Salmonella infections associated with mung bean sprouts: epidemiological and environmental investigations.

We investigated an outbreak of Salmonella Enteritidis (SE) infections linked to raw mung bean sprouts in 2000 with two case-control studies and reviewed six similar outbreaks that occurred in 2000-2002. All outbreaks were due to unusual phage types (PT) of SE and occurred in the United States (PT 33, 1, and 913), Canada (PT 11b and 913), and The Netherlands (PT 4b). PT 33 was in the spent irrigation water and a drain from one sprout grower. None of the growers disinfected seeds at recommended concentrations. Only two growers tested spent irrigation water; neither discarded the implicated seed lots after receiving a report of Salmonella contamination. We found no difference in the growth of SE and Salmonella Newport on mung beans. Mung bean sprout growers should disinfect seeds, test spent irrigation water, and discontinue the use of implicated seed lots when pathogens are found. Laboratories should report confirmed positive Salmonella results from sprout growers to public health authorities.

Activation of the androgen receptor alters the intracellular calcium response to glutamate in primary hippocampal neurons and modulates sarco/endoplasmic reticulum calcium ATPase 2 transcription.

Androgens have been shown to have a number of effects on hippocampal function. Although androgen receptors (AR) are found at high levels in hippocampal neurons, the intracellular mechanisms responsible for androgen's actions are unknown. If androgens were capable of altering internal calcium concentration ([Ca(2+)](i)), they could influence a variety of intracellular signaling pathways, maintain neuronal homeostasis and Ca(2+) induced excitotoxicity. In the present study, calcium imaging was used to measure the [Ca(2+)](i) in rat primary hippocampal neurons treated with either the AR agonist dihydrotestosterone (DHT), DHT+flutamide (AR antagonist), flutamide alone, or vehicle for 24 h and subsequently presented with an excitatory glutamate stimulus. In the absence of glutamate stimulation, DHT treatment caused a significant upward shift in baseline [Ca(2+)](i) when compared with neurons from all other groups. Glutamate had a greater effect on [Ca(2+)](i) in DHT-treated neurons and DHT-treated neurons returned to baseline levels significantly faster than all other groups. Cyclopiazonic acid, an inhibitor of sarco/endoplasmic reticulum calcium ATPase (SERCA) had a larger response in DHT-treated neurons compared with controls, suggesting increased Ca(2+) stores in DHT-treated neurons. In all cases the effects of DHT were blocked by treatment with flutamide indicating an AR-mediated mechanism. To determine a possible mechanism by which AR activation could be influencing [Ca(2+)](i), SERCA2 mRNA levels were measured in primary hippocampal neurons. SERCA2 is inserted into the endoplasmic reticulum (ER) membrane and functions to rapidly pump [Ca(2+)](i) into the ER. Following treatment of primary hippocampal neurons with DHT, SERCA2 mRNA was increased, an effect that was blocked in the presence of flutamide. Taken together these results indicate that DHT, working through AR, causes an up-regulation of SERCA2, which increases the sequestering of [Ca(2+)](i) in the endoplasmic reticulum of hippocampal neurons. Such changes may allow the neurons to respond more robustly to a stimulus and recover more quickly following a highly stimulatory challenge.

Outbreak of cryptosporidiosis at a California waterpark: employee and patron roles and the long road towards prevention.

In August-September 2004, a cryptosporidiosis outbreak affected >250 persons who visited a California waterpark. Employees and patrons of the waterpark were affected, and three employees and 16 patrons admitted to going into recreational water while ill with diarrhoea. The median illness onset date for waterpark employees was 8 days earlier than that for patrons. A case-control study determined that getting water in one's mouth on the waterpark's waterslides was associated with illness (adjusted odds ratio 7.4, 95% confidence interval 1.7-32.2). Laboratory studies identified Cryptosporidium oocysts in sand and backwash from the waterslides' filter, and environmental investigations uncovered inadequate water-quality record keeping and a design flaw in one of the filtration systems. Occurring more than a decade after the first reported outbreaks of cryptosporidiosis in swimming pools, this outbreak demonstrates that messages about healthy swimming practices have not been adopted by pool operators and the public.

Outbreak of Serratia marcescens infections following injection of betamethasone compounded at a community pharmacy.

