Kids get sick often, and while most illnesses are mild, it’s not always easy to know what kind of care they need. Not every cough or fever requires antibiotics, since these medicines only work against bacterial infections—not viral ones.
Understanding the difference can help you know what to expect, when antibiotics may be appropriate, and why your child’s doctor might recommend other ways to help kids feel better.
What Are Bacterial and Viral Infections?
Bacterial infections are caused by single-celled bacteria. Some common examples of pediatric bacterial infections include:
- Strep throat
- Some ear infections
- Certain skin infections
- Some sinus infections
Antibiotics can treat many (but not all) types of bacterial illnesses in children.
Viral infections, on the other hand, are caused by viruses that need our cells to grow and multiply. Examples of common viruses include:
- The common cold, which can be caused by more than 100 different viruses
- Influenza (the flu)
- RSV (Respiratory syncytial virus, which affects the lungs)
- COVID-19
- Chickenpox
- Adenovirus, which can cause cold symptoms, sore throats, conjunctivitis (pink eye), or bronchitis
- Rotavirus and norovirus, which cause “stomach bugs” and symptoms like diarrhea, nausea or vomiting
- Less commonly, measles and other serious viruses that children can be vaccinated against
Antibiotics don’t work for viruses.
Instead, care for viruses—in both children and adults—focuses on rest, fluids, and symptom relief, such as the use of pain relievers (like acetaminophen or ibuprofen).
Viruses are common and don’t necessarily require a visit to a doctor. For context, the average adult gets 2-3 colds per year, and children often have more, such as 6-8 each year.
Most colds, and even the flu, last about a week (or sometimes up to two weeks) and resolve on their own without a prescription. In addition to colds, many children have 1-2 other viruses each year.
Key Differences in Bacterial Infection Symptoms Vs. Virus Symptoms That You Might Notice
Here’s how symptoms behave depending on the type of illness:
- Viral symptoms: “All over” symptoms, often including runny or stuffy nose, cough, low-grade fever, body aches, fatigue and sore throat that come with nasal symptoms.
- Bacterial symptoms: More localized problems, such as severe sore throat, a single red/tender area on the skin or ear pain with a bulging eardrum.
A viral illness that improves, then gets worse again (such as causing a higher fever and new pain) might signal a secondary bacterial infection. When this happens, it’s time to call your pediatrician for an evaluation, as antibiotics may be needed.
How Infections and Viruses Spread
Viruses often spread through respiratory droplets and contaminated hands or surfaces.
Bacteria can spread in the same ways, but many bacterial problems (like strep throat or impetigo) rely more on close contact with secretions, including fluids released when someone sneezes or coughs, or sores on their skin.
How They’re Treated
Bacterial infections are usually treated with antibiotics (when indicated).
The right antibiotic, dose and duration matter. Finishing the full course is important in preventing relapse and resistance.
Using antibiotics when they’re not needed can cause side effects and fuel antibiotic resistance, which is a major health threat that causes more than 2.8 million resistant infections each year in the United States.
Viral infections are treated with supportive care, not antibiotics.
Antibiotics don’t treat viruses. Focus on fluids, rest, fever reducers (if needed), nasal saline or humidification, and patience when you or your child has a virus. Antivirals are used selectively (such as for the flu in higher-risk kids) based on a clinician’s advice.
Sometimes “watchful waiting” is the best approach when your child is sick.
For example, for some children with acute ear infections, doctors may recommend 2-3 days of observation with pain control before starting antibiotics, because many ear infections resolve on their own.
When to See the Doctor
Call your pediatrician (or seek urgent care) if your child has any of the following:
- Trouble breathing
- Fast breathing
- Unusual sleepiness
- Dehydration
- Fever lasting more than 5 days
- Symptoms that last more than 10 days without improving, or get better and then worsen
- Severe localized pain (ear, throat, sinus, chest), a stiff neck, or a new rash with fever
Why Antibiotic Stewardship Matters
Using antibiotics only when they’re truly needed protects your child from side effects and helps preserve antibiotic effectiveness for serious bacterial infections.
National data show that a substantial portion of outpatient antibiotic prescriptions are unnecessary or inappropriate, especially for viral respiratory illnesses. This is why it’s always okay to ask, “Is an antibiotic really needed here?”
Preventing Infections in Kids
- Handwashing is your family’s superpower. Use soap and water for 20 seconds, especially after blowing noses, before eating and after using the bathroom.
- Vaccinations (including flu and COVID-19 vaccinations as recommended) reduce the risk of severe viral infections and bacterial complications.
- Healthy habits—including getting good sleep, eating nutritious food and playing outdoors in fresh air—support a resilient immune system.
- Don’t share drinks or utensils, and teach kids to cover coughs/sneezes and to keep their hands away from their faces.
Most childhood illnesses are viral and get better with time and comfort care. Bacterial infections do occur and often need antibiotics, but only when truly indicated. If you’re unsure which your child has, your pediatrician can examine him or her, run tests if needed and tailor their treatment depending on the result.
When in doubt, reach out for help, as early evaluation can prevent complications and unnecessary medicines. At Stony Brook Children’s Services, our pediatric specialists are here to guide families through everything from everyday colds to more complex infections. We provide thorough evaluations, rapid testing when needed, and evidence-based treatment plans that put your child’s health and comfort first and help them recover as quickly as possible.
Call (631) 444-KIDS (5437) to schedule an appointment.
