“Polio, or poliomyelitis, is an infectious viral disease that can harm the nervous system. Post-polio syndrome (PPS) usually occurs 15-40 years after the infection and recovery. PPS is believed to be the result of a deterioration of nerve cells called motor neurons over many years that leads to loss of muscle strength and dysfunction from Polio virus.

Polio and post-polio syndrome are caused by poliovirus. Unlike polio, PPS is not contagious but more a extended result from it for some who get PPS. Only a polio survivor can develop PPS yet not everyone who survives polio will develop PPS.

The polio vaccine is the answer and has essentially eradicated a lot of polio from the U.S. However, polio still exists in some countries and cases of PPS still arise.”

National Institute of Neurological Disorders and Stroke – NIH

(https://www.ninds.nih.gov/health-information/disorders/post-polio-syndrome)

The answer is even with a name; it is called Post-polio syndrome.

Around 40% of people who survive paralytic polio may develop additional symptoms 15–40 years after the original illness. These symptoms – called post-polio syndrome – include new progressive muscle weakness, severe fatigue and pain in the muscles and joints.

This is how it works:

What is post-polio syndrome?

Post-polio syndrome is an illness of the nervous system that can appear 15 to 50 years after you had polio. It affects your muscles and nerves, and it causes you to have weakness, fatigue, and muscle or joint pain.

Although post-polio syndrome can make some day-to-day activities more difficult, treatment can help control symptoms and help you stay active. Your symptoms may not get worse for many years. Post-polio syndrome usually progresses very slowly.

Only people who have had polio can get post-polio syndrome. But having post-polio syndrome doesn’t mean that you have polio again. Unlike polio, post-polio syndrome doesn’t spread from person to person.

What causes post-polio syndrome?

Post-polio syndrome most likely arises from the damage left over from having the polio viruse in the body still.

The polio virus harms the nerves that control muscles, and it makes the muscles weak. If you had polio, you may have gained back the use of your muscles. But the nerves that connect to the muscles could be damaged without your knowing it. The nerves may break down over time and cause you to have weak muscles again.

Researchers are studying other possible causes of post-polio syndrome. One theory is that the immune system plays a role.

What are the symptoms?

Symptoms of post-polio syndrome tend to show up very slowly. The main symptoms are:

• New muscle weakness. This is most common in the muscles that had nerve damage from polio. You may also have weakness in muscles that you didn’t realize had been affected by polio. Overuse or underuse of the muscles can lead to weakness.
• Fatigue. You may find that the activities you used to do without getting tired are now causing fatigue. You may often feel tired, have a heavy feeling in your muscles, or feel sleepy. At times you may have trouble thinking clearly.
• Muscle or joint pain. Muscles affected by polio tend to be weaker than normal. To make up for this weakness, other muscles have to work harder. This puts extra wear and tear on muscles, joints, and tendons, sometimes leading to aches, cramping, and pain.

Depending on which muscles are affected, this trio of muscle weakness, fatigue, and pain can make daily activities more difficult. For example, people with shoulder or arm weakness may have trouble getting dressed. People who have weakness in their legs may have trouble walking or climbing stairs.

Post-polio syndrome is rarely life-threatening, but the symptoms can significantly interfere with an individual’s ability to function independently. Respiratory muscle weakness, for instance, can result in trouble with proper breathing, affecting daytime functions and sleep.  Weakness in swallowing muscles can result in aspiration of food and liquids into the lungs and lead to pneumonia.

Only a polio survivor can develop PPS.

The severity of weakness and disability after recovery from poliomyelitis tends to predict the relative risk of developing PPS.  Individuals who had minimal symptoms from the original illness are more likely to experience only mild PPS symptoms.  A person who was more acutely affected by the polio virus and who attained a greater recovery may experience a more severe case of PPS, with greater loss of muscle function and more severe fatigue.

The exact incidence and prevalence of PPS is unknown.  The U.S. National Health Interview Survey in 1987 contained specific questions for persons given the diagnosis of poliomyelitis with or without paralysis.  No survey since then has addressed the question.  Results published in 1994-1995 estimated there were about 1 million polio survivors in the U.S., with 443,000 reporting to have had paralytic polio.  Accurate statistics do not exist today, as a percentage of polio survivors have died and new cases have been diagnosed.  Researchers estimate that the condition affects 25 to 40 percent of polio survivors.

What causes PPS?

