Early detection and response to meningococcal disease epidemics in sub-Saharan Africa: appraisal of the WHO strategy

OBJECTIVE

To assess the sensitivity, specificity and predictive value positive of the WHO threshold strategy for detecting meningococcal disease epidemics in sub-Saharan Africa and to estimate the impact of the strategy on an epidemic at district level.

METHODS

Data on meningitis cases at the district level were collected weekly from health ministries, WHO country and regional offices, and nongovernmental organizations in countries where there were epidemics of meningococcal disease in 1997. An epidemic was defined as a cumulative district attack rate of at least 100 cases per 100,000 population from January to May, the period of epidemic risk. The sensitivity, specificity and predictive value positive of the WHO threshold rate were calculated, and curves of sensitivity against (1 - specificity) were compared with alternatively defined threshold rates and epidemic sizes. The impact of the WHO strategy on a district epidemic was estimated by comparing the numbers of epidemic cases with cases estimated to have been prevented by vaccination.

FINDINGS

An analysis was made of 48 198 cases reported in 174 districts in Benin, Burkina Faso, the Gambia, Ghana, Mali, Niger, and Togo. These cases were 80.3% of those reported from Africa to WHO during the 1997 epidemic period. District populations ranged from 10,298 to 573,908. The threshold rate was crossed during two consecutive weeks in 69 districts (39.7%) and there were epidemics in 66 districts (37.9%). Overall, the sensitivity of the threshold rate for predicting epidemics was 97%, the specificity was 95%, and the predictive value positive was 93%. Taken together, these values were equivalent or better than the sensitivity, specificity and predictive value positive of alternatively defined threshold rates and epidemics, and remained high regardless of district size. The estimated number of potential epidemic cases decreased by nearly 60% in the age group targeted for vaccination in one district where the guidelines were followed in a timely manner.

CONCLUSION

The use of the WHO strategy was sensitive and specific for the early detection of meningococcal disease epidemics in countries of sub-Saharan Africa during 1997 and had a substantial impact on a district epidemic. Nevertheless, the burden of meningococcal disease in these countries remains formidable and additional control measures are needed.

Introduction of Hib conjugate vaccines in the non-industrialized world: experience in four 'newly adopting' countries

Hib conjugate vaccines are widely used in the industrialized world, but are just now beginning to be introduced into other countries. To identify factors facilitating rapid global introduction, we evaluated the decision-making process, mode of introduction, effectiveness, and impact on the immunization program of Hib conjugate vaccine introduction in four non- industrialized countries through site visits and use of a standardized questionnaire. The key promoters of Hib introduction were the pediatric community and ministries of health. Local surveillance and severity data were critical in the decision to adopt Hib vaccine. Assistance with surveillance, introduction guidelines, educational material, tenders, and funding is needed to accelerate wider adoption.

Efficacy of Haemophilus influenzae type b conjugate vaccines and persistence of disease in disadvantaged populations. The Haemophilus Influenzae Study Group

OBJECTIVES

The purpose of this study was to evaluate the effectiveness of Haemophilus influenzae type b (Hib) conjugate vaccines among children aged 2 to 18 months and to determine risk factors for invasive Hib disease during a period of declining incidence (1991-1994).

METHODS

A prospective population-based case-control study was conducted in a multistate US population of 15.5 million. A laboratory-based active surveillance system was used for case detection.

RESULTS

In a multivariate analysis, having a single-parent mother (odds ratio [OR] = 4.3, 95% confidence interval [CI] = 1.2, 14.8) and household crowding (OR = 3.5, 95% CI = 1.03, 11.7) were risk factors for Hib disease independent of vaccination status. After adjustment for these risk factors, the protective efficacy of 2 or more Hib vaccine doses was 86% (95% CI = 16%, 98%). Among undervaccinated subjects, living with a smoker (P = .02) and several indicators of lower socioeconomic status were risk factors for Hib disease.

CONCLUSIONS

Hib disease still occurs at low levels in the United States, predominantly in socioeconomically disadvantaged populations. Low immunization coverage may facilitate continuing transmission of Hib. Special efforts to achieve complete and timely immunization in disadvantaged populations are needed.

Informal workshop on potential regulatory and 2 licensing issues for pneumococcal conjugate vaccines. 13 June 1998, Helsingor, Denmark

(1) It is likely that a seven-valent pneumococcal conjugate vaccine will be licensed in the next few years based on efficacy studies. Licensure of nine- or 11-valent vaccines will be sought soon thereafter. Further studies of nine- or 11-valent vaccines which can evaluate efficacy of the added serotypes will be unlikely. (2) Licensure of other vaccines (including those with additional serotypes), will depend on evaluation of surrogates for efficacy. (3) The most accepted surrogate of efficacy at this point is some combination of functional assay (e.g. opsonophagocytosis), and/or serology of anticapsular antibody by ELISA or RIA that correlates closely with the functional test. (4) An additional important correlate of immunity for polysaccharide conjugate vaccines may be measurement of the booster response. (5) Although effect on nasopharyngeal carriage may be developed into a useful correlate of efficacy in the future, much additional work must be done before carriage data can be interpreted usefully for this purpose. (6) Testing for consistency of production of pneumococcal conjugate vaccines will follow lines similar to that for Hib conjugate vaccines. Thus, instead of one set of universally applicable lot release criteria, vaccine-specific criteria must be developed collaboratively between industry and national control authorities.

Epidemiology of Haemophilus influenzae type b disease and impact of Haemophilus influenzae type b conjugate vaccines in the United States and Canada

Haemophilus influenzae type b (Hib) was the major cause of invasive bacterial disease in the United States and Canada before the introduction of Hib conjugate vaccines. Between 10000 and 20000 cases of Hib meningitis and other serious diseases occurred each year, leading to death in at least 3% of all patients and long term neurologic problems in up to 25% of survivors of meningitis. Introduction of Hib conjugate vaccines in Canada and the United States, first in children 18 months and older and later as a routine infant immunization, dramatically decreased the incidence of disease. By 1995 Hib disease levels had declined by more than 95% below preimmunization levels. The remarkably rapid reduction in disease incidence was partly because of the ability of the vaccine to reduce nasopharyngeal carriage of the organism, leading, when given widely, to reduced rates of exposure and infection even in those not immunized. Complete elimination of Hib disease in North America, however, will require achievement of relatively high coverage rates, especially in hard to reach populations where much of the remaining disease is occurring.

Immunogenicity of two efficacious outer membrane protein-based serogroup B meningococcal vaccines among young adults in Iceland

Serum bactericidal activity (SBA) and ELISA antibody levels elicited by two efficacious serogroup B meningococcal vaccines were measured in a controlled trial involving 408 15- to 20-year-olds. Subjects were given two doses at a 6-week interval of a serogroup B or control vaccine. Response was defined as > or = 4-fold rise in antibody level. After two doses of the Finlay Institute (Havana) vaccine at 12 months, the proportions of SBA and ELISA responders were not different from those of the control group (15% and 17% [vaccine] vs. 13% and 9% [control], P > .05). After two doses of the National Institute of Public Health (Oslo) vaccine, there were more SBA and ELISA responders than in the control group (47% and 34% [vaccine] vs. 10% and 1% [control]) or the Finlay Institute vaccine group (P < .05 for both). SBA and ELISA may be insensitive correlates for protective efficacy for some outer membrane protein-based serogroup B meningococcal vaccines.

