Pontiac fever is a short-term illness linked to breathing in water droplets that contain Legionella bacteria. People with Pontiac fever often develop flu-like symptoms such as fever, chills, headache, muscle aches, and tiredness, but it does not cause pneumonia. The early symptoms of Pontiac fever usually begin within a few hours to 3 days after exposure, and the illness often clears within 2 to 5 days without specific treatment. Not everyone will have the same experience, but Pontiac fever can affect people of any age who are exposed, including after time in buildings with contaminated water systems. Pontiac fever is rarely life-threatening, and care is usually supportive with rest, fluids, and medicines to lower fever or ease aches.
How many people live with Pontiac fever?
Worldwide, there is no reliable estimate of how many people have Pontiac fever at any given time, and no single authoritative global count is consistently reported. In the United States, there is also no widely accepted national estimate, largely because Pontiac fever is a short-lived illness that often goes untested and unreported.
Overview
Pontiac feverSymptoms
Pontiac fever usually causes flu-like symptoms such as fever, chills, headache, muscle aches, and tiredness. Early symptoms of Pontiac fever often start within a few days after exposure, but it does not cause pneumonia.
Outlook and prognosis
Pontiac fever usually gets better on its own within 2 to 5 days. Most people with Pontiac fever recover fully without lasting problems. Rest, fluids, and fever relief are often enough, though older adults or people who feel very unwell may need medical advice.
Causes and risk factors
Pontiac fever is caused by breathing in tiny water droplets contaminated with Legionella bacteria. Risk rises after exposure to poorly maintained hot tubs, cooling towers, showers, or plumbing systems, especially in older adults, smokers, and people with lung disease.
Genetic influences
Genetics do not appear to play a major role in Pontiac fever. It is mainly linked to exposure to Legionella bacteria, though small differences in immune response may affect who gets sick.
Diagnosis
Pontiac fever is usually diagnosed from recent exposure, a sudden flu-like illness, and the absence of pneumonia. There is no single standard test, but doctors may use Legionella testing during outbreaks or to rule out Legionnaires' disease.
Treatment and drugs
Pontiac fever is usually treated with rest, fluids, and medicines such as acetaminophen or ibuprofen to ease fever, headache, and body aches. Because it does not cause pneumonia, antibiotics are usually not needed.
Symptoms
Pontiac fever often comes on quickly and can feel a lot like the flu, with fever, chills, body aches, and a heavy sense of being unwell. The early symptoms of Pontiac fever usually start within a few days of exposure and may leave people feeling wiped out enough to miss work or stay in bed. Unlike pneumonia, Pontiac fever does not usually cause a lung infection, even though a cough can happen. Symptoms vary from person to person and can change over time.
A fever is one of the most common symptoms and often starts suddenly. Many people with Pontiac fever feel hot, flushed, and generally sick at the same time.
Chills can come with the fever and may cause shaking or a hard-to-warm-up feeling. Day to day, it can feel like needing extra blankets even when the room is not cold.
Headaches are common and can range from dull pressure to a stronger, throbbing pain. For many, this can make it harder to focus, read, or get through a normal workday.
Body aches often affect the back, legs, and other large muscles. What once felt effortless can start to require more energy or focus.
How people usually first notice Pontiac fever?
Pontiac fever usually comes on suddenly, often within 1 to 3 days after breathing in contaminated water mist, and many people first notice it as a flu-like illness with fever, chills, headache, muscle aches, and a strong sense of feeling unwell. Unlike Legionnaires’ disease, it does not cause pneumonia, so the first signs of Pontiac fever are more often body aches, tiredness, and sometimes a dry cough rather than trouble breathing or chest pain. For many people, the illness is mild and short-lived, but if symptoms are severe, last more than a few days, or include shortness of breath, it is important to get medical care to rule out a more serious lung infection.
Types of Pontiac fever
Pontiac fever does not have clearly recognized subtypes in everyday medical use. It is generally treated as a single, mild flu-like illness linked to exposure to Legionella bacteria, rather than a disease with separate forms. Symptoms don’t always look the same for everyone, so one person may mainly feel tired and achy while another notices more fever, chills, and headache. When people ask about the types of Pontiac fever, the main point is that doctors do not usually divide it into distinct variants.
