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.

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 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.

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.

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.

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.

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.

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.

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.

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.

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 </=6 years old; 23% were hospitalized. Case patients were more likely than controls to have consumed cantaloupe (88% vs. 45%; matched odds ratio [MOR], 15. 5; 95% confidence interval [CI], 1.7-139) and precut cantaloupe (59% vs. 19%; MOR, 14.5; 95% CI, 1.6-128). The trace-back study identified 1 growing region in Mexico as the source of cantaloupes for 95% of the patients who ate cantaloupes. Only 17% of case patients washed cantaloupes before cutting them. This outbreak is another example of gastrointestinal disease in the United States associated with imported contaminated produce. Consumers and retailers should wash cantaloupes before cutting them; there should be international efforts to ensure food safety.

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.

Mushroom poisoning due to amatoxin. Northern California, Winter 1996-1997

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Effect of dexamethasone on osseointegration: a preliminary experimental study

The peri-implant reparative process is one of the factors involved in osseointegration. Local and systemic factors may contribute to the peri-implant micro-environment. The aim of this study was to assess the effect of dexamethasone (DXM) on the first stages of the post-implantation reparative process using a quantitative osseointegration experimental model previously developed at our laboratory. A titanium laminar implant was inserted into the right tibiae of nine male Wistar rats under ether anesthesia, following a technique we previously described. Six rats received 120 micrograms/kg/day i.p. doses of DXM (Decadron Sidus, Argentina) for 14 days pre-implantation and 14 days post-implantation. The remaining three (controls) were injected with an equivalent volume of saline. On day 14 post-implantation, all animals were killed, and their tibiae were resected, radiographed, and processed before being embedded in methylmethacrylate. Microscopic observation and histomorphometric studies were performed. Results show that, in this experimental model, the extension of osteogenic peri-implant response was greater in DXM-treated animals than in controls. Thus, our laminar implant test may prove useful to study the effects of corticosteroids on the osseointegration process.

Wound botulism associated with black tar heroin among injecting drug users

CONTEXT

Wound botulism (WB) is a potentially lethal, descending, flaccid, paralysis that results when spores of Clostridium botulinum germinate in a wound and elaborate neurotoxin. Since 1988, California has experienced a dramatic increase in WB associated with injecting "black tar" heroin (BTH), a dark, tarry form of the drug.

OBJECTIVE

To identify risk factors for WB among injecting drug users (IDUs).

DESIGN

Case-control study based on data from in-person and telephone interviews.

PARTICIPANTS

Case patients (n=26) were IDUs who developed WB from January 1994 through February 1996. Controls (n=110) were IDUs newly enrolled in methadone detoxification programs in 4 counties.

MAIN OUTCOME MEASURES

Factors associated with the development of WB.

RESULTS

Among the 26 patients, the median age was 41.5 years, 15 (58%) were women, 14 (54%) were non-Hispanic white, 11 (42%) were Hispanic, and none were positive for the human immunodeficiency virus. Nearly all participants (96% of patients and 97% of controls) injected BTH, and the mean cumulative dose of BTH used per month was similar for patients and controls (27 g and 31 g, respectively; P=.6). Patients were more likely than controls to inject drugs subcutaneously or intramuscularly (92% vs 44%, P<.001) and used this route of drug administration more times per month (mean, 67 vs 24, P<.001), with a greater cumulative monthly dose of BTH (22.3 g vs 6.3 g, P<.001). A dose-response relationship was observed between the monthly cumulative dose of BTH injected subcutaneously or intramuscularly and the development of WB (chi2 for linear trend, 26.5; P<.001). In the final regression model, subcutaneous or intramuscular injection of BTH was the only behavior associated with WB among IDUs (odds ratio, 13.7; 95% confidence interval, 3.0-63.0). The risk for development of WB was not affected by cleaning the skin, cleaning injection paraphernalia, or sharing needles.

CONCLUSIONS

Injection of BTH intramuscularly or subcutaneously is the primary risk factor for the development of WB. Physicians in the western United States, where BTH is widely used, should be aware of the potential for WB to occur among IDUs.