Efficacy of meningococcal vaccine and barriers to vaccination

CONTEXT

Use of the quadrivalent meningococcal vaccine for control of outbreaks has increased in recent years, but the efficacy of meningococcal vaccine during mass vaccination campaigns in US civilian populations has not been assessed.

OBJECTIVES

To evaluate the efficacy of the quadrivalent meningococcal vaccine against serogroup C meningococcal disease in a community outbreak setting and to evaluate potentially modifiable barriers to vaccination in an area with persistent meningococcal disease following immunization.

DESIGN

Matched case-control study of vaccine efficacy using cases of serogroup C meningococcal disease in persons eligible for vaccination during mass vaccination campaigns. Control patients were matched by neighborhood and age. The control group was used to identify possible barriers to vaccination.

SETTING

Gregg County, Texas, population 106076, from 1993 to 1995.

PARTICIPANTS

A total of 17 case patients with serogroup C meningococcal disease eligible for vaccine and 84 control patients.

MAIN OUTCOME MEASURES

Vaccine efficacy and risk factors associated with nonvaccination.

RESULTS

Vaccine efficacy among 2- to 29-year-olds was 85% (95% confidence interval, 27%-97%) and did not change in bivariate analyses with other risk factors that were significant in univariate analysis. Among control patients, older age was strongly associated with nonvaccination; vaccination rates for 2- to 4-year-olds, 5- to 18-year-olds, and 19- to 29-year-olds were 67%, 48%, and 20%, respectively (chi2 for linear trend, P=.01).

CONCLUSIONS

The meningococcal polysaccharide vaccine was effective against serogroup C meningococcal disease in this community outbreak. Although specific barriers to vaccination were not identified, older age was a risk factor for nonvaccination in the target population of 2- to 29-year-olds. In future outbreaks, emphasis should be placed on achieving high vaccination coverage, with special efforts to vaccinate young adults.

Molecular epidemiology of sporadic (endemic) serogroup C meningococcal disease

Understanding the basis of sporadic (endemic) meningococcal disease may be critical to prevention of meningococcal epidemic outbreaks and to understanding fluctuations in incidence. Active, prospective, population-based surveillance and molecular epidemiologic techniques were used to study sporadic serogroup C meningococcal disease in a population of 2.34 million persons (Atlanta area). During 1988-1994, in which no outbreaks or case clusters were reported, 71 patients developed sporadic serogroup C meningococcal disease (annual incidence, 0.51/100,000). Eighty-three percent of patients were >2 years old. By multilocus enzyme electrophoresis, pulsed-field gel electrophoresis, and serotyping, 84% (52/62) of the isolates available for study were identical or closely related members of the electrophoretic type 37 (ET 37) complex responsible for multiple serogroup C outbreaks in the United States in the 1990s. Sporadic disease caused by 9 clonal strains occurred over periods up to 4 years and accounted for 45% (28/62) of cases. Sporadic serogroup C meningococcal disease was most often due to a limited number of related strains that appear to slowly circulate in the population.

Bacterial meningitis in the United States in 1995. Active Surveillance Team

BACKGROUND

Before the introduction of the conjugate vaccines, Haemophilus influenzae type b was the major cause of bacterial meningitis in the United States, and meningitis was primarily a disease of infants and young children. We describe the epidemiologic features of bacterial meningitis five years after the H. influenzae type b conjugate vaccines were licensed for routine immunization of infants.

METHODS

Data were collected from active, population-based surveillance for culture-confirmed meningitis and other invasive bacterial disease during 1995 in laboratories serving all the acute care hospitals in 22 counties of four states (total population, more than 10 million). The rates were compared with those for 1986 obtained by similar surveillance.

RESULTS

On the basis of 248 cases of bacterial meningitis in the surveillance areas, the rates of meningitis (per 100,000) for the major pathogens in 1995 were Streptococcus pneumoniae, 1.1; Neisseria meningitidis, 0.6; group B streptococcus, 0.3; Listeria monocytogenes, 0.2; and H. influenzae, 0.2. Group B streptococcus was the predominant pathogen among newborns, N. meningitidis among children 2 to 18 years old, and S. pneumoniae among adults. Pneumococcal meningitis had the highest case fatality rate (21 percent) and in 36 percent of cases was caused by organisms that were not susceptible to penicillin. From these data, we estimate that 5755 cases of bacterial meningitis were caused by these five pathogens in the United States in 1995, as compared with 12,920 cases in 1986, a reduction of 55 percent. The median age of persons with bacterial meningitis increased greatly, from 15 months in 1986 to 25 years in 1995, largely as a result of a 94 percent reduction in the number of cases of H. influenzae meningitis.

CONCLUSIONS

Because of the vaccine-related decline in meningitis due to H. influenzae type b, bacterial meningitis in the United States is now a disease predominantly of adults rather than of infants and young children.

Tobacco smoke as a risk factor for meningococcal disease

BACKGROUND

Since 1992 the US Pacific Northwest has experienced a substantial increase in the incidence of serogroup B meningococcal disease. The current meningococcal polysaccharide vaccine is poorly immunogenic in young children and does not protect against N. meningitidis serogroup B. Defining alternative approaches to the prevention and control of meningococcal disease is of considerable public health importance.

METHODS

We performed a case-control study comparing 129 patients in Oregon and southwest Washington with 274 age- and area-matched controls. We used conditional logistic regression analysis to determine which exposures remained associated with disease after adjusting for other risk factors and confounders and calculated the proportion of disease attributable to modifiable exposures.

RESULTS

After adjustment for all other significant exposures identified, having a mother who smokes was the strongest independent risk factor for invasive meningococcal disease in children < 18 years of age [odds ratio (OR), 3.8; 95% confidence interval (CI) 1.6 to 8.9)], with 37% (CI 15 to 65) of all cases in this age group potentially attributable to maternal smoking. Adult patients were more likely than controls to have a chronic underlying illness (OR 10.8, CI 2.7 to 43.3), passive tobacco smoke exposure (OR 2.5, CI 0.9 to 6.9) and to smoke tobacco (OR 2.4, CI 0.9 to 6.6). Dose-response effects were seen for passive smoke exposure and risk of disease in all age groups.

CONCLUSION

Tobacco smoke exposure independently increases the risk of developing meningococcal disease.

School-based clusters of meningococcal disease in the United States. Descriptive epidemiology and a case-control analysis

OBJECTIVE

To evaluate the epidemiologic features and risk factors for multiple cases of meningococcal disease in schools.

DESIGN

Population-based prospective evaluation and case-control study of clusters of meningococcal disease that occurred in schools from January 1989 to June 1994.

SETTING

Surveillance conducted through state health departments in the United States.

MAIN OUTCOME MEASURES

Descriptive epidemiology of school-based clusters of meningococcal disease and determinants of their occurrence.

RESULTS

We identified 22 clusters of meningococcal disease in 15 states. The estimated incidence of secondary meningococcal disease among schoolchildren aged 5 to 18 years was 2.5 per 100000 population, a relative risk of 2.3 (95% confidence interval [CI], 1.6-3.3). The median number of students per cluster was 2 (range, 2-4). Of 30 subsequent cases, 10 (33%) occurred 2 or fewer days after the index case, and 22 (73%) occurred 14 or fewer days after the index case. Among the 8 schools with 2 or more cases, 50% of the additional cases occurred 2 or more days after the second case. Secondary schools (grades 7 through 12) accounted for 15 (75%) of 20 cluster schools compared with 9 (45%) of 20 matched control schools (P<.05). In 16 (73%) of 22 clusters, interaction between case patients was noted. The index patient in cluster schools was more likely than the controls to have participated in a school-based group activity 14 or fewer days before illness (matched odds ratio, 7.0; 95% CI, 0.9-57).