No distinct types
No distinct types of Pontiac fever are widely recognized. Most differences are in which symptoms show up and how strong they feel, not in separate disease forms. Pontiac fever usually stays a short-lived illness without the pneumonia seen in Legionnaires' disease.
Can I slow down the onset of symptoms?
No, there is no good evidence that lifestyle changes or medicine can meaningfully delay the start of symptoms in Pontiac fever once you have been exposed. The main proven step is lowering the chance of getting it at all by avoiding contaminated water mist from poorly maintained hot tubs, showers, or large building water systems, because this reduces risk rather than preventing symptoms after the illness has already started; research is focused more on safer water systems than on delaying onset in individuals. If symptoms begin after a possible exposure, medical advice can help make sure it is not a more serious lung infection, and the good news is that Pontiac fever usually gets better on its own.
What genetics can tell you about symptoms
For Pontiac fever, genetics usually cannot tell you much about which symptoms will happen, how strong they will be, or when they start. This illness is a short-term reaction to breathing in Legionella bacteria, and symptoms are driven mainly by the exposure itself and a person’s overall health rather than by known inherited gene changes. Researchers have looked at why some people seem more likely to get sick than others, but there is no established genetic test that predicts the symptom pattern of Pontiac fever in everyday care.
Causes and risk factors
Many people get Pontiac fever after breathing in tiny droplets of water that carry Legionella bacteria. Pontiac fever from hot tubs is one well-known example, and using a contaminated hot tub or working near cooling towers can raise exposure. Risk is higher when warm water sits in pipes or tanks, when disinfectant levels are low, or when large building water systems are poorly maintained. People of any age can get Pontiac fever, but differences in the immune response may affect who gets symptoms. Not everyone with the same risk develops the condition, and a clear inherited genetic risk is not known.
What are the most common causes or risk factors?
Pontiac fever is most often caused by breathing in tiny drops of water that carry Legionella, a type of bacteria, from places like hot tubs, cooling towers, showers, or building plumbing. The biggest risk factor is recent exposure to one of these contaminated water systems, especially during an outbreak in a hotel, hospital, office, factory, or other large building. There are no well-known inherited genetic risk factors, and unlike the more serious Legionnaires' disease, Pontiac fever can affect otherwise healthy people too.
Environmental and biological risk factors
Pontiac fever is usually linked to breathing in tiny droplets of water that contain Legionella bacteria, often from man-made water systems. Some risks are carried inside the body, others come from the world around us. The main risk factors for Pontiac fever are contaminated water sources, poor system upkeep, and heavier exposure to aerosolized water.
Pontiac fever starts after breathing in fine spray or mist that carries Legionella bacteria. It is linked to a shared environmental exposure, not to spread from one person to another.
Legionella grows more easily in warm, stagnant water, especially around 25-45°C (77-113°F). Low-flow plumbing, storage tanks, and dead-end pipes can give the bacteria time to multiply.
Hot tubs, cooling towers, decorative fountains, showers, and some humidifying systems can spread contaminated droplets when cleaning and disinfection are not kept up. Scale, sediment, and biofilms inside pipes or tanks can help the bacteria persist.
Hospitals, hotels, apartment buildings, and offices with complex plumbing have more places where water can sit and disinfectant levels can fall. Risk can also rise after shutdowns, low occupancy, or construction that disturbs the water system.
Genetic risk factors
Pontiac fever does not have any well-established inherited cause, and experts have not identified a specific gene that makes it run in families. Right now, genetic risk factors for Pontiac fever are still unclear, so family history is not used the way it is for many inherited disorders. Researchers suspect that natural differences in immune response may help explain why some people get sick and others do not, but no DNA-based test or routine genetic screening is recommended.
No known gene: No single gene or inherited change has been shown to cause Pontiac fever. It is not known to follow a clear family pattern.
Family history: Having a relative who had Pontiac fever is not a proven genetic risk factor. Doctors do not use family history alone to predict who will develop it.
Immune response: People can react differently to the same bacteria because immune systems are not identical. Even so, no specific immune-response gene has been confirmed as a clear genetic cause of Pontiac fever.
Genetic testing: There is no standard genetic test for Pontiac fever risk. Routine genetic screening is not recommended because established inherited risk factors have not been found.