Enhanced control of an outbreak of Mycoplasma pneumoniae pneumonia with azithromycin prophylaxis

There are currently no recommended epidemic-control measures for Mycoplasma pneumoniae pneumonia outbreaks in closed communities. Previous studies have suggested the usefulness of chemoprophylaxis administered to close contacts of case-patients. To evaluate the effectiveness of various epidemic-control measures during an institutional outbreak, an observational study was undertaken during a very large outbreak of M. pneumoniae pneumonia at a facility for developmentally disabled residents (n = 142 cases). Control measures evaluated included no control, standard epidemic-control measures, and targeted azithromycin prophylaxis (500 mg on day 1, 250 mg/day on days 2-5) plus standard epidemic-control measures. The combined use of azithromycin prophylaxis and standard epidemic-control measures was associated with a significant reduction in the secondary attack rate. This study suggests that the addition of antibiotic prophylaxis to standard epidemic-control measures can be useful during institutional outbreaks of M. pneumoniae pneumonia.

Coccidioidomycosis in Tulare County, California, 1991: reemergence of an endemic disease

In 1991, 1208 cases of coccidioidomycosis were reported to the California Department of Health Services, compared with an annual average of 450 during 1986-90. We conducted a study in Tulare County to define the epidemiology of the disease and identify risk factors for severe disease, focusing on the epidemic period September 1991-December 1991. To identify cases, we used data from the Coccidioidomycosis Serology Laboratory at the University of California, Davis, other laboratories, and the Tulare County Health Department's coccidioidomycosis reporting system. We compared patients who were hospitalized with those who were not to determine risk factors for severe disease. We identified 128 cases of acute coccidioidomycosis diagnosed between 1 September and 31 December 1991 (attack rate 41/100,000); south central Tulare County had the highest attack rate. Thirty-five (27%) case-patients were hospitalized. Male sex (relative risk (RR) 2.5, 95% confidence interval (CI) 1.2-5.0), black people and Asian races (RR 4.8, 95% CI 2.4-9.6), and age > or = 20 years (RR 8.3, 95% CI 1.2-57.4) were univariately significant and remained independently associated with hospitalization in multivariate analysis. The 1991 Tulare County outbreak of coccidioidomycosis was part of a much larger outbreak that began in California during 1991 and continued through 1993. The outbreak was preceded by an unusually rainy spring. Although dust reduction measures during times of increased coccidioidomycosis incidence can help reduce exposure, definitive control awaits the development of a safe, effective vaccine.

Postoperative Serratia marcescens wound infections traced to an out-of-hospital source

From 25 August to 28 September 1994, 7 cardiovascular surgery (CVS) patients at a California hospital acquired postoperative Serratia marcescens infections, and 1 died. To identify the outbreak source, a cohort study was done of all 55 adults who underwent CVS at the hospital during the outbreak. Specimens from the hospital environment and from hands of selected staff were cultured. S. marcescens isolates were compared using restriction-endonuclease analysis and pulsed-field gel electrophoresis. Several risk factors for S. marcescens infection were identified, but hospital and hand cultures were negative. In October, a patient exposed to scrub nurse A (who wore artificial fingernails) and to another nurse-but not to other identified risk factors-became infected with the outbreak strain. Subsequent cultures from nurse A's home identified the strain in a jar of exfoliant cream. Removal of the cream ended the outbreak. S. marcescens does not normally colonize human skin, but artificial nails may have facilitated transmission via nurse A's hands.

Cholera from raw seaweed transported from the Philippines to California

In March 1994, a California woman without any recent travel developed acute, profuse, watery diarrhea. Her astute physician diagnosed cholera after ordering the appropriate stool culture, and the patient improved on an oral antibiotic. Epidemiologic investigation implicated seaweed from the Philippines that was transported by a friend to California and subsequently eaten raw as the vehicle of infection.

Profile of raw milk consumers in California

OBJECTIVES

The authors sought to determine the prevalence of raw milk consumption in California--the largest producer of certified raw milk in the United States--and to describe the demographic and behavioral characteristics of raw milk consumers in that state.

METHODS

The authors analyzed responses to questions on the 1994 California Behavioral Risk Factor Surveillance System Survey that asked respondents about whether they drank raw milk, the amount consumed, the reason for drinking raw milk, and where raw milk was most often obtained.

RESULTS

Among 3999 survey respondents, 3.2% reported drinking raw milk in the previous year. Raw milk drinkers were more likely than nondrinkers to be younger than age 40, male, and Hispanic and to have less than a high school education.