CONCLUSIONS

Three quarters of the school clusters occurred in secondary schools, with over 70% of subsequent cases occurring within 2 weeks of the index case. Rapid initiation of a chemoprophylaxis program after 2 cases of meningococcal disease in a school would have potentially prevented 50% of subsequent cases in the clusters described.

Capsule switching of Neisseria meningitidis

The different sialic acid (serogroups B, C, Y, and W-135) and nonsialic acid (serogroup A) capsular polysaccharides expressed by Neisseria meningitidis are major virulence factors and are used as epidemiologic markers and vaccine targets. However, the identification of meningococcal isolates with similar genetic markers but expressing different capsular polysaccharides suggests that meningococcal clones can switch the type of capsule they express. We identified, except for capsule, isogenic serogroups B [(alpha2-->8)-linked polysialic acid] and C [(alpha2-->9)-linked polysialic acid] meningococcal isolates from an outbreak of meningococcal disease in the U. S. Pacific Northwest. We used these isolates and prototype serogroup A, B, C, Y, and W-135 strains to define the capsular biosynthetic and transport operons of the major meningococcal serogroups and to show that switching from the B to C capsule in the outbreak strain was the result of allelic exchange of the polysialyltransferase. Capsule switching was probably the result of transformation and horizontal DNA exchange in vivo of a serogroup C capsule biosynthetic operon. These findings indicate that closely related virulent meningococcal clones may not be recognized by traditional serogroup-based surveillance and can escape vaccine-induced or natural protective immunity by capsule switching. Capsule switching may be an important virulence mechanism of meningococci and other encapsulated bacterial pathogens. As vaccine development progresses and broader immunization with capsular polysaccharide conjugate vaccines becomes a reality, the ability to switch capsular types may have important implications for the impact of these vaccines.

Prevention practices for perinatal group B streptococcal disease: a multi-state surveillance analysis. Neonatal Group B Streptococcal Disease Study Group

OBJECTIVE

To evaluate hospital-based practices for perinatal group B streptococcal disease prevention and to identify institutional factors related to the disease.

METHODS

We surveyed microbiology laboratories and obstetric programs during 1994 at hospitals in five states with active surveillance for invasive group B streptococcal disease. Institutions provided information on methods for detecting carriers and on obstetric policies for group B streptococcal disease prevention. We used linear regression to identify prevention practices and hospital characteristics that correlated with the number of cases of early-onset disease.

RESULTS

Of 295 hospitals, 247 (84%) laboratories and 154 (52%) obstetric programs completed the survey. Most (83%) laboratories performed group B streptococcal cultures on rectal and vaginal specimens, but only 12 (6%) used selective broth media. Among the obstetric programs, 54 (35%) had policies on some aspect of group B streptococcal disease prevention. Of the hospitals with policies, 21 (48%) recommended intrapartum antimicrobial prophylaxis for women with risk factors outlined by the 1992 ACOG statement. Adjusting for the number of births, there were more cases of early-onset group B streptococcal disease in institutions providing care for more African American women and for more women with no prenatal care. Institutions that had group B streptococcal screening policies had fewer early-onset cases.

CONCLUSIONS

Many institutions with prevention policies followed practices that differed from those recommended in published prevention statements. Having any screening policy, however, was associated with reduced early-onset disease, independent of the risk profile of the patient population. Adopting prevention policies is most urgent for practices serving individuals at increased risk, such as African American women and women without prenatal care.

Molecular epidemiology of diphtheria in Russia, 1985-1994

The largest diphtheria outbreak in the developed world since the 1960s began in the Russian federation in 1990. One hundred fifty-six Corynebacterium diphtheriae strains from throughout Russia, selected for temporal and geographic diversity, were assayed by ribotyping and multilocus enzyme electrophoresis (MEE). These tests showed significant genetic diversity within the C. diphtheriae species, and ribotyping and MEE data generally correlated well with epidemiologic data. A distinct clonal group of C. diphtheriae isolates (ET 8 complex) emerged in Russia in 1990 as the current outbreak began, and as the outbreak has progressed, these organisms have made up increasingly larger proportions of the strains that are isolated. Furthermore, the main characteristic of the epidemic strains is a specific combination of ET 8 and ribotypes G1 and G4. This study confirms the epidemiologic utility of the molecular subtyping methods that detected the epidemic clone and addresses the clone's origin and relation to C. diphtheriae from throughout Russia.

Evaluation of the use of mass chemoprophylaxis during a school outbreak of enzyme type 5 serogroup B meningococcal disease

BACKGROUND

A vaccine for prevention of serogroup B meningococcal disease is not available in the United States, and indications for the use of mass chemoprophylaxis for control of meningococcal outbreaks are not well-defined. In response to an outbreak of six cases of enzyme type 5 serogroup B meningococcal disease among students at a middle school, we implemented a program of mass rifampin prophylaxis and evaluated the effectiveness of this preventive measure.

METHODS

Oropharyngeal cultures were obtained from 351 of the 900 students before prophylaxis; 196 participants were recultured 3 weeks later. Meningococcal isolates were subtyped and tested for rifampin susceptibility, and risk factors for disease or carriage among students were evaluated.

RESULTS

No cases occurred after prophylaxis. Before prophylaxis 10% (34 of 351) of students were meningococcal carriers and 3.4% (12 of 351) carried the epidemic strain. After prophylaxis 2.5% (5 of 196) were carriers and 1.0% (2 of 196) carried the epidemic strain. Rifampin was 85% effective in eradicating carriage, and the rate of acquisition of carriage during the 3-week period was low (0.5%). Carriage persisted after prophylaxis in 4 students; 3 of these postprophylaxis isolates were rifampin-resistant. Rifampin resistance thus developed in 12% (3 of 26) of preprophylaxis isolates. Disease/epidemic strain carriage was associated with enrollment in the school band and certain other classes.

CONCLUSIONS

These findings suggests that mass chemoprophylaxis may be effective and should be considered for control of school serogroup B meningococcal outbreaks. This approach is less likely to be effective for control of outbreaks affecting larger, less well-defined populations and is associated with the rapid development of antibiotic resistance.

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.

Invasive disease due to Haemophilus influenzae serotype f: clinical and epidemiologic characteristics in the H. influenzae serotype b vaccine era. The Haemophilus influenzae Study Group

With the decline in the rate of infections caused by Haemophilus influenzae serotype b, H. influenzae serotype f (Hif) is becoming a relatively important cause of invasive disease due to H. influenzae. We identified 91 cases of invasive Hif infections in a multistate area over a 6-year period. The incidence of invasive Hif disease was 0.5 case per 1,000,000 population in 1989 and 1.9 cases per 1,000,000 population in 1994. The proportion of all invasive H. influenzae disease caused by Hif rose from 1% in 1989 to 17% in 1994. Seventy-two percent of cases occurred in adults, and 26% of cases occurred in children younger than 5 years of age. Respiratory tract infections accounted for 82% of adult cases, and most adults had significant underlying diseases. In children, pneumonia and meningitis each accounted for 40% of cases, respectively. Overall mortality was 30% among adults, and 21% among children. Molecular typing demonstrated limited overall diversity in Hif isolates. Continued surveillance is warranted to evaluate the trend toward the increasing incidence of Hif disease that was noted in this study.

