Pneumonia in Immunocompromised Patients: Overview, Causes of Pneumonia, HIV/AIDS

Everything You Need To Know About Pneumonia

Pneumonia is an infection caused by bacteria, viruses, or fungi. It leads to inflammation in the air sacs of one or both lungs. These sacs, called alveoli, fill with fluid or pus, making it difficult to breathe.

Both viral and bacterial pneumonia is contagious. This means they can spread from person to person through inhalation of airborne droplets from a sneeze or cough.

You can also get these types of pneumonia by coming into contact with surfaces or objects that are contaminated with pneumonia-causing bacteria or viruses.

You can contract fungal pneumonia from the environment. It does not spread from person to person.

Pneumonia is further classified according to where or how it was acquired:

Hospital-acquired pneumonia (HAP). This type of bacterial pneumonia is acquired during a hospital stay. It can be more serious than other types, as the bacteria involved may be more resistant to antibiotics.

Community-acquired pneumonia (CAP). This refers to pneumonia that's acquired outside of a medical or institutional setting.

Ventilator-associated pneumonia (VAP). When people who are using a ventilator get pneumonia, it's called VAP.

Aspiration pneumonia. Inhaling bacteria into your lungs from food, drink, or saliva can cause aspiration pneumonia. It's more likely to occur if you have a swallowing problem, or if you're too sedated from the use of medications, alcohol, or other drugs.

Walking pneumonia

Walking pneumonia is a milder case of pneumonia. People with walking pneumonia may not even know they have pneumonia. Their symptoms may feel more like a mild respiratory infection than pneumonia. However, walking pneumonia may require a longer recovery period.

The symptoms of walking pneumonia can include things like:

mild fever

dry cough lasting longer than a week

chills

shortness of breath

chest pain

reduced appetite

Viruses and bacteria, like Streptococcus pneumoniae or Haemophilus influenzae, often cause pneumonia. However, in walking pneumonia, the bacteria Mycoplasma pneumoniae most commonly causes the condition.

Learn more about pneumonia during pregancy (maternal pneumonia).

Pneumonia may be classified based off the area of the lungs it's affecting:

Bronchopneumonia

Bronchopneumonia can affect areas throughout both of your lungs. It's often localized close to or around your bronchi. These are the tubes that lead from your windpipe to your lungs.

Lobar pneumonia

Lobar pneumonia affects one or more lobes of your lungs. Each lung is made of lobes, which are defined sections of the lung.

Lobar pneumonia can be further divided into four stages based off how it's progressed:

Congestion. Lung tissue appears heavy and congested. Fluid filled with infectious organisms has accumulated in the air sacs.

Red hepatization. Red bloods cells and immune cells have entered into the fluid. This makes the lungs appear red and solid in appearance.

Gray hepatization. The red blood cells have begun to break down while immune cells remain. The breakdown of red blood cells causes a change in color, from red to gray.

Resolution. Immune cells have begun to clear the infection. A productive cough helps eject remaining fluid from the lungs.

Pneumonia symptoms can be mild to life threatening. They can include:

coughing that may produce phlegm (mucus)

fever

sweating or chills

shortness of breath that happens while doing normal activities, or even while resting

chest pain that's worse when you breathe or cough

feelings of tiredness or fatigue

loss of appetite

nausea or vomiting

headaches

Other symptoms can vary according to your age and general health:

Infants may appear to have no symptoms, but sometimes they may vomit, lack energy, or have trouble drinking or eating.

Children under 5 years old may have fast breathing or wheezing.

Older adults may have milder symptoms. They can also experience confusion or a lower-than-normal body temperature.

Pneumonia happens when germs get into your lungs and cause an infection. The immune system's reaction to clear the infection results in inflammation of the lung's air sacs (alveoli). This inflammation can eventually cause the air sacs to fill up with pus and liquids, causing pneumonia symptoms.

Several types of infectious agents can cause pneumonia, including bacteria, viruses, and fungi.