The cause of PPS is unknown but experts have offered several theories to explain the phenomenon—ranging from the fatigue of overworked nerve cells to possible brain damage from a viral infection to a combination of mechanisms.  The new weakness of PPS appears to be related to the degeneration of individual nerve terminals in the motor units.   A motor unit is formed by a nerve cell (or motor neuron) in the spinal cord or brain stem and the muscle fibers it activates.  The polio virus attacks specific neurons in the brain stem and spinal cord.  In an effort to compensate for the loss of these motor neurons, surviving cells sprout new nerve-end terminals and connect with other muscle fibers.  These new connections may result in recovery of movement and gradual gain in power in the affected limbs.

Years of high use of these recovered but overly extended motor units adds stress to the motor neurons, which over time lose the ability to maintain the increased work demands.  This results in the slow deterioration of the neurons, which leads to loss of muscle strength.  Restoration of nerve function may occur in some fibers a second time, but eventually nerve terminals malfunction and permanent weakness occurs.  This hypothesis explains why PPS occurs after a delay and has a slow and progressive course.

Through years of studies, scientists at the National Institute of Neurological Disorders and Stroke (NINDS) and at other institutions have shown that the weakness of PPS progresses very slowly.  It is marked by periods of relative stability, interspersed with periods of decline.

How is PPS diagnosed?

The diagnosis of PPS relies nearly entirely on clinical information.  There are no laboratory tests specific for this condition and symptoms vary greatly among individuals.  Physicians diagnose PPS after completing a comprehensive medical history and physical examination, and by excluding other disorders that could explain the symptoms.

Physicians look for the following criteria when diagnosing PPS:

• Prior paralytic poliomyelitis with evidence of motor neuron loss.  This is confirmed by history of the acute paralytic illness, signs of residual weakness and atrophy of muscles on neuromuscular examination, and signs of motor neuron loss on electromyography (EMG).  Rarely, people had subtle paralytic polio where there was no obvious deficit.  In such cases, prior polio should be confirmed with an EMG study rather than a reported history of non-paralytic polio.
• A period of partial or complete functional recovery after acute paralytic poliomyelitis, followed by an interval (usually 15 years or more) of stable neuromuscular function.
• Slowly progressive and persistent new muscle weakness or decreased endurance, with or without generalized fatigue, muscle atrophy, or muscle and joint pain.  Onset may at times follow trauma, surgery, or a period of inactivity, and can appear to be sudden.  Less commonly, symptoms attributed to PPS include new problems with breathing or swallowing.
• Symptoms that persist for at least a year.
• Exclusion of other neuromuscular, medical, and skeletal abnormalities as causes of symptoms.

PPS may be difficult to diagnose in some people because other medical conditions can complicate the evaluation.  Depression, for example, is associated with fatigue and can be misinterpreted as PPS.   A number of conditions may cause problems in persons with polio that are not due to additional loss of motor neuron function.  For example, shoulder osteoarthritis from walking with crutches, a chronic rotator cuff tear leading to pain and disuse weakness, or progressive scoliosis causing breathing insufficiency can occur years after polio but are not indicators of PPS.

Polio survivors with new symptoms resembling PPS should consider seeking treatment from a physician trained in neuromuscular disorders.  It is important to clearly establish the origin and potential causes for declining strength and to assess progression of weakness not explained by other health problems.   Magnetic resonance imaging (MRI) and computed tomography (CT) of the spinal cord, electrophysiological studies, and other tests are frequently used to investigate the course of decline in muscle strength and exclude other diseases that could be causing or contributing to the new progressive symptoms.  A muscle biopsy or a spinal fluid analysis can be used to exclude other, possibly treatable, conditions that mimic PPS.  Polio survivors may acquire other illnesses and should always have regular check-ups and preventive diagnostic tests.   However, there is no diagnostic test for PPS, nor is there one that can identify which polio survivors are at greatest risk.

Is there a treatment for PPS?

There are currently no effective pharmaceutical treatments that can stop deterioration or reverse the deficits caused by the syndrome itself.  However, a number of controlled studies have demonstrated that non-fatiguing exercises may improve muscle strength and reduce tiredness.   Most of the clinical trials in PPS have focused on finding safe therapies that could reduce symptoms and improve quality of life.

Researchers at the National Institutes of Health (NIH) have tried treating persons having PPS with high doses of the steroid prednisone and demonstrated a mild improvement in their condition, but the results were not statistically significant.  Also, the side effects from the treatment outweighed benefits, leading researchers to conclude that prednisone should not be used to treat PPS.

