Robert W. Pinner

Investigation of bioterrorism-related anthrax, United States, 2001: epidemiologic findings.

In October 2001, the first inhalational anthrax case in the United States since 1976 was identified in a media company worker in Florida. A national investigation was initiated to identify additional cases and determine possible exposures to Bacillus anthracis. Surveillance was enhanced through health-care facilities, laboratories, and other means to identify cases, which were defined as clinically compatible illness with laboratory-confirmed B. anthracis infection. From October 4 to November 20, 2001, 22 cases of anthrax (11 inhalational, 11 cutaneous) were identified; 5 of the inhalational cases were fatal. Twenty (91%) case-patients were either mail handlers or were exposed to worksites where contaminated mail was processed or received. B. anthracis isolates from four powder-containing envelopes, 17 specimens from patients, and 106 environmental samples were indistinguishable by molecular subtyping. Illness and death occurred not only at targeted worksites, but also along the path of mail and in other settings. Continued vigilance for cases is needed among health-care providers and members of the public health and law enforcement communities.

The epidemiology of candidemia in two United States cities: results of a population-based active surveillance.

We conducted prospective, active population-based surveillance for candidemia (defined as any Candida species isolated from blood) in Atlanta and San Francisco (total population, 5.34 million) during 1992-1993. The average annual incidence of candidemia at both sites was 8 per 100,000 population. The highest incidence (75 per 100,000) occurred among infants </=1 year old. In 19% of patients, candidemia developed prior to or on the day of admission. Underlying medical conditions included cancer (26%), abdominal surgery (14%), diabetes mellitus (13%), and human immunodeficiency virus infection (10%). In 47% of cases, species of Candida other than Candida albicans were isolated, most commonly Candida parapsilosis, Candida glabrata, and Candida tropicalis. Antifungal susceptibility testing of 394 isolates revealed minimal levels of azole resistance among C. albicans, C. tropicalis, and C. parapsilosis. These data document the substantial burden of candidemia and its changing epidemiology. Continued surveillance will be important to monitor the epidemiology of candidemia and to detect emergence of resistance to azoles.

Progress toward eliminating Haemophilus influenzae type b disease among infants and children--United States, 1987-1997.

Haemophilus influenzae type b (Hib) causes serious invasive diseases among previously healthy children aged <5 years. Before the availability of conjugate vaccines in 1988, Hib was the most common cause of bacterial meningitis among preschool-aged children. Since 1993, the incidence of Hib invasive disease (defined as illness clinically compatible with invasive disease such as meningitis or sepsis, with isolation of the bacterium from a normally sterile site) among children aged <5 years has declined >95% in the United States. This report describes the continued decline of reported Hib invasive disease cases and underscores the need for investigation of Haemophilus influenzae (Hi) invasive disease cases.

Cryptococcosis: Population-Based Multistate Active Surveillance and Risk Factors in Human Immunodeficiency Virus—Infected Persons

To determine the incidence of cryptococcosis and its risk factors among human immunodeficiency virus (HIV)-infected persons, population-based active surveillance was conducted in four US areas (population, 12.5 million) during 1992-1994, and a case-control study was done. Of 1083 cases, 931 (86%) occurred in HIV-infected persons. The annual incidence of cryptococcosis per 1000 among persons living with AIDS ranged from 17 (San Francisco, 1994) to 66 (Atlanta, 1992) and decreased significantly in these cities during 1992-1994. Among non-HIV-infected persons, the annual incidence of cryptococcosis ranged from 0.2 to 0.9/100,000. Multivariate analysis of the case-control study (158 cases and 423 controls) revealed smoking and outdoor occupations to be significantly associated with an increased risk of cryptococcosis; receiving fluconazole within 3 months before enrollment was associated with a decreased risk for cryptococcosis. Further studies are needed to better describe persons with AIDS currently developing cryptococcosis in the era of highly active antiretroviral therapy.

Neurocysticercosis in radiographically imaged seizure patients in U.S. emergency departments.

Neurocysticercosis appears to be on the rise in the United States, based on immigration patterns and published cases series, including reports of domestic acquisition. We used a collaborative network of U.S. emergency departments to characterize the epidemiology of neurocysticercosis in seizure patients. Data were collected prospectively at 11 university-affiliated, geographically diverse, urban U.S. emergency departments from July 1996 to September 1998. Patients with a seizure who underwent neuroimaging were included. Of the 1,801 patients enrolled in the study, 38 (2.1%) had seizures attributable to neurocysticercosis. The disease was detected in 9 of the 11 sites and was associated with Hispanic ethnicity, immigrant status, and exposure to areas where neurocysticercosis is endemic. This disease appears to be widely distributed and highly prevalent in certain populations (e.g., Hispanic patients) and areas (e.g., Southwest).

