Nancy L. Barrett

Mortality from invasive pneumococcal pneumonia in the era of antibiotic resistance, 1995-1997.

OBJECTIVES This study examined epidemiologic factors affecting mortality from pneumococcal pneumonia in 1995 through 1997. METHODS Persons residing in a surveillance area who had community-acquired pneumonia requiring hospitalization and Streptococcus pneumoniae isolated from a sterile site were included in the analysis. Factors affecting mortality were evaluated in univariate and multivariate analyses. The number of deaths from pneumococcal pneumonia requiring hospitalization in the United States in 1996 was estimated. RESULTS Of 5837 cases, 12% were fatal. Increased mortality was associated with older age, underlying disease. Asian race, and residence in Toronto/Peel, Ontario. When these factors were controlled for, increased mortality was not associated with resistance to penicillin or cefotaxime. However, when deaths during the first 4 hospital days were excluded, mortality was significantly associated with penicillin minimum inhibitory concentrations of 4.0 or higher and cefotaxime minimum inhibitory concentrations of 2.0 or higher. In 1996, about 7000 to 12,500 deaths occurred in the United States from pneumococcal pneumonia requiring hospitalization. CONCLUSIONS Older age and underlying disease remain the most important factors influencing death from pneumococcal pneumonia. Mortality was not elevated in most infections with beta-lactam-resistant pneumococci.

The Epidemiology of Invasive Group A Streptococcal Infection and Potential Vaccine Implications: United States, 2000–2004

BACKGROUND Invasive group A Streptococcus (GAS) infection causes significant morbidity and mortality in the United States. We report the current epidemiologic characteristics of invasive GAS infections and estimate the potential impact of a multivalent GAS vaccine. METHODS From January 2000 through December 2004, we collected data from Centers for Disease Control and Preventions Active Bacterial Core surveillance (ABCs), a population-based system operating at 10 US sites (2004 population, 29.7 million). We defined a case of invasive GAS disease as isolation of GAS from a normally sterile site or from a wound specimen obtained from a patient with necrotizing fasciitis or streptococcal toxic shock syndrome in a surveillance area resident. All available isolates were emm typed. We used US census data to calculate rates and to make age- and race-adjusted national projections. RESULTS We identified 5400 cases of invasive GAS infection (3.5 cases per 100,000 persons), with 735 deaths (case-fatality rate, 13.7%). Case-fatality rates for streptococcal toxic shock syndrome and necrotizing fasciitis were 36% and 24%, respectively. Incidences were highest among elderly persons (9.4 cases per 100,000 persons), infants (5.3 cases per 100,000 persons), and black persons (4.7 cases per 100,000 persons) and were stable over time. We estimate that 8950-11,500 cases of invasive GAS infection occur in the United States annually, resulting in 1050-1850 deaths. The emm types in a proposed 26-valent vaccine accounted for 79% of all cases and deaths. Independent factors associated with death include increasing age; having streptococcal toxic shock syndrome, meningitis, necrotizing fasciitis, pneumonia, or bacteremia; and having emm types 1, 3, or 12. CONCLUSIONS GAS remains an important cause of severe disease in the United States. The introduction of a vaccine could significantly reduce morbidity and mortality due to these infections.

Epidemiology of invasive group a streptococcus disease in the United States, 1995-1999.

Severe invasive group A streptococcal (GAS) disease is believed to have reemerged during the past 10-20 years. We conducted active, laboratory, population-based surveillance in 5 US states (total population, 13,214,992). From 1 July 1995 through 31 December 1999, we identified 2002 episodes of invasive GAS (3.5 cases per 100,000 persons). Rates varied by age (higher among those <2 or >/=65 years old), surveillance area, and race (higher among black individuals) but did not increase during the study period. The 5 most common emm types (1, 28, 12, 3, and 11) accounted for 49.2% of isolates; newly characterized emm types accounted for 8.9% of isolates. Older age; presence of streptococcal toxic shock syndrome, meningitis, or pneumonia; and infection with emm1 or emm3 were all independent predictors of death. We estimate that 9600-9700 cases of invasive GAS disease occur in the United States each year, resulting in 1100-1300 deaths.

