COVID-19 is a widespread respiratory illness that emerged as a global health concern, presenting with a diverse range of symptoms. Among these, fever has been a frequently discussed indicator of the illness. Understanding how often fever accompanies COVID-19 is important for public awareness, offering clarity on what individuals might expect if they contract the virus.
How Often Does Fever Accompany COVID-19?
Fever has been recognized as a common symptom of COVID-19 across many cases. In a comprehensive review involving thousands of adult patients, the overall pooled prevalence of fever was found to be approximately 79.43%.
Despite its commonality, fever does not appear in all individuals infected with the virus. About one in five adults testing positive for COVID-19 may not develop a fever. For instance, a study of hospitalized patients noted that only 44% had a fever upon admission, although 89% subsequently developed one during their hospital stay. In pediatric cases, the pooled prevalence of fever was notably lower, at around 45.86%.
Key Factors Influencing Fever Presentation
The presentation of fever in COVID-19 can vary due to several influencing factors, including the specific viral variant, an individual’s vaccination status, and their age. During the period when the Omicron variant became dominant, fever was reported less frequently, appearing in 29.2% of cases, compared to 32.7% during the Delta variant’s prevalence.
Vaccination against COVID-19 generally leads to milder symptoms if a breakthrough infection occurs. Vaccinated individuals are less likely to experience severe illness, which can include a reduced likelihood or intensity of fever. Unvaccinated individuals, conversely, face a higher risk of developing more pronounced symptoms and requiring hospitalization.
Age also plays a role in how fever presents. Children generally experience milder symptoms than adults, with a lower overall fever prevalence. However, the Omicron variant has been reported to cause more symptoms in children, including fever. Older adults, particularly those over 65, may have a lower baseline body temperature and a reduced immune response, which can result in a less noticeable fever even when they are infected.
Understanding and Tracking Fever
A fever is medically defined as a body temperature of 100.4°F (38°C) or higher when measured orally, rectally, or via the temporal artery. While the average body temperature is often cited as 98.6°F (37°C), individual temperatures can vary slightly. An armpit temperature of 99°F (37.2°C) or higher is also considered a fever.
Monitoring body temperature is a practical step for personal health awareness, especially when feeling unwell. Digital thermometers are recommended for accurate readings, with oral and rectal methods generally providing the most precise measurements of core body temperature. Tracking fever can offer valuable information for understanding one’s health status and can help in making informed decisions about seeking medical attention.