Detecting 2009 pandemic influenza A (H1N1) virus infection: availability of diagnostic testing led to rapid pandemic response.

Diagnostic tests for detecting emerging influenza virus strains with pandemic potential are critical for directing global influenza prevention and control activities. In 2008, the Centers for Disease Control and Prevention received US Food and Drug Administration approval for a highly sensitive influenza polymerase chain reaction (PCR) assay. Devices were deployed to public health laboratories in the United States and globally. Within 2 weeks of the first recognition of 2009 pandemic influenza H1N1, the Centers for Disease Control and Prevention developed and began distributing a new approved pandemic influenza H1N1 PCR assay, which used the previously deployed device platform to meet a >8-fold increase in specimen submissions. Rapid antigen tests were widely used by clinicians at the point of care; however, test sensitivity was low (40%-69%). Many clinical laboratories developed their own pandemic influenza H1N1 PCR assays to meet clinician demand. Future planning efforts should identify ways to improve availability of reliable testing to manage patient care and approaches for optimal use of molecular testing for detecting and controlling emerging influenza virus strains.

A recurrent outbreak of nosocomial legionnaires' disease detected by urinary antigen testing: evidence for long-term colonization of a hospital plumbing system.

BACKGROUND: In 1994, a hospital reported an increase in nosocomial legionnaires' disease after implementing use of a rapid urinary antigen test for Legionella pneumophila serogroup 1 (Lp-1). This hospital was the site of a previous nosocomial legionnaires' disease outbreak during 1980 to 1982. METHODS: Infection control records were reviewed to compare rates of nosocomial pneumonia and the proportion of cases attributable to legionnaires' disease during the 1994 outbreak period with those during the same period in 1993. Water samples were collected for Legionella culture from the hospital's potable water system and cooling towers, and isolates were subtyped by monoclonal antibody (MAb) testing and arbitrarily primed polymerase chain reaction (AP-PCR). RESULTS: Nosocomial pneumonia rates were similar from April through October 1993 and April through October 1994: 5.9 and 6.6 per 1,000 admissions, respectively (rate ratio [RR], 1.1; P=.56); however, 3.2% of nosocomial pneumonias were diagnosed as legionnaires' disease in 1993, compared with 23.9% in 1994 (RR, 9.4; P<.001). In 1994, most legionnaires' disease cases were detected by the urinary antigen testing alone. MAb testing and AP-PCR demonstrated identical patterns among Lp-1 isolates recovered from a patient's respiratory secretions, the hospital potable water system, and stored potable water isolates from the 1980 to 1982 outbreak. CONCLUSIONS: There may have been persistent transmission of nosocomial legionnaires' disease at this hospital that went undiscovered for many years because there was no active surveillance for legionnaires' disease. Introduction of a rapid urinary antigen test improved case ascertainment. Legionella species can be established in colonized plumbing systems and may pose a risk for infection over prolonged periods.

Perspectives in fatal epidemics.

This article discusses four epidemics of fatal infectious diseases: a 1993 cluster of deaths among previously healthy persons in the southwestern United States that led to the identification of a new clinical syndrome, hantavirus pulmonary syndrome; the first epidemic of Ebola hemorrhagic fever identified in nearly two decades occurring in 1995 in Zaire, which resulted in 317 cases with a mortality rate of 77%; an outbreak of Legionnaires' disease among cruise ship passengers in 1994; and a 1989 cluster of illnesses among nonhuman primates in Reston, Virginia leading to the identification of a new strain of Ebola virus. In each outbreak, the public health emergency was recognized and reported by alert clinicians, and the control of disease was facilitated through rapid, coordinated responses involving multiple agencies. Such collaboration between clinical and public health entities and among various agencies will be increasingly needed as surveillance and diagnostic capabilities for emerging and reemerging infectious diseases are enhanced around the world.

Electronic laboratory-based reporting for public health.

This article describes the role of laboratory-based reporting for public health in the United States and outlines a vision for electronic laboratory-based reporting (ELR). It emphasizes the importance of adoption and implementation of standards to the successful development of ELR. In particular, it describes the role of Health Level 7 as a standard for electronic message formats and the roles of LOINC (Logical Observation Identifiers, Names, and Codes) and SNOMED (Systematized Nomenclature for Human and Veterinary Medicine) as standards for test names and results, respectively. In addition, the article describes ongoing and planned ELR projects

Methicillin-resistant Staphylococcus aureus infections among healthy full-term newborns.

