Hospitalization of paediatric patients for methicillin-resistant Staphylococcus aureus skin and soft-tissue infection, 1998-2006.

Hospital discharge reports have provided data for studies of methicillin-resistant Staphylococcus aureus (MRSA) skin and soft-tissue infection (SSTI) studies. This analysis determined the sensitivity and positive predictive value of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code combinations to calculate hospitalization incidence rates, representativeness of a set of three ICD-9-CM codes to define MRSA SSTI, and hospitalization incidence rate trends for paediatric MRSA SSTIs in Los Angeles County (LAC). Using 133 cases from 31 hospitals, we found that the set of three ICD-9-CM codes used to define laboratory-confirmed cases had one of the highest positive predictive values (49%). There was no difference in age and race between those categorized using three codes vs. other code combinations. A dramatic increase in paediatric MRSA SSTI cases occurred in LAC during 1998-2006. We conclude that this combination of codes may be used to determine the rise of MRSA SSTIs in paediatric populations.

A risk-based restaurant inspection system in Los Angeles County.

The majority of local health departments perform routine restaurant inspections. In Los Angeles County (LAC), California, approximately $10 million/year is spent on restaurant inspections. However, data are limited as to whether or not certain characteristics of restaurants make them more likely to be associated with foodborne incident reports. We used data from the LAC Environmental Health Management Information System (EHMIS), which records the results of all routine restaurant inspections as well as data regarding all consumer-generated foodborne incidents that led to a special restaurant inspection by a sanitarian (investigated foodborne incidents [IFBIs]). We analyzed a cohort of 10,267 restaurants inspected from 1 July 1997 to 15 November 1997. We defined a "case restaurant" as any restaurant with a routine inspection from 1 July 1997 to 15 November 1997 and a subsequent IFBI from 1 July 1997 to 30 June 1998. Noncase restaurants did not have an IFBI from I July 1997 to 30 June 1998. We looked for specific characteristics of restaurants that might be associated with the restaurant subsequently having an IFBI, including the size of restaurant (assessed by number of seats), any previous IFBIs, the overall inspection score, and a set of 38 violation codes. We identified 158 case restaurants and 10,109 noncase restaurants. In univariate analysis, middle-sized restaurants (61 to 150 seats; n = 1,681) were 2.8 times (95% confidence interval [CI] = 2.0 to 4.0) and large restaurants (>150 seats; n = 621) were 4.6 times (95% CI = 3.0 to 7.0) more likely than small restaurants (< or =60 seats; n = 7,965) to become case restaurants. In addition, the likelihood of a restaurant becoming a case restaurant increased as the number of IFBIs in the prior year increased (chi2 for linear trend, P value = 0.0005). Other factors significantly associated with the occurrence of an IFBI included a lower overall inspection score, the incorrect storage of food, the reuse of food, the lack of employee hand washing, the lack of thermometers, and the presence of any food protection violation. In multivariate analysis, the size of restaurant, the incorrect storage of food, the reuse of food, and the presence of any food protection violation remained significant predictors for becoming a case restaurant. Our data suggest that routine restaurant inspections should concentrate on those establishments that have a large seating capacity or a poor inspection history. Evaluation of inspection data bases in individual local health departments and translation of those findings into inspection guidelines could lead to an increased efficiency and perhaps cost-effectiveness of local inspection programs.

Survival in children with perinatal HIV infection and very low CD4 lymphocyte counts.

OBJECTIVES: To evaluate clinical conditions associated with mortality in HIV-infected children with CD4+ counts <100 cells/microl. METHODS: The Pediatric Spectrum of HIV Disease Project is a longitudinal medical record review study with eight study sites in the United States, which have been enrolling children since 1989. Survival time from baseline very low CD4 count (<100 cells/microl) to death was estimated using the Kaplan-Meier method. Cox proportional hazards models were used to evaluate the effect of clinical variables on mortality. RESULTS: Of 522 children (>/=1 year of age) with serial CD4+ T-lymphocyte measurements, the median age at the first very low CD4 count was 4.8 years. The estimated median survival following the first very low CD4 count was 36 months. The following factors present at the first very low CD4 count were independently associated with a higher risk of death: younger age, weight-for-age >2 standard deviations below the mean, and previously diagnosed AIDS. The subsequent development of cytomegalovirus (CMV)-associated disease, Mycobacterium avium intracellulare (MAI) infection, wasting syndrome, or esophageal candidiasis was also independently associated with a higher risk of death. CONCLUSION: Survival in HIV-infected children with very low CD4 counts before introduction of highly active antiretroviral therapy was highly variable. Poor nutritional status and the development of CMV disease or MAI infection were associated with the shortest survival times.