Listeria monocytogenes contamination of turkey franks: Evaluation of a production facility

A facility which produced turkey franks that had been microbiologically linked to a case of human listeriosis was evaluated to establish prevalence of contamination and identify potential points for intervention. Listeria monocytogenes was isolated from only two of 41 environmental samples obtained in the plant. Among production line product samples analyzed by the Centers for Disease Control, 0 to 8% of samples from the production stages before the peeler-conveyor belt apparatus were positive for the case strain of L. monocytogenes , whereas 12 of 14 (86%) samples collected from this apparatus were positive (p <0.001). The most probable number (MPN) of L. monocytogenes in finished product purchased from a retail outlet was less than 0.3 per gram; however, the opened package of franks from the case patients refrigerator had an MPN of >1100 per gram. These data suggest that systematic culturing and analysis of products and production facilities may help identify appropriate interventions to reduce L. monocytogenes contamination in food processing plants and contribute to control of L. monocytogenes in ready-to-eat meat products.

EMERGEncy ID NET: An Emergency Department-Based Emerging Infections Sentinel Network

Acute infectious disease presentations among many at-risk patient groups (eg, uninsured, homeless, and recent immigrants) are frequently seen in emergency departments. Therefore EDs may be useful sentinel sites for infectious disease surveillance. This article describes the background, development, and implementation of EMERGE ncy ID NET, an interdisciplinary, multicenter, ED-based network for research of emerging infectious diseases. EMERGE ncy ID NET was established in cooperation with the National Center for Infectious Diseases, Centers for Disease Control and Prevention (CDC) as part of the CDCs strategy to expand and complement existing disease detection and control activities. The network is based at 11 university-affiliated, urban hospital EDs with a combined annual patient visit census of more than 900,000. Data are collected during ED evaluation of patients with specific clinical syndromes, and are electronically stored, transferred, and analyzed at a central receiving site. Current projects include investigation of bloody diarrhea and the prevalence of Shiga toxin-producing Escherichia coli, animal exposures and rabies postexposure prophylaxis practices, seizures and prevalence of neurocysticercosis, nosocomial ED Mycobacterium tuberculosis transmission, and hospital isolation bed use for adults admitted for pneumonia or suspected tuberculosis. EMERGE ncy ID NET also was developed to be a mechanism for rapidly responding to new diseases or epidemics. Future plans include study of antimicrobial use, meningitis, and encephalitis, and consideration of other public health concerns such as injury and national and international network expansion.

Disease Surveillance and the Academic, Clinical, and Public Health Communities

The Emerging Infections Programs (EIPs), a population-based network involving 10 state health departments and the Centers for Disease Control and Prevention, complement and support local, regional, and national surveillance and research efforts. EIPs depend on collaboration between public health agencies and clinical and academic institutions to perform active, population-based surveillance for infectious diseases; conduct applied epidemiologic and laboratory research; implement and evaluate pilot prevention and intervention projects; and provide capacity for flexible public health response. Recent EIP work has included monitoring the impact of a new conjugate vaccine on the epidemiology of invasive pneumococcal disease, providing the evidence base used to derive new recommendations to prevent neonatal group B streptococcal disease, measuring the impact of foodborne diseases in the United States, and developing a systematic, integrated laboratory and epidemiologic method for syndrome-based surveillance.

Epidemiologic investigations of bioterrorism-related anthrax, New Jersey, 2001.

At least four Bacillus anthracis–containing envelopes destined for New York City and Washington, D.C., were processed at the Trenton Processing and Distribution Center (PDC) on September 18 and October 9, 2001. When cutaneous anthrax was confirmed in a Trenton postal worker, the PDC was closed. Four cutaneous and two inhalational anthrax cases were identified. Five patients were hospitalized; none died. Four were PDC employees; the others handled or received mail processed there. Onset dates occurred in two clusters following envelope processing at the PDC. The attack rate among the 170 employees present when the B. anthracis–containing letters were sorted on October 9 was 1.2%. Of 137 PDC environmental samples, 57 (42%) were positive. Five (10%) of 50 local post offices each yielded one positive sample. Cutaneous or inhalational anthrax developed in four postal employees at a facility where B. anthracis–containing letters were processed. Cross-contaminated mail or equipment was the likely source of infection in two other case-patients with cutaneous anthrax.

Etiology of Bloody Diarrhea among Patients Presenting to United States Emergency Departments: Prevalence of Escherichia coli O157:H7 and Other Enteropathogens

Escherichia coli O157:H7 and other Shiga toxin-producing E. coli (STEC) infections have been associated with bloody diarrhea. The prevalence of enteropathogens among patients with bloody diarrhea was determined by a prospective study at 11 US emergency departments. Eligible patients had bloody stools, > or =3 loose stool samples per 24-h period, and an illness lasting <7 days. Among 873 patients with 877 episodes of bloody diarrhea, stool samples for culture were obtained in 549 episodes (62.6%). Stool cultures were more frequently ordered for patients with fever, >10 stools/day, and visibly bloody stools than for patients without these findings. Enteropathogens were identified in 168 episodes (30.6%): Shigella (15.3%), Campylobacter (6.2%), Salmonella (5.8%), STEC (2.6%), and other (1.6%). Enteropathogens were isolated during 12.5% of episodes that physicians thought were due to a noninfectious cause. The prevalence of STEC infection varied by site from 0% to 6.2%. Hospital admissions resulted from 195 episodes (23.4%). These data support recommendations that stool samples be cultured for patients with acute bloody diarrhea.