OBJECTIVE: Methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged in the community, causing disease among healthy people lacking traditional risk factors for MRSA infection. This article describes an outbreak of MRSA among healthy full-term newborns. DESIGN: Cases were identified and corresponding medical information collected. Telephone interviews were conducted with mothers of cases and surveillance cultures from mothers and newborns were performed. MRSA isolates were genotyped. SETTING: Hospital in Chicago, Illinois, USA. PARTICIPANTS: Newborns, their mothers and hospital healthcare workers. INTERVENTION: Nursery infection control practices were enhanced. The MRSA-colonised healthcare workers received intranasal mupirocin. MAIN OUTCOME: Within 4-23 days of birth, 11 newborns were identified with pustules, vesicles or blisters located on the head, groin, perineum, ears, legs, chin and trunk. All received antimicrobials and recovered without incident. RESULTS: None of 432 peripartum women, one of 399 newborns, and two of 135 healthcare workers were nasal MRSA carriers. Available isolates from six patients, two healthcare workers, and one from an MRSA-colonised newborn were similar by pulsed-field gel electrophoresis. Other than contact with the hospital, no common exposures of MRSA transmission were identified. CONCLUSIONS: MRSA strains that initially emerged in the community are now causing disease in healthcare settings. Providers should be aware that MRSA can cause skin infections among healthy newborns. Adherence to standard infection control practices is important to prevent transmission of MRSA in nurseries.

Community-associated methicillin-resistant Staphylococcus aureus skin infections in a religious community.

In September 2004, an outbreak of community-associated methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTI) was reported among members of a religious community. We conducted a retrospective cohort study on all 175 community members; performed a nasal carriage survey, and environmental swab testing. We identified 24 MRSA cases (attack rate 14%). In multivariate analysis, sauna use [odds ratio (OR) 19.1, 95% confidence interval (CI) 2.7-206.1] and antimicrobial use within 12 months before infection (OR 11.7, 95% CI 2.9-47.6) were risk factors for infection. MRSA nasal carriage rate was 0.6% (1/174). Nine of 10 clinical isolates and an isolate from an administrative office within the community had the pulsed-field gel electrophoresis type USA300. Targeted hygiene improvement, wound care, and environmental cleaning were implemented. We describe the first reported outbreak of MRSA SSTI in a religious community. Adherence to appropriate personal and environmental hygiene might be critical factors in controlling transmission.

Sentinel surveillance as an alternative approach for monitoring antibiotic-resistant invasive pneumococcal disease in Washington State.

OBJECTIVES: As an alternative to statewide, mandated surveillance for antibiotic-resistant Streptococcus pneumoniae, a sentinel surveillance network of 27 hospitals was developed in Washington State. METHODS: The utility of targeted surveillance in population centers was assessed, current laboratory susceptibility testing practices were evaluated, and a baseline of pneumococcal resistance in Washington State was obtained for use in a statewide campaign promoting the judicious use of antibiotics. RESULTS: Between July 1997 and June 1998, 300 cases were reported; 67 (22%) had diminished susceptibility to penicillin. Only 191 (64%) were fully tested with penicillin and an extended-spectrum cephalosporin (ESC) as nationally recommended; 10.5% were resistant to penicillin and 6.8% were resistant to an ESC. The number of isolates inadequately tested declined through the year. The findings were similar to those from more comprehensive active surveillance in Oregon for the same time period. CONCLUSIONS: Targeted surveillance may be an adequate alternative for limited monitoring of antibiotic resistance for states that choose not to mandate reporting.

Minimizing the impact of drug-resistant Streptococcus pneumoniae (DRSP). A strategy from the DRSP Working Group.

Emergence of drug-resistant Streptococcus pneumoniae (DRSP) presents a challenge to the medical and public health communities since the magnitude of the problem is not known, the clinical impact of DRSP infections is not well described, national vaccination rates are low, and antimicrobial drugs are often used excessively and inappropriately. To address the problem of DRSP, a working group by Centers for Disease Control and Prevention was formed in June 1994 consisting of public health practitioners, health care providers, and clinical laboratorians representing state and federal agencies and various professional organizations. Through periodic open meetings, the working group has developed a strategy for surveillance, investigation, prevention, and control of infections due to DRSP. The strategy focuses on (1) implementing an electronic laboratory-based surveillance (ELBS) system for reporting invasive DRSP infections and providing clinically relevant feedback to clinicians, (2) identifying risk factors and outcomes of DRSP infection, (3) increasing pneumococcal vaccination, and (4) promoting judicious antimicrobial drug use. Data received through ELBS will be used to make timely estimates of the community-specific prevalence of drug-resistant pneumococci. National, regional, and local trends will be made available to health care providers and clinicians to promote optimal antimicrobial drug use and increased vaccination in targeted areas. Once in operation, the ELBS network will be adaptable to other diseases, improving the comprehensiveness and timeliness of public health surveillance. The intended outcome of the strategy is to reduce complications of DRSP infection, such as long-term sequelae of infection, health care expenditures, morbidity, and mortality.

