ADVICE
Dr. Roach: Learn more about Legionnaires’ disease and how it’s spread
Dr. Keith Roach
To Your Health
Aug. 21, 2026, 5:02 a.m. ET
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Dear Dr. Roach: I’ve been hearing about Legionnaires’ disease. What is it? How’s it spread? Can it really be spread through windshield wipers?
Dear D.G.: Legionnaires’ disease is a pneumonia caused by Legionella pneumophilia. It was first described in 1976, when an outbreak killed 34 people at an American Legion convention in Philadelphia. Since then, much has been learned about this condition
Legionella live in soil and water, and water remains the most importantrough aerosolized water. Air-conditioning cooling towers and water systems are the usualhis in New York City
There’s (almost) no person-to-person transmission of Legionnaires’ disease. Anyone can get Legionnaires’ disease, but it’s more common and more dangerous in older adults or those who have immune system diseases
Legionnaires’ disease can look like any other type of pneumonia, both clinically and in X-rays. However, people with Legionnaires’ disease are more likely to have gastrointestinal symptoms such as nausea, vomiting and diarrhea. Some blood tests are more likely to be abnormal (low sodium levels, abnormal liver tests, and exceedingly high inflammatory markers)
Because Legionnaires’ disease doesn’t respond to some of the most common antibiotics, clinicians need to have a high index of suspicion for Legionella to use the effective treatments. (Clarithromycin, azithromycin and levofloxacin are the most commonly used treatments.) A culture or PCR test of what a person coughs up is very accurate at making the diagnosis; a urine test can be done as well
It’s true that windshield wipers can spread the disease. Legionella is commonly found in drinking water, and windshield wipers are very good at turning fluid into a fine spray. With windshield wiper fluid, there’s not a chance of an infection. But tap water can have Legionella and lead to an infection if a person inhales the wiper mist when the reservoir’s filled with tap water
Dear Dr. Roach: I have resistant hypertension. My cardiologist prescribed hydralazine, but we can’t find any available supply. What can be used as a substitute for hydralazine?
— D.G.
Dear D.G.: There really isn’t any exact substitute for hydralazine, which is a powerful but short-acting drug that dilates (opens up) the small arteries. It is indicated by the Food and Drug Administration for moderate or severe hypertension, and I do see it being used occasionally for this
However, I most commonly see it used with heart failure, often along with nitroglycerine-type drugs. Newer drugs have largely supplanted the use of hydralazine, which is normally dosed three times daily
Only your doctor can give you the closest substitute; however, I’m very surprised that you’re having trouble finding it. It’s an old and inexpensive medicine (about 5 cents a pill). I checked with two large online pharmacies (Cost Plus and Amazon), and both had hydralazine available. (Injection hydralazine has had manufacturing issues, but I didn’t see any trouble with the oral form.)
If your local pharmacies really can’t get it (speak to the pharmacist directly), you can have your doctor send it to a national pharmacy for mail or local delivery. Readers may email questions to ToYourGoodHealth@med.cornell.edu
