This resource is written in partnership with Freestate Healthcare.
Your child wakes you at 3 AM. She has a fever and feels sick, and as a parent, it’s difficult to know whether or not to seek emergency care. It often boils down to whether or not the cause is a bacterial or viral infection.
While there are rare, non-infectious diseases that cause fever, these are usually chronic problems best diagnosed by a primary or specialty doctor over time. If your child is not known to have one of these problems, fever usually means infection. Most infections are caused by viruses or bacteria.
How to Tell the Difference: Viral vs. Bacterial Infections
| Virus | Bacteria | |
| Fever
Note: Fever is the WORST way to differentiate because some viruses can cause high or prolonged fever (flu, mono, others), though most do not. |
Often less than 101. Lasts 1 or 2 days then stops. Sometimes there is no fever. | Often above 102, sometimes worse with time. Usually does not go away quickly or keeps coming back unless treatment started. |
| Symptom Location | Usually multiple body areas at once. Example: Runny nose, congestion, sore throat, earache, cough at the same time. | Usually just one area, or no obvious area. Example: High fever but no other symptoms. High fever with very sore throat. High fever with worsening cough but nothing else. |
| Symptoms Over Time | Usually start mild, get a little worse for a few days, then slowly get better. | May be severe and get worse quickly, e.g., “The worst sore throat I’ve ever had.” |
| Contagiousness | Spreads easily in the home. Example: “All of us are sick this week!” “His brother had it a few days ago and now he’s sick too!” | Rarely spreads easily in the home. It would be unusual (not impossible) for everyone in the family to get the same bacterial infection over a few days. |
| General Appearance | Most children will look fine in between episodes of fever, or even look fine despite running a fever. Example: 2-year-old with fever running around playing happily with a runny nose and cough. | Many children will feel worse and worse with time. Low energy, tired, weaker, sleeping more. Generally look and feel more sick. |
| Antibiotics | Will not help. Giving unnecessarily may also cause harm. | Usually help |
| Do I Need to Speak to a Doctor Quickly? | Usually not unless warning signs (see below). | Yes |
When to Seek Care Immediately:
No matter what type of infection you think your child has, if you see any of the following you should seek immediate medical attention:
- Change in Mental Status/Decrease in Alertness
- Difficulty Breathing
- Severe or worsening pain
- Rapid worsening of child’s overall condition
- ANY fever in a child less than 60 days old.
Are Antibiotics Needed?
If you decide to take your child to an urgent care or ER for possible infection, viral or bacterial, it is possible your child will receive an antibiotic.
For some infections even with initial testing it is not possible to tell for sure whether an antibiotic is needed. Since Urgent Cares and ERs usually do not have the ability to follow up or provide continuity of care they err on the side of caution (or treatment).
If you aren’t sure whether an antibiotic is needed, always ask the provider to explain their reasoning, or follow up with your primary care doctor for a second opinion as soon as possible.
This resource was written to serve as guidance on determining bacterial versus viral infections and should not be taken as concrete medical advice. As with any medical questions or concerns, please make an appointment with your primary care physician to discuss your own personal situation and treatment options.
Freestate Healthcare is meant to be the foundation for a new kind of healthcare delivery, built only to support excellent clinical medicine, and the needs of patients. Avoid expensive emergency room visits using our affordable 24/7 call service from the comfort of your home. Our providers can handle most problems as an outpatient, and provide follow up care as well. If you are thinking about going to urgent care or the ER, give us a call first.