National shortages of antimicrobial agents: results of 2 surveys from the Infectious Diseases Society of America Emerging Infections Network.

In November 1999 and August 2000, the Infectious Diseases Society of America Emerging Infections Network (EIN) surveyed its members about shortages of antimicrobial agents in their hospitals and medical centers. Almost 90% of the members had encountered shortages of 1 or more agents in 1999. Of 496 respondents, 382 (77%) reported diminished supplies of penicillin G. Other agents in short supply included meropenem (38%), ticarcillin with or without clavulanate (24%), cefazolin (20%), gentamicin (50%), and nafcillin-oxacillin (13%). In 2000, 291 (60%) of 485 respondents reported shortages of penicillin G, but significantly fewer members had experienced a lack of other agents. In both surveys, members indicated that shortages had affected numerous therapeutic indications. In 1999, members estimated that shortages had affected thousands of patients. In 2000, they estimated that fewer patients were affected. The results of these 2 EIN surveys raise questions about the forces that govern the availability of these valuable therapeutic resources.

A novel multiresistant Streptococcus pneumoniae serogroup 19 clone from Washington State identified by pulsed-field gel electrophoresis and restriction fragment length patterns.

In 1997, a cluster of multiresistant invasive serogroup 19 pneumococcus infections, including two fatalities, was reported in Washington State. Further investigation identified other cases. Fourteen Washington Streptococcus pneumoniae isolates, four from Alaska, and eight isolates from eastern Canada with reduced penicillin susceptibility (MIC of > or =1 microg/ml) were included in the study. Pulsed-field gel electrophoresis (PFGE) with ApaI, SacII, and SmaI restriction enzymes and IS1167 and mef restriction fragment length polymorphism (RFLP) pattern analysis were performed. Twenty of the 26 isolates had identical or related PFGE patterns, with two or all three enzymes, and identical or related IS1167 RFLP patterns, indicating that they were genetically related. These 20 isolates contained the mef gene conferring erythromycin resistance and had identical mef RFLP patterns. The PFGE and RFLP patterns were distinct from those of six multiresistant clones previously described and suggest that a new multiresistant clone has appeared in Washington, Alaska, and eastern Canada. This newly characterized clone should be included in the Pneumococcal Molecular Epidemiology Network.

Pulmonary infection due to Legionella cincinnatiensis in renal transplant recipients: two cases and implications for laboratory diagnosis.

We report two cases of pneumonia caused by Legionella cincinnatiensis, a species previously identified as a pathogen in only one other instance. Both infections occurred in renal transplant recipients who were receiving only moderate doses of immunosuppressive drugs several years after transplantation; both patients had no recent episodes of rejection. Their clinical courses varied from mild symptoms to multisystem organ failure and death. Species identification by direct fluorescent antibody testing was misleading; initial results revealed infection due to Legionella longbeachae for one patient and infection due to Legionella dumoffii for the other patient. Slide agglutination testing eventually identified both isolates as L. cincinnatiensis. Infection with Legionella species, including L. cincinnatiensis, should be considered not only in the first months after transplantation but also later in the posttransplantation period as either a nosocomial or community-acquired infection.

Rapid evaluation of risk of white particulate matter in blood components by a statewide survey of transfusion reactions.

BACKGROUND: In January 2003, white particulate matter (WPM) was detected in blood components. Because the composition and cause of WPM was not understood at that time, there was uncertainty about whether WPM could endanger patient safety. To investigate possible adverse patient events associated with WPM, transfusion reaction rates were examined. STUDY DESIGN AND METHODS: A questionnaire was distributed to Georgia medical centers. Data collected included the number of components transfused and reported adverse reactions by component type from January 2002 through January 2003, and date, reaction type, and blood supplier for events in January 2003. RESULTS: Of 124 transfusion services contacted, 108 (87%) responded. During the survey period, there were 1213 reported transfusion reactions and 528,412 units transfused, or 2.3 reactions per 1000 units transfused; for RBCs, 2.4 (range, 1.8-3.1); plasma, 1.5 (range, 0.6-3.5); and PLTs, 3.4 (2.1-5.4) per 1000 units. Transfusion reaction rates by component for January 2003 did not differ significantly from the rate for January 2002 or for the calendar year. The 86 reported reactions that occurred in January 2003 were attributed to bacterial contamination (n = 2, 2.3%), other febrile nonhemolytic (n = 49, 57.0%), allergic (n = 14, 16.3%), and "other" reactions (n = 21, 24.4%); the proportions of reaction types did not differ significantly during the month. CONCLUSION: No overall changes in reported adverse reaction rates occurred over the survey period or in the proportion of reaction types during January 2003 when WPM was detected. Statewide surveillance of transfusion reactions could be useful to evaluate potential threats to blood safety.