Human immunodeficiency virus-infected adolescents: a descriptive study of older children in New York City, Los Angeles County, Massachusetts and Washington, DC.

BACKGROUND: Children infected with HIV are entering adolescence with challenging and changing medical and social needs. Through chart review we describe certain medical and social characteristics of adolescents who acquired HIV as children. METHODS: HIV-infected children 12 years of age and older in 1995 were monitored through the Pediatric Spectrum of HIV Disease study from four US sites. In addition to standard 6-month medical chart reviews, a special chart abstraction in 1997 collected available psychosocial and sexual history information. RESULTS: A total of 131 adolescents HIV-infected as children were studied: 52 infected perinatally; 44 infected through a contaminated blood transfusion; 30 through receipt of contaminated blood products for hemophilia; and 5 with unknown transmission mode. Mean age at last medical contact was 15.5 years, 67% were Hispanic or African-American, 12% were employed, 66% attended regular school, 66% knew their HIV status and 48% (8% for the perinatally infected) lived with their biologic mother. Information on sexual activity showed that 18% had sexual relations, 28% did not and for 53% sexual activity was not recorded in the medical chart. Four percent used illicit drugs, which along with sexual activity showed a positive association with age. Forty-two percent had an AIDS-defining opportunistic infection, and 56% had a recent CD4+ lymphocyte count <200 cells/microl. CONCLUSIONS: Adolescents in this study represent a heterogeneous group of surviving HIV-infected children some of whom are sexually active and potential sources of HIV transmission. Clinicians who treat HIV-infected and high risk adolescents face the challenges of providing care and prevention services appropriate to adolescent development.

Haff disease: from the Baltic Sea to the U.S. shore.

Haff disease, identified in Europe in 1924, is unexplained rhabdomyolysis in a person who ate fish in the 24 hours before onset of illness. We describe a series of six U.S. patients from 1997 and report new epidemiologic and etiologic aspects. Although Haff disease is traditionally an epidemic foodborne illness, these six cases occurred in two clusters and as one sporadic case.

Strengths and limitations of molecular subtyping in a community outbreak of Legionnaires' disease.

An epidemiological and microbiological investigation of a cluster of eight cases of Legionnaires' disease in Los Angeles County in November 1997 yielded conflicting results. The epidemiological part of the investigation implicated one of several mobile cooling towers used by a film studio in the centre of the outbreak area. However, water sampled from these cooling towers contained L. pneumophila serogroup 1 of another subtype than the strain that was recovered from case-patients in the outbreak. Samples from two cooling towers located downwind from all of the case-patients contained a Legionella strain that was indistinguishable from the outbreak strain by four subtyping techniques (AP-PCR, PFGE, MAb, and MLEE). It is unlikely that these cooling towers were the source of infection for all the case-patients, and they were not associated with risk of disease in the case-control study. The outbreak strain also was not distinguishable, by three subtyping techniques (AP-PCR, PFGE, and MAb), from a L. pneumophila strain that had caused an outbreak in Providence, RI, in 1993. Laboratory cross-contamination was unlikely because the initial subtyping was done in different laboratories. In this investigation, microbiology was helpful for distinguishing the outbreak cluster from unrelated cases of Legionnaires' disease occurring elsewhere. However, multiple subtyping techniques failed to distinguish environmental sources that were probably not associated with the outbreak. Persons investigating Legionnaires' disease outbreaks should be aware that microbiological subtyping does not always identify a source with absolute certainty.

Pyrogenic reactions associated with single daily dosing of intravenous gentamicin.