CONCLUSIONS

Raw milk continues to be consumed by some residents of California despite the documented hazards associated with this dietary practice.

Epidemic Salmonella enteritidis infection in Los Angeles County, California. The predominance of phage type 4

Between April and July 1994, 501 cases of Salmonella enteritidis infection were reported in Los Angeles County, California, nearly 5 times the number reported between April and July 1993; of these, 422 (84%) were sporadic (not related to known outbreaks). A case-control study was done to determine risk factors for sporadic illness; the distribution of S enteritidis phage types was evaluated. Case-patients (n = 58) were county residents older than 1 year with culture-confirmed S enteritidis infection in August 1994. One to two acquaintance controls (n = 98) were matched to each case by age, sex, and race. Two risk factors-eating raw or undercooked eggs (matched odds ratio [MOR] = 6.6; 95% confidence interval [CI] = 1.9, 23.0) and eating in restaurants (MOR = 4.9; 95% CI = 1.2, 19.4) in the 3 days before the onset of illness-remained significant in the conditional logistic regression model. Of 16 randomly selected S enteritidis case-isolates, 15 (94%) were phage type 4. The reasons for the regional predominance of phage type 4, an S enteritidis subtype recently associated with large and destructive increases in salmonellosis among poultry and humans in Britain and much of Europe, are unclear. To minimize human S enteritidis infection, food service workers need frequent training in the proper handling of raw foods, eggs should be kept refrigerated during distribution and storage, and eggs should be cooked until the yolk is firm, particularly for persons at the greatest risk for serious illness: pregnant women, elderly persons, and those with compromised immune systems. Clinicians should obtain stool specimens for culture from patients who present with diarrhea and fever or bloody diarrhea or who are possibly part of an outbreak.

A new route of transmission for Escherichia coli: infection from dry fermented salami

OBJECTIVES

This study evaluated the production of dry fermented salami associated with an outbreak of Escherichia coli O157.H7 infection in Washington State and California.

METHODS

Facility inspections, review of plant monitoring data, food handler interviews, and microbiological testing of salami products were conducted.

RESULTS

Production methods complied with federal requirements and industry-developed good manufacturing practices. No evidence suggested that postprocessing contamination occurred. Calculations suggested that the infectious dose was smaller than 50 E. coli O157:H7 bacteria.

CONCLUSIONS

Dry fermented salami can serve as a vehicle of transmission for O157:H7 strains. Our investigation and prior laboratory studies suggest that E. coli O157:H7 can survive currently accepted processing methods.

Invasive group A streptococcal infections in children with varicella in Southern California

OBJECTIVE

To describe demographic and clinical features of invasive group A streptococcal (GAS) infections in children with varicella in Southern California in early 1994.

METHODS

From hospitals of Los Angeles and Orange Counties, children with invasive GAS infections after varicella between January 1 and April 8, 1994, were identified by hospital infection control nurses. Medical records of patients were reviewed, and any available GAS isolate was further tested.

RESULTS

Twenty-four cases were identified; 54% were male, 50% were Hispanic and the median age was 3 years (range, 0.5 to 8). Four cases died before hospitalization. The other 20 were hospitalized for a median of 10 days (range, 4 to 50): 14 presented with cellulitis (1 with concomitant epiglottitis), 2 with myositis/necrotizing fasciitis, 2 with pneumonia and 2 with bacteremia without apparent source. Five had evidence of multiorgan involvement including two patients fulfilling criteria of streptococcal toxic shock-like syndrome. Of 19 patients with blood cultures, 10 (53%) had GAS bacteremia. Onset of GAS infection was suggested, as a median, on Day 4 of varicella, with fever, vomiting and localized swelling being commonly reported. The mean maximum temperature on the day of admission was 39.4 degrees C (102.9 degrees F). Four GAS isolates were M1T1 and one was M3T3. Five isolates produced streptococcal pyrogenic exotoxins A and B.

CONCLUSIONS

Invasive GAS disease, including streptococcal toxic shock-like syndrome, is a serious complication of varicella. Physicians should be alert for the complication of GAS when fever and localized swelling or signs of cellulitis develop 3 days or more after the onset of varicella. Widespread use of varicella vaccine may decrease invasive GAS infections in this setting.

