Virus or bacteria: What’s causing my child’s illness?


Virus or bacteria: What’s causing my child’s illness?

It’s never fun to see children suffering from a hacking cough, runny nose, painful earache or fever.
Parents may wonder whether the illness was caused by a virus or bacteria, an important distinction because it makes a big difference in how the illness should be treated.
Bacteria are tiny, single-celled organisms that can live in almost any type of environment. The vast majority are harmless to humans.
Viruses, on the other hand, are parasitic so they can’t survive without a host. Much smaller and less complex than bacteria, most viruses do cause disease in humans.

How viruses and bacteria are spread

While bacteria and viruses are different, they are spread in similar ways, including:

  • Coughing or sneezing, which can release tiny droplets containing bacteria or viruses into the air. People nearby may breathe in those droplets.
  • Contact with contaminated surfaces. This can happen when you shake hands with someone who is ill or touch a surface, such a doorknob, that has a virus or bacteria on it, then touch your eyes, mouth or nose.

Antibiotics are effective only for bacterial infections

Only bacterial infections can be effectively treated with antibiotics. Children who are suffering an illness caused by bacteria will often begin to feel better 24-48 hours after they begin taking the medication.
“Antibiotics target the cell wall of bacteria,” says Dr. Michelle McCauley, a resident physician at Tidelands Health Family Medicine at Holmestown Road. “Viruses, meanwhile, don’t have a cell wall, so illnesses caused by a virus can’t be treated by antibiotics.”

How to recognize the difference between a viral and a bacteria-linked infection

To tell whether an illness is caused by a virus or bacteria and to make sure the illness is treated appropriately, McCauley advises making an appointment for your child with a pediatrician, family medicine physician or other qualified care provider, especially if the illness is accompanied by fever.

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  • Parents should seek medical care immediately if an infant younger than 3 months old develops a fever of 100.4 degrees or higher. Older children should be seen promptly if their fever reaches 103 degrees or higher.
    Otherwise, symptoms that warrant an appointment with a care provider include:
  • Excessive yellow or green mucus
  • Symptoms that last more than eight to 10 days
  • Congestion or headache that won’t go away

If a child has difficulty breathing or there are other signs of a more serious problem, seek immediate medical care, McCauley says.


To avoid getting either a viral or a bacterial infection, McCauley recommends paying close attention to hand hygiene.
“Maintaining good hand hygiene is perhaps the single-most important thing you can do to stop the spread of either type of illness,” she says.
She also recommends regularly disinfecting common surfaces such as doorknobs, toys and switches, and keeping your hands away from your mouth, eyes and nose.

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Dr. Michelle McCauley is a family medicine physician at Tidelands Health Family Medicine at Andrews. She is accepting new patients.

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