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This study examines an outbreak of invasive pneumococcal disease in a long-term care facility, including background information on pneumonia, epidemiology of Streptococcus pneumoniae, outbreak investigation, and descriptive analysis. The study highlights the unique population characteristics in LTCFs and identifies limitations and areas for improvement.
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An Outbreak of Invasive Pneumococcal Disease in a Long-Term Care Facility Sherif Ibrahim, MD, MPH Division of Infectious Disease Epidemiology 02/18/2010
Objectives • Background information on pneumonia • Review the unique characteristics of the population in LTCF • Epidemiology of streptococcus pneumoniae • Outbreak investigation and timeline of events • Outbreak descriptive analysis and results • Limitations of the study • What Went Wrong? Conclusions
Background: Pneumonia • An inflammation of the lung tissues due to either infectious or non-infectious agents • Commonly associated with predisposing factors and triggers • Annually, in the U.S., 2-3 million people develop pneumonia • In 2006, pneumonia caused 1.2 million hospitalizations and 55,477 deaths in the U.S. • High risk groups (who is at risk?)
Background: Pneumonia Cont. • Clinical Picture:fever, chills, productive cough, pleuritic chest pain, dyspnea, tachypnea, and tachycardia • Vaccines: several types of pneumonia can be prevented by vaccines • Classification: according to the anatomical site of the lung, causative organism, and the setting in which it develops
Background: Pneumonia Cont. • Hospital-acquired: 48 hours after hospitalization. Pathogens: gram-negative bacilli and staph. (Drug -resistant organisms are of main concern) • Community-acquired: no contact with medical institutions Pathogens: Streptococcus pneumoniae, Haemophilus influenzae and atypical organisms • Long-Term Care Facility (LTCF) -acquired
LTCF-Acquired Pneumonia • LTCF: institutions provide health care to people who are unable to manage independently in the community. LTCF include nursing homes, assisted living, rehab, etc. • Nursing homeis a licensed facility that has organized professional staff and inpatient bed to provide health services to individuals who are not in acute phase of an illness • In the U.S. about 2.5 millions resides in LTCF and 1.5 millions in over 16,000 nursing homes
LTCF-Acquired Pneumonia • 2nd most common cause of infection and leading cause of death from infections in LTCF • LTCF residents develop pneumonia almost 10 times more frequently than their peers in the community and they have hospitalization rate of nearly 30 times higher • Etiologic agents (bacterial) • Streptococcus pneumoniae • Haemophilus influenzae • Staphylococcus Aureus • Moraxella catarrhalis • Gram-negative bacilli • Legionella
LTCF-Acquired PneumoniaPopulation Characters: Several predisposing factors: • Old age • Poor cognitive and functional status • Difficulty swallowing and tube feeding • Inadequate oral care • Immune system dysfunction due to multiple underlying chronic conditions, malnutrition, etc • Polypharmacy • Invasive devices • Frequent hospitalizations
LTCF-Acquired PneumoniaPopulation Characters: • Triggering factors: Upper respiratory tract viral infection (influenza, parainfluenza & Respiratory Syncytial Virus) • Atypical clinical picture Symptoms: anorexia, weakness, restlessness and agitation, falling, incontinence, dyspnea Signs: altered mental status, diminished or absent responsiveness, fever, tachycardia, tachypnea, wheezes or crackles, and decrease in O2 Sat
LTCF-Acquired PneumoniaPopulation Characters: Institutional factors: • Larger facilities with a single nursing unit or multiple units with a shared nursing staff • Heterogeneous populations • Closed environment & group activities • Low immunization rates (staff and residents) • Excessive use of antibiotics • Widespread colonization of residents with antimicrobial-resistant organisms
Epidemiology of Streptococcus pneumoniae • Lancet-shaped, gram-positive, anaerobic bacteria • Has polysaccharides capsule which acts as a primary basis for its pathogenicity • Several serotypes have been identified • Commonly colonizes the nasopharynx of 5-70% of healthy adults • Rates and duration of asymptomatic carriage vary with age, environment and the presence of URTI
Epidemiology of Streptococcus pneumoniae Cont. • Major clinical syndrome: Pneumonia, Meningitis, and Bacteremia • Transmission: • Direct person-to-person via droplets. • Autoinoculation in persons carrying the bacteria in their URT • Season: winter and early spring • Incubation Period: 1-3 days • Communicability: unknown
Epidemiology of Streptococcus pneumoniae Cont. • Is the most common cause of community-acquired pneumonia (accounts for 25-30%) • Causes an estimated 40,000 deaths annually • Incidence of invasive disease vary with age • More than 90 serotypes may cause invasive disease. The 23-valent polysaccharide vaccine (adult) covers 88% of these serotypes • Who should get the pneumococcal vaccine?
