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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
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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