BACKGROUND: In June 2001, following the report of 4 patients with Serratia marcescens meningitis who received epidural injections of betamethasone compounded at a community pharmacy, we initiated an outbreak investigation. METHODS: All patients who received injections of betamethasone from the production lot common to the 4 patients were evaluated. A case patient was defined as a patient who received compounded betamethasone and had S. marcescens isolated from a sterile site or clinical and laboratory evidence of infection. We cultured all recovered betamethasone, environmental specimens from the pharmacy, and medications recovered from an ambulatory surgery center. The California Board of Pharmacy reviewed the procedures used to prepare the betamethasone. RESULTS: We identified 11 patients with culture-confirmed S. marcescens (8 patients) or clinical infection (3 patients) following injection of compounded betamethasone from 25 May through 31 May 2001. Case patients had meningitis (5 patients, with 3 deaths), epidural abscesses (5 patients), or an infected hip (1 patient). S. marcescens was isolated from 35 (69%) of 51 betamethasone vials recovered, from pharmacy specimens of 1% carboxymethylcellulose stock solution, from pharmacy surfaces, and from multiple parenteral materials used at the ambulatory surgery center. Pulsed-field gel electrophoresis patterns of S. marcescens isolates of representative specimens from patients, the betamethasone, the pharmacy, and the ambulatory surgery center were identical. Deficient practices in compounding of betamethasone included inadequate autoclaving temperatures and failure to perform terminal sterilization. CONCLUSIONS: This outbreak of serious S. marcescens infection followed improper compounding of betamethasone in a community pharmacy. Enforceable national standards for pharmaceutical compounding are needed to reduce the risk of such outbreaks.

A multi-state outbreak of Salmonella serotype Thompson infection from commercially distributed bread contaminated by an ill food handler.

Foodborne transmission is estimated to account for 95% of non-typhoidal Salmonella infections reported in the United States; however, outbreaks of salmonellosis are rarely traced to food handlers. In August 2000, an increase in Salmonella serotype Thompson infection was noted in Southern California; most of the cases reported eating at a restaurant chain (Chain A) before illness onset. A case-control study implicated the consumption of burgers at Chain A restaurants. The earliest onset of illness was in a burger bun packer at Bakery B who had not eaten at Chain A but had worked while ill. Bakery B supplied burger buns to some Chain A restaurants in Southern California and Arizona. This outbreak is notable for implicating a food handler as the source of food contamination and for involving bread, a very unusual outbreak vehicle for Salmonella . Inadequate food-handler training as well as delayed reporting to the health department contributed to this outbreak.

A large outbreak of scombroid fish poisoning associated with eating escolar fish (Lepidocybium flavobrunneum).

In August 2003, an outbreak of scombroid fish poisoning occurred at a retreat centre in California, USA. In a retrospective cohort study, 42 (75%) of the 56 dinner attendees who ate escolar fish (Lepidocybium flavobrunneum) met the case definition. Individuals who ate at least 2 oz of fish were 1.5 times more likely to develop symptoms than those who ate less (relative risk 1.5, 95% confidence interval 0.9-2.6), and to develop more symptoms (median 7 vs. 3 symptoms, P = 0.03). Patients who took medicine had a longer duration of symptoms than those who did not (median 4 vs. 1.5 h, P = 0.05), and experienced a greater number of symptoms (median 8 vs. 3 symptoms, P = 0.0002). Samples of fish contained markedly elevated histamine levels (from 2000 to 3800 ppm). This is one of the largest reported outbreaks of scombroid fish poisoning in the United States and was associated with a rare vehicle for scombroid fish poisoning, escolar.

Epidemic and sporadic cases of nontuberculous mycobacterial keratitis associated with laser in situ keratomileusis.

PURPOSE: To report national case-finding results for nontuberculous mycobacterial keratitis and describe its association with laser in situ keratomileusis (LASIK). DESIGN: Enhanced passive disease reporting. METHODS: In April 2001, we investigated a California cluster of Mycobacterium chelonae keratitis associated with hyperopic LASIK using a contact lens mask. To identify other possibly related cases, the American Academy of Ophthalmology e-mailed its members asking them to report recent cases of nontuberculous mycobacterial keratitis to the Centers for Disease Control and Prevention. RESULTS: Forty-three additional cases of keratitis were reported (onsets between August 2000 and June 2001). Of these, 31 occurred as part of two unrelated LASIK-associated outbreaks. The 12 other reported cases occurred in sporadic fashion. Of the latter cases, 4 were associated with LASIK surgery. None of the reported cases were related to the M. chelonae cluster in California. CONCLUSIONS: Laser in situ keratomileusis-associated keratitis with nontuberculous mycobacteria may be more common than previously known.

Alfalfa sprouts and Salmonella Kottbus infection: a multistate outbreak following inadequate seed disinfection with heat and chlorine.

