LEGIONNAIRE’S DISEASE

Dr. Ramkesh Prasad

Department of Community Medicine

Gauhati Medical College

Legionnaire’s Disease

Caused by Legionella pneumophila Ranks fourth among the causes of

pneumonia(S. pneumoniae, H. influenzae,

Chlamydophila pneumoniae ) One of the atypical pneumonias, Gram

stained sputum smear does not show organisms.

Prevalent worldwide

Epidemiology

Each year, between 8,000 and 18,000 people are hospitalized with Legionnaires' disease in the U.S.

While Legionellae are ubiquitous in freshwater environments, and likely have been for centuries, it is their unique growth requirements in the environment coupled with the advent of human technology favoring complex water systems that has led to the designation of legionellosis as an emerging infectious disease in the late twentieth century.

Outbreaks

Year City Venue Source Cases Deaths

Fatality rate

July 1973 Benidorm, Spain Rio Park Hotel Not known 4 4 100%

July 1976

Philadelphia, Pennsylvania

Bellevue-Stratford Hotel

Air conditioning 221 34 15.4%

April 1985

Stafford, England

Stafford District Hospital

Air conditioning 175 28 16.0%

March 1999

Bovenkarspel, Netherlands

Westfrisian Flora flower exhibition

Hot tub 318 32 10.0%

2005 Toronto, CanadaSeven Oaks

Home for the Aged

Cooling tower 127 21 16.5%

OutbreaksYear City Venue Source Cases

Deaths

Fatality rate

April 2000

Melbourne Australia

Melbourne Aquarium

Cooling tower 95

July 2001

Murcia, Spain Hospital Cooling towers800

(449)10 17.8%

2002Barrow –in-

FurnessBarrow –in-

FurnessAir

conditioning172 7 4.1%

2005Fredrikstad,

NorwayFactory Air scrubber 56 4 4.2%

2008 New JerseySaint Peter’s University Hospital

Drinking water 6 3 0.3%

Feb 2012

Calp, SpainAR Diamante Beach Hotel

Not known 14 3 17%

HISTORYThe 1976 Philadelphia epidemic Legionnaires' disease was first recognized

as a distinct entity during an epidemic of pneumonia that occurred in Philadelphia, in the July1976. About 4,000 members of the Pennsylvania

State American Legion, an organization of former military veterans, met in July for American Bicentennial celebration, which lasted from 21 - 24 July.

On 27th July, one of the legionnaire died of a pneumonia like illness

On 30th July a physician in Bloomsburg, realized that the 3

patients he was treating from similar condition had all attended

the convention

On the same day, a nurse in Chambersburg Hospital noted a

similar condition in 3 patients who had gone to the convention

By Aug 2nd it was realized that there was some undeniable

connection

By August, 18 legionnaires had already died, it attracted huge

media coverage Out of the 221 cases - 72 were people who were not involved in

the American Legion convention - people who had either been inside the Bellevue Stratford Hotel, or had walked past it.

On January 18, 1977 CDC announced that the cause of

Legionnaire’s disease was isolated. (Thanks to the works of Dr

Joseph McDade * )

The source of the breeding site of the organism traced to the

cooling towers that were connected to the air conditioners of the

hotel.

Agent Legionella pneumophila Gram negative, aerobic bacteria bacterial cells are 0.5–1 µm wide and 2–50

µm long and motile, with one or more polar or lateral flagella

Ubiquitous worldwide Do not grow on routine microbiologic media. Requires Iron, L cystiene and temperature

25-45 °C Grown on Buffered charcoal yeast extract

(BCYE) agar medium.

Breeding grounds

Found in lakes, streams, and other bodies of water,

Grows inside free living ameba (Acanthameba,

Naegleria, Hartmannell)

Grows best in warm water, like in hot tubs, cooling towers, hot water tanks, large plumbing systems, or parts of the air-conditioning systems of large buildings. Indoor ornamental fountains have been confirmed as a

cause of Legionnaires' disease outbreaks, in which submerged lighting as a heat source was attributed to the outbreak in all documented cases.