Bacillary angiomatosis and bacillary peliosis in patients infected with human immunodeficiency virus: clinical characteristics in a case-control study

Clinical characteristics associated with bacillary angiomatosis and bacillary peliosis (BAP) in patients with human immunodeficiency virus (HIV) infection were evaluated in a case-control study; 42 case-patients and 84 controls were matched by clinical care institution. Case-patients presented with fever (temperature, > 37.8 degrees C; 93%), a median CD4 lymphocyte count of 21/mm3, cutaneous or subcutaneous vascular lesions (55%), lymphadenopathy (21%), and/or abdominal symptoms (24%). Many case-patients experienced long delays between medical evaluation and diagnosis of BAP (median, 4 weeks; range, 1 day to 24 months). Case-patients were more likely than controls to have fever, lymphadenopathy, hepatomegaly, splenomegaly, a low CD4 lymphocyte count, anemia, or an elevated serum level of alkaline phosphatase (AP) (P < .001). In multivariate analysis, a CD4 lymphocyte count of < 200/mm3 (matched odds ratio [OR], 9.9; P < .09), anemia reflected by a hematocrit value of < 0.36 (OR, 19.7; P < .04), and an elevated AP level of > or = 2.6 mukat/L (OR, 23.9; P < .05) remained associated with disease after therapy with zidovudine was controlled for. BAP should be considered an AIDS-defining opportunistic infection and should be included in the differential diagnosis for febrile, HIV-infected patients with cutaneous or osteolytic lesions, lymphadenopathy, abdominal symptoms, anemia, or an elevated serum level of AP.

Outbreak of serogroup C meningococcal disease associated with campus bar patronage

Between February 1991 and April 1992, eight undergraduates at a US residential university and one at a nearby 2-year college contracted serogroup C meningococcal disease. A case-control investigation with 20 controls per case, oropharyngeal carriage surveys, and multilocus enzyme electrophoresis (MEE) of serogroup C isolates were used to identify factors contributing to the outbreak. All eight sterile-site isolates from cases were closely related by MEE and were similar (though not identical) to the strain associated with the 1991-1992 epidemic of meningococcal disease in eastern Canada. Disease was associated with cigarette smoking (p = 0.012), recent patronage of campus-area bars (p = 0.034), estimated amount of time spent in campus-area bars (p = 0.0003), and, especially, recent patronage of one specific bar, bar A (p = 0.0006; odds ratio = 23.1, 95% confidence interval 3.0-571.5). In carriage surveys, 1,528 throat cultures taken from (primarily student) noncases yielded only five (0.3%) strains that were identical by MEE to those from cases. Two of these were found among 22 cultures obtained from bar A employees in spring 1992. Some cases in this outbreak may have followed transmission of the epidemic strain in bar A. Campus bar environments may facilitate the spread of meningococcal disease among teenagers and young adults.

Utility of emergency, telephone-based national surveillance for Hantavirus pulmonary syndrome. Hantavirus Task Force

On May 27, 1993, in response to the outbreak investigation of newly recognized Hantavirus pulmonary syndrome (HPS) in the Four Corners states (New Mexico, Arizona, Utah, and Colorado), the Centers for Disease Control and Prevention established a national surveillance case definition for severe, unexplained respiratory disease to determine the extent of HPS throughout the United States. A toll-free telephone hotline number was instituted to provide updated information about unexplained respiratory illness and to serve as a passive mechanism for reporting suspected cases. Clinical information was obtained from callers reporting suspected cases, and diagnostic specimens and medical record reviews were requested from health care providers. From June 3 through December 31, 1993, the hotline received 21,443 telephone inquiries; callers identified 280 suspected cases living outside the Four Corners states with at least one specimen available for diagnostic testing. By December 31, 1993, 21 confirmed cases (age range, 14 to 58 years) residing in 11 states outside the Four Corners region had been identified. This passive surveillance system was successful in rapidly identifying the widespread sporadic geographic distribution for HPS cases throughout the United States and could serve as a model for similar emergencies. Expanding and coordinating surveillance systems for the early detection, tracking, and evaluation of emerging infections is a critical component of disease prevention.

Sporadic meningococcal disease in adults: results of a 5-year population-based study

OBJECTIVE

To define the incidence, demographics, clinical features, and risk factors for sporadic meningococcal disease in adults (> or = 18 years) residing in metropolitan Atlanta.

DESIGN

Prospective, population-based surveillance, with retrospective review of clinical and laboratory records.

SETTING

Eight-county metropolitan Atlanta area.

PATIENTS

All adult patients in whom Neisseria meningitidis was isolated from normally sterile sites (blood, cerebrospinal fluid) during the period 1 December 1988 to 30 November 1993.

MEASUREMENTS

Incidence, relative risk, clinical and laboratory parameters, and serogroup of meningococcal isolates.

RESULTS

For the 5-year period, 44 (33%) of 132 cases of meningococcal disease in Atlanta occurred in adults (annual incidence, 0.50/100,000 adults per year). Twenty-three (52%) of the 44 adults presented without rash or meningitis, the two most obvious signs of meningococcal disease. Pneumonia, sinusitis, or purulent tracheobronchitis, but without rash, were the likely sources of meningococcal bacteremia in 15 (34%) of the 44 adults. Twelve of the 15 patients with meningococcal respiratory infection were older than 50 years of age or were immunocompromised (or both), and three fourths of the 15 patients had disease caused by serogroups B, Y, and W-135. Overall, two thirds of adults older than 24 years of age with meningococcal disease had one or more immunocompromising conditions (for example, low complement 50 level [CH50], corticosteroid use, congestive heart failure, multiple myeloma, human immunodeficiency virus infection). Meningococcemia or meningococcal meningitis, often caused by serogroup C, were the presentations in 14 of 15 adults 18 to 24 years old; only 2 had an identified underlying condition.

CONCLUSIONS

In this 5-year population-based study, one third of all cases of sporadic meningococcal disease occurred in adults. Over half of the adults presented without rash or meningitis. Pneumonia, sinusitis, and tracheobronchitis are important sources of bacteremic meningococcal disease, especially in immunocompromised patients and elderly persons.