A cluster of Escherichia coli O157:H7 infections with the hemolytic-uremic syndrome and death in California. A mandate for improved surveillance

In mid-January 1993, an outbreak of Escherichia coli O157:H7 infections associated with eating hamburger patties at a fast-food restaurant chain (chain A) was reported in Washington State. From mid-December to mid-January, 9 cases of E coli O157:H7-associated bloody diarrhea and the hemolytic-uremic syndrome had been reported in San Diego County, California. A total of 34 persons had bloody diarrhea, the hemolytic-uremic syndrome, or E coli O157:H7 organisms isolated from stool during the period November 15, 1992, through January 31, 1993. Organisms of E coli O157:H7 identified from 6 persons were indistinguishable from those of the Washington outbreak strain. Illness was associated with eating at chain A restaurants in San Diego (odds ratio, 13; 95% confidence interval, 1.7, 99) and with eating regular-sized hamburgers (odds ratio, undefined; lower-limit 95% confidence interval, 1.3). Improved surveillance by mandating laboratory- and physician-based reporting of cases of E coli O157:H7 infection and the hemolytic-uremic syndrome might have alerted health officials to this outbreak sooner, which could have resulted in earlier investigation and the institution of measures to prevent more cases.

Nosocomial outbreak of Candida albicans sternal wound infections following cardiac surgery traced to a scrub nurse

From August 1988 through October 1989, 15 patients at 1 hospital developed Candida albicans sternal wound infections after cardiac surgery. An investigation found that case-patients were more likely than cardiac surgery patients without sternal wound infections to have surgeries lasting > 165 min (11/15 vs. 20/45; odds ratio [OR], 5.0; 95% confidence interval [CI], 1.5-16.3) or exposure to first scrub nurse A (15/15 vs. 22/45; OR, infinity; 95% CI, 2.5, infinity). Molecular typing of 5 case-patient C. albicans isolates revealed a common strain. Nurse A had a history of recurrent vaginal infections responding to topical antifungal agents; however, cultures of multiple samples from nurse A, beginning 3 weeks after the last infected patient's surgery, failed to yield C. albicans. Following her voluntary transfer from cardiac surgery, no additional infections of case-patients were detected. This study demonstrates the utility of combining epidemiologic methods and molecular typing in investigating C. albicans infection clusters and suggests that a common exogenous source can be responsible for C. albicans surgical wound infections.

Hantavirus pulmonary syndrome in California: report of two cases and investigation

We report two cases of hantavirus pulmonary syndrome that were probably acquired in California. Genetic analysis of tissue specimens from one of the patients revealed that the virus isolated is a variant of the strain (Sin Nombre virus) identified in the outbreak of hantavirus pulmonary syndrome that occurred in the Four Corners region of the southwestern United States in 1993. In addition to presenting the clinical features of the two cases, we discuss the possible risk factors for infection.

Wound botulism in a patient with a tooth abscess: case report and review

We describe a case of wound botulism associated with a tooth abscess in a 5-year-old boy. We reviewed the literature and reports to the Centers for Disease Control and Prevention (Atlanta) of laboratory-confirmed cases of wound botulism. From 1943 through 1990, 47 cases were reported. Type A botulinus toxin was identified in 32 cases, type B in 13, types A and B in 1, and an unknown type in 1. Botulism was associated with wounds from trauma, use of injectable drugs, and surgery. Sinusitis after use of intranasal cocaine has also been associated with botulism. Treatment for wound botulism includes prompt debridement of the wound for eliminating anaerobic conditions, intensive care, and treatment with antitoxin.

Epidemiology of Aeromonas infections in California

In May 1988, California became the first state to make aeromonas infection a reportable condition, thereby permitting the first population-based study of the epidemiology of infection caused by Aeromonas organisms. Case investigations were carried out on 219 of the 280 patients whose infections were reported during the first year of notification. The overall incidence rate for Aeromonas isolation was 10.6 cases per 1 million population. The gastrointestinal tract was the most commonly reported site from which Aeromonas was isolated (81%), with wounds being the next most common source (9%). Five (2%) of the 219 patients died; all five had serious underlying medical conditions apart from aeromonas infection. No common-source enteric outbreaks were reported. The high rate of gastrointestinal symptoms and isolation of organisms from medically vulnerable patients and the fact that other bacterial enteric pathogens were rarely isolated from symptomatic patients support evidence from previous studies that Aeromonas is an enteric pathogen. The evidence from these case reports in California suggests that aeromonas infections are not an important public health problem and are largely nonpreventable. Thus, public health surveillance is not necessary and mandatory reporting has been discontinued.

