PNEUMONIAS & LOWER RESPIRATORY TRACT INFECTIONS Infectious Disease Epidemiology Section Office of Public Health Louisiana Dept of Health & Hospitals ...Your Taxes at Work… 504-568-5005 *** 800-256-2748 www.oph.dhh.louisiana.gov Clinical Presentation: Lower respiratory Tract Infection Prodrome ± Symptoms of upper respiratory tract infection: sore throat, rhinorrhea Fever, chills Nausea, vomiting, diarrhea Headache, dizziness Clinical Presentation: Lower respiratory Tract Infection Acute Infection: Fever, chills Back pain, myalgias, arthralgias Headache, malaise, chills Nausea, vomiting Chest Infection: Cough Chest pain Rales, wheezing, noisy chest Characteristic changes on chest x-rays Increasing respiratory distress, may require mechanical ventilation Diagnostic etiology of pneumonia About 40-60% of persons with pneumonia do not have a defined etiology… even after extensive testing for known respiratory pathogens Community Acquired Pneumonia Age-specific rates of hospital admission for community-acquired pneumonia caused by S. pneumoniae, M. pneumoniae, C. pneumoniae, or Legionella species Pneumonia Acute Respiratory Disease & Fever S.pneumo Legionella TB Plague Tularemia RICIN toxin Staphylococcal Enterotoxin B SARS Pneumonia Acute Respiratory Disease & Fever • They all look alike, sound alike • Not easy to differentiate from other pneumonias • Bronchoscopy, sputum, bronchial lavage… • Blood culture • Look for antibodies in serum Pneumococci Pneumococci Infection type Otitis media Pneumonia Bacteremia Meningitis Deaths Cases Mortality 7,000,000 500,000 5% 50,000 20% 3,000 30% 40,000 colonizes the upper respiratory tract cause: disseminated invasive infections - bacteremia - meningitis pneumonia & other lower respiratory tract infections upper respiratory tract infections - otitis media - sinusitis Risk Factors/ Increased risk for developing pneumococcal infection or experiencing severe disease and complications Children < 2 & adults aged > 65 years Underlying medical conditions chronic cardiovascular diseases (CHF/ cardiomyopathy) chronic pulmonary diseases (COPD or emphysema) chronic liver diseases (cirrhosis) Diabetes mellitus with CV or renal dysfunction Chronic renal failure or nephrotic syndrome Asthma NO unless with chronic bronchitis… Risk Factors/ Increased risk for developing pneumococcal infection or experiencing severe disease and complications Asplenia Functional or anatomic (SCD or splenectomy) clearance of encapsulated bacteria from the bloodstream antigens as in immunosuppressive conditions decreased responsiveness to polysaccharide Immunosuppressive conditions: AIDS, CIDS, leukemia, lymphoma, multiple myeloma, Hodgkins disease, or generalized malignancy, organ or bone marrow transplantation; rx with alkylating agents, antimetabolites, or systemic corticosteroids Pneumonia in HIV Most common bacterial cause of pneumonia in HIV Invasive pneumococcal disease often first clinical manifestation of children HIV AIDS: annual attack rate of pneumococcal bacteremia ~ 1% Pneumococcal Vaccine Pneumovax-Merck and Pneu-Immune® 23 Lederle include 23 purified capsular polysaccharide antigens serotype-specific antibody develops within 2-3 weeks in >80% of healthy young adults responses not consistent among 23 serotypes immunocompromised patients & children aged < 2 whose immune systems are immature: antibody responses Pneumococcal Vaccine Effectiveness against invasive disease: 56% to 81% in case-control studies not effective for prevention of common upper respiratory diseases (e.g., sinusitis in children) efficacy for non-bacteremic pneumonia was not demonstrated in elderly or in persons with chronic medical conditions Side effects mild, local (pain at site, erythema, swelling), < 48 hrs, systemic reactions (fever, myalgias) severe local reactions rare Legionella Legionnaires Disease 58th annual convention of the American Legion’s Pennsylvania Department at Bellevue Stanford Hotel in Philadelphia, July 21-24 1976 Starting July 22 - convention attendees and others who entered hotel became sick: pneumonia 182 hotel cases + 39 neighborhood cases 34 deaths Six months later a small bacterium named Legionella lung tissues of the cases pneumophila isolated from guinea pigs inoculated with the Legionnaires Disease Similar agents isolated before but never before so thoroughly characterized soldier in Fort Bragg, NC scuba diver 1943 L. micdadei from blood of febrile in 1959 L.bozemannii from lung tissue of identified as the causative for Pontiac fever retrospectively by serology outbreak of acute febrile illness, 1968, MI DOH building in Pontiac Bacteriology Legionella small (0.3 - 0.9 ) bacteria ~ very small Gram neg