Meningococcal carriage, alcohol consumption, and campus bar patronage in a serogroup C meningococcal disease outbreak

Community outbreaks of serogroup C invasive meningococcal disease are increasing in North America (L. H. Harrison, JAMA 273:419-421, 1995; L. A. Jackson, A. Schuchat, M. W. Reeves, and J. D. Wenger, JAMA 273:382-389, 1995; C. M. Whalen, J. C. Hockin, A. Ryan, and F. Ashton, JAMA 273:390-394). In a recent 15-month university outbreak, disease was linked to patronage of a specific campus-area bar, suggesting that aspects of a campus bar environment might promote meningococcal transmission (P. B. Imrey, L. A. Jackson, P. H. Ludwinski, et al., Am. J. Epidemiol., in press). To investigate this hypothesis, oropharyngeal carriage results from samples taken from 867 university health service clients and 85 campus-area bar employees during the last 3 months of the outbreak were analyzed to determine factors correlated with carriage of any strain of Neisseria meningitidis. Results were validated with data from samples from 344 health center clients and 211 campus bar employees taken 8 months after the last outbreak case. Recent alcohol consumption (adjusted prevalence odds ratio = 3.8 for > 15 versus 0 drinks in last week [P = 0.0012]) and campus bar patronage (adjusted odds ratio = 1.9 for any versus no patronage in last 2 weeks [P = 0.0122]) showed separate effects in both univariate and multiple logistic regression analyses of data from the 1992 health center clients. Prevalence of meningococcal carriage among 1992 campus bar workers was 3.8 times that among health center clients; this prevalence ratio was roughly 2.5 after adjustment for alcohol consumption and bar patronage. Recent antibiotic usage was protective (prevalence odds ratio = 0.3) among health center clients and bar workers. These findings were generally supported by the validation samples. If alcohol consumption and other aspects of the campus bar environment facilitate transmission of and/or colonization by N. meningitidis, then the introduction of a highly pathogenic substrain into the campus bar environment may provide an unusual opportunity for invasive meningococcal disease within a campus community.

Application of PCR for detection of toxigenic Corynebacterium diphtheriae strains isolated during the Russian diphtheria epidemic, 1990 through 1994

A total of 250 Corynebacterium diphtheriae isolates from clinical cases and carriers in Russia were assayed by PCR directed at the A subunit of the diphtheria toxin gene to distinguish toxigenic from nontoxigenic strains; 170 strains were positive as indicated by the presence of the 248-bp amplicon. The results of this PCR assay were in complete concordance with those of the standard immunoprecipitation assay (Elek), and the PCR assay is a useful tool for rapid identification in clinical laboratories.

Risk factors for group B streptococcal disease in adults

OBJECTIVE

To determine risk factors for community-acquired and nosocomial group B streptococcal disease in adults.

DESIGN

Case-control study.

SETTING

3 metropolitan areas in the United States with an aggregate population of 6.6 million persons.

PATIENTS

219 nonpregnant adults with invasive group B streptococcal infection identified by a population-based surveillance in 1991 and 1992 and 645 hospital-matched controls.

RESULTS

The following conditions were associated with a significantly increased risk for community-acquired group B streptococcal infection after controlling for age in multivariate analysis: cirrhosis (odds ratio, 9.7 [95% CI, 3.5 to 26.9]; P < 0.001), diabetes (odds ratio, 3.0 [CI, 1.9 to 4.7]; P < 0.001), stroke (odds ratio, 3.5 [CI, 1.9 to 6.4]; P < 0.001), breast cancer (odds ratio, 4.0 [CI, 1.6 to 9.8]; P = 0.002), decubitus ulcer (odd ratio, 4.0 [CI, 1.6 to 9.8]; P = 0.002), and neurogenic bladder (odds ratio, 4.6 [CI, 1.4 to 15.1]; P = 0.01). Sixty-three percent of community case-patients had at least one of these conditions. Nosocomial infection (48 cases [22%]) was independently associated with the placement of a central venous line (odds ratio, 30.9 [CI, 5.2 to 184.1]; P < 0.001), diabetes, congestive heart failure, and seizure disorder.

CONCLUSIONS

Several chronic conditions were independently associated with group B streptococcal disease, and most case-patients had at least one of these conditions. If group B streptococcal vaccines being developed for prevention of neonatal disease are protective in adults, a vaccination strategy targeting those at highest risk has the potential to substantially reduce the burden of invasive group B streptococcal infection in adults.

Barriers to prevention of perinatal group B streptococcal disease

During 1992 the American College of Obstetricians and Gynecologists (ACOG) and the American Academy of Pediatrics (AAP) issued statements on prevention of group B streptococcal (GBS) disease. To assess prevention practices and identify barriers to preventing GBS disease, we surveyed obstetricians, family practitioners and general practitioners in Georgia during 1993. A standard questionnaire was mailed to 1190 clinicians in August and to nonresponders again in September. Of 436 (38%) physicians who responded, 192 (44%) provided obstetric care. Among these 192 obstetric care providers, 121 (63%) screened patients for GBS carriage antenatally. The most frequently cited reasons for not screening were "no clear guidelines" and "not cost-effective" (52 and 39%, respectively). Clinicians who screened patients were significantly more likely to believe that screening was cost-effective (P = 0.05). Of obstetric care providers who screened, only 9% obtained specimens using culture sites recommended by ACOG or AAP. Although most clinicians were aware that antenatal antibiotic treatment of carriers does not prevent perinatal GBS disease, 64% of those who screened reported that they gave oral antibiotics when carriage was detected during pregnancy. Of clinicians who reported using obstetric risk factors to guide prophylaxis choices, < 15% reported using intrapartum antibiotics for the conditions identified in the ACOG and AAP statements as those that suggest the need for prophylaxis when screening is not performed. Many Georgia obstetric care providers do not use effective practices to prevent perinatal GBS disease. Education on appropriate culture methods, obstetric risk factors and the cost effectiveness of prevention strategies might lead to more effective preventive practices.

Cutaneous manifestations of opportunistic infections in patients infected with human immunodeficiency virus

Bacillary angiomatosis (BA) presents most commonly as a cutaneous disease and is caused by two organisms. Bartonella (Rochalimaea) henselae and Bartonella (Rochalimaea) quintana. Biopsy confirmation of cutaneous BA is essential because lesions can mimic nodular Kaposi's sarcoma in appearance. Although the vast majority of human immunodeficiency virus (HIV)-infected patients with BA have CD4 lymphocyte counts of less than 100 cells per mm3, the disease responds well to antimicrobial therapy. Staphylococcus aureus is the most common bacterial skin pathogen affecting HIV-infected patients. The prevalence of skin disease due to S. aureus may be explained by high nasal carriage rates for the organism ( > or = 50%) and altered immune function in conjunction with an impaired cutaneous barrier. Herpes simplex virus causes mucocutaneous disease early in the course HIV infection and ulcerative lesions at any site in advanced HIV infection. Herpes zoster is common early in the course of HIV infection; recurrent and disseminated herpes zoster infections are characteristic of patients with advanced HIV disease. Acyclovir resistance is usually seen in patients with large, untreated, ulcerative lesions of herpes simplex virus and in patients with chronic, verrucous lesions of varicella-zoster virus. Cutaneous cryptococcosis, histoplasmosis, and coccidiomycosis are markers of disseminated disease and require biopsy confirmation. Scabies is easily diagnosed but may be atypical in presentation and difficult to eradicate in advanced HIV disease.

Should college students be vaccinated against meningococcal disease? A cost-benefit analysis

Outbreaks and sporadic cases of meningococcal disease among college students have prompted consideration of a policy of routine vaccination for this group. Purchase and administration of the vaccine for routine vaccination would cost $56 million per year. Savings in medical care and indirect costs would not equal this amount unless the annual rate of disease among students is at least 6.5/100,000. The actual rate among students is unknown; however, surveillance data suggest it could not be more than 1.3/100,000. At rates near this estimate, the net cost of the program would be approximately $45 million annually. More cost-effective prevention strategies might be yielded by further studies to identify students at substantial risk of meningococcal disease, or by the development of a conjugate serogroup C vaccine that could be administered during infancy.

Reduction in the incidence of human listeriosis in the United States. Effectiveness of prevention efforts? The Listeriosis Study Group

BACKGROUND

Food-borne transmission is now recognized as a major cause of human listeriosis.

