PNEUMONIAS PNEUMONIAS & LOWER RESPIRATORY & LOWER RESPIRATORY

TRACT INFECTIONSTRACT INFECTIONS

Infectious Disease Epidemiology SectionOffice of Public Health

Louisiana Dept of Health & Hospitals...Your Taxes at Work…

504-568-5005 *** 800-256-2748www.oph.dhh.louisiana.gov

Clinical Presentation: Lower respiratory Tract

Infection

Prodrome ±

Symptoms of upper respiratory tract infection: sore throat, rhinorrhea

Fever, chillsNausea, vomiting, diarrheaHeadache, 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

PneumoniaAcute Respiratory Disease &

Fever

Plague Tularemia

RICIN toxinStaphylococcal Enterotoxin B

TBLegionella

SARS

S.pneumo

PneumoniaAcute 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

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

decreased responsiveness to polysaccharide antigens as in immunosuppressive conditions

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 deathsSix months later a small bacterium named Legionella

pneumophila isolated from guinea pigs inoculated with the lung tissues of the cases

Legionnaires Disease

Similar agents isolated before but never before so thoroughly characterized

1943 L. micdadei from blood of febrile soldier in Fort Bragg, NC

in 1959 L.bozemannii from lung tissue of scuba diver

identified as the causative for Pontiac fever retrospectively by serology outbreak of acute febrile illness, 1968, MI DOH

building in Pontiac

Bacteriology

Legionellasmall (0.3 - 0.9 ) bacteria

~ very small Gram neg bacteriagrows 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

Legionella pneumophila multiplying inside a cultured human lung fibroblast

18 species

Legionella pneumophila serogroup 1 is the predominant species in USA

Bacteriology

in nature, infect free living amebae as Acanthamoeba, Naegleria and Harmanella multiply within amebae

do not colonize respiratory tractphagocytized by the macrophages, then

multiply within macrophagescell surface protein, macrophage infectivity

potentiator (Mip) necessary for invasion of phagocytes and expression of virulence

mutation in the Mip gene increase virulence 80-fold

Natural Habitat

Occurs worldwidepreferred habitat: WATERpreferably WARM WATERS with scale, sediment, metallic ions and commensal florawell 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 systemsmultiplies 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 diagnostic tests for recent Legionella not

routineretrospective & 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 responseasymptomatic 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 seraAntibodies to Mycoplasma

pneumoniae, Campylobacter jejuni, Pseudomonas aeruginosa and Bacteroides fragilis, may cause false-positive 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 Csusceptible 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 negBordet Gengou agar

with 15% sheep blood or Regan Lowe

Swabs to be inoculated immediately

Delays isolation incubated at 35 C, in

moist airGrowth 5 days

Transmission

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%

Humans Humans onlyonly

large droplets from upper

respiratory tract NOT by droplet

nuclei or fomites Asymptomatic

cases exist, role ??

Period of Communicability

Incubation7d (6-25 d)

CATHARRHAL10-14d

CommunicabilityOnset + 21 d

Exposed HCW: ex+6 until +21 or rx+5d

Infected HCW: Onset +21 or Rx+5d

PAROXYSMAL7-14d Convale

scenceweeks

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 worldwideoutbreaks 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 IgAVaccine did not prevent transmission

25% of adults with persistent cough have serologic evidence of recent pertussis infection

Pertussis in the USA

Log scal

e

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

Diagnosisnasopharyngeal culture

nasopharyngeal mucus collected on Dacron or calcium alginate swab

then inoculated on special culture media Bordet Gengou agar

with sheep’s blood Regan-Lowe medium

Stuart’s transport medium if delay

culture + from beginning of catarrhal stage+ 3 weeks

a whooping cough syndrome similar to pertussisBordetella parapertussis, Chlamydia trachomatis adenoviruses

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 chemoprophylaxismonitor for respiratory for 14 days after

contact brokenhousehold 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: children on

chemoprophylaxis may return 5 days after initiation of erythromycin

Childhood Immunization Childhood Immunization ScheduleSchedule

Birth 1m 2m 3m 4m 6m 12m 15m 18m 4-6y 11-12y Birth 1m 2m 3m 4m 6m 12m 15m 18m 4-6y 11-12y

HBV3

DTP

HBV1HBV2

DTPDTP DTP

HibHib

Hib Hib

Polio Polio Polio

MMR MMR or MMR

VaricellaVaricella VaricellVaricellaa

Pertussis Vaccine

Whole cell vaccinesAcellular 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

Health Care Worker1-suspected HCW : removed from patient contact until

status determined2-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

Isolation of the hospital patientDroplet precautions until onset+21d

or rx+7dExclusion from school & day care

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