Bacterial pneumonia

The most common cause of bacterial pneumonia is Streptococcus pneumoniae. Other causes include:

Viral pneumonia

Respiratory viruses are often the cause of pneumonia. Examples of viral infections that can cause pneumonia include:

Although the symptoms of viral and bacterial pneumonia are very similar, viral pneumonia is usually milder. It can improve in 1 to 3 weeks without treatment.

According to the National Heart, Lung, and Blood Institute, people with viral pneumonia are at risk of developing bacterial pneumonia.

Fungal pneumonia

Fungi from soil or bird droppings can cause pneumonia. They most often cause pneumonia in people with weakened immune systems. Examples of fungi that can cause pneumonia include:

Pneumocystis jirovecii

Cryptococcus species

Histoplasmosis species

Coccidioides species

Risk factors

Anyone can get pneumonia, but certain groups do have a higher risk. These groups include:

infants from birth to 2 years old

people ages 65 and older

people with weakened immune systems due to:

pregnancy

HIV

the use of certain medications, such as steroids or certain cancer drugs

people with certain chronic medical conditions, such as:

people who've been recently or are currently hospitalized, particularly if they were or are on a ventilator

people who've had a brain disorder, which can affect the ability to swallow or cough, such as:

stroke

head injury

dementia

Parkinson's disease

people who've been regularly exposed to lung irritants, such as air pollution and toxic fumes, especially on the job

people who live in a crowded living environment, such as a prison or nursing home

people who smoke, which makes it more difficult for the body to get rid of mucus in the airways

people who use drugs or drink heavy amounts of alcohol, which weakens the immune system and increases the odds of inhaling saliva or vomit into the lungs due to sedation

Your doctor will start by taking your medical history. They'll ask you questions about when your symptoms first appeared and your health in general.

They'll then give you a physical exam. This will include listening to your lungs with a stethoscope for any abnormal sounds, such as crackling.

Depending on the severity of your symptoms and your risk of complications, your doctor may also order one or more of these tests:

Chest X-ray

An X-ray helps your doctor look for signs of inflammation in your chest. If inflammation is present, the X-ray can also inform your doctor about its location and extent.

Blood culture

This test uses a blood sample to confirm an infection. Culturing can also help identify what may be causing your condition.

Sputum culture

During a sputum culture, a sample of mucus is collected after you've coughed deeply. It's then sent to a lab to be analyzed to identify the cause of the infection.

Pulse oximetry

A pulse oximetry measures the amount of oxygen in your blood. A sensor placed on one of your fingers can indicate whether your lungs are moving enough oxygen through your bloodstream.

CT scan

CT scans provide a clearer and more detailed picture of your lungs.

Fluid sample

If your doctor suspects there's fluid in the pleural space of your chest, they may take a fluid sample using a needle placed between your ribs. This test can help identify the cause of your infection.

Bronchoscopy

A bronchoscopy looks into the airways in your lungs. It does this using a camera on the end of a flexible tube that's gently guided down your throat and into your lungs.

Your doctor may do this test if your initial symptoms are severe, or if you're hospitalized and not responding well to antibiotics.

If you need help finding a primary care doctor, then check out our FindCare tool here.

Your treatment will depend on the type of pneumonia you have, how severe it is, and your general health.

Prescription medications

Your doctor may prescribe a medication to help treat your pneumonia. What you're prescribed will depend on the specific cause of your pneumonia.

Oral antibiotics can treat most cases of bacterial pneumonia. Always take your entire course of antibiotics, even if you begin to feel better. Not doing so can prevent the infection from clearing, and it may be harder to treat in the future.

Antibiotic medications don't work on viruses. In some cases, your doctor may prescribe an antiviral. However, many cases of viral pneumonia clear on their own with at-home care.

Antifungal medications are used to treat fungal pneumonia. You may have to take this medication for several weeks to clear the infection.

OTC medications

Your doctor may also recommend over-the-counter (OTC) medications to relieve your pain and fever, as needed. These may include:

Your doctor may also recommend cough medicine to calm your cough so you can rest. Keep in mind coughing helps remove fluid from your lungs, so you don't want to eliminate it entirely.