Lifestyle risk factors
Pontiac fever has relatively few well-established lifestyle contributors compared with many other infections. In practice, lifestyle risk factors for Pontiac fever mostly involve habits that weaken the lungs or reduce the body’s ability to handle Legionella exposure. The strongest evidence points to smoking and heavy alcohol use, while other health habits may play a smaller supporting role.
Smoking damages the airways and reduces normal lung defenses that help clear inhaled germs. This may make it easier for Legionella exposure to trigger Pontiac fever symptoms.
Frequent heavy drinking can weaken immune responses and lower the body’s ability to fight infections effectively. It may increase the chance of becoming ill after Legionella exposure and can make recovery feel harder.
Habits that chronically irritate the lungs, such as regular vaping or ongoing smoke exposure from personal choices, may reduce airway resilience. While less studied than cigarette smoking, they may still affect how lifestyle affects Pontiac fever by making respiratory symptoms more likely or more noticeable.
Ongoing patterns of poor sleep, inadequate nutrition, and physical inactivity can weaken general immune function over time. These habits do not directly cause Pontiac fever, but they may leave the body less prepared to respond well after exposure.
Risk prevention
Pontiac fever is usually prevented by lowering exposure to tiny droplets of contaminated water, especially in buildings with complex water systems, hot tubs, and some workplace settings. Most people do not catch Pontiac fever from another person, so prevention is mainly about the environment rather than isolation. Prevention works best when combined with regular check-ups if you were exposed at work or have ongoing lung symptoms. For many, this can mean paying attention to places where warm water, mist, or poor maintenance allow germs to spread.
The best way to lower the risk of Pontiac fever is to keep building water systems clean, well maintained, and at safe temperatures. This includes regular flushing, disinfection, and preventing water from sitting still in pipes, tanks, or cooling systems.
Hot tubs, whirlpools, and spa pools need proper cleaning and the right disinfectant levels to reduce germ growth. Warm, bubbling water can spread contaminated mist into the air, which is a common way people are exposed.
Humidifiers, room misters, and similar devices should be emptied, dried, and cleaned as directed. Using clean water and not letting water stand for long periods can reduce the risk of Pontiac fever from contaminated water systems.
People working around cooling towers, industrial water systems, or aerosol-producing equipment may need workplace-specific prevention steps. Good ventilation, routine system testing, and following safety rules can lower exposure.
Can you prevent Pontiac fever?
You usually cannot prevent Pontiac fever completely, but the risk can be lowered by limiting exposure to contaminated water mist. The most reliable way to prevent it is careful upkeep of water systems, hot tubs, cooling towers, showers, and humidifiers so the germ that causes it, called Legionella, does not grow and spread. Because exposure can happen in places you do not control, prevention is not always fully possible.
Transmission
Pontiac fever is usually picked up by breathing in tiny droplets or mist from water that contains Legionella bacteria, often from places like hot tubs, showers, cooling towers, or building plumbing systems. If you are wondering how Pontiac fever spreads, it almost always comes from a shared water source rather than from another sick person.
Pontiac fever is not thought to spread from person to person, so it is not considered contagious in the usual sense. Even so, several people can become ill around the same time if they were exposed to the same contaminated water system.
When to test your genes
For Pontiac fever, genetic testing is not recommended for early detection or to tailor care. This illness is a short-lived reaction to breathing in Legionella-contaminated water droplets, so what matters most is recognizing symptoms after a shared exposure and, if needed, testing the environment rather than your genes.
Diagnosis
Pontiac fever is usually diagnosed by looking at the timing of your symptoms, the kind of exposure you may have had, and the fact that it does not cause pneumonia. It often comes on within a few hours to a few days after breathing in contaminated water droplets, such as from hot tubs, cooling systems, or plumbing aerosols. Doctors usually begin with a medical history and exam, because how Pontiac fever is diagnosed is often more about the overall pattern than one single test. It’s natural to worry when symptoms don’t have a clear explanation.
Doctors look for flu-like symptoms such as fever, chills, headache, muscle aches, and tiredness that start soon after a possible exposure. Pontiac fever usually gets better on its own within a few days and does not typically cause the severe breathing problems seen with pneumonia.
A recent stay in a hotel, hospital, cruise ship, workplace, or building with a shared water system can provide an important clue. Hot tubs, showers, fountains, and air-cooling systems are common sources when Legionella bacteria are involved.
The exam helps check temperature, breathing, heart rate, and signs of dehydration or other illness. In many people with Pontiac fever, the exam may show fever and general discomfort but no clear signs of lung infection.
