How to Tell the Difference Between the Flu and a Cold?

SUMMARY:  

The CDC provides information on how to discriminate between the flu and the ‘common cold’. Both conditions are viral in origin. Co-infection with bacteria is possible and in the case of infection with influenza virus, can lead to significant and serious complications.  

‘Signs and Symptoms’ Comparisons

Influenza Cold
Symptom onset Abrupt Gradual
Fever Usual Rare
Aches Usual Slight
Chills Fairly common Uncommon
Fatigue, weakness Usual Sometimes
Sneezing Sometimes Common
Stuffy nose Sometimes Common
Sore throat Sometimes Common
Chest discomfort, cough Common Mild to moderate
Headache Common Rare

Credit: Centers for Disease Control and Prevention

KEY POINTS:  

Flu Symptoms  

Patient may experience just a few or many 

  • Fever or feeling feverish/chills 
  • Cough 
  • Sore throat 
  • Runny or stuffy nose 
  • Muscle or body aches 
  • Headaches 
  • Fatigue (tiredness) 
  • Some people may have vomiting and diarrhea, though this is more common in children than adults

Note: Not everyone with flu will have a fever

Flu Complications 

  • Moderate complications 
    • Sinus and ear infections  
  • Serious flu complications (can result from either influenza virus infection alone or from co-infection of flu virus and bacteria) 
    • Pneumonia 
    • Heart inflammation (myocarditis) 
    • Brain inflammation (encephalitis)  
    • Muscle inflammation (myositis, rhabdomyolysis)  
    • Multi-organ failure (e.g., respiratory and kidney failure) 
    • Sepsis 
    • Exacerbation of chronic medical problems  
      • Asthma attacks  
      • Worsening of heart disease  

High Risk Categories  

The following are at high risk of complications related to influenza virus infection 

  • Young children 
  • Adults aged 65 years and older  
  • Pregnant women are at especially high risk 

Note: To see the comprehensive list of high risk flu categories (and more), see the CDC Emergency Advisory below in the ‘Related ObG Topics’ section

Learn More – Primary Sources:  

CDC: What is the difference between a cold and the flu?

CDC: Information for Health Professionals

CDC Guidelines on the Prevention and Control of Influenza in Pregnancy

SUMMARY:  

The CDC has released guidance for managing pregnant women who have suspected or confirmed flu. Of note, pregnant women are considered to be in the high-risk category.

Pre-Delivery 

Suspected or laboratory-confirmed influenza  

  • Place in a private room on Droplet Precautions 
    • If patient is hospitalized, continue Droplet Precautions for 7 days after illness onset or until 24 hours after the resolution of fever and respiratory symptoms, whichever is longer 
    • Discharge patient from medical care when clinically appropriate, not based on the period of potential virus shedding or recommended duration of Droplet Precautions 
  • Instruct patient to follow respiratory hygiene and cough etiquette, including wearing a facemask, if being transported outside of her room 
  • Health care personnel entering rooms of pregnant women with suspected or confirmed influenza should adhere to Standard and Droplet Precautions, which include  
    • Donning a facemask upon entry into the room 
    • Performing hand hygiene 
    • Wearing gloves for any contact with potentially infectious materials 
    • Wearing gowns for any patient-care activity where contact with body fluids may occur 
  • Patient and visitor education  
    • Inform regarding the risks of influenza virus transmission  
    • Instruct about adherence to respiratory hygiene and cough etiquette, hand hygiene, and use of personal protective equipment (PPE) according to current facility policy 

During Delivery 

Suspected or confirmed influenza, on labor & delivery floor  

  • Patient should remain on Droplet Precautions 
  • Health care personnel on labor & delivery should adhere to Standard and Droplet Precautions, including practicing hand hygiene before and after handling the newborn 

