Is there a consensus on the cut off point for the definition of pyrexia for temperature screening?
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In A Nutshell
There is no clear consensus on the definition of pyrexia for temperature screening; however, several prominent organisations including the CDC2 and NLM5 in the United States, the HSE1 and the greater majority of the literature10, 11, 13, 15, 16, 17 state that a fever is deemed to be a measured temperature of 38°C or higher2. NHS guidance3 defines fever as a temperature above 37.8°C. In a study of healthcare workers’ symptoms of COVID-19 in two Dutch hospitals, Kluytmans-van Dr Bergh et al11 designated fever as a body temperature of 38°C or higher. Wei-Jei et al defined fever as being an axillary temperature of 37.5°C or higher12. A systematic review by Geneva et al6 concluded that when deciding normal body temperature,the most important patient factors remain site of measurement and patient age.
Older adults age ≥60 had a lower temperature than younger adults age <60 by 0.23°C on average7. In a systematic review of published research from 1935 to 2017, Geneva et al6 found only insignificant gender difference.
Hsiao et al17 recommended that medical institutions with outpatient services should take patients’ body temperature for a second time after the patients have acclimatised to being indoors.
12, 18 >37.5°C
6 ~ >37.76°C
NICE [paediatric] >38°C
10, 11, 13, 15, 16, 17 >38°C
IRISH AND INTERNATIONAL GUIDANCE
What does the HSE say?
Your body’s normal temperature is between 36 and 36.8 degrees Celsius.
A high temperature or fever, for most people, is when your body temperature is 38°C or higher.
What do the Centers for Disease Control and Prevention (United States) say?
CDC considers a person to have a fever when he or she has a measured temperature of 100.4° F (38°C) or greater, or feels warm to the touch, or gives a history of feeling feverish. CDC note that even though measured temperature is the preferred and most accurate method to determine fever, it is not always possible to take a person’s temperature.
As part of its criteria requiring admission to hospital, NHS guidance defines fever ≥37.8°C and at least one of the following respiratory symptoms, which must be of acute onset: persistent cough [with or without sputum], hoarseness, nasal discharge or congestion, shortness of breath, sore throat, wheezing, sneezing or a loss of or change in normal sense of taste or smell [anosmia] in isolation or in combination with any other symptoms.
Your normal body temperature is approximately 37°C. A fever is usually when your body temperature is37.8°C or higher. You may feel warm, cold or shivery.
Normal body temperature varies by person, age, activity and time of day. The average normal body temperature is generally accepted as 98.6°F (37°C). Some studies have shown that the ‘normal’ body temperature can have a wide range, from 97°F (36.1°C) to 99°F (37.2°C).
A temperature over 100.4°F (38°C) most often means you have a fever caused by an infection or illness.
What does the international literature say?
PubMed was searched from 1935 to December 2017 with a variety of search phrases among article titles. The references of the identified manuscripts were then manually searched. The inclusion criteria were as follows: 1. the paper presented data on measured normal body temperature of healthy human subjects ages 18 and older; 2. a prospective design was used; and 3. the paper was written in or translated into the English language. 36 articles met the inclusion criteria. This comprised 9,227 measurement sites from 7,636 subjects. The calculated ranges (mean ± 2 standard deviations) were 36.32–37.76 (rectal), 35.76–37.52 (tympanic), 35.61–37.61 (urine), 35.73–37.41 (oral), and 35.01–36.93 (axillary). Older adults age ≥60 had lower temperature than younger adults age <60 by 0.23°C on average. There was only insignificant gender difference. Compared with the currently established reference point for normothermia of 36.8°C, our means are slightly lower but the difference likely has no physiological importance. We conclude that the most important patient factors remain site of measurement and patient’s age.
A review of normal body temperature in adults10 including studies from 1935-1999 concluded the range of normal oral temperature was 35.6°C to 38.2°C. The American College of Critical Care Medicine defines fever as core body temperature greater or equal to 38.3°C. NICE consider an infant or child to have a fever if their temperature is 38°C or higher.
A systematic review of normal body temperature found that older adults age ≥60 had a lower temperature than younger adults age <60 by 0.23°C on average.
The purpose of this study was to investigate normal body temperature in adult men and women. Studies from 1935 to 1999 were included. Articles were classified as 1 strong, 2 fairly strong and 3 weak evidence. When summarizing studies with strong or fairly strong evidence the range for oral temperature was 33.2-38.2 degrees C, rectal: 34.4-37.8 degrees C, tympanic: 35.4- 37.8 degrees C and axillary: 35.5-37.0 degrees C. The range in oral temperature for men and women, respectively, was 35.7-37.7 and 33.2-38.1 degrees C, in rectal 36.7-37.5 and 36.8-37.1 degrees C, and in tympanic 35.5-37.5 and 35.7-37.5 degrees C. The ranges of normal body temperature need to be adjusted, especially for the lower values. When assessing body temperature it is important to take site of measurement and gender into consideration. Studies with random samples are needed to confirm the range of normal body temperature with respect to gender and age.
A retrospective cohort study of 149 RT-PCR confirmed positive patients. 114 patients had fever. The baseline recorded temperature was 37.86±0.87.
All laboratory-confirmed COVID-19 cases in adults admitted to an academic medical center in Seattle, WA between March 2 and March 26, 2020 were included. The total number of patients included was 105. The median age was 69.
Fever was defined as a recorded temperature of 38.0°C or higher. Only 39% had fever in the first 24 hours.