OBJECTIVE: To identify risk factors associated with an unexpected outbreak of pyrogenic reactions (PR) following intravenous gentamicin. DESIGN: We conducted two cohort studies. PRs were defined as chills, rigors, or shaking within 3 hours after initiating the gentamicin infusion during the preepidemic (December 1, 1997-January 15, 1998) or epidemic (May 1-June 15, 1998) periods. We tested gentamicin vials for endotoxin using the limulus amebocyte lysate assay. SETTING: Inpatient services of a large community hospital in Los Angeles, California. RESULTS: During the epidemic period, 22 (15%) of 152 patients developed documented PRs following intravenous gentamicin. PRs were more likely among patients receiving single daily dosing (SDD) than multiple daily dosing gentamicin (20/73 [27%] vs. 2/79 [3%]; relative risk, 10.8; 95% confidence interval, 2.6 44.7). Laboratory analysis of gentamicin vials found endotoxin levels that were higher among Fujisawa-brand gentamicin (implicated brand) than gentamicin used after the outbreak terminated (non-implicated brand). Although endotoxin levels in the vials did not exceed US Pharmacopeia limits (1.7 endotoxin units/mg gentamicin), the use of SDD gentamicin may place patients at greater risk of receiving doses of endotoxin above the threshold for PRs in humans. CONCLUSIONS: Reassessment of the acceptable amounts of endotoxin in gentamicin and other parenteral products should be considered when dosing intervals used in clinical practice change.

A multistate nosocomial outbreak of Ralstonia pickettii colonization associated with an intrinsically contaminated respiratory care solution.

From 1 February through 30 April 1998, 4 hospitals reported a total of 34 patients colonized with Ralstonia pickettii. All but 1 had been exposed to 0.9% saline solution manufactured by 1 company (Modudose; Kendall, Mainsfield, MA), which was used during endotracheal suctioning. Culture of saline solution from previously unopened vials yielded R. pickettii. All available product and patient isolates were genotypically related by pulsed-field gel electrophoresis (PFGE) analysis. The contaminated saline solution was manufactured at the same plant that had been associated with a similar outbreak in 1983. The 1983 and 1998 R. pickettii isolates were unrelated, as determined by PFGE. In both 1983 and 1998, a 0. 2-microm cartridge filter was used for terminal sterilization. The detection of R. pickettii should alert hospital personnel to the possibility of product contamination. In this outbreak, prompt notification of public health agencies resulted in rapid notification of other health care providers, which likely prevented additional outbreaks.

Varicella outbreaks after vaccine licensure: should they make you chicken?

In 1998, 3 years after vaccine licensure, child care centers (CCC) in Los Angeles County continued to report varicella outbreaks. We investigated outbreaks at 2 CCCs to determine the cause for them, such as low vaccination coverage levels or unexpected low vaccine effectiveness. We collected information on past history of varicella, illness during the outbreak, and prior varicella vaccination among CCC attendees. We found that CCC "H" had a vaccination coverage of 87% (34/39) compared with 30% (6/20) in CCC "L." The overall attack rate was lower in CCC "H" (31%) than in "L" (61%; P value =.03). Vaccine effectiveness for any varicella was 71% in "H" and 100% in "L." Vaccinated children with varicella had milder disease than unvaccinated. In conclusion, we found varicella outbreaks in CCCs with both high and low vaccination coverage. Vaccine effectiveness was within the range predicted by the literature. Vaccination led to a lower attack rate in the highly vaccinated CCC and appeared to protect from severe disease.

Prevention of Vibrio vulnificus infections. Assessment of regulatory educational strategies.

CONTEXT: Vibrio vulnificus-related disease caused by eating contaminated raw oysters prompted California to implement regulatory educational initiatives in 1991. OBJECTIVE: To assess California guidelines and education efforts with regard to the prevention of V. vulnificus infections in Los Angeles County and to evaluate compliance with state regulations mandating posting of warning signs concerning risks of eating raw oysters. DESIGN: Review of epidemiologic investigations of V. vulnificus infections in Los Angeles County between 1993 and 1995; telephone interviews of patients or surrogates; and a survey of restaurants serving raw oysters in Los Angeles County. SETTING: General community. MAIN OUTCOME MEASURES: Prior warning of patients and posting of warning signs in restaurants. RESULTS: Recent cases of V. vulnificus infections in Los Angeles County suggest that a unique, vulnerable group (uninsured Hispanic men with viral or alcoholic liver disease) has not been reached through education efforts. Of a total of 11 cases, information regarding being warned about the hazard of eating raw shellfish was available for 8; of these, only 1 case was reported as having been warned, but he had misunderstood the preventive message. Warning signs were not posted adequately in more than 50% of restaurants surveyed and one third of these establishments had signs in English only. Warnings were never located on dining tables and rarely included in menus. CONCLUSION: A more effective strategy is required to prevent V.vulnificus infections in Los Angeles County.

Children hospitalized for varicella: a prevaccine review.

