 microg/mL or higher were serotype Typhimurium but these isolates had different pulsed-field gel electrophoresis patterns. Thirteen of these 15 isolates collected between 1996 and 1998 were positive for a 631-base pair polymerase chain reaction product obtained by using primers specific for the ampC gene of Citrobacter freundii. CONCLUSIONS: Domestically acquired ceftriaxone-resistant Salmonella has emerged in the United States. Most ceftriaxone-resistant Salmonella isolates had similar AmpC plasmid-mediated resistance.

An outbreak of salmonellosis among children attending a reptile exhibit at a zoo.

OBJECTIVE: In January 1996, an outbreak of diarrhea caused by Salmonella Enteritidis occurred in children attending a Komodo dragon exhibit at a metropolitan zoo. We sought to determine the extent of the outbreak and mode of transmission. STUDY DESIGN: A case-control study was conducted. Controls were randomly selected from zoo membership lists and matched to patients by age group and date of exhibit visit. RESULTS: Of 65 patients identified, 39 had confirmed and 26 had suspected cases. The median age was 7 years (range, 3 months to 48 years); 55% were enrolled in the case-control study. No patients and two (4%) controls reported touching a dragon; however, 83% of patients but only 52% of controls touched the wooden barrier that surrounded the dragon pen (odds ratio = 4.0, 95% CI 1.2 to 13.9). Washing hands at the zoo after visiting the dragons was highly protective (OR = 0.14, 95% CI 0.03 to 0.7). Cultures from the patients, one dragon, and the exhibit barriers yielded Salmonella Enteritidis, phage type 8. On the basis of an attack rate of 4.3% among exhibit attendees under 13 years old on whom data were collected, we estimate that 315 additional cases of salmonellosis occurred among visitors in this age group. CONCLUSION: This large outbreak demonstrates the importance of environmental contamination in the transmission of Salmonella from reptiles, and the protective value of hand washing. Recommendations regarding reptile exhibits and reptilian pets should emphasize this indirect route.

The use of hygiene, cohorting, and antimicrobial therapy to control an outbreak of shigellosis.

Shigellae are easily transmitted in day-care centers to children and adult staff by contamination of diaper-changing surfaces and fomites or directly from person to person. Appropriate antimicrobial therapy may shorten the duration of diarrhea caused by shigellae and eliminate the organism from the feces. Current recommendations of the American Academy of Pediatrics and the American Public Health Association are that infected children be isolated until three and two, respectively, consecutive stool cultures are negative. We utilized a disease control strategy based on use of antibiotics to control diarrheal symptoms and reduce infectiousness, cohorting of asymptomatic infected children in the center, and scrupulous attention to hygiene and environmental cleanliness. This strategy was effective in stopping transmission, was more practical than some of the measures now recommended by the American Academy of Pediatrics and the American Public Health Association, and was well accepted by parents and center staff. The strategy should be evaluated in other day-care settings.

Prevalence of Giardia lamblia and risk factors for infection among children attending day-care facilities in Denver.

A sample of children in the toddler age group was surveyed in Denver, CO, to determine the prevalence of Giardia lamblia and to identify risk factors for the intestinal disease. The sample consisted of 236 children attending day-care centers (DCC) and 79 who were not attending. Thirty-eight children (16 percent) attending DCCs and 7 (9 percent) who had not were positive for G. lamblia in stool samples. Risk factors for those attending DCC facilities included increasing duration of attendance, time per week attending DCCs, low family income, and large family size. The only risk factor for those not attending DCC facilities was travel to Colorado mountains. Multivariate analysis showed that risk factors for all children in the sample included travel to Colorado mountains, large family size, and attending DCC facilities. Infection was not associated with symptoms.

Standards and criteria: group child care for sick children.

With the establishment of several statewide sick child care programs, a group of concerned health professionals recognized the need to develop guidelines and nursing care criteria for these centers. A task force was formed to design guidelines for the planning and development of facilities that provide care for children with recuperating illnesses.

Surveillance for injuries: cluster of finger amputations from snowblowers.

In an investigation of the health effects of a Christmas eve snowstorm in 1982, a review of emergency room records in the Denver area identified a cluster of 17 cases of finger amputations. Fifteen (88) percent of these amputations were associated with snowblower use. An additional 12 persons with hand or finger injuries without amputations from snowblowers were identified. A case-control study was performed comparing these patients with a control group who had used snowblowers. Patients were more likely than controls to have had their machines become clogged with snow (odds ratio [OR], 3.4, 95 percent confidence limits [CL], 0.74-15.4). Using a hand to dislodge trapped snow was the only risk factor identified for the patients (OR, 116; 95 percent CL, 16-820). No differences were found for other variables such as type of snowblower, instruction for use, or previous experience using a snowblower. The findings suggest that the most feasible measure to prevent such injuries is a change in snowblower design to preclude entry of a hand while the machine is running. This investigation illustrates the importance of surveillance in detecting and controlling injuries. Without such surveillance, the similarity among injuries reported on this paper would not have been recognized. Ongoing surveillance for injuries might identify other clusters of injuries.

Waterborne disease in Colorado: three years' surveillance and 18 outbreaks.

The Colorado Department of Health conducted intensive surveillance for waterborne diseases during the three-year period July 1, 1980-June 30, 1983. Eighteen outbreaks of waterborne illness were investigated. Outbreaks involved from 15 to 1,500 ill persons. Giardia lamblia was confirmed or suspected as the agent in nine outbreaks, rotavirus in one, and no agent could be identified in eight. Seventeen outbreaks occurred on surface-water systems; none of these had adequate chemical pretreatment and filtration. Investigation of water systems exhibiting positive coliform results during the first year detected no outbreaks. Activities important to effective surveillance included educational outreach programs to local health agencies, physicians and the public, and the designation of one individual to whom all water-related public complaints and health department inquiries were directed.

Campylobacter enteritis associated with undercooked barbecued chicken.

An outbreak of Campylobacter enteritis occurred in 1982 among 11 of 15 members and friends of an extended family gathering in Colorado. Median onset for illness, characterized by diarrhea, abdominal cramps, fever and headache, was four days after the party. Illness was associated with eating undercooked chicken. Two ill persons had stool specimens positive for C. jejuni. Eight of ten ill persons tested had Immunoglobulin-M-specific indirect fluorescent antibody (IFA) titers to C. jejuni greater than or equal to 32. IFA titers to C. jejuni peaked within three weeks of exposure and decreased to control levels within three months after exposure. Inadequate cooking of poultry may increase the risk of these infections.