Raw sprouts have been implicated in a number of foodborne disease outbreaks. Because contaminated seeds are usually responsible, many sprout producers attempt to disinfect seeds before germination and detect sprout contamination during production. In March 2001, we detected an increased number of Salmonella serotype Kottbus isolates in California. Overall, we identified 31 cases from three western states. To identify the cause, we conducted a case-control study with the first 10 identified case-patients matched to 20 controls by age, sex, and residential area. Our case-control study found illness to be statistically associated with alfalfa sprout consumption. The traceback investigation implicated a single sprouter, where environmental studies yielded Salmonella Kottbus from ungerminated seeds and floor drains within the production facility. Pulsed-field gel electrophoresis patterns of all patient, seed, and floor drain Salmonella Kottbus isolates were indistinguishable. Most implicated sprouts were from seeds that underwent heat treatment and soaking with a 2,000-ppm sodium hypochlorite solution rather than the Food and Drug Administration (FDA)-recommended 20,000-ppm calcium hypochlorite soak. Other implicated seeds had been soaked in a calcium hypochlorite solution that, when tested, measured only 11,000 ppm. The outbreak might have been averted when screening tests of sprout irrigation water detected Salmonella in January; however, confirmatory testing of these samples was negative (but testing improperly utilized refrigerated irrigation water). Producers should use the enrichment broth of positive screening samples, not refrigerated irrigation water, for confirmatory testing. Until other effective disinfection technologies are developed, producers should adhere to FDA recommendations for sprout seed disinfection.

A multistate outbreak of Salmonella enterica serotype Baildon associated with domestic raw tomatoes.

Salmonella enterica serotype Baildon, a rare serotype, was recovered from 86 persons in eight states; 87% of illnesses began during a 3-week period ending January 9, 1999. Raw restaurant-prepared tomatoes were implicated in multiple case-control studies. Contamination likely occurred on the farm or during packing; more effective disinfection and prevention strategies are needed.

Escherichia coli O157 and Salmonella infections associated with sprouts in California, 1996-1998.

BACKGROUND: In California, from 1996 through 1998, more than 50% of multicounty outbreaks with confirmed food vehicles were related to alfalfa or clover sprouts. OBJECTIVE: To summarize investigations of sprout-associated outbreaks. DESIGN: Matched case-control studies. SETTING: California. PATIENTS: Outbreak-associated patients and matched population controls. MEASUREMENTS: Matched odds ratios and 95% CIs; traceback and environmental investigations of sprout and seed growers; and pulsed-field gel electrophoresis of isolates from patients, sprouts, and seeds. RESULTS: Five sprout-associated outbreaks of salmonellosis and one outbreak of infection with nonmotile Shiga toxin-producing Escherichia coli O157 occurred. Six hundred patients had culture-confirmed disease, and two died. It is estimated that these outbreaks caused 22 800 cases of gastrointestinal illness or urinary tract infection. In the case-control studies, odds ratios for the association between illness and alfalfa sprout consumption ranged from 5.0 to infinity (all were statistically significant). Three sprout growers were implicated, and each was associated with two outbreaks. Outbreak strains of Salmonella were isolated from sprouts supplied by two sprout growers and from seeds used by the third sprout grower. CONCLUSIONS: As currently produced, sprouts can be a hazardous food. Seeds can be contaminated before sprouting, and no method can eliminate all pathogens from seeds. Seed and sprout growers should implement measures to decrease contamination. The general public should recognize the risks of eating sprouts, and populations at high risk for complications from salmonellosis or E. coli O157 infection should avoid sprout consumption.

Risk factors for severe pulmonary and disseminated coccidioidomycosis: Kern County, California, 1995-1996.

Surveillance for coccidioidomycosis (CM) and a case-control study for risk factors among adults were conducted in Kern County, California. From January 1995 through December 1996, 905 cases of CM were identified, for an annual incidence of 86 cases per 100,000 population. A total of 380 adults were enrolled in the case-control study: 77 had severe pulmonary disease, 33 had disseminated disease, and 270 control patients had mild disease. Independent risk factors for severe pulmonary disease included diabetes, recent history of cigarette smoking, income of < $15,000 per year, and older age. Oral antifungal therapy before hospitalization was associated with a reduced risk of CM pneumonia. Risk factors for disseminated disease were black race, income of < $15,000 per year, and pregnancy. Early treatment of CM with oral antifungal agents may prevent severe pulmonary disease in groups considered to be at high risk, such as elderly individuals, persons with diabetes, and smokers. Persons at risk for severe CM may benefit from vaccination once an effective CM vaccine is available.

An outbreak of Salmonella serotype Thompson associated with fresh cilantro.