OBJECTIVES: To describe varicella complications in healthy and previously ill children hospitalized for varicella and to explore trends in group A beta-hemolytic streptococcus complications of varicella. METHODS: A retrospective record review of children hospitalized for varicella between January 1, 1990, and March 31, 1994, was conducted in nine large acute care hospitals in Los Angeles County, California. RESULTS: We identified 574 children hospitalized for varicella in study hospitals during the 4.25-year study period (estimated risk of hospitalization, approximately 1 in 550 cases of varicella); 53% of the children were healthy before the onset of varicella and 47% were previously ill with underlying cancers or other chronic illnesses. Children were hospitalized for treatment of complications (n = 427, 74%) or for prophylactic antiviral therapy or observation (n = 147, 26%). Systems involved in complications included skin/soft tissue (45%), neurologic (18%), respiratory (14%), gastrointestinal (10%), and hematologic, renal, or hepatic (8% or less). The mean age of children with skin/soft tissue infections was 2.7 years (range < 1 to 16 years) compared with 4.7 years (< 1 to 18 years) for other complications. Children with skin/soft tissue and neurologic complications were more often previously healthy (p < 0.05), whereas those with respiratory complications were more often previously ill (p < 0.001). Hospitalizations for skin/soft tissue infections increased during the study period. The proportion of complications as a result of group A beta-hemolytic streptococcus infection increased from 4.7% before 1993 to 12.2% for the remainder of the study period (p = 0.02). CONCLUSIONS: Prior health status was predictive of the type of complications experienced by children with varicella requiring hospitalization. Our data suggest a recent increase in skin/soft tissue complications of varicella requiring hospitalization and an increase in the proportion of complications related to group A beta-hemolytic streptococcus. Wide-scale vaccine use should reverse this trend and reduce the overall impact of varicella on both healthy and previously ill children.

Meningococcal disease in Los Angeles County, California, and among men in the county jails.

BACKGROUND: From January through March 1993, there were 54 cases of meningococcal disease in Los Angeles County, California, of which 9 occurred among men incarcerated in the county's jail system, which was 40 percent above capacity at the time. Several of the 45 patients from the community had had contact with men recently released from a county jail. METHODS: We interviewed patients from the community (n=42) and neighborhood controls matched with the patients for age, race, and ethnic group (n=84) about potential exposures. We collected and cultured pharyngeal swabs for Neisseria meningitidis from men entering the central jail (n=162), men leaving the central jail (n=379), members of the jail staff (n=121), and patients at a community health center (n=214). Meningococcal isolates were identified by serotyping and multilocus enzyme electrophoresis. RESULTS: The presence of community-acquired meningococcal disease was strongly associated with exposure to a person who had been in or worked at one of the county jails (multivariate matched odds ratio, 18.5; 95 percent confidence interval, 3.8 to 90.8; P<0.001). Pharyngeal carriage of meningococcus was significantly more frequent among men released from jail (19 percent) or entering jail (17 percent) than among workers at the jails (3 percent) or community residents seen at the clinic (1 percent). Among men entering jail, those who had previously been incarcerated were more often carriers than those who had not (21 percent vs. 7 percent, P=0.03). Of the isolates from nine community residents with serogroup C meningococcal disease, eight were the same strain as that isolated from the eight inmates with serogroup C disease. CONCLUSIONS: In this outbreak of meningococcal disease in Los Angeles County, nearly half of community residents with the disease had contact with persons who had been in a county jail. The high rates of carriage among recidivists and released inmates suggests that the men became meningococcal carriers while in jail.

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.

Natural history of human immunodeficiency virus disease in perinatally infected children: an analysis from the Pediatric Spectrum of Disease Project.