bacteria grows on buffered charcoal yeast extract agar (BCYE) supplemented by antibiotics to prevent overgrowth of Legionella dye to give Legionella a distinctive color grows slowly, 3-5 days to have small colonies Bacteriology 18 species Legionella pneumophila serogroup 1 is the predominant species in USA Legionella pneumophila multiplying inside a cultured human lung fibroblast Bacteriology in nature, infect free living amebae as Acanthamoeba, Naegleria and Harmanella multiply within amebae do not colonize respiratory tract phagocytized by the macrophages, then multiply within macrophages cell surface protein, macrophage infectivity potentiator (Mip) necessary for invasion of phagocytes and expression of virulence fold mutation in the Mip gene increase virulence 80- Natural Habitat Occurs worldwide preferred habitat: WATER preferably WARM WATERS with scale, sediment, metallic ions and commensal flora well adapted to hot water distribution system in dwellings: colonizes hot water heaters, storage tanks, pipes, shower heads, plumbing materials, faucet aerators, AC cooling towers, evaporative condensers found in 1-30% of home hot water systems multiplies in free living amebae: Acanthamoeba, Naegleria.. Transmission Inhalation of aerosols of water contaminated with Legionella primary mechanism of entry: aerosols generated by cooling towers, showers, faucets, respiratory therapy equipment and room-air humidifiers aspiration of contaminated potable water also proposed NO Person-to-person transmission Epidemiology Incubation 2-10 days 80% of reported cases are SPORADIC Outbreaks in hospitals, cruise ships, hotels and other large buildings Clinical: Pneumonia Common cause of PNEUMONIA % community acquired pneumonias due to Legionella is difficult to estimate routine diagnostic tests for recent Legionella not retrospective & prospective studies 1%-5% CAP pneumonias depending on geographic setting immunocompromised or chronically ill individuals risk higher among cigarette smokers, elderlies, Clinical wide range of clinical response asymptomatic serologic conversion self limited febrile illness (Pontiac fever) headache, chills myalgias or progressive severe pneumonia (Legionnaire’s disease) Legionnaire’s disease cannot be distinguished clinically or radiologically from other pneumonias Diagnosis Isolation of Legionella from respiratory secretion cultures Visualization of Legionella in respiratory secretions or tissue by immunofluorescence Detection of Legionella serogroup 1 antigen in the urine by radioimmunoassay, or enzyme immunoassay (EIA) more sensitive and specific than IF on respiratory tract secretions rapid diagnosis but only detects infection due to this species and serogroup Diagnosis Four fold rise in antibody titer to Legionella rising to above 1:128 in paired sera Antibodies to Mycoplasma pneumoniae, Campylobacter jejuni, Pseudomonas aeruginosa and Bacteroides fragilis, may cause falsepositive IFA test results Diagnosis One elevated antibody titer does NOT confirm case of recent legionellosis 1% - 16% of adults have IFA titers 1:256 Safe Water ”ways” grows poorly at < 20 C and > 50 C killed at temperatures > 60 C susceptible to chlorine and bromine disinfectants ozone heavy metal ions UV studies performed under lab conditions not always successful in predicting effectiveness under field conditions Safe Water ”ways” Cooling towers and evaporative condensers disinfected by hyperchlorination safer approaches would be to place them away from public areas to use drift eliminators to clean from organic matter periodically to dose automatically with a biocide Cooling Tower Safe Water ”ways” Whirlpool spas halogen levels at 4 - 10 mg/L, monitor frequently pH at 7.2 - 7.8 drain and clean system frequently replace filters regularly Safe Water”ways” Hot water system flushing for >5mn at > 65 C hyperchlorination (flushing with water 10 mg/L free residual chlorine) • • • • • • • may grow back unless hot water maintained at 50 C cold water at 20 C residual chlorine at 1-2 mg/L of free chlorine risk of scalding users hyperchlorination causes corrosion remove scale and sediments UV, ozone and heavy metals + Pertussis Bacteriology Bordetella pertussis fastidious Gram neg Bordet Gengou agar with 15% sheep blood or Regan Lowe immediately Swabs to be inoculated Delays isolation incubated at 35 C, in moist air Growth 5 days Transmission large droplets from upper Humans only respiratory tract NOT by droplet nuclei or fomites Asymptomatic cases exist, role ?? Without immunity, susceptibility = 100%, no child escaped pertussis Household exposure: attack rate pertussis = 90% to 100%, (in school 50%) mumps = 31% measles=75% chickenpox=61% Period