Preliminary studies indicate that intravenous immunoglobulin may reduce pain and increase quality of life in post-polio survivors.

A small trial to treat fatigue using lamotrigine (an anticonvulsant drug) showed modest effect but this study was limited and larger, more controlled studies with the drug were not conducted to validate the findings.

Although there are no effective treatments, there are recommended management strategies.  Patients should consider seeking medical advice from a physician experienced in treating neuromuscular disorders.  Patients should also consider judicious use of exercise, preferably under the supervision of an experienced health professional.  Physicians often advise patients on the use of mobility aids, ventilation equipment, revising activities of daily living activities to avoid rapid muscle tiring and total body exhaustion, and avoiding activities that cause pain or fatigue lasting more than 10 minutes.  Most importantly, patients should avoid the temptation to attribute all signs and symptoms to prior polio, thereby missing out on important treatments for concurrent conditions.   Always go to your physician for advisement before starting any exercise regimen to make sure your M.D. clears the activity first, for your safety!

There is no cure for polio, only treatment to alleviate the symptoms.  Heat and physical therapy is used to stimulate the muscles and antispasmodic drugs are given to relax the muscles. While this can improve mobility, it cannot unfortunately reverse permanent polio paralysis.

How Polio can be PREVENTED:

Polio can be prevented through immunization. Polio vaccine, given multiple times, almost always protects a child for life.  Post Polio if it happens in a polio pt too late and no cure or if diagnosed with Polio too late for cure.  So vaccinate when young so you’ll never get it!

Polio – a disease many have prematurely consigned to history – made headlines around the world in recent months when the virus was detected in relatively high-income country settings from New York, London, Montreal and Jerusalem. This apparent comeback in polio-free countries has left many questioning the feasibility of eradication. On the contrary, we have never been closer to achieving our goal of a polio-free world: this resurgence only underscores the urgent need for  eradication.

When the Global Polio Eradication Initiative (GPEI) was launched in 1988, nearly 1,000 children were being paralyzed with wild poliovirus (WPV) infection across 125 countries every single day. Since then, a concerted effort of health workers, communities, local governments, and global partners such as Rotary International have helped eradicate two of the three serotypes of wild poliovirus (WPV2 and WPV3) and cornered the remaining strain of WPV – type 1 (WPV1) – to small areas of Pakistan and Afghanistan – the last wild polio-endemic countries. The genetic diversity of the remaining chains of WPV1 is also on the decline, indicating the virus might very well be on the verge of being wiped out.

However, this incredible progress is in jeopardy. Due in part to the COVID-19 pandemic, the world has seen a worrying drop in immunization rates over the past few years, creating pockets of under-immunized communities at heightened risk of polio infection and paralysis. Children missing polio vaccinations creates opportunities for polio to re-emerge and spread – as seen in 2022 when WPV1 originating in Pakistan was detected in paralyzed children in Malawi and Mozambique. This episode served as a poignant reminder that as long as polio exists anywhere in the world, it remains a threat to people everywhere.”

Speaking of Medicine and Health (https://speakingofmedicine.plos.org/2023/03/17/why-is-polio-making-a-comeback-and-what-can-we-do-about-it/)

A virus is a small, infectious agent that is made up of a core of genetic material surrounded by a shell of protein. The genetic material (which is responsible for carrying forward hereditary traits from parent cells to offspring) may be either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). Viruses are at the borderline between living and nonliving matter. When they infect a host cell, they are able to carry on many life functions, such as metabolism and reproduction. But outside a host cell, they are as inactive as a grain of sand.

Viruses cause disease by infecting a host cell and taking over its biochemical functions. In order to produce new copies of itself, a virus must use the host cell’s reproductive “machinery.” The newly made viruses then leave the host cell, sometimes killing it in the process, and proceed to infect other cells within the organism.

Viruses can infect plants, bacteria, and animals. The tobacco mosaic virus, one of the most studied of all viruses, infects tobacco plants. Animal viruses cause a variety of diseases, including AIDS (acquired immuno deficiency syndrome), hepatitis, chicken pox, smallpox, polio, measles, rabies, the common cold, and some forms of cancer.

Viruses that affect bacteria are called bacteriophages, or simply phages (pronounced FAY-jez). Phages are of special importance due to the susceptibility of the viruse transmission. The disease Polio (poliomyelitis) in time will be transmitted throughout the bloodstream and the highly viral infectious disease is now spreading in the body.