Home remedies

Although home remedies don't actually treat pneumonia, there are some things you can do to help ease symptoms.

Coughing is one of the most common symptoms of pneumonia. Natural ways to relieve a cough include gargling salt water or drinking peppermint tea.

Cool compresses can work to relieve a fever. Drinking warm water or having a nice warm bowl of soup can help with chills. Here are more home remedies to try.

You can help your recovery and prevent a recurrence by getting a lot of rest and drinking plenty of fluids.

Although home remedies can help ease symptoms, it's important to stick to your treatment plan. Take any prescribed medications as directed.

Hospitalization

If your symptoms are very severe or you have other health problems, you may need to be hospitalized. At the hospital, doctors can keep track of your heart rate, temperature, and breathing. Hospital treatment may include:

antibiotics injected into a vein

respiratory therapy, which involves delivering specific medications directly into the lungs, or teaching you to perform breathing exercises to maximize your oxygenation

oxygen therapy to maintain oxygen levels in your bloodstream (received through a nasal tube, face mask, or ventilator, depending on severity)

Pneumonia may cause complications, especially in people with weakened immune systems or chronic conditions, such as diabetes.

Complications may include:

Worsened chronic conditions. If you have certain preexisting health conditions, pneumonia could make them worse. These conditions include congestive heart failure and emphysema. For certain people, pneumonia increases their risk of having a heart attack.

Bacteremia. Bacteria from the pneumonia infection may spread to your bloodstream. This can lead to dangerously low blood pressure, septic shock, and, in some cases, organ failure.

Lung abscesses. These are cavities in the lungs that contain pus. Antibiotics can treat them. Sometimes they may require drainage or surgery to remove the pus.

Impaired breathing. You may have trouble getting enough oxygen when you breathe. You may need to use a ventilator.

Acute respiratory distress syndrome. This is a severe form of respiratory failure. It's a medical emergency.

Pleural effusion. If your pneumonia isn't treated, you may develop fluid around your lungs in your pleura, called pleural effusion. The pleura are thin membranes that line the outside of your lungs and the inside of your rib cage. The fluid may become infected and need to be drained.

Kidney, heart, and liver damage. These organs may be damaged if they don't receive enough oxygen, or if there's an overreaction of the immune system to the infection.

Death. In some cases, pneumonia can be fatal. According to the CDC, nearly 44,000 people in the United States died from pneumonia in 2019.

In many cases, pneumonia can be prevented.

Vaccination

The first line of defense against pneumonia is to get vaccinated. There are several vaccines that can help prevent pneumonia.

Prevnar 13 and Pneumovax 23

These two pneumonia vaccines help protect against pneumonia and meningitis caused by pneumococcal bacteria. Your doctor can tell you which one might be better for you.

Prevnar 13 is effective against 13 types of pneumococcal bacteria. The CDC recommends this vaccine for:

children under age 2

people between ages 2 and 64 with chronic conditions that increase their risk of pneumonia

adults ages 65 and older, on the recommendation of their doctor

Pneumovax 23 is effective against 23 types of pneumococcal bacteria. The CDC recommends it for:

adults ages 65 and older

adults ages 19 to 64 who smoke

people between ages 2 and 64 with chronic conditions that increase their risk of pneumonia

Flu vaccine

Pneumonia can often be a complication of the flu, so be sure to also get an annual flu shot. The CDC recommends that everyone ages 6 months and older get vaccinated, particularly those who may be at risk of flu complications.

Covid vaccine

COVID-19 can lead to pneumonia. The CDC recommends that everyone 6 months and older should receive an updated COVID-19 vaccine.

Hib vaccine

This vaccine protects against Haemophilus influenzae type b (Hib), a type of bacterium that can cause pneumonia and meningitis. The CDC recommends this vaccine for:

all children under 5 years old

unvaccinated older children or adults who have certain health conditions

people who've gotten a bone marrow transplant

According to the National Heart, Lung, and Blood Institute, pneumonia vaccines won't prevent all cases of the condition.

But if you're vaccinated, you're likely to have a milder and shorter illness as well as a lower risk of complications.