Declining Incidence of Invasive Streptococcus pneumoniae Infections among Persons with AIDS in an Era of Highly Active Antiretroviral Therapy, 1995—2000

BACKGROUND Our goal was to describe trends in invasive pneumococcal disease incidence among persons with acquired immunodeficiency syndrome (AIDS) since the introduction of highly active antiretroviral therapy (HAART). METHODS We used time-trend analysis of annual invasive pneumococcal disease incidence rates from a population-based, active surveillance system. Annual incidence rates were calculated for 5 July-June periods by use of data from San Francisco county, the 6-county Baltimore metropolitan area, and Connecticut. The numerators were the numbers of invasive Streptococcus pneumoniae infections among persons 18-64 years of age with AIDS; the denominators were the numbers of persons living with AIDS, estimated on the basis of AIDS surveillance data. RESULTS The annual incidence of invasive pneumococcal disease declined from 1094 cases/100,000 persons with AIDS (July 1995-June 1996) to 467 cases/100,000 persons living with AIDS (July 1999-June 2000). The annual percentage changes in incidence were -34%, -29%, -8%, and -1%. Declines were similar by surveillance area, sex, and race/ethnicity. During the final year of the study, the invasive pneumococcal disease incidence in persons with AIDS was half that of the pre-HAART era but was still 35 times higher than that in similarly aged non-HIV-infected adults. CONCLUSIONS In the United States, invasive pneumococcal disease incidence declined sharply across a range of subgroups living with AIDS during the period after widespread introduction of HAART. Despite these gains, persons with AIDS remain at high risk for invasive pneumococcal disease.

Preventability of Invasive Pneumococcal Disease and Assessment of Current Polysaccharide Vaccine Recommendations for Adults: United States, 2001–2003

UNLABELLED BACKGROUND. To prevent Streptococcus pneumoniae infection among persons at highest risk for invasive pneumococcal disease (IPD), the pneumococcal polysaccharide vaccine (PPV) is currently recommended for persons >or=65 years old and persons 2-64 years old with certain underlying conditions. Policymakers have considered expanding recommendations for PPV to include persons who are 50-64 years old and additional populations at risk for IPD. Our objectives were to determine the proportion of IPD cases that might have been prevented if all persons with vaccine indications had been vaccinated and to evaluate new indications. METHODS From 2001 to 2003, we performed a case series study of IPD in adults at 6 sites of the Active Bacterial Core surveillance-Emerging Infections Program Network. A case of IPD was defined as isolation of pneumococcus from a normally sterile site from a resident of 1 of the surveillance areas. RESULTS Among 1878 case patients, 1558 (83%) had at least 1 current vaccine indication; of these, 968 case patients (62%) were unvaccinated. Adherence to existing vaccine recommendations would have prevented 21% of all cases. The proportions of all cases potentially prevented by each new indication were as follows: lowering the universal age of recommended vaccination to 50 years, 5.0%-7.0%; adding new risk-based indications to include current smoking, 1.5%-2.5%; former smoking, 0.4%-0.7%; black race, 1.0%-1.4%; and asthma, 0.3%-0.4%. CONCLUSIONS Increasing vaccine coverage rates among persons with a current indication may prevent more cases than expanding existing indications. Of the potential new indications studied, the strategy that may prevent most cases is lowering the recommended age for universal vaccination to 50 years.