After Delivery 

To reduce the risk of influenza virus transmission to the newborn 

  • Consider temporarily separating the mother who is ill with suspected or confirmed influenza from her baby following delivery during the hospital stay 
  • Discuss the risks and benefits of temporary separation with the mother  
    • Ideal setting for care of a healthy term newborn while in the hospital is within the mother’s room 
    • Newborns infected with influenza virus are at increased risk for severe complications 
  • Decisions about temporary separation should be made in accordance with the mother’s wishes 
  • Throughout the course of temporary separation 
    • Feedings should be provided by a healthy caregiver if possible 
    • Mothers should be encouraged to express their milk to establish and maintain milk supply 
    • Expressed breastmilk should be fed to the newborn 
  • Because the ideal length of temporary separation in the hospital is not yet established, assess on a case-by-case basis and consider the following in the decision process  
    • Risk/benefit factors  
    • If the mother has been afebrile without antipyretics for >24 hours 
    • Whether the mother can control her cough and respiratory secretions 
  • If co-location (“rooming in”) of the newborn with his/her ill mother in the same hospital room, limit influenza-virus exposure of the newborn using the following strategies  
    • Use engineering controls like physical barriers (e.g., a curtain between the mother and newborn) 
    • Keep the newborn ≥6 feet away from the ill mother 
    • Ensure a healthy adult is present to care for the newborn 
    • If no other healthy adult is present in the room to care for the newborn 
      • Instruct the mother to put on a facemask and practice hand hygiene before each feeding or other close contact with her newborn 
      • Retain use of facemask during contact with the newborn  
      • Continue these practices while on Droplet Precautions in the hospital 
  • Once contact between mother and newborn is resumed 
    • Droplet Precautions for influenza should continue to be observed in the hospital until at least 7 days after maternal illness onset 

Nursery 

If a newborn of a mother with suspected or confirmed influenza is in the nursery  

  • Newborn care can be provided by a non-ill person using Standard Precautions and the newborn should be closely observed for signs of infection 
  • Symptomatic mothers, care givers, and family members should not enter the nursery 
  • If a newborn develops signs of the flu, place on Droplet Precautions and have the newborn examined by a physician 
    • Test for influenza  
    • Consider oseltamivir treatment 

KEY POINTS:  

Treatment  

CDC considers women who are pregnant or postpartum (within 2 weeks after delivery) to be at high-risk  

  • CDC recommends starting oseltamivir treatment as soon as possible for 
    • Hospitalized patients with suspected or confirmed influenza 
    • High-risk outpatients with suspected or confirmed influenza 
  • Administer antiviral treatment as early as possible   
    • Ideally, within 48 hours of symptom onset  
    • Do not delay treatment even for a few hours while awaiting test results 
    • Treatment initiation even after 48 hours can still be beneficial   
  • Adult dose for oseltamivir is 75 mg twice daily for 5 days

Visitors

  • Visitors should be limited to persons who are necessary for patient’s care/wellbeing   
  • Visitors who have been in contact with an infected patient before and during her hospitalization are a possible source of influenza for other patients, visitors, and staff 
  • Screen all visitors for acute respiratory illness  
    • Only allow asymptomatic individuals to visit 
    • Instruct visitors to limit their movement within the facility 
  • Facilities should provide instruction, before visitors enter patients’ rooms, on proper hygiene and procedures 

Before Hospital Discharge 

  • Strongly encourage and, if possible, provide the flu vaccination to 
    • Any unvaccinated family members aged 6 months and older  
    • Caregivers in contact with the newborn 
  • Advise caregivers that they should 
    • Contact their health care provider promptly if the newborn develops signs that suggest a flu infection 
    • Isolate any individuals in the home who become ill to protect the newborn 
    • Ensure that the ill postpartum woman follows hand hygiene and respiratory hygiene and cough etiquette when having contact with her newborn 
  • Caregivers, if possible, should be limited to vaccinated non-ill adults until the mother’s flu resolves 

How Flu Spreads

The CDC provides the following information on contagiousness of the flu

Person to Person
People with flu can spread it to others up to about 6 feet away. Most experts think that flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Less often, a person might get flu by touching a surface or object that has flu virus on it and then touching their own mouth, nose, or possibly their eyes.

When Flu Spreads
People with flu are most contagious in the first three to four days after their illness begins.  Most healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Children and some people with weakened immune systems may  pass the virus for longer than 7 days.

Symptoms can begin about 2 days (but can range from 1 to 4 days)  after the virus enters the body. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. Some people can be infected with the flu virus but have no symptoms. During this time, those people may still spread the virus to others.

Period of Contagiousness
You may be able to pass on flu to someone else before you know you are sick, as well as while you are sick.

People with flu are most contagious in the first 3-4 days after their illness begins.
Some otherwise healthy adults may be able to infect others beginning 1 day before symptoms develop and up to 5 to 7 days after becoming sick.
Some people, especially young children and people with weakened immune systems, might be able to infect others with flu viruses for an even longer time.

Learn More – Primary Sources:  

CDC Guidance for the Prevention and Control of Influenza in the Peri- and Postpartum Settings

CDC: Influenza Antiviral Medications: Summary for Clinicians

CDC: How Flu Spreads

ACOG Committee Opinion 753: Assessment and Treatment of Pregnant Women with Suspected or Confirmed Influenza