Other prevention tips

In addition to vaccination, there are other things you can do to avoid pneumonia:

If you smoke, try to quit. Smoking makes you more susceptible to respiratory infections, especially pneumonia.

Regularly wash your hands with soap and water for at least 20 seconds.

Cover your coughs and sneezes. Promptly dispose used tissues.

Maintain a healthy lifestyle to strengthen your immune system. Get enough rest, eat a balanced diet, and get regular exercise.

Together with vaccination and additional prevention steps, you can help reduce your risk of getting pneumonia. Here are even more prevention tips.

A variety of infectious agents cause pneumonia. With proper recognition and treatment, many cases of pneumonia can be cleared without complications.

For bacterial infections, stopping your antibiotics early can cause the infection to not clear completely. This means your pneumonia could come back.

Stopping antibiotics early can also contribute to antibiotic resistance. Antibiotic-resistant infections are more difficult to treat.

Viral pneumonia often resolves in 1 to 3 weeks with at-home treatment. In some cases, you may need antivirals.

Antifungal medications treat fungal pneumonia. It may require a longer period of treatment.

Pneumonia can become dangerous quickly, particularly in young children. Here's how to avoid complications.

Most people respond to treatment and recover from pneumonia. Like your treatment, your recovery time will depend on the type of pneumonia you have, how severe it is, and your general health.

A younger person may feel back to normal in a week after treatment. Others may take longer to recover and may have lingering fatigue. If your symptoms are severe, your recovery may take several weeks.

Consider taking these steps to aid in your recovery and help prevent complications from occurring:

Stick to the treatment plan your doctor has developed, and take all medications as instructed.

Make sure to get plenty of rest to help your body fight the infection.

Drink plenty of fluids.

Ask your doctor when you should schedule a follow-up appointment. They may want to perform another chest X-ray to make sure your infection has cleared.

Pneumonia is a lung infection caused by bacteria, viruses, or fungi. The immune system's reaction to this infection causes the lung's air sacs to fill with pus and fluids. This leads to symptoms such as trouble breathing, a cough with or without mucus, fever, and chills.

To diagnose pneumonia, your doctor will do a physical exam and discuss your medical history. They may recommend further testing, such as a chest X-ray.

Treatment depends on the cause of the infection. It may involve antibiotics, antiviral medication, or antifungal medication.

Pneumonia often clears up in a few weeks. See a doctor right away if your symptoms get worse, as you may need to be hospitalized to prevent or treat more serious complications.

What's Going Around: Walking Pneumonia, Colds, Strep

WellSpan Pediatric Medicine Physicians across the Midstate are seeing enterovirus, the common cold, strep throat and metapneumovirus, which is in the same virus family as RSV.

This week, pediatricians at Penn State Health Children's Hospital are seeing some colds, stomach bugs, and allergies.

This week, the providers at UPMC Children's Community Pediatrics in York and Spring Grove continue to see many cases of viral illnesses.

Penn Medicine Lancaster General Health Physicians Roseville Pediatrics reports a sharp increase in walking pneumonia and infections caused by mycoplasma, a specific type of bacteria. These infections have included intense, wet-sounding cough, fevers, fatigue, and congestion. In children with asthma, they have seen these infections trigger asthma exacerbations as well.

Strep throat is still being seen in high numbers. Outdoor-related diagnoses of poison ivy and swimmer's ear have increased. They are still seeing decent numbers of viral colds, including enterovirus and adenovirus.

Dr. Joan Thode offered the following advice on walking pneumonia:

"Walking pneumonia is the more commonly heard term to describe atypical pneumonia, which refers to an infectious inflammatory process dispersed throughout the lungs rather than localized in a small single area of the lungs. The term atypical pneumonia references the mycoplasma bacteria that cause the pneumonia, not that the pneumonia or the patient are atypical. What makes the bacteria not typical is its lack of a cell wall, making antibiotic choice very important.

With walking pneumonia, symptoms tend to be much more mild, allowing a person to walk around with it and not realize, especially in the beginning of the course. This type of pneumonia is more common in the school-aged and teen pediatric populations than in young children and toddlers.