of Communicability Incubation 7d (6-25 d) CATHARRHAL PAROXYSMAL Convales 10-14d 7-14d cence Communicability weeks Onset + 21 d Infected HCW: Onset +21 or Rx+5d Exposed HCW: ex+6 until +21 or rx+5d Epidemiology: before Vaccine endemic with epidemics at 3 - 5 years interval in unimmunized population majority among children 40% among infants < months 75% among children < 5 years of age incidence rate of whooping cough was about 150 /100,000 /year distributed worldwide outbreaks any time, slightly more during summer & early fall Epidemiology After Vaccine Immunization or immunity after disease prevents disease but NOT infection US rates down to 0.5 - 1 /100,000/yr nowadays resurgence pertussis = epidemic with 2 - 5 years cycles immunization cases but did not change cycles Epidemiology After Vaccine Common among adults IgA antibodies only produced after a natural infection, not after immunization Prevalence of IgA antibodies similar among adults in countries with generalized immunization (USA) or in countries with no systematic pertussis immunization (Germany in the 1970s): vaccine did not prevent production of IgA Vaccine did not prevent transmission 25% of adults with persistent cough have serologic evidence of recent pertussis infection Pertussis in the USA Log scale Pertussis in the USA Clinical first week: catarrhal phase: cough increases paroxysmal stage lasts for 3-4 weeks: starts after 2 weeks severe spells of coughing typical whoop: The whoop created by vigorous inspiration through the glottis at end of paroxysm during paroxysms, the child may turn blue or vomit fever usually low subconjunctival, cerebral and nose hemorrhages Mortality related to age: 50% in young infants negligible after 5 pulmonary complications Encephalopathy otitis media, mastoiditis, inanition and diarrhea are common in developing countries permanent neurological Diagnosis nasopharyngeal culture nasopharyngeal mucus collected on Dacron or calcium alginate swab a whooping cough syndrome similar to pertussis then inoculated on special culture media Bordet Gengou agar with sheep’s blood Regan-Lowe medium if delay Bordetella parapertussis, Chlamydia trachomatis adenoviruses Direct Stuart’s transport medium culture + from beginning of catarrhal stage+ 3 weeks ImmunoFluorescence Assay (DFA) not as specific or as sensitive as culture Prevention: Early Case Finding EARLY DETECTION essential to institute prevention Mild upper respiratory infection mild fever + coughing > 1 week duration SUSPECT PERTUSSIS Prevention: Contact Investigation identify individuals at risk, evaluate immunization status implement isolation and chemoprophylaxis monitor for respiratory for 14 days after contact broken household and other close contacts irrespective of their immunization status: erythromycin po (40 to 50 mg/kg/day in 4 divided doses, maximum 2 g) for 14 days eliminates carriage, may prevent disease if early immune are protected against new disease but not against infection and serve as transmitters compliance poor 5 day azithromycin, or 7 day clarithromycin OK Trimethoprim-Sulfamethoxazole alternate Prevention: Day Care Centers immunization as appropriate and chemoprophylaxis: same doses as the household contacts symptomatic children excluded pending medical evaluation: may return 5 days after initiation of erythromycin children on chemoprophylaxis Childhood Immunization Schedule Birth 1m 2m 3m 4m 6m 12m 15m 18m 4-6y 11-12y HBV2 DTP DTP HBV1 HBV3 DTP Hib Hib Polio MMR Varicella MMR or MMR Varicella DTP Hib Hib Polio Polio Pertussis Vaccine Whole cell vaccines Acellular vaccines: 5 immunogenic components capable individually or combined, of producing immunity acellular DPT vaccines initially developed in Japan inactive form of pertussis toxin, filamentous hemagglutinin, agglutinogens, outer membrane protein use of acellular vaccine reduces side effects: fever & irritability USA: acellular vaccines combined with DT recommended Prevention: Isolation /Exclusion Isolation of the hospital patient Droplet precautions until onset+21d or rx+7d Exclusion from school & day care Health Care Worker 1-suspected HCW : removed from patient contact until status determined 2-infectedHCW: + culture even if asymptomatic) removed from direct patient contact from onset to 21 days or until 7 days after rx start 3-exposed HCW: asymptomatic and neg cultures can continue Prevention in Health Care Facilities: Triage Questions patients with fever and respiratory symptoms Triage at first points of contact or before performing history-taking or examinations Surgical mask on suspect patients early during the triage process
"PNEUMONIAS _ LOWER RESPIRATORY TRACT INFECTIONS"