Legionella

 Legionnaires disease has a deep history of being mistaken, the cause of legionnaires disease and the causative organism was unknown till late seventies.   To understand the current situation related with legionella infections in build environment, we need to understand its history. Beginning in 1976 when the American legion was celebrating its bicentennial in Philadelphia, USA where 600 veterans were staying at the Bellevue Strafford Hotel. Soon after their celebrations almost 200 of them started showing pneumonia-like symptoms. The doctors were treating them aggressively for pneumonia without any positive change their conditions.  The infection initially shows severe lung infection, headaches, and muscle aches. Like that of pneumonia, but then it progresses to coughing up mucus and occasionally blood, chest pains, gastrointestinal symptoms, and mental changes.

It was on the 27th of July 1976 when the disease claimed its first patient and then in a weeks’ time the death rate had increased to 18. The numbers continued to increase to 221 infected and 34 dead by mid-August. During this time, intensive investigations were conducted in the patients’ homes and shared places of interaction. The cause was found to be the infected water supply of the hotels' Air Conditioning unit. In honor of the legionnaires who lost their lives, the disease was named legionnaires disease, and the bacterium was named Legionella.

Considering the threat potential and risk involved, exhaustive studies were conducted on the disease, identifying it as a water-borne disease.  The sources of infection included but are not limited to Hot tubs, whirlpools, hot water systems, fountains, sprinklers, drinking water, cooling towers, and air conditioning units. Over time with advancing understanding and technologies, the bacterial spread has continued to grow exponentially with conducive conditions in the build environment.

Based on the understanding of Legionella's history, transmission modes and biology, preventive strategies, investigative standards, and regulations have evolved to curtail the growing rate of infectious cases.  Some of the most stringent regulations are listed below: -

ü  Dubai Municipality - Local order No -11 of 2003, Control of Legionella in water systems. Revision-2 (06/ 2010) Public Health Safety Department.

ü  Water quality regulations (Forth Edition) by Regulatory and Supervisory Bureau, Government of Abu Dhabi 

ü  UK / Europe - Health & Safety Executive - ACOP L8 Control of Legionella bacteria in water systems.

ü  European Technical Guidelines 2017: Prevention, Control, and Minimizing the risk from Legionella infections in building water systems.

ü  European Agency for Safety and Health at Work (2011), Directive 2000/54/EC, Protection of workers from risks related to exposure to biological agents at work.

ü  Legionella and the prevention of legionellosis. Geneva: World Health Organization.

ü  United States Environmental Protection Agency (USEPA) (2016). Technologies for Legionella control in premise plumbing systems.

ü  World Health Organization (1990). Epidemiology, prevention and control of Legionellosis.

ü  World Health Organization (2011). Guidelines for drinking-water quality.

 

EHS consultants base their risk assessment on the current building schematics and water usage facilities at that time. The team analyzes every aspect of the water consumption and use with the facilities, including hot water systems, irrigation systems, potable water systems, cooling towers, and fire water systems. Based on the comprehensive investigation conducted to identify the risk in water systems, we develop a mitigation plan keeping in mind the possible constraints of the system. Recommending the best, most suitable, and practical action plan, customized to the facility and its needs.

The report will include a Mitigation Plan to support the current water management team with the following aspects:

·         Minimizing Legionnaires’ disease risks to their employees, and visitors to the facilities.

·         Minimize the risk of workplace infections for legal compliance.

·         Ensure a plan is in place to prevent, prepare and respond to any negative deviation in water quality and in case of any Legionella infection.

·         Assure workplace safety by social commitment towards duty of care.

 

The Legionella control action plan implemented by EHS Consultants team is based on the detailed risk assessment of the water systems. The action plan is interactive with defined roles and responsibilities for the water system management team and competency enhancement with awareness trainings.  The efficacy of the mitigation plan needs to be re-assessed /validated with routine quality testing and scheduled audits.