Kluytmans-van den Bergh et al (2020) Prevalence and Clinical Presentation of Health Care Workers With Symptoms of Coronavirus Disease 2019 in 2 Dutch Hospitals During an Early Phase of the Pandemic[xi]
A cross-sectional study of 9,705 HCWs who reported fever or respiratory symptoms.
Figure 3 included demographic characteristics, self-reported symptoms and outcomes. Fever was defined as a body temperature of 38.0 °C or higher.
Data for 1,099 hospitalized patients and outpatients with laboratory-confirmed COVID-19, as reported to the National Health Commission between December 11, 2019, and January 29, 2020. COVID-19 was diagnosed on the basis of the WHO interim guidance. Fever was defined as an axillary temperature of 37.5°C or higher. Lymphocytopenia was defined as a lymphocyte count of less than 1500 cells per cubic millimeter.
A case series of 5700 patients with COVID-19 admitted to 12 hospitals in New York City, Long Island and Westchester County, New York. The study included all sequentially hospitalized patients between March 1 and April 4, 2020 inclusive. Triage criteria defined high temperature as greater than 38°C.
A retrospective cohort study of adult inpatients with laboratory confirmed COVID-19 from two hospitals in Wuhan, China, in January 2020. Fever was defined as axillary temperature of at least 37·3°C.
A series of 21 cases in which the authors describe the clinical presentation, characteristics and outcomes of incident cases of COVID-19 admitted to the ICU at Evergreen Hospital to inform other clinicians treating critically ill patients with COVID-19. Fever is defined as a temperature greater than 38.0°C.
A retrospective study investigating the clinical features and characteristics of all patients hospitalized with SARS-CoV2 infection in a community hospital in the Mid-West region of the US. Vital signs on admission were extracted from ER notes and EMR query. Fever was defined as forehead temperature >38°C (>100.4 F).
In March 2020, 40,887 patients attended Kaohsiung Municipal Da-Tung Hospital, Taiwan, for medical services. Five patients were found to have fever (>38°) at the outdoor quarantine station. However, a further 37 patients were identified with fever when a second temperature recording was made inside. As such, it is recommended that medical institutions with outpatient services should take patients’ body temperature for a second time after they have acclimatized to being indoors.
A study of 44 patients admitted to a single hospital in Pavia, Italy, 21 to 28 February, 2020. Fever was defined as a body temperature > 37.5°C.
This study evaluated the performance of two types of tympanic infrared thermometers and an industrial infrared thermometer. The results showed that these infrared thermometers provide good precision. A fixed offset between tympanic and forehead temperature were found. The measurement values for wrist temperature show significant offsets with the tympanic temperature and cannot be used to screen fevers. A standard operating procedure for the measurement of body temperature using an infrared thermometer was proposed. The suggestion threshold for the forehead temperature is 36 °C for screening of fever. The body temperature of a person who is possibly ill is then measured using a tympanic infrared thermometer for the purpose of double checking.
[i]HSE. Fever in Adults. www.hse.ie https://www2.hse.ie/conditions/fever-in-adults.html Updated 18/3/2020 [Accessed 26/5/2020]
[ii] Centres for Disease Control & Prevention (CDC) Definitions of Symptoms for Reportable Illnesses https://www.cdc.gov/quarantine/air/reporting-deaths-illness/definitions-symptoms-reportable-illnesses.html [Accessed 25.5.2020]
[iii] NHS Guidance COVID-19: investigation and initial clinical management of possible cases https://www.gov.uk/government/publications/wuhan-novel-coronavirus-initial-investigation-of-possible-cases/investigation-and-initial-clinical-management-of-possible-cases-of-wuhan-novel-coronavirus-wn-cov-infection [Accessed 26/5/2020]
[iv] NHS Inform: Fever in Adults, 24th March 2020 https://www.nhsinform.scot/illnesses-and-conditions/infections-and-poisoning/fever-in-adults [Accessed 25/5/2020]
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[viii] Sund-Levander M, Forsberg C, Wahren LK. Normal oral, rectal, tympanic and axillary body temperature in adult men and women: a systematic literature review. Scand J Caring Sci. 2002;16(2):122‐128. doi:10.1046/j.1471-6712.2002.00069.
[ix] Yang W, Cao Q, Qin L, et al. Clinical characteristics and imaging manifestations of the 2019 novel coronavirus disease (COVID-19):A multi-center study in Wenzhou city, Zhejiang, China. J Infect. 2020;80(4):388‐393. doi:10.1016/j.jinf.2020.02.016 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7102539/ [Accessed 25/5/2020]
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[xii] Wei-Jie G, Zheng-yi N., Yu H. et al. Clinical Characteristics of Coronavirus Disease 2019 in China 30th April 2020 N Engl J Med 2020; 382:1708-1720 DOI: 10.1056/NEJMoa2002032 https://www.nejm.org/doi/full/10.1056/NEJMoa2002032 [Accessed 25/5/2020]
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Produced by the members of the National Health Library and Knowledge Service Evidence Team†. Current as at 26 May 2020. This evidence summary collates the best available evidence at the time of writing and does not replace clinical judgement or guidance. Emerging literature or subsequent developments in respect of COVID-19 may require amendment to the information or sources listed in the document. Although all reasonable care has been taken in the compilation of content, the National Health Library and Knowledge Service Evidence Team makes no representations or warranties expressed or implied as to the accuracy or suitability of the information or sources listed in the document. This evidence summary is the property of the National Health Library and Knowledge Service and subsequent re-use or distribution in whole or in part should include acknowledgement of the service.
Dympna Lynch, Librarian, Cavan General Hospital [Author]; Margaret Morgan, Librarian, Regional Hospital Mullingar [Author]; Brendan Leen, Area Library Manager, HSE South [Editor]