If cough, shortness of breath, or chest pain raises concern for pneumonia, your provider may order a chest X-ray. A normal X-ray supports Pontiac fever, while new lung changes suggest Legionnaires' disease or another infection instead.
How is Pontiac fever diagnosed?
Pontiac fever is usually diagnosed based on the pattern of illness: a sudden flu-like sickness with fever, chills, headache, and body aches, plus a recent exposure to mist or water droplets from a contaminated building water system, hot tub, or air system. A doctor will often ask about where you have been and when symptoms started, and may do a chest X-ray or similar check to make sure there is no lung infection, because Pontiac fever does not cause pneumonia. Lab tests for the germ that causes it are not usually needed for routine care, but they may sometimes be used during outbreak investigations.
Stages of Pontiac fever
Pontiac fever does not have defined progression stages. This is because it usually causes a short, sudden illness that comes on after exposure and then gets better, rather than a disease that steadily moves through set phases. Doctors usually start with a conversation about when symptoms began, possible exposure to contaminated water systems, and whether anyone else nearby became ill. Early symptoms of Pontiac fever are usually tracked with a medical history and exam, and tests may be done mainly to rule out other infections if the picture is unclear.
Outlook and prognosis
The outlook for Pontiac fever is excellent, with symptoms usually resolving on their own within 2 to 5 days and without lasting lung damage. Unlike Legionnaires' disease, it does not progress to pneumonia and rarely causes serious complications. Most people recover fully with rest, fluids, and symptom relief, and antibiotics are not typically needed because Pontiac fever is a self-limited illness. Deaths from Pontiac fever have not been reported, so mortality is considered essentially absent. Recurrence is uncommon, although people can become ill again if they are re-exposed to contaminated water aerosols.
Long-term effects
Most people with Pontiac fever recover fully, and lasting health problems are not expected. Symptoms usually improve within a few days, and unlike Legionnaires' disease, Pontiac fever does not cause pneumonia or ongoing lung damage. Long-term effects vary widely across illnesses, but with Pontiac fever they are uncommon.
Pontiac fever is generally a short-lived illness, and most people return to their usual health without permanent effects. For many, this means no lasting problems with the lungs, heart, or other organs.
Some people feel tired or run down for a little while after the fever and body aches settle. This usually improves on its own and is not a sign of chronic infection.
Even though the early symptoms of Pontiac fever can feel flu-like and unpleasant, this illness does not typically injure the lungs. Lasting shortness of breath or lung scarring would be unusual and should prompt medical review for another cause.
Pontiac fever does not usually turn into a long-term Legionella infection. Once the illness passes, it is not known to keep smoldering in the body or cause relapsing disease.
How is it to live with Pontiac fever?
Pontiac fever usually arrives fast, like a sudden flu after exposure to contaminated water mist, and for a few days many people feel wiped out by fever, chills, headache, muscle aches, and deep fatigue. In daily life, that can mean missing work, school, exercise, or family plans while you rest, drink fluids, and wait for your strength to return, but the illness is typically short-lived and does not become pneumonia. It does not usually spread from person to person, so the main effect on people around you is often practical and emotional: they may help with errands or childcare while you recover, and they may also want reassurance that the illness itself is generally temporary.
Treatment and drugs
Pontiac fever is usually treated with supportive care, not antibiotics, because it does not cause pneumonia and most people get better on their own within a few days. Treatment often focuses on rest, drinking enough fluids, and using over-the-counter medicines such as acetaminophen or ibuprofen to ease fever, headache, and muscle aches. Supportive care can make a real difference in how you feel day to day. If symptoms are severe, last longer than expected, or include cough, chest pain, or shortness of breath, a doctor may want to check for Legionnaires' disease, which needs different treatment. For many living with Pontiac fever, recovery is complete without long-term problems.
Can you cure Pontiac fever?
There is no special cure for Pontiac fever, but the good news is that it usually gets better on its own within a few days. Treatment is mainly about helping you feel better with rest, plenty of fluids, and over-the-counter medicine for fever, headache, or body aches. If symptoms are severe, last longer than expected, or include trouble breathing, it is important to get medical care to make sure it is not a different, more serious illness.