An outbreak of Bacillus cereus food poisoning--are caterers supervised sufficiently

Bacillus cereus is an uncommonly reported cause of foodborne illness in the United States. In May 1989, an outbreak of B. cereus gastroenteritis occurred among 140 guests who had attended a catered wedding reception in Napa, CA. Investigation established Cornish game hens served at the event as the vehicle for disease transmission (OR = 29, P = 0.0001). Although the spores of B. cereus are ubiquitous, large numbers of toxin-producing organisms (more than 10(5) per gram of food) are required for illness to occur. In the Napa outbreak, bacterial multiplication was facilitated at several points during the preparation and transportation of the food. While a licensed restaurant kitchen was used, the facilities were clearly inadequate for the event. At present, the California Health and Safety Code does not address the scope of catering operations. As caterers increase in number, there will be a growing need for governmental oversight to ensure that food production on a large scale is conducted safely.

Outbreak of Pontiac fever due to Legionella anisa

An outbreak of Pontiac fever occurred among 34 of 56 people attending conferences at a hotel in Santa Clara County, California, in 1988. Two groups had an acute febrile upper respiratory illness, with a mean attack rate of 82% and a mean incubation period of 56 hours. Symptoms resolved spontaneously within 5 days. Legionella anisa, which had not previously been associated with outbreaks of Pontiac fever or legionnaires' disease, was isolated from a decorative fountain in the hotel lobby. In addition, 5 of 8 pairs of serum samples from cases showed a more than fourfold rise in antibody titre to the L anisa recovered from the fountain. 42% of hotel employees had titres greater than or equal to 256 against L anisa, whereas none of 48 serum samples from matched controls had titres greater than or equal to 128. The findings raise concern about water treatment protocols for extent of disease that might be caused by exposure to aerosols containing L anisa and other Legionella species.

Risk factors associated with a school-related outbreak of serogroup C meningococcal disease

An outbreak of Neisseria meningitidis sero-group C disease occurred in four eighth grade students and in a younger sibling of another eighth grade student attending an intermediate school (seventh and eighth grades) in Santa Clara County, CA. Four cases had onset within 3 days in January, 1989, with the fifth case occurring approximately 10 days later. A case-control study was performed to determine risk factors associated with serogroup C meningococcal infection (disease or carriage) in this eighth grade class. Students were more likely to be infected if they had had a preceding viral-like respiratory illness characterized by fever (odds ratio (OR) 5.3, P = 0.03) or cough (OR 5.1, P = 0.048). A ski trip (OR 6.3, P = 0.01) and a poster-making session for a school dance (OR 3.7, P = 0.08) were identified as possible settings for a common exposure. Spending time with two specific students during lunchtime or outside of school was associated with an increased risk of infection (OR 7.0, P = 0.054; OR 5.8, P = 0.04).

Staphylococcal food poisoning associated with an Easter egg hunt

Staphylococcal contamination of intact, hard-boiled eggs resulted in the food poisoning of an estimated 300 children out of 850 who had participated in an Easter egg hunt. Enterotoxigenic staphylococci that were isolated from the Easter eggs matched that obtained from an infected cook who prepared the eggs three to five days before the hunt and which he left unrefrigerated. Experimental studies demonstrated that heated eggs can absorb 2 mL of contaminated cool water through intact eggshells. When water was inoculated with pathogenic staphylococci at even low contamination levels, rapid growth and enterotoxin production within cooked eggs could be easily duplicated. This is the first large outbreak of its type; safeguards can and should be employed to prevent future ones.

