Health officials in New Mexico report investigating a Legionnaires’ disease cluster in Chaves County in the southeastern part of the state.

Chaves County, New Mexico Image/ David Benbennick
Chaves County, New Mexico
Image/ David Benbennick

The New Mexico Department of Health (NMDOH) has identified six patients from Chaves County with confirmed Legionnaires’ disease since the first week of October 2016.

Two of the six cases, a 69-year-old woman and a 65-year-old woman, died. All 6 patients had other health issues that increased the risk of infection. NMDOH is working to determine the source of the infections with the support of Eastern New Mexico Medical Center.

LISTEN: Legionnaires’ disease: An interview with Dr. Mark Edwards and Sarah Ferrari

“We are working with the patients and their family members to determine if there is a common link or exposure among the patients,” said Department of Health Secretary Lynn Gallagher.

Investigations of clusters of Legionnaires’ disease are often not able to identify a common environmental source. Because the patients all live in the same area and their illnesses have occurred during the same time frame there is concern that a common exposure or source of infection may exist.

Outbreak investigations of Legionnaires’ disease focus on where patients may have been exposed to contaminated water in the 14 days before onset of illness. Legionella bacteria do not usually spread from person to person, but are usually breathed in, often through a mist. The Legionella bacteria are found naturally in freshwater environments like lakes and streams and become a health concern when they grow and spread in human-made water systems. Previous outbreaks have been linked to numerous different water sources including water cooling towers, hot tubs, decorative fountains and water heaters. The best prevention for stopping outbreaks is appropriate water system maintenance so that the bacteria are not able to grow.

Legionnaires’ disease is caused by Legionella bacteria and can cause severe pneumonia. Individuals with underlying health problems such as chronic lung disease (like chronic obstructive pulmonary disease or COPD, or emphysema) and people with weak immune systems from diseases like cancer, diabetes, or kidney failure are more likely to develop severe disease. It is fatal in about 10% of cases.

Symptoms of Legionnaires’ disease include cough, fever, difficulty breathing, muscle aches and headaches. Sometimes patients will have diarrhea, nausea and confusion. Frequently, patients will seek care at the emergency room where a chest x-ray will identify pneumonia.

The bacteria that causes Legionnaires’ disease was first identified in 1976 when people attending an American Legion convention in Philadelphia developed pneumonia. The source of that outbreak was determined to be the contaminated air cooling system in the hotel where the convention was being held.