HostRisk Factors Age: Elderly are more susceptible cigarette smoking; chronic lung disease; advanced age; Immunosuppression/immunodeficiency

transplantation, HIV infection treatment with glucocorticoids or tumor

necrosis factor antagonists

Transmission Inhalation of Legionellae in aerosolized droplets is the primary means of

transmission

These aerosolized droplets must be of a respirable size (1–5 μm).

No person-to-person transmission of Legionnaires’ disease has been

documented.

A number of devices have been implicated as sources of aerosol transmission

of Legionellae.

These sources are associated with both potable and non-potable water.

Sources producing aerosols of contaminated potable water include

showers, faucets, and respiratory therapy equipment.

Sources utilizing non-potable water include cooling towers, heated spas,

decorative fountains, humidifiers, ultrasonic mist machines, and

industrial manufacturing systems.

Disease occurs after exposure to aquatic settings that promote

bacterial growth—the aquatic environment is somewhat stagnant,

the water is warm (25°C – 42°C), the water must be aerosolized so that the

bacteria can be inhaled into the lungs

These 3 conditions are met almost exclusively in developed or industrialized settings

Pathogenesis

Legionella enters the lungs through aspiration or direct inhalation.

Attachment to host cells is mediated by bacterial type IV pili, heat-shock proteins, a major outer-membrane protein, and complement.

Because the organism possesses pili that mediate adherence to respiratory tract epithelial cells, conditions that impair mucociliary clearance, including cigarette smoking, lung disease, or alcoholism, predispose to Legionnaires' disease.

Clinical Feature

Fever

Pleurisy

Grossly purulent sputum

Diarrhoea

Renal failure

Diagnosis

Chest X-ray Culture

Sputum Tracheal Aspirate

Direct fluorescent antibody staining of sputum

Urinary antigen testing Antibody serolgy - fourfold

seroconversion

Treatment

Macrolide: Azithromycin, Clarithromycin,

Fluoroquinolones: Levofloxacin,

Ciprofloxacin, Moxifloxacin, Levofloxacin

Tetracycline,

Prognosis

Mortality rates vary with patient's underlying disease and its severity, the patient's immune status, the severity of pneumonia, and the timing of administration of appropriate

antimicrobial therapy. With appropriate and timely antibiotic

treatment, mortality rates in immunocompetent patients range from 0 to 11%; without treatment, the figure may be as high as

31%

Prevention There is no vaccine for legionellosis, Antibiotic prophylaxis is not effective always.

Travelers at increased risk for infection, such as the elderly or those with immunocompromising conditions such as cancer or diabetes, may choose to avoid high-risk areas, such as whirlpool spas.

If exposure cannot be avoided, travelers should be advised to seek medical attention promptly if they develop symptoms of Legionnaires’ disease or Pontiac fever

Chemoprophylaxis with a macrolide antibiotic has been effective in immunocompromised patients during nosocomial epidemics of the disease

Routine environmental culture of hospital water supplies is recommended as an approach to the prevention of hospital-acquired Legionnaires' disease

Hyperchlorination and superheating of water

can help control the multiplication of legionellae

in water and in air-conditioning systems.

Use of monochloramine, rather than chlorine to

treat public drinking water to reduce

colonization

Proper building and plumbing design and

construction can reduce frequency and intensity

of L. pneumophila contamination of potable

water.

Proper insulation of hot water pipes to prevent

warming of water in adjacent cold water pipes.

Maintaining hot water temperature above 50 °C

and cold water below 20 °C

Recreational spas must be properly constructed,

regularly maintained and closely monitored to

prevent high level of bacterial growth.

Pontiac Fever

An acute, self-limiting, flu-like illness with

an incubation period of 24–48 h.

Pneumonia does not develop.

Malaise, fatigue, and myalgia are the

most common symptoms.

Complete recovery occurs within a few

days; antibiotic therapy is unnecessary.