Effect of patent ductus arteriosus on lower extremity blood flow velocity patterns in preterm infants

We used a 20-MHz, range-gated, pulsed Doppler device to measure noninvasively femoral artery blood flow velocity patterns in 24 preterm infants with patent ductus arteriosus (PDA). Mean spatial flow velocity and its temporal average were recorded by illumination of the entire flow stream. Peak systolic forward flow velocity (Vs), peak diastolic retrograde flow velocity (VD), mean flow velocity (Vf), and the peak to peak-mean velocity ratio, (VS-VD)/Vf, were determined serially in each patient. The changes in the femoral flow velocity pattern preceded or coincided with other evidence of ductal left to right shunting. Prior to PDA closure, (VS-VD)/Vf averaged 14.1 and Vf averaged 4.4 cm/sec; after ductal closure, (VS-VD)/Vf fell to 3.7 (P less than .001) and Vf rose to 9.1 cm/sec, more than twice the preclosure value (P less than .001). Large diastolic reverse flow velocity vectors and low mean velocity correlated with large left to right PDA shunts estimated from other methods of assessment. The noninvasive femoral artery Doppler approach detects patency of the ductus early in life, reflects left to right shunting in diastole, and emphasizes the impact of the PDA on systemic blood flow.

Primary plague pneumonia contracted from a domestic cat at South Lake Tahoe, Calif

Primary plague pneumonia occurred in a 47-year-old South Lake Tahoe woman shortly after face-to-face exposure to her plague pneumonia-infected cat. Both died. Field investigation revealed a recent plague epizootic in squirrels and chipmunks around the patient's home. Control measures included active surveillance and chemoprophylaxis of 197 contacts to the victim, a community alert on methods of self- and pet protection, and application of insecticide to reduce rodent flea populations. No secondary cases occurred.

Legionellosis--the 1980 San Francisco outbreak

During the first half of March 1980, an unseasonal outbreak of legionellosis, which involved at least 14 of approximately 1,000 workers, occurred in a 6-month-old office building in San Francisco. An epidemiologic investigation revealed that persons 50 yr of age and older were at increased risk of disease. The outbreak was temporally associated with operation of the building's air conditioning system. In addition, Legionella pneumophila Serogroups 1, 4, and 6 were identified in water samples taken from a rooftop air conditioning cooling tower located directly across the street from an area of recent excavation.

A sensitive analytical apparatus for measuring hydrogen production rates. II. Application to studies in human infants

We estimated hydrogen (H2) production by determining simultaneously the end-tidal concentration (ETH2) and the direct pulmonary excretion rate (VeH2) in normal-sized, healthy, term and preterm neonates between 2 days and 7 weeks of life who were receiving all their calories enterally as breast milk or a proprietary formula. We found that there was no peak or pattern in H2 production during the first 3 postprandial hours (mean VeH2 = 1.00 +/- 0.97 SD ml/kg/h; mean ETH2 = 40.3 +/- 33.1 SD ppm). Frequently, there was marked short-term variability of the ETH2 in a given infant (coefficient of variation = 13.4% +/- 18.7%). H2 production was elevated in normal neonates without signs of malabsorption. We found that VeH2 correlated with ETH2 using both nasopharyngeal catheter (r = 0.63; p less than 0.001) and nasal prong (r = 0.71; p less than 0.001) collection techniques. We conclude that breath hydrogen determinations in neonates are not readily comparable to similar studies in older patients. Longitudinal studies of individual infants may reveal changes in breath H2 excretion of sufficient magnitude to be distinguishable from moment-to-moment variations, and correlatable with certain intercurrent clinical problems affecting intestinal H2 production or pulmonary H2 excretion. However, interpretation of breath H2 determinations in human infants will be difficult.

Association between raw milk and human Salmonella dublin infection

Between 1971 and 1975 the mean annual incidence of human Salmonella dublin infection in California increased more than five-fold. Investigation of the increase showed an association with exposure to raw milk in 44 out of 113 cases. Of these 44 patients, 35 had used certified raw milk from a single dairy. Faecal swabs confirmed S dublin infection in the dairy herd and the milk, and so a pasteurisation order was issued. S dublin appears to be an unusually invasive and life-threatening salmonella serotype: 65% of isolations were obtained from non-faecal specimens (mainly blood cultures), 89 patients (80%) were admitted to hospital and 22 patients died. Almost three-quarters of the patients were aged 20 or over, and half had serious underlying diseases, particularly leukaemias and lymphomas. Five patients presented with infected vascular lesions that included aneurysms with abscesses and infections of previous arterial graft sites. The public's increasing desire for a "health food" such as raw milk should be tempered with an appreciation of its attendant risk to health.