Risk Factors for Meningococcal Disease in Students in Grades 9-12

Background: Meningococcal disease is a serious problem in adolescents, including high school students. Universal immunization of adolescents with meningococcal conjugate vaccine was recently recommended. We studied risk factors for meningococcal disease in students in grades 9–12. Methods: This was a matched case-control study using surveillance for meningococcal disease in students in grades 9–12 in sites throughout the United States. For each case-patient, up to 4 controls were selected from the home room classroom. All subjects answered an extensive questionnaire. Logistic regression was performed to identify risk factors associated with meningococcal disease. Meningococcal isolates were characterized. Results: Of 69 eligible patients, 49 (71%) were enrolled and had at least 1 control. Isolates were available for 59 (86%) cases. Attending at least 1 barbeque or picnic [matched odds ratio (MOR): 0.26, P value = 0.003] or school dance (MOR: 0.30, P = 0.04) were independently associated with decreased risk of meningococcal disease. Male gender (MOR: 2.94, P = 0.009), upper respiratory infection symptoms (MOR: 2.43, P = 0.04), marijuana use (MOR: 4.21, P = 0.009), and nightclub/disco attendance (MOR: 3.30, P = 0.04) were associated with increased risk. Among 54 students not from Oregon (where serogroup B strains predominate) with available serogroup, 38 (73.1%) cases were potentially vaccine preventable: 18 (34.6%) serogroup C, 19 (36.5%) serogroup Y, and 1 (1.9%) serogroup W-135. Conclusions: Certain behaviors increase the risk of meningococcal infection, whereas others are associated with decreased risk. Most meningococcal disease in high school students can be prevented if recommendations on use of meningococcal conjugate vaccine are implemented.

Aggregated Antibiograms and Monitoring of Drug-Resistant Streptococcus pneumoniae

Community-specific antimicrobial susceptibility data may help monitor trends among drug-resistant Streptococcus pneumoniae and guide empiric therapy. Because active, population-based surveillance for invasive pneumococcal disease is accurate but resource intensive, we compared the proportion of penicillin-nonsusceptible isolates obtained from existing antibiograms, a less expensive system, to that obtained from 1 year of active surveillance for Georgia, Tennessee, California, Minnesota, Oregon, Maryland, Connecticut, and New York. For all sites, proportions of penicillin-nonsusceptible isolates from antibiograms were within 10 percentage points (median 3.65) of those from invasive-only isolates obtained through active surveillance. Only 23% of antibiograms distinguished between isolates intermediate and resistant to penicillin; 63% and 57% included susceptibility results for erythromycin and extended-spectrum cephalosporins, respectively. Aggregating existing hospital antibiograms is a simple and relatively accurate way to estimate local prevalence of penicillin-nonsusceptible pneumococcus; however, antibiograms offer limited data on isolates with intermediate and high-level penicillin resistance and isolates resistant to other agents.

Invasive Group A Streptococcal Infection in Older Adults in Long-term Care Facilities and the Community, United States, 1998–20031

Invasive infection develops almost 6 times as frequently in the elderly in long-term care facilities.

Gram-positive Rod Surveillance for Early Anthrax Detection

Connecticut established telephone-based gram-positive rod (GPR) reporting primarily to detect inhalational anthrax cases more quickly. From March to December 2003, annualized incidence of blood isolates was 21.3/100,000 persons; reports included 293 Corynebacterium spp., 193 Bacillus spp., 73 Clostridium spp., 26 Lactobacillus spp., and 49 other genera. Around-the-clock GPR reporting has described GPR epidemiology and enhanced rapid communication with clinical laboratories.

Suspected Brazilian Purpuric Fever in a Toddler with Overwhelming Epstein-Barr Virus Infection

We describe a toddler from Connecticut who developed purulent conjunctivitis, fever, and a morbilliform rash. Blood cultures were positive for Haemophilus influenzae biogroup aegyptius; further investigation was performed to assess the possibility that the illness was consistent with Brazilian purpuric fever, which, to our knowledge, has not been reported in the United States. This isolate shared morphological and some biochemical characteristics with previously studied H. influenzae biogroup aegyptius strains but differed according to slide agglutination testing, plasmid characterization, and ribotyping. Blood and tissue samples obtained during his hospitalization were also positive for Epstein-Barr virus. The child died 8 days after hospitalization. Fifty other cases of invasive H. influenzae infection were identified by active surveillance studies. Of the 49 viable surveillance isolates, 10 were biotype III (two of which had the same ribotype as the strain from our case.