Non-drug treatment
Pontiac fever usually gets better on its own within a few days, so care is mainly about easing symptoms and helping the body recover. Managing this condition often means rest, plenty of fluids, and simple comfort measures rather than formal therapy. For many living with Pontiac fever, the main goal is to feel better while watching for signs that the illness may be something more serious, such as pneumonia. If you are wondering how to recover from Pontiac fever, supportive care and avoiding the source of exposure are the key steps.
Fatigue, chills, and body aches can make even normal tasks feel draining, so extra sleep and a lighter schedule can help. Taking it easy for a few days may support recovery and lower the chance of feeling wiped out for longer.
Fever and sweating can leave you dehydrated, especially if you are not eating or drinking much. Water, soups, or oral rehydration drinks can help replace lost fluids and may ease headaches and weakness.
A cool room, light clothing, and a lukewarm washcloth can make fever and chills easier to tolerate. Small comfort steps like these may help while the illness runs its course.
Heavy exercise or long workdays can feel much harder when you have Pontiac fever. Gentle movement is fine if you feel up to it, but many people do better by waiting until the fever and aches have settled.
Your genes may have an impact on how drugs work for you
For people with Pontiac fever, treatment is usually simple home care, like rest, fluids, and common fever or pain relievers, because this illness often gets better on its own without antibiotics. In day-to-day life, this means most people are not taking special medicines where inherited differences are known to change treatment in an important way. So, for Pontiac fever, genetic differences in how the body handles drugs are not usually a key part of care, and choices about medicine are mostly based on symptoms, age, other health problems, and what else someone is taking.
Pharmacological treatments
Pontiac fever is usually treated by easing symptoms while the illness runs its course, rather than with a specific drug that targets the cause. Medication can feel like a big step, but most people with Pontiac fever only need short-term symptom relief for a few days. Because this condition does not cause pneumonia and tends to get better on its own, antibiotics are not usually helpful. If symptoms are severe, last longer than expected, or early symptoms of Pontiac fever seem to be getting worse, a doctor may check for another illness.
Acetaminophen can help lower fever and ease headache, body aches, and chills. It is often a good option when Pontiac fever leaves you feeling sore, run-down, and too uncomfortable to rest.
Ibuprofen or naproxen may also help with fever, muscle aches, and general discomfort. These medicines are not right for everyone, especially people with stomach ulcers, kidney disease, certain heart problems, or blood thinner use.
Antibiotics are not usually used for Pontiac fever because this illness is self-limited and does not behave like Legionnaires' disease. If a clinician suspects pneumonia or another bacterial infection instead, treatment may change after evaluation.
If nausea or vomiting is making it hard to keep fluids down, a doctor may prescribe an anti-nausea medicine such as ondansetron. This is not needed for everyone, but it can help some people stay hydrated while symptoms pass.
Genetic influences
If several people feel feverish and achy after being around the same hot tub or building water system, it is understandable to wonder why some develop Pontiac fever while others do not. Genetics is only one piece of the puzzle, but current evidence suggests Pontiac fever is mainly linked to exposure to Legionella bacteria rather than to an inherited gene change. Family history is not considered a major risk factor for Pontiac fever, and genetic testing is not usually part of care. Researchers think small differences in how the immune system responds may help explain who gets symptoms after the same exposure, but no specific genetic cause has been firmly established for most people with Pontiac fever. In practice, questions about the risk of Pontiac fever are usually answered more by where and how someone was exposed than by what runs in the family.
Is Pontiac fever genetic?
Genetics do not appear to play a major role in Pontiac fever. It is mainly linked to exposure to Legionella bacteria, though small differences in immune response may affect who gets sick.
Having a genetic risk is not necessarily a diagnosis
Genetic changes are a normal part of human biology and are common throughout the general population. Most of these changes do not directly affect health and simply reflect natural human diversity. For many genes, carrying a change associated with a condition points to a possible link rather than a definite diagnosis, especially when several genes and environmental factors are involved. In some situations, though, a single well-studied change in a particular gene can be enough to confirm a diagnosis.