Legionnaire’s Disease in India

Agrawal L, Dhunjibhoy KR, Nair KG. Isolation of Legionella pneumophila from patients of respiratory tract disease and environmental samples. Indian J Med Res 1991; 93: 364-5.

In this preliminary study, 45 patients suffering from pneumonia were screened for L. pneumophila.

17 random environmental samples, water from a cooling system used for air conditioning units, and samples from a respirator-humidifier were screened.

Four of the 45 clinical specimens (9 %) and 13 of the 17 environmental samples (76 %) showed the presence of L. pneumophila. This is the 1st report from India of the isolation of L. pneumophila

Chaudhry R, Dhawan B, Dey AB. The incidence of Legionella pneumophila: a prospective study in a tertiary care hospital in India. Trop Doct 2000; 30: 197-200.

Between April 1997 and December 1998, 60 patients with CAP

admitted to the All India Institute of Medical Sciences were

included in the study.

Etiological diagnosis was based on the results of routine

microbiological blood culture for bacteria and serological test

by ELISA for L. pneumophila serogroup 1-7.

Eight patients (13 %) had a conventional bacterial etiology and

9 patients (15 %) had serological evidence of recent infection

with L. pneumophila.

Legionnaire’s Disease in India

Sero diagnosis of Legionella infection in community acquired pneumonia, Sabah Javed, Rama Chaudhry, Kapil Passi, Sutikshan Sharma, Padmaja K., Benu Dhawan & A.B. Dey, Indian J Med Res 131, January 2010, pp 92-96

All 113 clinical samples of paediatric (27) and adult (86) patients were collected during May 2005 to January 2008 on their first visit to the AIIMS, New Delhi, with the symptoms of pneumonia

Thirty one of the 113 cases (27.43%) were

serologically positive.

Isolation of Legionella pneumophila from clinical & environmental sources in a tertiary care hospital, S. Anbumani, A. Gururajkumar & A. Chaudhury, Indian J Med Res 131, June 2010, pp 761-764

Study done at Sri Venkateswara Institute of Medical Sciences, Tirupati, India

A total of 470 lower respiratory tract samples and 24 water samples from hospital outlets were examined. Culture was done on buffered charcoal yeast extract agar with supplements and identification of the isolates was done by microscopy and biochemical tests.

L. pneumophila could be isolated from 12 (2.55%) patients suffering from community-acquired lower respiratory tract infection, unassociated with other aetiological agents of bacterial pneumonia. Of the 24 water samples tested, 8 (33.3%) grew the same organism.

A 53 years old British tourist had come to India in November 2003, and had visited Delhi, Agra, Jaipur, and Goa. He went back to the United Kingdom on 5 Dec 2003 and died 2 days later.

According to the British High Commission, the person died of Legionnaire’s disease

Thank You

Thank You

Why it Took so Long to Find the Bacillus

It was no ordinary microbe. It could not be grown under typical conditions, being dependent upon ridiculous demands: high levels of the amino acid cysteine and inorganic iron supplements, low sodium concentrations, as well as activated charcoal to absorb free radicals. In addition, it preferred elevated temperatures, which was highly abnormal among pathogens, who preferred near-body temperatures.

It did not help that the team of CDC researchers had been using the wrong animal model at the start, and had only gotten results when they switched from mice to guinea pigs

where exactly was this bacteria from, and how did it come to infect the World War II

veterans?

Dr Carl Fliermans solved the first part of the puzzle when he discovered that L pneumophila lipids resembled those of the thermophilic bacteria he'd found in the thermal regions of the Yellowstone National Park, and that this bacteria tended to live as biofilm (scum) associated with certain species of algae. Subsequently, Fliermans began poking around aquatic habitats and found - guess what? - this bacteria residing in thermal waters discharged from a nuclear reactor at Savannah River Laboratory.

This bacteria was later found to be living in natural hot springs all over the United States and, most importantly, in air-conditioning cooling towers.