Treating cardiovascular disease with antimicrobial agents: a survey of knowledge, attitudes, and practices among physicians in the United States.

To assess physicians' knowledge, attitudes, and prescribing behaviors with regard to the association between Chlamydia pneumoniae and cardiovascular disease, we surveyed 750 physicians in Alaska, 1172 in West Virginia, and 569 infectious disease (ID) specialists in a nationwide network during February-May 1999. Eighty-five percent knew of the association between C. pneumoniae and atherosclerosis, but this awareness was more common among ID specialists and cardiologists than among generalists (96% vs. 77%; P<.001). Knowledge scores were significantly higher among ID specialists and cardiologists (P<.001) and among physicians who saw relatively more patients who had myocardial infarction and/or were at risk of atherosclerotic disease. Four percent of physicians had treated or recommended treating cardiovascular diseases with antimicrobial agents; this percentage was significantly higher among cardiologists, physicians who empirically treat patients with peptic ulcers with antimicrobial agents, and physicians with a relatively high knowledge score.

Clinical and epidemiologic characteristics of Mycobacterium haemophilum, an emerging pathogen in immunocompromised patients.

OBJECTIVE: To describe 13 infections caused by Mycobacterium haemophilum. DESIGN: Identification of patients by microbiologic record review, followed by medical record review and a case-control study. SETTING: Seven metropolitan hospitals in New York. PATIENTS: All patients with M. haemophilum infections diagnosed between January 1989 and September 1991 and followed through September 1992. Surviving patients were enrolled in the case-control study. RESULTS: Infection with M. haemophilum causes disseminated cutaneous lesions, bacteremia, and diseases of the bones, joints, lymphatics, and the lungs. Improper culture techniques may delay laboratory diagnosis, and isolates may be identified incorrectly as other mycobacterial species. Persons with profound deficits in cell-mediated immunity have an increased risk for infection. These include persons with human immunodeficiency virus infection or lymphoma and those receiving medication to treat immunosuppression after organ transplant. Various antimycobacterial regimens have been used with apparent success to treat M. haemophilum infection. However, standards for defining antimicrobial susceptibility to the organism do not exist. CONCLUSIONS: Clinicians should consider this pathogen when evaluating an immunocompromised patient with cutaneous ulcerating lesions, joint effusions, or osteomyelitis. Microbiologists must be familiar with the fastidious growth requirements of this organism and screen appropriate specimens for mycobacteria using an acid-fast stain. If acid-fast bacilli are seen, M. haemophilum should be considered as the infecting organism as well as other mycobacteria, and appropriate media and incubation conditions should be used.

Outbreak of Legionnaires' disease among cruise ship passengers exposed to a contaminated whirlpool spa.

BACKGROUND: Outbreaks of travel-related Legionnaires' disease present a public-health challenge since rapid, sensitive, and specific diagnostic tests are not widely used and because detection of clusters of disease among travellers is difficult. We report an outbreak of Legionnaires' disease among cruise ship passengers that occurred in April, 1994, but that went unrecognised until July, 1994. METHODS: After rapid diagnosis of Legionnaires' disease in three passengers by urine antigen testing, we searched for additional cases of either confirmed (laboratory evidence of infection) or probable Legionnaires' disease (pneumonia of undetermined cause). A case-control study was conducted to compare exposures and activities on the ship and in ports of call between each case-passenger and two or three matched control-passengers. Water samples from the ship, from sites on Bermuda, and from the ship's water source in New York City were cultured for legionellae and examined with PCR. FINDINGS: 50 passengers with Legionnaires' disease (16 confirmed, 34 probable) were identified from nine cruises embarking between April 30 and July 9, 1994. Exposure to whirlpool spas was strongly associated with disease (odds ratio 16.2, 95% Cl 2.8-351:7); risk of acquiring Legionnaires' disease increased by 64% (95% Cl 12-140) for every hour spent in the spa water. Passengers spending time around the whirlpool spas, but not in the water, were also significantly more likely to have acquired infection. Legionella pneumophila serogroup 1 was isolated only from the sand filter in the ship's whirlpool spa. This isolate matched a clinical isolate from the respiratory secretions of a case-passenger as judged by monoclonal antibody subtyping and by arbitrarily primed PCR. INTERPRETATION: This investigation shows the benefit of obtaining a recent travel history, the usefulness or urine antigen testing for rapid diagnosis of legionella infection, and the need for improved surveillance for travel-related Legionnaires' disease. New strategies for whirlpool spa maintenance and decontamination may help to minimise transmission of legionellae from these aerosol-producing devices.