Poliomyelitis (POLIO) is a viral disease. There are three types of poliovirus and many strains of each type. The virus enters through the mouth and multiplies in the throat and gastrointestinal tract, then moves into the bloodstream and is carried to the central nervous system where it replicates and destroys the motor neuron cells. Motor neurons control the muscles for swallowing, circulation, respiration, and the trunk, arms, and legs.

Human nerve cells have a protruding protein structure on their surface whose precise function is unknown. When poliovirus encounters the nerve cells, the protruding receptors attach to the virus particle, and infection begins. Once inside the cell, the virus hijacks the cell’s assembly process, and makes thousands of copies of itself in hours. The virus kills the cell and then spreads to infect other cells.

A virus is a small, infectious agent that is made up of a core of genetic material surrounded by a shell of protein. The genetic material (which is responsible for carrying forward hereditary traits from parent cells to offspring) may be either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). Viruses are at the borderline between living and nonliving matter. When they infect a host cell, they are able to carry on many life functions, such as metabolism and reproduction. But outside a host cell, they are as inactive as a grain of sand.

How polio is spread:

The virus enters through the mouth and multiplies in the throat and gastrointestinal tract, then moves into the bloodstream and is carried to the central nervous system where it replicates and destroys the motor neuron cells. Motor neurons control the muscles for swallowing, circulation, respiration, and the trunk, arms, and legs.

Human nerve cells have a protruding protein structure on their surface whose precise function is unknown. When poliovirus encounters the nerve cells, the protruding receptors attach to the virus particle, and infection begins. Once inside the cell, the virus hijacks the cell’s assembly process, and makes thousands of copies of itself in hours. The virus kills the cell and then spreads to infect other cells.

Polio is spread through person-to-person contact. When a child is infected with wild poliovirus, the virus enters the body through the mouth and multiplies in the intestine. It is then shed into the environment through the feces where it can spread rapidly through a community, especially in situations of poor hygiene and sanitation. If a sufficient number of children are fully immunized against polio, the virus is unable to find susceptible children to infect, and dies out. Young children who are not yet toilet-trained are a ready source of transmission, regardless of their environment. Polio can be spread when food or drink is contaminated by feces. There is also evidence that flies can passively transfer polio virus from feces to food. Most people infected with the poliovirus have no signs of illness and are never aware they have been infected. These people with no symptoms carry the virus in their intestines and can “silently” spread the infection to thousands of others before the first case of polio paralysis emerges. For this reason, WHO considers a single confirmed case of polio paralysis to be evidence of an epidemic – particularly in countries where very few cases occur.

The signs and symptoms of Polio:

Most people infected with the poliovirus have no signs of illness and are never aware they have been infected.

These symptomless people carry the virus in their intestines and can “silently” spread the infection to thousands of others before the first case of polio paralysis emerges. For this reason, WHO considers a single confirmed case of polio paralysis to be evidence of an epidemic – particularly in countries where very few cases occur.

Most infected people (90%) have no symptoms or very mild symptoms and usually go unrecognized. In others, initial symptoms include fever, headache, vomiting, stiffness in the neck and pain in the limbs.

Polio is a viral infection!!!

There are three types of poliovirus and many strains of each type.

There are three types of wild poliovirus (WPV):

Type 1, Type 2, and Type 3.

People must protect themselves against all three types of the virus to prevent polio disease.

Polio vaccination is the best protection.  There are two vaccines used to protect against polio disease: oral polio vaccine and inactivated poliovirus vaccine.

Type 2 wild poliovirus was declared eradicated in September 2015. The last detection was in India, 1999.

Type 3 wild poliovirus was declared eradicated in October 2019. It was last detected in November 2012. Only type 1 wild poliovirus remains.

Presently the CDC states “Type 2 wild poliovirus was declared eradicated in September 2015. The last detection was in India, 1999. Type 3 wild poliovirus was declared eradicated in October 2019. It was last detected in November 2012. Only type 1 wild poliovirus remains.”.

TYPES:

Acute flaccid paralysis (AFP): One in 200 infections leads to irreversible paralysis, usually in the legs. This is caused by the virus entering the blood stream and invading the central nervous system. As it multiplies, the virus destroys the nerve cells that activate muscles. The affected muscles are no longer functional and the limb becomes floppy and lifeless – a condition known AFP = Acute Flaccid Paralysis.

