Brian D. Plikaytis

Epidemic listeriosis associated with Mexican-style cheese.

In Los Angeles County, California, 142 cases of human listeriosis were reported from January 1 through August 15, 1985. Ninety-three cases (65.5 percent) occurred in pregnant women or their offspring, and 49 (34.5 percent) in nonpregnant adults. There were 48 deaths: 20 fetuses, 10 neonates, and 18 nonpregnant adults. Of the nonpregnant adults, 98 percent (48 of 49) had a known predisposing condition. Eighty-seven percent (81 of 93) of the maternal/neonatal cases were Hispanic. Of the Listeria monocytogenes isolates available for study, 82 percent (86 of 105) were serotype 4b, of which 63 of 86 (73 percent) were the same phage type. A case-control study implicated Mexican-style soft cheese (odds ratio, 5.5; 95 percent confidence interval, 1.2 to 24.8) as the vehicle of infection; a second case-control study showed an association with one brand (Brand A) of Mexican-style soft cheese (odds ratio, 8.5; 95 percent confidence interval, 2.4 to 26.2). Laboratory study confirmed the presence of L. monocytogenes serogroup 4b of the epidemic phage type in Brand A Mexican-style cheese. In mid-June, all Brand A cheese was recalled and the factory was closed. An investigation of the cheese plant suggested that the cheese was commonly contaminated with unpasteurized milk. We conclude that the epidemic of listeriosis was caused by ingestion of Brand A cheese contaminated by one phage type of L. monocytogenes serotype 4b.

Pasteurized milk as a vehicle of infection in an outbreak of listeriosis.

Between June 30th and August 30th, 1983, 49 patients in Massachusetts acquired listeriosis. Seven cases occurred in fetuses or infants and 42 in immunosuppressed adults; 14 patients (29 per cent) died. Of 40 Listeria monocytogenes isolates available for testing, 32 were serotype 4b. Two case-control studies, one matching for neighborhood of residence and the other for underlying disease, revealed that the illness was strongly associated with drinking a specific brand of pasteurized whole or 2 per cent milk (odds ratio = 9, P less than 0.01 for the neighborhood-matched study; odds ratio = 11.5, P less than 0.001 for the illness-matched study). The association with milk was further substantiated by four additional analyses that suggested the presence of a dose-response effect, demonstrated a protective effect of skim milk, associated cases with the same product in an independent study in another state, and linked a specific phage type with the disease associated with milk. The milk associated with disease came from a group of farms on which listeriosis in dairy cows was known to have occurred at the time of the outbreak. Multiple serotypes of L. monocytogenes were isolated from raw milk obtained from these farms after the outbreak. At the plant where the milk was processed, inspections revealed no evidence of improper pasteurization. These results support the hypothesis that human listeriosis can be a foodborne disease and raise questions about the ability of pasteurization to eradicate a large inoculum of L. monocytogenes from contaminated raw milk.

Trends in Mortality Due to Invasive Mycotic Diseases in the United States, 1980–1997

To determine national trends in mortality due to invasive mycoses, we analyzed National Center for Health Statistics multiple-cause-of-death record tapes for the years 1980 through 1997, with use of their specific codes in the International Classification of Diseases, Ninth Revision (ICD-9 codes 112.4-118 and 136.3). In the United States, of deaths in which an infectious disease was the underlying cause, those due to mycoses increased from the tenth most common in 1980 to the seventh most common in 1997. From 1980 through 1997, the annual number of deaths in which an invasive mycosis was listed on the death certificate (multiple-cause [MC] mortality) increased from 1557 to 6534. In addition, rates of MC mortality for the different mycoses varied markedly according to human immunodeficiency virus (HIV) status but were consistently higher among males, blacks, and persons > or =65 years of age. These data highlight the public health importance of mycotic diseases and emphasize the need for continuing surveillance.