OBJECTIVE

To assess the impact of prevention efforts, listeriosis rates before interventions were initiated in 1989 were compared with more recent rates (1990 through 1993).

DESIGN

From 1989 through 1993, multistate, laboratory-based active surveillance was conducted to identify all cases in which Listeria monocytogenes was isolated from cultures or ordinarily sterile sites in an aggregate population of more than 19 million.

SETTING

All laboratories serving acute care hospitals in up to nine surveillance areas in the United States.

INTERVENTIONS

In 1989, a well-publicized case report of listeriosis linked to processed poultry led US regulatory agencies to enforce aggressive food monitoring policies and prompted industry to invest in cleanup efforts. In May 1992, consumer guidelines for listeriosis prevention were disseminated.

OUTCOME MEASURES

Cases of perinatal and nonperinatal listeriosis.

RESULTS

The rate of listeriosis decreased in all surveillance areas. Projection of these rates to the US population suggests an estimated 1965 cases and 481 deaths occurred in 1989 compared with an estimated 1092 cases and 248 deaths in 1993, a 44% and 48% reduction in illness and death, respectively. Among adults 50 years of age and older, rates declined from 16.2 per 1 million in 1989 to 10.2 per 1 million in 1993 (P = .02). Perinatal disease decreased from 17.4 cases per 100,000 births in 1989 to 8.6 cases per 100,000 births in 1993 (P = .003). Three serotypes (1/2a, 1/2b, and 4b) of L monocytogenes accounted for more than 96% of cases during each year of the study (1989 through 1993).

CONCLUSIONS

The incidence of listeriosis in study areas was substantially lower in 1993 than in 1989. The temporal association of this reduction with industry, regulatory, and educational efforts suggests these measures were effective.

Multistate case-control study of maternal risk factors for neonatal group B streptococcal disease. The Active Surveillance Study Group

Risk factors for early onset disease (EOD) caused by Group B streptococci (GBS) that are the foundation of prevention guidelines were identified in studies conducted in a few hospital centers. We investigated cases of EOD identified through laboratory-based active surveillance during 1991 and 1992 in a multistate population of 17 million. Ninety-nine cases were compared with 253 controls matched for hospital, date of birth and birth weight. Prematurity (< 37 weeks of gestation) was present in 28% of cases; 53% of case mothers had rupture of membranes > 12 hours; and 48% reported intrapartum fever. The incidence of EOD in each surveillance area was higher among blacks. By multivariate analysis, case mothers were more likely than controls to have rupture of membranes before labor onset (adjusted odds ratio 8.7, P < 0.001), intrapartum fever (adjusted odds ratio 11.9, P < 0.001), and history of urinary infection during pregnancy (adjusted odds ratio 4.3, P < 0.05). Young maternal age was also associated with risk of disease. Three-fourths of case mothers had intrapartum fever, < 37 weeks of gestation and/or prolonged rupture of membranes, indicators previously used to select high risk women for intrapartum chemoprophylaxis. Our findings extend data from single hospitals and suggest prenatal screening and selective intrapartum chemoprophylaxis of high-risk mothers could potentially prevent the majority of EOD in the United States.

National trends in Haemophilus influenzae meningitis mortality and hospitalization among children, 1980 through 1991

OBJECTIVE

Haemophilus influenzae type b (Hib) conjugate vaccines were licensed for routine use in the United States in December 1987. We compared national trends in deaths and hospitalization from H influenzae meningitis among children < 5 years old before and after Hib conjugate vaccine licensure.

METHODS

H influenzae meningitis mortality rates were calculated using data from the 1980 through 1991 computerized national mortality files. Hospitalization rates from H influenzae meningitis were calculated using data from the 1980 through 1991 National Hospital Discharge Surveys. Trends in H influenzae mortality and hospitalization from 1980 through 1887 were compared with trends from 1988 through 1991. Trends for Streptococcus pneumoniae and Neisseria meningitidis meningitis were also examined.

RESULTS

From 1980 through 1987, mortality from H influenzae meningitis decreased an average of 8.5% each year, compared with a 48% annual decrease from 1988 through 1991 (P < .001 for difference in trends). H influenzae meningitis hospitalization rates increased 1% each year from 1980 through 1987, and decreased an average of 34% each year from 1988 through 1991. There was no significant difference in mortality or hospitalization trends for S pneumoniae or N meningitidis meningitis during the two periods. Among infants, H influenzae meningitis mortality decreased an average of 8% per year from 1980 through 1987 and 43% per year from 1988 through 1991. One- to four-year-old children had similar average annual declines, 8% and 58% for the two periods. Although there were regional differences in the absolute mortality rates, all regions of the country had similar trends in meningitis mortality.

CONCLUSIONS

Among US children < 5 years old, we found substantial decreases in deaths and hospitalization from H influenzae meningitis, but not S pneumoniae or N meningitidis meningitis, in the years after Hib conjugate vaccine licensure. These results suggest that the declines in H influenzae meningitis were due primarily to the use of Hib conjugate vaccines.

Duration of antibody response after meningococcal polysaccharide vaccination in US Air Force personnel

The long-term kinetics of the immunologic response after vaccination of adults with Neisseria meningitidis polysaccharide vaccine is unknown. Total meningococcal anti-capsular antibody response (measured by ELISA) and serum bactericidal activity after routine vaccination with quadrivalent meningococcal vaccine were evaluated in US Air Force personnel. In a retrospective cross-sectional study, blood samples were obtained from approximately 40 personnel before vaccination, at 1 and 4-6 months, and at 2, 3, 4, 6, 8, and 10 years after vaccination. Total anti-group A and -group C capsular antibody levels and bactericidal activity peaked 1 month after vaccination and declined substantially by 2 years. At each interval, significantly higher levels of total antibody and bactericidal activity were detected than before vaccination. Anti-capsular antibodies and bactericidal activity persisted for up to 10 years after immunization. These and further studies on the serologic measure of protection against meningococcal disease are important for evaluation of candidate vaccines and development of recommendations for immunization.

Prevalence of Neisseria meningitidis relatively resistant to penicillin in the United States, 1991. Meningococcal Disease Study Group

To estimate the prevalence of Neisseria meningitidis relatively resistant to penicillin in the United States, antimicrobial susceptibility testing was performed on all US meningococcal isolates submitted to the Centers for Disease Control and Prevention in 1991, including isolates identified through population-based surveillance for invasive meningococcal disease in selected areas of the United States. Three of the 100 isolates tested had MICs of penicillin of 0.125 microgram/mL. All were serogroup B, beta-lactamase-negative, and unique by multilocus enzyme electrophoresis subtyping. None of the 3 patients had been treated solely with penicillin; all recovered completely. About 4% of the isolates obtained from the population-based surveillance system were relatively penicillin-resistant. Given the low prevalence and uncertain clinical significance of infection with these organisms, routine susceptibility testing of meningococcal isolates is not indicated at this time; however, continued surveillance is necessary to monitor trends in antimicrobial susceptibility of meningococci in the United States.

Cat scratch disease in the United States: an analysis of three national databases

OBJECTIVES

Current knowledge of the epidemiology of cat scratch disease is based primarily on information from case series. We used three national databases to obtain more representative data to determine the incidence and demographics of cat scratch disease.

METHODS

Records coded with the diagnosis of cat scratch disease from two hospital discharge databases and an ambulatory care database were analyzed. Costs of diagnostic tests and hospitalization were obtained from a sample of providers and published data.

