Pediatric Infectious Disease

These infections are frequently or exclusively caused by bacteria. While most bacteria are harmless to humans and some are even helpful (such as bacteria that help with food digestion), several can cause illnesses. These include:

Abdominal abscesses

Pockets of infected fluid, called pus, that form in the tissues or organs of the belly (such as stomach, kidneys, liver, or pancreas).

Bone and joint infections

Young children can be vulnerable to infections of the bone (osteomyelitis) or joint tissues (septic arthritis). They are usually caused by infections of staph bacteria.

Cellulitis

Skin infection that usually affects the lower leg and can cause painful red rashes that are warm to the touch.

Central nervous system infections

This includes a variety of brain and spinal cord conditions, such as bacterial infection of the protective layer around these tissues (bacterial meningitis) and pus-filled abscesses in the brain.

Clostridioides difficile (C. diff)

This highly contagious bacteria can damage the large intestine and cause severe and sometimes bloody diarrhea, abdominal pain, vomiting, and other symptoms. Taking certain antibiotics, often for an unrelated bacterial infection, can increase the risk of C. diff infection.

Complicated pneumonia

Severe lung infection (pneumonia) that causes additional complications, such as significant buildup of pus in the spaces surrounding the lungs (pleural empyema).

Complicated urinary tract infections (complicated UTIs)

This includes UTIs that are especially difficult to treat (for example, because they were caused by a drug-resistant bacteria or affect the upper part of the urinary tract) or are likely to make symptoms (such as pain when urinating, belly pain, and fever) more severe than with a typical UTI.

Endocarditis

Infection of the inner lining of the heart.

Methicillin-resistant Staphylococcus aureus (MRSA)

Skin infections caused by a type of bacteria that is especially resistant to antibiotics. It is spread through skin-to-skin contact or touching contaminated items or surfaces. The affected area of skin may be red, swollen, painful, or filled with pus.

Recurrent infections

Infections are recurrent if they keep returning multiple times in a relatively short period of time. Children are often susceptible due to having underdeveloped immune systems and frequent opportunities for exposure (for example, being at school).

Recurrent sinopulmonary infections

Recurrent infections that target the lungs or sinuses, which can result in coughing, chest tightness, or difficulty breathing.

Surgical-site infections

Redness, pus, warmth in the infected area, or other signs of infection can develop if bacteria enter the body through surgical incisions.

Tuberculosis (TB)

Infection by a type of bacteria that primarily affects the lungs and can cause coughing, chest pain, difficulty breathing, fever, loss of appetite, and other symptoms.

These infections are frequently or exclusively caused by fungi, which are organisms (including various types of mold, yeast, and mushrooms) that grow by breaking down and absorbing organic material in their surrounding environment. Examples include:

Fungal pneumonia

Lung infections caused by fungi, usually after a child breathes in airborne fungal spores.

Histoplasmosis

Infections caused by the Histoplasma fungus, which can be thrown into the air and breathed in when tainted soil is disturbed (for example, by construction). Severe histoplasmosis can cause heart and lung damage.

Lung nodules

Some types of fungi can cause small masses of tissue, called nodules, to form in the lungs. This most often occurs when someone with a weakened immune system breaths in fungal spores present in the environment.

Vector-borne diseases occur when an infected organism passes germs or parasites to a human. The most common way this happens is through insect bites. Examples include:

Lyme disease

This bacterial infection is usually caused by a tick bite. Early symptoms include a circular red rash that slowly expands from the bite site, as well as fever, headache, fatigue, and joint pain. If untreated, symptoms can become more severe and affect more parts of the body.

Malaria

This condition is caused when parasites enter the bloodstream after a bite from an infected mosquito. It is common in tropical and subtropical climates. Symptoms typically begin within a few weeks of a bite and can include fever and chills, nausea, diarrhea, fatigue, and pain.

The root causes of these conditions are often complex and not fully understood. However, they are more likely to develop in children who have recently experienced a viral, bacterial, or fungal infection. Examples include:

Chronic fatigue syndrome (myalgic encephalomyelitis)

Constant, extreme tiredness that does not fully improve with rest, typically lasting for at least six months. It may be triggered by viral infections, recurrent infections of varying origins, or any other conditions that strain the immune system.

Kawasaki disease

Swelling of small blood vessels in young children, which can lead to additional symptoms like fever, swollen hands, and red eyes. It typically affects children under age 5, often after a viral infection.

Myositis

In this condition, the immune system mistakenly attacks muscle tissue, which can cause muscle weakness, pain, fatigue, and even irregular heartbeat if the heart muscle is affected.

These infections are frequently or exclusively caused by viruses, which are sub-microscopic germs much smaller than bacteria. They spread by taking control of living cells and making copies of themselves in a host organism. Examples include:

Fever of unknown origin

Elevated body temperature for an extended period of time — commonly defined as more than three weeks — for which the cause still remains unknown after the first medical evaluation. There are hundreds of possible root causes, with viral infection the most common one.

Hepatitis B

Liver infection caused by the hepatitis B virus (HBV). Symptoms can include abdominal pain, dark urine, nausea, and yellowing of eyes and skin (jaundice). Young children who contract HBV are more likely than adults to develop long-term symptoms and chronic liver damage later in life.

Hepatitis C

Liver infection caused by the hepatitis C virus (HCV). This condition damages the liver over time, but symptoms may not be noticeable for years or decades, after liver damage is already significant.

Human immunodeficiency virus (HIV)

This virus gradually destroys the cells of the immune system, weakening it over time. In time, it can progress to acquired immune deficiency syndrome (AIDS), in which the immune system is so weak that even minor infections can cause prolonged illnesses and complications. However, regular HIV treatment can significantly improve immune system function and greatly reduce the risk of developing AIDS.

Myocarditis

Inflammation of the heart muscle tissue.

Pericarditis

Inflammation of the pericardium, a fluid-filled sac that surrounds and protects the heart.

Recurrent fever

Multiple fevers that occur over a relatively short period of time (for example, one or more multi-day fevers per month). Often there is no obvious initial cause, though viral infection is the most likely culprit.

Our team provides specialized testing and care for children who are at increased risk of developing serious infections or complications — for example, due to recent life events or underlying health conditions of the child or mother. These include:

Congenital and perinatal infections

These infections are transmitted to a child from a mother during pregnancy (congenital) or during labor and delivery (perinatal). Examples include hepatitis C (which causes liver damage), congenital syphilis (which can lead to significant, lifelong health challenges), and cytomegalovirus (which can increase the risk of developmental delays and future hearing loss).

Infections in immune-compromised children

Children with conditions that weaken their immune systems are more susceptible to infections and may require specialized care for relatively common infections (such as influenza or UTIs) that children with healthy immune systems overcome more easily.

Infections in international adoptees

Adopted children who enter the U.S. from foreign countries may be at increased risk of various parasitic, viral, or bacterial infections for many reasons, such as high infection rates, lack of appropriate vaccines, or lack of screening tests in their countries of origin.

Infections related to cancer

Certain infections can affect the structure or function of DNA and increase a child’s future risk of developing cancer. Additionally, children with cancer are often more likely to develop various infections due to a compromised immune system.

Travel-related infections

Traveling to other countries or regions can expose individuals to infectious diseases that are common in those regions due to differences in climate, lack of sanitation, or other factors. Examples include malaria (spread through mosquito bites) or intestinal parasites acquired by eating or drinking contaminated food or water.