Pharmacogenetics—how genetics influence drug effects
For most people with Pontiac fever, treatment is about getting through a few uncomfortable days with rest, fluids, and medicines that ease fever, headache, and body aches. Antibiotics are usually not needed, because Pontiac fever typically improves on its own. Not every difference in response is genetic, but inherited differences can affect how some people process common symptom medicines such as acetaminophen or ibuprofen, which may slightly change how well a dose works or how likely side effects are. Even so, there is no routine genetic test used to choose the best treatment for Pontiac fever, since care is mostly supportive and factors like age, pregnancy, liver or kidney problems, and interactions with other medicines usually matter more. If symptoms are severe, last longer than expected, or include breathing trouble, medical care is important so doctors can make sure it is Pontiac fever and not a different illness that needs specific treatment.
Interactions with other conditions
Pontiac fever can feel a lot like a sudden viral illness, so day to day it may be hard to tell whether a fever, body aches, and tiredness are coming from Pontiac fever or from something else such as the flu, COVID-19, or another infection. Having more than one diagnosis can make symptoms feel harder to untangle. For people with asthma, COPD, heart disease, or other long-term health problems, the illness itself does not usually directly worsen those conditions, but fever, poor sleep, and not drinking enough fluids can leave them feeling more run down. A key point is that Pontiac fever is not the same as Legionnaires' disease, which is a more serious lung infection caused by the same type of bacteria. Because the early symptoms can overlap, many living with Pontiac fever may need medical assessment if they also have cough, shortness of breath, chest pain, or symptoms that are getting worse instead of better. This matters especially for older adults and people with weaker immune systems, since doctors may need to make sure a more serious infection is not being missed.
How genes can cause diseases
Humans have more than 20,000 genes, each carrying out one or a few specific functions in the body. One gene instructs the body to digest lactose from milk, another tells the body how to build strong bones and another prevents the body's cells from beginning to multiply uncontrollably and developing into cancer. As all of these genes combined are the building instructions for our body, a defect in one of these genes can have severe health consequences.
Through decades of genetic research, we know the genetic code of any healthy/functional human gene. We have also identified that in certain positions on a gene, some individuals may have a different genetic letter from the one you have. We call these hotspots "Genetic Variations" or "Variants" in short. In many cases, studies have been able to show that having the genetic letter "G" in the position makes you healthy, but having the letter "A" in the same position disrupts the gene function and causes a disease. Genopedia allows you to view these variants in genes and summarizes all that we know from scientific research, which genetic letters (Genotype) have good or bad consequences on your health or on your traits.
What other conditions can cause similar symptoms to Pontiac fever?
The flu, COVID-19, and other common virus infections can look a lot like Pontiac fever at first, with fever, chills, headache, body aches, and feeling very tired. A chest infection such as pneumonia, especially Legionnaires' disease, can also be confused with it because it may begin with similar flu-like symptoms but is usually more serious and often causes cough or trouble breathing. Doctors may also think about other short-term infections that cause fever and body aches, depending on your symptoms and where you may have been exposed.
History
In the late 1960s, a group of workers in Pontiac, Michigan, came down with a sudden flu-like illness after spending time in the same building. People felt feverish, achy, and worn out, as if they had been hit by a brief but intense viral bug, yet doctors could not pin it on the usual causes. The illness passed on its own and, unlike pneumonia, did not seem to damage the lungs in the same way.
That outbreak became the first well-known description of what is now called Pontiac fever. Early reports showed a pattern: symptoms started quickly after exposure, affected many people at once, and usually cleared within a few days. At first, it was mainly understood through these symptoms and the shared exposure, because the exact cause was not immediately clear.
A few years later, after the better-known 1976 Legionnaires' disease outbreak in Philadelphia, researchers were able to connect the earlier Pontiac illness to the same group of bacteria, Legionella. This helped explain why Pontiac fever and Legionnaires' disease can appear in similar settings, such as large buildings with complex water systems, while causing very different levels of illness. For many, this can mean hearing about the two together even though Pontiac fever is the milder condition and does not usually cause pneumonia.
In recent decades, awareness has grown as testing, outbreak investigations, and building water safety practices have improved. Health officials now recognize Pontiac fever as a short-term illness linked to breathing in contaminated water droplets or mist, often from sources like cooling systems, showers, or hot tubs. The way the condition has been understood has changed over time, but the early Michigan outbreak remains the key starting point in its medical history.
Knowing this history helps make sense of why doctors may ask about recent travel, hotel stays, workplace exposures, or time spent around indoor water systems when looking into the early symptoms of Pontiac fever. What once seemed like a mysterious cluster of fevers is now a well-described public health condition, even if it is still less familiar to many people than Legionnaires' disease.