RESULTS

The incidence of patients discharged from hospitals with a diagnosis of cat scratch disease was between 0.77 and 0.86 per 100,000 population per year. Fifty-five percent of the case patients were 18 years of age or younger. Males accounted for 60% of cases. Incidence varied by season; approximately 60% of case patients were discharged in the months September through January. The estimated incidence of disease in ambulatory patients was 9.3 per 100,000 population per year. On the basis of these rates, we estimated the annual health care cost of the disease to be more than $12 million.

CONCLUSIONS

The rates and seasonality of cat scratch disease found in this study were consistent with previous reports. Adults represented a higher percentage of the total than reported in previous case series, suggesting that the disease may affect more adults than previously recognized.

Impact of Haemophilus influenzae type b vaccines on the epidemiology of bacterial meningitis

Haemophilus influenzae type b (Hib) was the most common cause of bacterial meningitis in the United States in the 1980s. Although introduction of Hib polysaccharide vaccines had little impact on disease incidence, development and use of Hib polysaccharide-protein conjugate vaccines dramatically reduced Hib meningitis rates. With widespread use of the new Hib conjugate vaccine, elimination of Hib meningitis in the United States may be achieved. Development of similar vaccines for other bacterial agents of meningitis are in progress.

Increased risk of meningitis and bacteremia due to Listeria monocytogenes in patients with human immunodeficiency virus infection

The incidence, demographics, and clinical outcome of infections due to Listeria monocytogenes in individuals infected with the human immunodeficiency virus (HIV) were evaluated by prospective population-based surveillance. During a 2-year study period, 37 cases of invasive listeriosis occurred in metropolitan Atlanta (annual incidence, 0.8 case per 100,000 population). Seven of these cases occurred in known HIV-infected individuals (19% of all cases); five had an AIDS-defining illness, and the other two had CD4 lymphocyte cell counts of < 200/microL. The estimated incidence of listeriosis among HIV-infected patients in metropolitan Atlanta was 52 cases per 100,000 patients per year, and among patients with AIDS it was 115 cases per 100,000 patients per year, rates 65-145 times higher than those among the general population. HIV-associated cases occurred in adults who were 29-62 years of age and in postnatal infants who were 2 and 6 months of age. Mortality among the HIV-infected group was 29%. L. monocytogenes serotypes 1/2a, 1/2b, and 4b were isolated from the HIV-infected patients. L. monocytogenes is an important opportunistic pathogen in HIV-infected patients.

Cat scratch disease in Connecticut. Epidemiology, risk factors, and evaluation of a new diagnostic test

BACKGROUND

Although cat scratch disease is commonly diagnosed in patients who have unexplained regional lymphadenopathy after encounters with cats, its epidemiology and the risk factors for disease are not clearly defined, and there is no generally accepted diagnostic test.

METHODS

We conducted a physician survey to identify cases of cat scratch disease occurring over a 13-month period in cat owners in Connecticut. We interviewed both the patients (or their parents) and controls matched for age who owned cats. Serum from the patients was tested for antibodies to Rochalimaea henselae with a new, indirect fluorescent-antibody test.

RESULTS

We identified 60 patients with cat scratch disease and 56 age-matched subjects. Patients were more likely than controls to have at least one pet kitten 12 months old or younger (odds ratio, 15), to have been scratched or bitten by a kitten (odds ratio, 27), and to have had at least one kitten with fleas (odds ratio, 29). A conditional logistic-regression analysis found that in kitten-owning households, patients were more likely than controls to have been scratched or bitten by a cat or kitten (odds ratio, 12.4; 95 percent confidence interval, 1.0 to 150). Of 45 patients, 38 had serum samples with titers of 1:64 or higher for antibody to R. henselae, as compared with 4 of 112 samples from controls (P < 0.001). The positive predictive value of the serologic test was 91 percent. Of 48 serum samples from patients' cats, 39 were positive for antibodies to R. henselae, as compared with positive samples from 11 of 29 control cats (P < 0.001).

CONCLUSIONS

Cat scratch disease is strongly associated with owning a kitten, and fleas may be involved in its transmission. The serologic test for rochalimaea may be useful diagnostically, and our results suggest an etiologic role for this genus.

Carriage of Haemophilus influenzae type b in children after widespread vaccination with conjugate Haemophilus influenzae type b vaccines

Rates of invasive Haemophilus influenzae type b (Hib) disease in children decreased very rapidly after licensure of Hib conjugate vaccines. A role for a vaccine-related reduction in nasopharyngeal carriage of Hib has been suggested. We studied oropharyngeal carriage of Hib and vaccination rates in a population of 2- to 5-year-old children in metropolitan Atlanta. Among 584 children 75% were vaccinated with an Hib conjugate vaccine, 17% had not been vaccinated and 8% had no vaccination records available. Forty-one percent of the children were colonized with H. influenzae. One child was colonized with Hib. Hib carriage (0.17%; upper 95% confidence interval boundary, 0.97%) was substantially lower than the estimates of Hib carriage from prior studies of children who had not received Hib conjugate vaccines. Our data are consistent with a decline in Hib carriage induced by widespread use of conjugate Hib vaccines, which may have contributed to the decline of Hib disease in United States children.

A population-based assessment of invasive disease due to group B Streptococcus in nonpregnant adults

BACKGROUND

Group B streptococci (Streptococcus agalactiae) are a major cause of meningitis and septicemia in neonates and pregnant women, but the importance of group B streptococcal disease in nonpregnant adults has not been clearly defined.

METHODS

We conducted a prospective surveillance of the pathogens responsible for meningitis for a period of 24 months in 35 hospitals and a referral laboratory in metropolitan Atlanta. We reviewed the clinical and laboratory records of all the nonpregnant adults identified as having invasive group B streptococcal disease during this period.

RESULTS

During 1989 and 1990 there were 424 patients with invasive group B streptococcal disease (annual incidence, 9.2 cases per 100,000 population). Of these patients, 46 percent were 1 month of age or younger, 6 percent were older than 1 month but younger than 18 years of age, and 48 percent were 18 or older. Men and nonpregnant women accounted for 68 percent (n = 140) of all cases among adults (annual incidence, 4.4 per 100,000). Clinical and laboratory records were available for 137. In the nonpregnant adult patients (age, 18 to 99 years), the most common clinical diagnoses were skin, soft-tissue, or bone infection (in 36 percent); bacteremia with no identified source (30 percent); urosepsis (14 percent); pneumonia (9 percent); and peritonitis (7 percent). Risk factors included older age (> or = 60 years), the presence of diabetes mellitus, the presence of malignant neoplasms, and infection with the human immunodeficiency virus. The mortality rate in nonpregnant adults was 21 percent, accounting for 67 percent of all deaths related to group B streptococcal infection during the surveillance period.

CONCLUSIONS

Invasive group B streptococcal infection is a major problem not only in pregnant women and neonates but also in nonpregnant adults, especially those who are elderly and those who have chronic diseases.

Laboratory-based surveillance for meningococcal disease in selected areas, United States, 1989-1991

PROBLEM/CONDITION

Neisseria meningitidis is a leading cause of bacterial meningitis and septicemia in the United States. Accurate surveillance for meningococcal disease is required to detect trends in patient characteristics, antibiotic resistance, and serogroup-specific incidence of disease.

