How long does covid last
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Duration of COVID-19: Incubation, Infectious Period, and Long-Term Effects
COVID-19 Incubation Period
The incubation period of COVID-19, which is the time between exposure to the virus and the onset of symptoms, has been a critical focus for public health strategies. Research indicates that the median incubation period for COVID-19 is approximately 5.1 days, with 97.5% of symptomatic cases developing symptoms within 11.5 days of exposure1 5. This aligns with the World Health Organization's (WHO) guidelines, which suggest a quarantine period of up to 14 days to account for the variability in incubation times5.
Duration of Infectious Period
The infectious period of COVID-19 varies between asymptomatic and symptomatic individuals. For asymptomatic cases, the median infectious period is estimated to be between 6.5 to 9.5 days2. For symptomatic individuals, the mean time from symptom onset to achieving two consecutive negative RT-PCR tests is approximately 13.4 days, although this can be shorter in children or less severe cases2. The potential maximal infectious period, from symptom onset to hospital discharge or death, averages around 18.1 days2.
Long-Term Effects of COVID-19 (Long COVID)
A significant number of COVID-19 patients experience long-term symptoms, a condition often referred to as "Long COVID." Studies show that about 80% of patients report at least one persistent symptom weeks to months after the initial infection3. Common long-term symptoms include fatigue, headache, attention disorders, hair loss, and dyspnea3. These symptoms can last from 1.5 to 6 months post-infection, with a notable proportion of non-hospitalized patients still experiencing issues such as dyspnea and loss of smell or taste10.
Predictors and Characteristics of Long COVID
Long COVID is more likely to occur in individuals with certain risk factors. Increasing age, higher body mass index (BMI), and female sex are associated with a higher likelihood of experiencing prolonged symptoms4. Additionally, experiencing more than five symptoms during the first week of illness significantly increases the odds of developing Long COVID4.
Conclusion
The duration of COVID-19 varies significantly across different stages of the disease. The incubation period typically lasts around 5 days, while the infectious period can extend up to 18 days in severe cases. Long-term effects, or Long COVID, can persist for several months, affecting a substantial portion of patients. Understanding these timelines is crucial for effective public health strategies and patient care.
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Most relevant research papers on this topic
The Incubation Period of Coronavirus Disease 2019 (COVID-19) From Publicly Reported Confirmed Cases: Estimation and Application
The median incubation period for COVID-19 is 5.1 days, similar to SARS, supporting current quarantine or active monitoring recommendations for potential exposed individuals.
Meta-Analysis
Rigorous Journal
Highly CitedInferred duration of infectious period of SARS-CoV-2: rapid scoping review and analysis of available evidence for asymptomatic and symptomatic COVID-19 cases
Inferring the infectious period of COVID-19 from repeated diagnosis, viral loads, and replication data alone has limitations and potential patient recall bias, but data provides a preliminary evidence base for models.
Systematic ReviewRigorous JournalHighly CitedMore than 50 long-term effects of COVID-19: a systematic review and meta-analysis
80% of COVID-19 patients develop one or more long-term symptoms, with fatigue, headache, attention disorder, hair loss, and dyspnea being the most common.
Meta-AnalysisRigorous JournalHighly CitedAttributes and predictors of long COVID
Long COVID symptoms, characterized by fatigue, headache, dyspnea, and anosmia, are more likely with increasing age, BMI, and female sex, and a simple model can identify individuals at risk early in the disease.
Observational StudyRigorous JournalHighly CitedThe estimations of the COVID-19 incubation period: A scoping reviews of the literature
The majority of published estimates suggest that the COVID-19 incubation period is a mean of 7.8 days, with a median of 5.01 days, falling within the WHO (0 to 14 days) and ECDC (2 to 12 days) ranges.
Systematic ReviewHighly CitedA Systematic Review of COVID-19 Epidemiology Based on Current Evidence
Current evidence suggests that COVID-19 epidemics take 3-7 days to double in size, with an incubation period of 4-6 days and a case fatality risk of 0.3% to 1.4% outside China.
Systematic ReviewRigorous JournalHighly CitedLongevity of immunity following COVID-19 vaccination: a comprehensive review of the currently approved vaccines
COVID-19 vaccines induce long-lasting immunity, with the mRNA-1273 vaccine providing protection for 6 months, followed by AZD1222, Ad26.COV2.S, and BNT162b2 within 2 months.
Systematic ReviewEuropean Respiratory Society statement on long COVID follow-up
Long COVID follow-up care is crucial and may improve patients' quality of life, but more evidence is needed to understand its causes, mechanisms, and risks.
Systematic ReviewRigorous JournalHighly CitedSerial interval of novel coronavirus (COVID-19) infections
Abstract Objective To estimate the serial interval of novel coronavirus (COVID-19) from information on 28 infector-infectee pairs. Methods We collected dates of illness onset for primary cases (infectors) and secondary cases (infectees) from published research articles and case investigation reports. We subjectively ranked the credibility of the data and performed analyses on both the full dataset (n = 28) and a subset of pairs with highest certainty in reporting (n = 18). In addition, we adjust for right truncation of the data as the epidemic is still in its growth phase. Results Accounting for right truncation and analyzing all pairs, we estimated the median serial interval at 4.0 days (95% credible interval [CrI]: 3.1, 4.9). Limiting our data to only the most certain pairs, the median serial interval was estimated at 4.6 days (95% CrI: 3.5, 5.9). Conclusions The serial interval of COVID-19 is close to or shorter than its median incubation period. This suggests that a substantial proportion of secondary transmission may occur prior to illness onset. The COVID-19 serial interval is also shorter than the serial interval of severe acute respiratory syndrome (SARS), indicating that calculations made using the SARS serial interval may introduce bias.
Highly CitedPersistent symptoms 1.5–6 months after COVID-19 in non-hospitalised subjects: a population-based cohort study
Persistent symptoms in non-hospitalized COVID-19 patients are associated with comorbidities and the number of symptoms during the acute phase.
Observational StudyRigorous JournalHighly Cited