In a follow-up to the cluster of Legionnaires’ disease cases at San Quentin State Prison, California corrections officials now say that six inmates have been confirmed with the bacterial infection.
Five of the inmates are being treated at outside facilities for their illness.
In addition, approximately 51 inmates are currently under observation for respiratory illness but have not been diagnosed with Legionnaires’ disease. All unconfirmed cases are being treated at San Quentin’s on-site medical unit.
While the investigation into the outbreak is ongoing, the source of the Legionella bacterium is still unknown.
Prison officials have taken several steps in preventing additional cases including limiting water use at San Quentin.
Secondary water sources such as bottled water and water tanks will continue to be used for consumption until it is deemed safe to resume normal water use.
Inmates are currently being served boxed meals to avoid exposure to steam and mist during cooking operations. In addition, portable shower units arrived at the prison on Saturday.
Legionnaires’ disease gained national notoriety in 1976 when the Centers for Disease Control and Prevention (CDC) discovered it during an epidemic of pneumonia among American legion members at a convention in Philadelphia.
The causative organism is the bacteria, Legionella pneumophila. Other species have also been implicated in Legionnaires’ disease. The legionella bacteria are found throughout nature, because of this most people become exposed to it but few develop symptoms.
The primary place in nature it’s found is water sources particularly at warmer temperatures; lakes, rivers and moist soil.
It is also found in man-made facilities (frequently the source of outbreaks) such as air-conditioning ducts and cooling towers, humidifiers, whirlpools and hospital equipment.
People get exposed through inhaling infectious aerosols from these water sources. There is no transmission from person to person.
The infection can appear in two clinical forms: Legionnaires’ disease and Pontiac fever.
Both conditions are typified by headache, fever, body aches and occasionally abdominal pain and diarrhea.
Legionnaires’ disease is the cause of pneumonia where a non-productive cough is typical. Fatality rates of this form of the infection are around 15 % even with improvements in treatment.
Pontiac fever is a self-limiting flu-like illness that does not progress to pneumonia or death. Diagnosis is usually made by typical symptoms in an outbreak setting.
Diagnosis of Legionnaires’ disease depends on identifying the bacteria in microbiological culture, detecting the antigen in urine samples or a fourfold increase in antibody titer.
Certain health conditions make you more susceptible to infection to include increasing age, smoking, chroniclung disease, malignancy and diabetes mellitus.
Legionnaires’ disease is treatable with antibiotics.
Robert Herriman is a microbiologist and the Editor-in-Chief of Outbreak News Today