OBJECTIVE: To describe the progression of human immunodeficiency virus (HIV) disease through clinical stages from birth to death among a large number of perinatally infected children. METHODS: The Pediatric Spectrum of Disease (PSD) project, coordinated by the Centers for Disease Control and Prevention (CDC), has conducted active surveillance for HIV disease since 1988 in seven geographic regions. PSD data are collected from medical and social service records every 6 months through practitioners at each participating hospital clinic. We analyzed data from perinatally HIV-infected children born between 1982 and 1993. The natural history of HIV disease was divided into five progressive stages using the clinical categories in the CDC 1994 pediatric HIV classification system: stage N, no signs or symptoms; stage A, mild signs or symptoms; stage B, moderate signs or symptoms; stage C, severe signs or symptoms; and stage D, death. A five-stage Markov model was fitted to the PSD data. To compare the estimates from the PSD project with the published estimates, we also fitted an alternative Markov model using acquired immunodeficiency syndrome (AIDS; 1987 case definition) in place of stage C and also calculated standard Kaplan-Meier estimates. RESULTS: A total of 2148 perinatally HIV-infected children were included in the analysis. The estimated mean times spent in each stage were: N, 10 months; A, 4 months; B, 65 months; and C, 34 months. We estimated that a child born with HIV infection has a 50% (95% confidence interval [CI], 40%-60%) chance of severe signs or symptoms developing by 5 years of age and a 75% (95% CI, 68%-82%) chance of surviving to 5 years of age. For a child in stage B, there is a 60% (95% CI, 49%-71%) chance of severe signs or symptoms developing within the next 5 years and a 65% (95% CI, 56%-73%) chance of surviving 5 more years. The estimated mean time from birth to stage C was 6.6 (95% CI, 5.7-7.5) years, and the estimated mean survival time from birth was 9.4 (95% CI, 8.1-10.7) years. From the alternative Markov model, the estimated mean time from birth to AIDS was 4.8 (95% CI, 4.5-5.2) years. CONCLUSION: Markov modeling using the revised pediatric classification system allowed us to describe the natural history of HIV disease in children before diagnosis of AIDS. On average, children progress to moderate symptoms in the second year of life and then remain moderately symptomatic for more than half of their expected lives, underscoring their need for clinical care before the onset of AIDS. The results from the Markov model are useful in family counseling, health care planning, and clinical trial designs.

Risk factors for invasive group A streptococcal infections in children with varicella: a case-control study.

OBJECTIVE: To identify characteristic clinical manifestations and potential risk factors for invasive group A streptococcal (GAS) disease in children with varicella. DESIGN AND PARTICIPANTS: A case-control study was conducted in Los Angeles and Orange Counties, CA. Cases were children with varicella who developed invasive GAS disease between January 1 and May 3, 1994 (n = 25). Controls were acquaintance, neighborhood or schoolmate children with uncomplicated varicella during the study period (n = 62). Cases were compared with controls with regard to underlying illness, child care practices, parental home health practices, health care-seeking behaviors, sociodemographic characteristics and clinical characteristics. RESULTS: Controlling for age we found that cases were more likely than controls: (1) to be cared for in the home vs. out-of-home child care (odds ratio (OR), 4.4 (95% confidence interval (95% CI), 1.1 to 17)); (2) to report having asthma (OR, 6.2 (95% CI, 1.2 to 41.0)) and to be taking albuterol (OR, 11.6 ((95% CI, 1.0 to 581)); (3) to be secondary varicella cases within a household (OR, 7.3 (95% CI, 2.2 to 25)); (4) to report fever after Day 2 of varicella; and (5) to have contacted their health care provider later than controls (Day 3.8 rather than Day 1.7, P < 0.001). CONCLUSIONS: To our knowledge this is the first case-control study exploring potential risk factors for invasive GAS disease in children with varicella. Both previously healthy children with varicella and those with underlying medical problems, including asthma, may be at increased risk for GAS complications. Interventions should be targeted to parents and health care providers to increase awareness of early signs and symptoms of invasive GAS disease in children with varicella. Additional studies are needed to confirm the associations suggested by this study between GAS complications of varicella and asthma, in-home child care, secondary vs. primary varicella household cases and delayed contact with medical care providers.

An outbreak of cholera from food served on an international aircraft.

In February 1992, an outbreak of cholera occurred among persons who had flown on a commercial airline flight from South America to Los Angeles. This study was conducted to determine the magnitude and the cause of the outbreak. Passengers were interviewed and laboratory specimens were collected to determine the magnitude of the outbreak. A case-control study was performed to determine the vehicle of infection. Seventy-five of the 336 passengers in the United States had cholera; 10 were hospitalized and one died. Cold seafood salad, served between Lima, Peru and Los Angeles, California was the vehicle of infection (odds ratio, 11.6; 95% confidence interval, 3.3-44.5). This was the largest airline-associated outbreak of cholera ever reported and demonstrates the potential for airline-associated spread of cholera from epidemic areas to other parts of the world. Physicians should obtain a travel history and consider cholera in patients with diarrhoea who have travelled from cholera-affected countries. This outbreak also highlights the risks associated with eating cold foods prepared in cholera-affected countries.