REPORTING PERIOD COVERED

January 1989 through December 1991.

DESCRIPTION OF SYSTEM

A case of meningococcal disease was defined by the isolation of N. meningitidis from a normally sterile site, such as blood or cerebrospinal fluid, in a resident of a surveillance area. Cases were reported by personnel in each hospital laboratory in the surveillance areas. The surveillance areas consisted of three counties in the San Francisco metropolitan area, eight counties in the Atlanta metropolitan area, four counties in Tennessee, and the entire state of Oklahoma.

RESULTS

Age- and race-adjusted projections of the U.S. population suggest that approximately 2,600 cases of meningococcal disease occurred annually in the United States. The case-fatality rate was 12%. Incidence declined from 1.3/100,000 in 1989 to 0.9/100,000 in 1991. Seasonal variation occurred, with the highest attack rates in February and March and the lowest in September. The highest rates of disease were among infants, with 46% of cases affecting those < or = 2 years of age. Males accounted for 55% of total cases, with an incidence of 1.2/100,000, compared with 1.0/100,000 among females (relative risk (RR) = 1.3, 95% confidence interval (CI) 1.0-1.6). The incidence was significantly higher among blacks (1.5/100,000) than whites (1.1/100,000) (RR = 1.4 [95% CI 1.1-1.8]). Serogroup B caused 46% of cases and serogroup C, 45% Thirty-eight percent of isolates were reported to be resistant to sulfa; none were reported to be resistant to rifampin.

INTERPRETATION

The decline in incidence of meningococcal disease from 1989 through 1991 cannot be explained by any change in public health control measures; this trend should be monitored by continued surveillance. The age, sex, and race distribution and seasonality of cases are consistent with previous reports. The proportion of N. meningitidis isolates resistant to sulfa continues to be substantial. A relatively small proportion of cases is potentially preventable by the use of the currently available polysaccharide vaccine, which induces protection against serogroups, A, C, Y, and W135 and is effective only for persons > 2 years of age.

ACTIONS TAKEN

Current recommendations against the use of sulfa drugs for treatment or prophylaxis of meningococcal disease unless the organism is known to be sensitive to sulfa should be continued. Since resistance to rifampin is rarely reported, it continues to be the drug of choice for prophylaxis. The development of vaccines effective for infants and vaccines inducing protection against serogroup B would be expected to have a substantial impact on disease.

The epidemiology of bacillary angiomatosis and bacillary peliosis

OBJECTIVE

To determine environmental risk factors for bacillary angiomatosis-bacillary peliosis (BAP), and to confirm infection with Rochalimaea species.

DESIGN

Case-control study.

SETTING

Community and university hospitals and clinics.

PATIENTS

Case patients (N = 48) had biopsy-confirmed BAP. Controls (N = 94) were matched to patients by institution and by human immunodeficiency virus (HIV) serological status.

MAIN OUTCOME MEASURES

Clinical information was obtained from medical records. Subjects were queried about environmental exposures. Univariate odds ratios (ORs) with 95% confidence intervals (CIs) were determined. Bivariate analyses were performed on variables associated with disease by univariate analysis. DNA from 22 available case-patient tissues and from 22 control tissues was amplified with the polymerase chain reaction (PCR) using primers designed to detect Rochalimaea species.

RESULTS

We identified five HIV-negative, immunocompetent case patients; one HIV-negative, immunodeficient case patient; and 42 HIV-positive case patients. There were no significant differences between case patients and controls by race, sex, age, or risk factors for HIV infection. Owning a cat (OR, 2.8; CI, 1.4 to 5.8) and history of a recent cat lick (OR, 1.95; CI, 1.0 to 3.8), cat scratch (OR, 3.7; CI, 1.7 to 8.0), or cat bite (OR, 3.9; CI, 1.8 to 8.9) were associated with disease in the univariate analysis. In bivariate analyses, only the variables representing traumatic contact with a cat (bite or scratch) remained associated with disease. No other environmental exposure was associated with disease. The PCR amplified a DNA fragment of the size expected for Rochalimaea species in all 22 case-patient tissue specimens.

CONCLUSIONS

These data suggest that BAP is a new zoonosis associated with both traumatic exposure to cats and infection with Rochalimaea species or a closely related organism.

The epidemiology of bacillary angiomatosis and bacillary peliosis

OBJECTIVE

To determine environmental risk factors for bacillary angiomatosis-bacillary peliosis (BAP), and to confirm infection with Rochalimaea species.

DESIGN

Case-control study.

SETTING

Community and university hospitals and clinics.

PATIENTS

Case patients (N = 48) had biopsy-confirmed BAP. Controls (N = 94) were matched to patients by institution and by human immunodeficiency virus (HIV) serological status.

MAIN OUTCOME MEASURES

Clinical information was obtained from medical records. Subjects were queried about environmental exposures. Univariate odds ratios (ORs) with 95% confidence intervals (CIs) were determined. Bivariate analyses were performed on variables associated with disease by univariate analysis. DNA from 22 available case-patient tissues and from 22 control tissues was amplified with the polymerase chain reaction (PCR) using primers designed to detect Rochalimaea species.

RESULTS

We identified five HIV-negative, immunocompetent case patients; one HIV-negative, immunodeficient case patient; and 42 HIV-positive case patients. There were no significant differences between case patients and controls by race, sex, age, or risk factors for HIV infection. Owning a cat (OR, 2.8; CI, 1.4 to 5.8) and history of a recent cat lick (OR, 1.95; CI, 1.0 to 3.8), cat scratch (OR, 3.7; CI, 1.7 to 8.0), or cat bite (OR, 3.9; CI, 1.8 to 8.9) were associated with disease in the univariate analysis. In bivariate analyses, only the variables representing traumatic contact with a cat (bite or scratch) remained associated with disease. No other environmental exposure was associated with disease. The PCR amplified a DNA fragment of the size expected for Rochalimaea species in all 22 case-patient tissue specimens.

CONCLUSIONS

These data suggest that BAP is a new zoonosis associated with both traumatic exposure to cats and infection with Rochalimaea species or a closely related organism.

Amplification of rDNA loci to detect and type Neisseria meningitidis and other eubacteria

In 1991-92, Neisseria meningitidis group C was isolated from the blood of eight students in Urbana, Illinois, USA, and from the cerebrospinal fluid of one student from a nearby community, Decatur, Illinois. These and other bacterial species were analysed by PCR fingerprinting using primers selected from the ribosomal (r)DNA loci. A rDNA primer pair spanning a region within the 16S rDNA amplified a predicted 280 base pair (bp) DNA fragment from Neisseria spp. and fragments of different sizes for other genera. This primer pair specifically detected a carrier of N. meningitidis in a small clinical battery. Identity of the fragment was confirmed by restriction endonuclease analysis. A 600 bp fragment was also amplified from the 16S-23S internal transcribed spacer (ITS) of N. meningitidis; amplification from six other genera yielded different-sized fragments. Digestion of the ITS fragment from N. meningitidis with Alu I revealed three patterns; pattern I was found only for serogroup C isolates, and it was the dominant pattern among recent isolates with the exception of the one from Decatur. The isolate from Decatur yielded pattern III which suggested a non-clonal relationship to the seven isolates from Urbana. Patterns II and III were more prevalent in isolates from the 1960's and 1980's. PCR-based analysis of these loci can complement the techniques which are currently used for the detection and typing of these and other eubacteria.