Walking pneumonia and the common cold can have overlapping symptoms of fever, headache, loss of appetite, and of course, cough. The cough tends to be much worse with pneumonia. The immune system of the lungs will attack the bacterial infection, which causes production of mucous. The cough with pneumonia will frequently sound wet due to this increased mucous. Even after the bacteria is killed by the immune system and antibiotics, the accumulated mucus needs to be cleared, so the cough can sometimes persist for a week after the acute infection is gone.

For walking pneumonia, antibiotics are typically prescribed. The choice of medication and dose will depend on the individual child's exam findings and weight. Pneumonias are contagious, though it is harder to spread a walking pneumonia than a more typical pneumonia."

Lack Of Gut Bacteria Diversity Linked To Higher Risk Of Severe Infections

This illustration depicts a photomicrographic view of Streptococcus (Diplococcus) pneumoniae ... [+] bacteria, using Gram-stain technique, 1979. Streptococcus pneumoniae is one of the most common organisms causing respiratory infections such as pneumonia and sinusitis, as well as bacteremia, otitis media, meningitis, peritonitis and arthritis. Streptococci. Image courtesy CDC. (Photo by Smith Collection/Gado/Getty Images).

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A higher abundance of beneficial bacteria in your intestines not only protects you from stomach issues but is also associated with an added layer of protection against severe infections like pneumonia, according to a new study published in The Lancet Microbe.

"Higher abundance of anaerobic butyrate-producing bacteria was associated with protection against severe infections, even when adjusted for demographics, lifestyle, antibiotic exposure, and comorbidities," the authors wrote in the study. Butyrate is a fatty acid that is produced when microbes residing in the lower intestinal tract ferment dietary fibers. Because human beings' intestinal systems are incapable of digesting dietary fiber on their own, we rely on our gut microbiome to do the job for us. In the past, mice studies have revealed that bacteria known to produce butyrate boost the immune system. This is because butyrate is known to induce the production of antimicrobial peptides, which in turn prevents pathogens from colonizing the lungs or even the bladder, thereby limiting tissue damage in those organs.

In 2019, the Global Burden of Disease study estimated that around 25% of all deaths that occurred across the globe were because of pathogens. Studies are now proving that even before antibiotic treatments, hospitalized patients display disruptions in their gut microbiome — which allows pathogenic bacteria to flourish.

To investigate further and delve into whether or not people with fewer butyrate-producing bacteria in their gut are at a higher risk of being hospitalized due to an infection, researchers based in the Netherlands and Finland observed 10,000 people for six years.

After collecting their stool samples and analyzing 16 different types of gut bacteria, they found that 600 people who had suffered from a severe infection — due to which they were hospitalized — had lower levels of butyrate-producing bacteria residing in their intestines compared to the other 9,400 study participants.

In a press release, study author Robert Kullberg from Amsterdam University Medical Center said: "But we didn't know whether the less healthy gut flora is due to the acute infection and its treatment or whether they have always had less of the butyrate-producing bacteria in their microbiome," says PhD student Bob Kullberg. "The study now answers this chicken-and-egg question. We saw that in people who have 10% more of those bacteria in their gut, the chance of getting an infection decreases by as much as 15 to 25%.

The researchers further warned that the use of certain types of antibiotics that target bacteria that can survive without oxygen (also known as anaerobic antibiotics) could result in the growth of a pathogen called Enterobacteriaceae in the gut because those antibiotics kill butyrate-producing gut microbiota. They advised clinicians to reconsider the widespread usage of anaerobic antibiotics for that reason.

"We showed that gut microbiome composition, specifically colonization with anaerobic butyrate-producing bacteria, was associated with a reduced risk of hospitalization for infectious diseases. This study defines potential opportunities for interventional studies evaluating gut microbiota-directed therapies (such as targeted delivery of butyrate-producing bacteria or limiting gut anaerobe depletion) aiming to decrease the susceptibility to systemic infections," the authors concluded.

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