 Know all cases of AFP among children under fifteen years old are reported and tested for poliovirus within 48 hours of onset.

All cases of acute flaccid paralysis (AFP) among children under fifteen years of age are reported and tested for poliovirus within 48 hours of onset.

Bulbar polio:  More extensive paralysis, involving the trunk and muscles of the thorax and abdomen, can result in   quadriplegia. In the most severe cases (bulbar polio), poliovirus attacks the nerve cells of the brain stem, reducing breathing capacity and causing difficulty in swallowing and speaking. Among those paralysed, 5% to 10% die when their breathing muscles become immobilized.

Risk factors for paralysis

No one knows why only a small percentage of infections lead to paralysis. Several key risk factors have been identified as increasing the likelihood of paralysis in a person infected with polio. These include:

• immune deficiency

• pregnancy

• removal of the tonsils (tonsillectomy)

• intramuscular injections, e.g. medications

• strenuous exercise

• injury.

Treatment and prevention

There is no cure for polio, only treatment to alleviate the symptoms.  Heat and physical therapy is used to stimulate the muscles and antispasmodic drugs are given to relax the muscles. While this can improve mobility, it cannot unfortunately reverse permanent polio paralysis.

Polio can be prevented through immunization. Polio vaccine, given multiple times, almost always protects a child for life.

“The first identified cases of Pontiac fever occurred in 1968 in Pontiac, Michigan, among people who worked at and visited the city’s health department.   The several workers at the county’s department of health came down with a fever and mild flu symptoms, but not pneumonia.  It wasn’t until Legionella was discovered after the 1976 Legionnaires’ disease outbreak in Philadelphia that public health officials were able to show that Legionella causes both diseases. The number of cases reported to CDC has been on the rise since 2000. Health departments reported nearly 10,000 cases of Legionnaires’ disease in the United States in 2018. However, because Legionnaires’ disease is likely underdiagnosed, this number may underestimate the true incidence. A recent study estimated that the true number of Legionnaires’ disease cases may be 1.8–2.7 times higher than what is reported.² More illness is usually found in the summer and early fall, but it can happen any time of year.”

Center for Disease Control and Prevention – CDC (https://www.cdc.gov/legionella/about/history.html)

Legionnaires’ disease and Pontiac fever outbreaks occur when two or more people are exposed to Legionella in the same place and get sick at about the same time!  Outbreaks are commonly associated with buildings or structures that have complex water systems, like hotels and resorts, long-term care facilities, hospitals, and cruise ships. These are high population environments

These structural places use water shared with other people from the main water line.  Examples apartment buildings, hospitals, cruise ships, etc…  The most likely sources of infection include water used for showering, hot tubs, decorative fountains, and cooling towers (structures that contain water and a fan as part of centralized air cooling systems for a building or industrial processes).

Legionnaires’ disease and Pontiac fever outbreaks can be difficult to identify. Sometimes people travel to a common location, are exposed to Legionella, and then return home before becoming sick. State, territorial, and local health departments take the lead in investigating outbreaks. They also identify control measures to remove Legionella from the water identified as the source of infection. CDC is only involved in outbreak investigations when a health department requests additional assistance. 

On July 17, 2015, the Bureau of Communicable Disease of the New York City (NYC) Department of Health and Mental Hygiene (DOHMH) detected an abnormal number and distribution of Legionnaires’ disease (LD) cases in the South Bronx. This cluster of cases would eventually grow into the largest outbreak of LD in NYC history.

PBS.org states that “New York City is facing the largest outbreak of Legionnaires’ disease in its history.

The airborne respiratory disease has killed 10 people since early July, with 100 cases reported. So far, it’s been limited to the city’s South Bronx neighborhood.”  So it is in contained area.

NYC.gov documents the following “In 2017, most Legionnaires’ disease cases (26%) occurred in Queens; however, the Bronx had the highest rate (7.0 cases per 100,000 people).”  So remember this is not new and at least yearly checked upon situation to prevent epidemics.  No panic is needed.

The CDC states today regarding the most recent information about Legionnaires is the following:

Legionella can cause Legionnaires’ disease and Pontiac fever, collectively known as legionellosis.

Scientists named the bacteria after an outbreak in Philadelphia in 1976. During that outbreak, many people who went to an American Legion convention got sick with pneumonia (lung infection).