An outbreak of Salmonella serotype Thompson in California was identified through laboratory-based surveillance and investigated with case-control, traceback, and laboratory studies. There were 35 "sporadic" cases and a restaurant-associated outbreak of 41 cases with onset between 6 March and 31 March 1999. Three case patients were hospitalized. A case-control study found a significant association between illness and eating cilantro at a restaurant (63% of case patients vs. 34% of control subjects; odds ratio, 3.5; 95% confidence interval, 1.1-11.4). Although common distributors of cilantro were identified, inadequate records prohibited the identification of a single farm supplying cilantro. At room temperature, Salmonella Thompson grew more rapidly and to a higher concentration on chopped cilantro, compared with whole-leaf cilantro. Freshly made salsa (pH 3.4) supported growth of Salmonella Thompson. Cilantro should be served promptly after chopping. Accurate records of the distribution of produce should be available, and bacterial contamination of produce should be prevented in retail and wholesale establishments, in packing sheds, and on farms.

High incidence of extra-intestinal infections in a Salmonella Havana outbreak associated with alfalfa sprouts.

OBJECTIVE: To determine a vehicle and point source for an outbreak of Salmonella Havana. METHODS: The authors conducted a case-control study and traceback investigation of 14 residents of California and four from Arizona with onsets of illness from Apr 15, 1998, to June 15, 1998, and Salmonella Havana infections with identical PFGE patterns. RESULTS: Seventeen of 18 patients were women. Seventeen were adults 20-89 years of age. Nine (50%) had diarrheal illness, 6 (33%) had urinary tract infections, 2 (11%) had sepsis, and one had an infected surgical wound after appendectomy. Four patients were hospitalized, and one died. Eating alfalfa sprouts was associated with S. Havana infection (OR = 10.0; 95% confidence interval 1.2, 83.1; P = 0.01). CONCLUSIONS: This outbreak resulted in a high incidence of extra-intestinal infections, especially urinary tract infections, and high morbidity. Raw alfalfa sprouts, often considered a safe "heath food," can be a source of serious foodborne disease outbreaks.

Wound botulism in California, 1951-1998: recent epidemic in heroin injectors.

California has reported most of the world's wound botulism (WB) cases and nearly three-fourths of the cases reported in the United States. We reviewed the clinical, epidemiologic, and laboratory features of WB. From the first case in 1951, through 1998, a total of 127 cases were identified-93 in the last 5 years. The dramatic increase has been due to an epidemic (of WB) in people who inject black tar heroin. Whereas early cases of WB occurred after gross trauma, all but 1 of the last 102 cases occurred in drug users, primarily those who inject drugs subcutaneously ("skin poppers"). Cases are occurring disproportionately in Hispanics and women. Misdiagnosis and diagnostic delays of up to 64 days have occurred. This unprecedented, ongoing epidemic is now being reported in other states. We discuss the clinical and laboratory features that distinguish botulism from conditions that can mimic it, the relative yield of various diagnostic laboratory tests for botulism, and its treatment.

The impact of health communication and enhanced laboratory-based surveillance on detection of cyclosporiasis outbreaks in California.

We investigated the timing of diagnosis, influence of media information on testing for Cyclospora, and the method used to identify cases during eight cyclosporiasis outbreaks in California in spring of 1997. We found that Internet information, media reports, and enhanced laboratory surveillance improved detection of these outbreaks.

Influence of host genetics on the severity of coccidioidomycosis.

Coccidioidomycosis, a mild flulike illness in approximately 40% of infected persons, progresses to severe pulmonary or disseminated disease in 1% to 10% of symptomatic cases. We examined host genetic influences on disease severity among class II HLA loci and the ABO blood group. Participants included African-American, Caucasian, and Hispanic persons with mild or severe disseminated coccidioidomycosis from Kern County, California. Among Hispanics, predisposition to symptomatic disease and severe disseminated disease is associated with blood types A and B, respectively. The HLA class II DRB1*1301 allele marks a pre-disposition to severe disseminated disease in each of the three groups. Reduced risk for severe disease is associated with DRB1*0301-DQB1*0201 among Caucasians and Hispanics and with DRB1*1501-DQB1*0602 among African-Americans. These data support the hypothesis that host genes, in particular HLA class II and the ABO blood group, influence susceptibility to severe coccidioidomycosis.

An outbreak of Salmonella serogroup Saphra due to cantaloupes from Mexico.

An outbreak of Salmonella serogroup Saphra (S. saphra) infections was studied by laboratory-based surveillance, case-control and trace-back studies, and a survey of cantaloupe preparation practices. Twenty-four patients with S. saphra infections had illness onsets between 23 February and 15 May 1997; 75% were