Epidemiology of Streptococcus pneumoniae Cont. Indications for pneumococcal vaccination: • People who are 65 years of age or older • People 2 years of age or older who have a chronic illness such as cardiovascular or pulmonary (lung) disease, sickle cell disease, etc. • People 2 years of age or older with a weakened immune system due to illnesses, medications, etc. • People 2 to 64 years of age who are living in LTCF • People 19-64 years of age who smoke cigarettes or have asthma
Outbreak of Streptococcus Pneumonia in a LTCFTimeline of The Outbreak • Feb 18, 2009 • Two Lab reports indicating positive blood culture for streptococcus pneumoniae sent to LHD (Do you have an outbreak? Do you have a diagnosis) • Reported to and consulted with state health officials • Site visit by local Health officials (Field work: What would you need with you?)
Timeline of The Outbreak Cont. • Immediate actions taken: • Initial chart review • Developing a provisional case definition • Creating a line list of cases • Request immunization records (residents & staff) • Request staff attendance and illness history • Active case finding: clinical evaluation, CXR, CBC, blood & sputum culture, NP swap for viral studies • Implementing infection control & prevention measures
Timeline of The Outbreak Cont. • Infection control and prevention measures: Standard Precautions: • Hand-hygiene • Personal Protective Equipment (PPE) • Cough etiquette • Environmental control • Needles and sharps • Soiled patient-care equipment • Safe injection practice
Timeline of The Outbreak Cont. • Droplet Precautions: • A single patient room if possible • Cohorting patients and staff • Maintain a distance > 3 feet and drawing a curtain between beds • Practice good hand hygiene, cough etiquette, and use PPE • Patients to wear a mask if they leave their rooms • Limit social gathering for patients • Implement visitor policy
Timeline of The Outbreak Cont. • Feb 20, 2009 - Site visit by state and local health officials - Reviewing infection control log and chart review - Revising the case definition - Reviewing and implementing infection control measures • Feb 24, 2009- Consultation with CDC by state and local health officials
Timeline of The Outbreak Cont. • Feb 26, 2009- Site visit by the state licensing agency - Closing the facility for new admissions - Antibiotic prophylaxis for all residents - Update all residents pneumococcal vaccination (> 5 Years) - Continue to implement infection control measures • Feb 27, 2009- Site visit by state and local health officials - Specimen collection. NP swabs, urine, and serum samples - Reviewing infection control measures • March 11, 2009 - End of illness investigation analysis time period - Reopen the facility for new admission - In-service training provided by state and local health officials
Descriptive Analysis – MethodDescriptive Epidemiology • Descriptive analysis of case-patients characteristics • Case definition: Residents with invasive pneumococcal infection or radiographically confirmed pneumonia with an illness onset between January 11 and March 11, 2009
Descriptive Analysis-Results • 28 cases:- Mean age: 83 years (M) and 85 years (F) - 3 cases (11%) had invasive pneumococcal infections- 25 (89%) had pneumonia • The attack rate, calculated using an average daily census, was 52.4% • 22 (79%) cases had previously received the pneumococcal vaccine • 15 (54%) hospitalizations and 7 (25%) deaths
Descriptive Analysis-Results Cont. • 22 (79%) cases had an onset of illness prior to outbreak notification • Streptococcus pneumoniae serotype 19a was isolated from all cases with invasive pneumococcal infection • 2 cases of respiratory syncytial virus by PCR • NP swabs were negative for influenza and urine samples were negative for Legionella
Limitations of the Study This was a case series study that describes clinical/epidemiological characteristics of a group of individuals with certain disease in a given time. Limitations: • Incomplete documentation • Exclusion of cases that did not match the case definition • Delay in collecting specimen for testing
What Went Wrong? • Delay in interpretation of the surveillance data failure of early detection of the outbreak delay in implementing control & prevention measures • Excessive use of empiric antibiotics • Physician’s standing orders for symptomatic treatment • Missteps in clinical evaluation and management • Gaps in documentation of clinical data • Staffing issues • Lack of adequate infection control training
Descriptive Analysis-Conclusions • An outbreak, likely caused by S. pneumoniae, occurred among residents of the long-term care facility • Co-infection with RSV may have contributed to illness severity • Proper infection control, including droplet precautions and investigative methods, was delayed by late outbreak notification • Outbreak detection could be improved by providing staff of long-term care facilities with training focused on disease surveillance and appropriate clinical evaluation of such population
Acknowledgment WVDHHR • Dee Bixler • Maria Del Rosario • Rachel Radcliffe • Thein Shwe • Lillie Clay OLS • Christi Clark MOVHD • Richard Wittberg CDC • Chris Van Beneden • The Team at the Respiratory Diseases Branch