Health departments reported nearly 10,000 cases of Legionnaires’ disease in the United States in 2018.¹ However, because Legionnaires’ disease is likely underdiagnosed, this number may underestimate the true incidence. A recent study estimated that the true number of Legionnaires’ disease cases may be 1.8–2.7 times higher than what is reported.²

About one in 10 people who gets sick from Legionnaires’ disease will die.^2,3

People can get Legionnaires’ disease or Pontiac fever when they breathe in small droplets of water in the air that contain Legionella.

In general, people do not spread Legionnaires’ disease to other people. However, this may be possible under rare circumstances.^3,4

Legionella occurs naturally in freshwater environments, like lakes and streams. It can become a health concern when it grows and spreads in human-made building water systems.”

(https://www.cdc.gov/legionella/fastfacts.html)

updated 11/21/2023 by Strive for Good Health

“Legionnaires’ disease is a multisystem disease which causes pneumonia due to gram-negative bacteria (Legionella spp.) found in freshwater environments around the world. Humans are infected by inhalation of aerosols containing Legionella. The infection can be fatal and outbreaks from a common environmental source can occur. Cases of Legionnaires’ disease are mainly reported in persons in older age groups, especially in males.  Legionellosis is an uncommon form of pneumonia. The disease has no particular clinical features that clearly distinguish it from other types of pneumonia, and laboratory investigations must be carried out to confirm the diagnosis. It normally takes between two to ten days to develop symptoms (typically five to six days) but very rarely some cases may take two to three weeks to develop symptoms.”

European Centre for Disease and Control (https://www.ecdc.europa.eu/en/legionnaires-disease/facts)

Who to Test for Legionnaires’ Disease:

·Patients who have failed outpatient antibiotic therapy

·Patients with severe pneumonia, in particular those requiring intensive care

·Immuno-compromised host with pneumonia

·Patients with pneumonia in the setting of a legionellosis outbreak

·Patients with a travel history [Patients that have traveled away from their home within two weeks before the onset of illness.]

·Patients suspected of healthcare-associated pneumonia

Diagnostic Tests done in checking for illness or infection of the lungs, in general:

Legionnaires’ disease is similar to other types of pneumonia. To help identify the presence of legionella bacteria quickly, your doctor may use a test that checks your urine for legionella antigens — foreign substances that trigger an immune system response. You may also have one or more of the following:

·Blood tests

·Chest X-ray, which doesn’t confirm Legionnaires’ disease but can show the extent of infection in your lungs

·Tests on a sample of your sputum or lung tissue

·A CT scan of your brain or a spinal tap (lumbar puncture) if you have neurological symptoms such as confusion or trouble concentrating.

How to test in particular for Legionnaires’ Disease Only:

·Urinary antigen assay & culture of respiratory secretions on selective media are the preferred diagnostic tests for Legionnaires’ disease

·Sensitivity varies depending on the quality and timing of specimen collection as well as technical skill of the laboratory performing the test.

TREATMENT:

·Legionnaires’ disease is treated with antibiotics. The sooner therapy is started, the less likely the chance of serious complications or death. In many cases, treatment requires hospitalization. Pontiac fever goes away on its own without treatment and causes no lingering problems.

LASTLY about “outbreaks of Legionnaire’s disease” are preventable, but prevention requires meticulous cleaning and disinfection of water systems, pools and spas.

Avoiding smoking is the single most important thing you can do to lower your risk of infection. Smoking increases the chances that you’ll develop Legionnaires’ disease if you’re exposed to legionella bacteria.

“Few people have heard of Pontiac fever, and yet most are aware of Legionnaires’ disease. It is intriguing therefore to discover that both illnesses are triggered by the same bacterium… called legionella. Pontiac fever is far milder and much less serious than Legionnaires’ disease. Indeed it may be possible for someone to contract Pontiac fever and assume they simply have the flu, since both present with very similar symptoms.  The main difference is pneumonia. Sufferers of Legionnaires’ disease will probably contract pneumonia and are therefore likely to require hospital treatment in order to make a successful recovery. This is why Legionnaires’ is more serious than Pontiac fever, which doesn’t present with this additional illness.  It is good to know that Pontiac fever is not as serious as Legionnaires’ disease. However it is still wise to identify it if at all possible. It may point to an outbreak of Legionnaires’ that could help others get more urgent treatment as a result.”

Legionella Control (https://legionellacontrol.com/legionella/pontiac-fever-legionnaires-disease/)