PNEUMONIAS _ LOWER RESPIRATORY TRACT INFECTIONS

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 entered hotel became sick: pneumonia  Starting July 22 - convention attendees and others who  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  risk higher among cigarette smokers, elderlies, immunocompromised or chronically ill individuals 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 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  Detection of Legionella serogroup 1 antigen 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 serologic evidence of recent pertussis infection  25% of adults with persistent cough have 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  Stuart’s transport medium  culture + from beginning of catarrhal stage+ 3 weeks Direct 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 DTP Hib Hib Polio Polio Hib Hib Polio MMR Varicella MMR or MMR Varicella 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