Protective efficacy of a serogroup B meningococcal vaccine in Sao Paulo, Brazil

Serogroup B Neisseria meningitidis is the most common cause of epidemic meningococcal disease in developed countries. Until recently no vaccine has been available for prevention of infection with this organism. In an attempt to control epidemic serogroup B meningococcal disease in greater Sao Paulo, Brazil, during 1989 and 1990, a Cuban-produced outer-membrane-protein-based serogroup B meningococcal vaccine was given to about 2.4 million children aged from 3 months to 6 years. We have done a case-control study to estimate the efficacy of the vaccine in greater Sao Paulo. Microbiologically confirmed cases of serogroup B meningococcal disease were identified through hospital-based surveillance. Controls were matched by neighbourhood and age. Vaccination status was confirmed by inspection of vaccination cards. Between June, 1990, and June, 1991, 112 patients and 409 matched controls with confirmed vaccine status were enrolled. Estimated vaccine efficacy varied by age: 48 months or older = 74% (95% Cl 16 to 92%), 24 to 47 months = 47% (-72 to 84%), and less than 24 months = -37% (< -100 to 73%). Our results suggest that the Cuban-produced vaccine may be effective for prevention of serogroup B meningococcal disease in older children and adults.

Excess mortality, hospital stay, and cost due to candidemia: a case-control study using data from population-based candidemia surveillance.

OBJECTIVE To determine the mortality, hospital stay, and total hospital charges and cost of hospitalization attributable to candidemia by comparing patients with candidemia with control-patients who have otherwise similar illnesses. Prior studies lack broad patient and hospital representation or cost-related information that accurately reflects current medical practices. DESIGN Our case-control study included case-patients with candidemia and their cost-related data, ascertained from laboratory-based candidemia surveillance conducted among all residents of Connecticut and Baltimore and Baltimore County, Maryland, during 1998 to 2000. Control-patients were matched on age, hospital type, admission year, discharge diagnoses, and duration of hospitalization prior to candidemia onset. RESULTS We identified 214 and 529 sets of matched case-patients and control-patients from the two locations, respectively. Mortality attributable to candidemia ranged between 19% and 24%. On multivariable analysis, candidemia was associated with mortality (OR, 5.3 for Connecticut and 8.5 for Baltimore and Baltimore County; P < .05), whereas receiving adequate treatment was protective (OR, 0.5 and 0.4 for the two locations, respectively; P < .05). Candidemia itself did not increase the total hospital charges and cost of hospitalization; when treatment status was accounted for, having received adequate treatment for candidemia significantly increased the total hospital charges and cost of hospitalization (

Serological criteria for evaluation and licensure of new pneumococcal conjugate vaccine formulations for use in infants

6,000 to

Enzyme-Linked Immunosorbent Assay for Quantitation of Human Antibodies to Pneumococcal Polysaccharides

29,000 and

Reduction in Functional Antibody Activity Against Streptococcus pneumoniae in Vaccinated Elderly Individuals Highly Correlates with Decreased IgG Antibody Avidity

3,000 to

Risk Factors for Group B Streptococcal Disease in Adults

22,000, respectively) and the length of stay (3 to 13 days). CONCLUSION Our findings underscore the burden of candidemia, particularly regarding the risk of death, length of hospitalization, and cost associated with treatment.

Pneumococcal Vaccine Efficacy in Selected Populations in the United States

The World Health Organization (WHO) is undertaking a series of consultations on serological criteria for the evaluation and licensure of new formulations/combinations or different vaccination schedules of pneumococcal conjugate vaccines. The lack of a definitive serological correlate of protection and the multiplicity of antigens involved, especially since the clinical efficacy of most of the individual serotypes represented in the only licensed vaccine has not been established, are hindering the formulation of criteria for licensure of new formulations or combinations of the vaccine. This report analyses the various options with their relative merits and drawbacks and provides preliminary recommendations as guidance to regulatory agencies in evaluating these vaccines for the purposes of licensure. More detailed recommendations for production and control of pneumococcal conjugate vaccines, including criteria for evaluation for licensure, are currently being drafted.