What are the many benefits of testing?
What are the many benefits of testing?
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Testing provides several benefits during a pandemic, including early diagnosis, contact tracing, prevention, and surveillance. Viral testing identifies if an individual is currently infected with the virus that causes COVID-19. At the individual level, it allows infected individuals who were potentially experiencing symptoms to be diagnosed and access the care they need. At the community level, viral testing prevents further infections since an infected individual can take all necessary precautions to not infect other people. It also allows public health experts to identify new cases and track the spread of the virus through contact tracing by following the chain of transmission. Viral testing is commonly used to test people who have symptoms of COVID-19 as well as caregivers, essential workers, travelers, and others who may not show active symptoms. Serology tests - also called antibody tests - are useful to find out if an individual has been previously infected with the virus that causes COVID-19. These kinds of tests look for antibodies in the blood, which determine if there was a previous infection. It allows public health experts to find out how many COVID-19 infections have occurred in the past, and to track what percentage of the population has been infected over time, which has important implications for surveillance. At a policy level, serology testing can guide social distancing or quarantine guidelines. The U.S. Centers for Disease Control use a serology surveillance strategy to better understand the spread of the virus by testing in different locations, at different points of time, and within different populations (ex. across age, ethnic and socioeconomic groups) in the United States. However, it's important to note that the evidence surrounding serology testing and its link to immunity (protection) is still evolving. We do not understand fully if prior infection is evidence of immunity, know how long antibodies can protect the body, or whether patients can get infected again after a previous infection.
Testing provides several benefits during a pandemic, including early diagnosis, contact tracing, prevention, and surveillance. Viral testing identifies if an individual is currently infected with the virus that causes COVID-19. At the individual level, it allows infected individuals who were potentially experiencing symptoms to be diagnosed and access the care they need. At the community level, viral testing prevents further infections since an infected individual can take all necessary precautions to not infect other people. It also allows public health experts to identify new cases and track the spread of the virus through contact tracing by following the chain of transmission. Viral testing is commonly used to test people who have symptoms of COVID-19 as well as caregivers, essential workers, travelers, and others who may not show active symptoms. Serology tests - also called antibody tests - are useful to find out if an individual has been previously infected with the virus that causes COVID-19. These kinds of tests look for antibodies in the blood, which determine if there was a previous infection. It allows public health experts to find out how many COVID-19 infections have occurred in the past, and to track what percentage of the population has been infected over time, which has important implications for surveillance. At a policy level, serology testing can guide social distancing or quarantine guidelines. The U.S. Centers for Disease Control use a serology surveillance strategy to better understand the spread of the virus by testing in different locations, at different points of time, and within different populations (ex. across age, ethnic and socioeconomic groups) in the United States. However, it's important to note that the evidence surrounding serology testing and its link to immunity (protection) is still evolving. We do not understand fully if prior infection is evidence of immunity, know how long antibodies can protect the body, or whether patients can get infected again after a previous infection.
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What our experts say
Testing provides several benefits during a pandemic, including early diagnosis, contact tracing, prevention, and surveillance. Viral testing identifies if an individual is currently infected with the virus that causes COVID-19. At the individual level, it allows infected individuals who were potentially experiencing symptoms to be diagnosed and access the care they need. At the community level, viral testing prevents further infections since an infected individual can take all necessary precautions to not infect other people. It also allows public health experts to identify new cases and track the spread of the virus through contact tracing by following the chain of transmission. Viral testing is commonly used to test people who have symptoms of COVID-19 as well as caregivers, essential workers, travelers, and others who may not show active symptoms.
Serology tests - also called antibody tests - are useful to find out if an individual has been previously infected with the virus that causes COVID-19. These kinds of tests look for antibodies in the blood, which determine if there was a previous infection. It allows public health experts to find out how many COVID-19 infections have occurred in the past, and to track what percentage of the population has been infected over time, which has important implications for surveillance. At a policy level, serology testing can guide social distancing or quarantine guidelines. The U.S. Centers for Disease Control use a serology surveillance strategy to better understand the spread of the virus by testing in different locations, at different points of time, and within different populations (ex. across age, ethnic and socioeconomic groups) in the United States.
However, it's important to note that the evidence surrounding serology testing and its link to immunity (protection) is still evolving. We do not understand fully if prior infection is evidence of immunity, know how long antibodies can protect the body, or whether patients can get infected again after a previous infection.
Testing provides several benefits during a pandemic, including early diagnosis, contact tracing, prevention, and surveillance. Viral testing identifies if an individual is currently infected with the virus that causes COVID-19. At the individual level, it allows infected individuals who were potentially experiencing symptoms to be diagnosed and access the care they need. At the community level, viral testing prevents further infections since an infected individual can take all necessary precautions to not infect other people. It also allows public health experts to identify new cases and track the spread of the virus through contact tracing by following the chain of transmission. Viral testing is commonly used to test people who have symptoms of COVID-19 as well as caregivers, essential workers, travelers, and others who may not show active symptoms.
Serology tests - also called antibody tests - are useful to find out if an individual has been previously infected with the virus that causes COVID-19. These kinds of tests look for antibodies in the blood, which determine if there was a previous infection. It allows public health experts to find out how many COVID-19 infections have occurred in the past, and to track what percentage of the population has been infected over time, which has important implications for surveillance. At a policy level, serology testing can guide social distancing or quarantine guidelines. The U.S. Centers for Disease Control use a serology surveillance strategy to better understand the spread of the virus by testing in different locations, at different points of time, and within different populations (ex. across age, ethnic and socioeconomic groups) in the United States.
However, it's important to note that the evidence surrounding serology testing and its link to immunity (protection) is still evolving. We do not understand fully if prior infection is evidence of immunity, know how long antibodies can protect the body, or whether patients can get infected again after a previous infection.
Context and background
COVID-19 access to viral testing (diagnostic tests that tell you if you are currently infected with the virus) has varied significantly during the course of the pandemic. In the US, testing was largely unavailable except for those with acute symptoms until recent months. According to the U.S. Centers for Disease Control and Prevention (CDC), specimens tested by both the CDC and public health labs multiplied by more than 12 times from the beginning of March to the beginning of May. Limited testing early in the pandemic has left gaps in the data, particularly with regards to asymptomatic cases; however, because testing was initially (and in some regions still is) limited, there has been confusion about the benefits. While viral testing is not perfect in terms of accuracy and will not alone slow the pandemic, it is a crucial piece of the response effort. If one can get regularly tested, one should. In the initial months of the pandemic, countries that rapidly scaled up viral testing capacity, such as South Korea, were able to better contain the spread of COVID-19 in comparison to countries that were slow to increase testing, such as the United States.
Serology (antibody) testing has also varied in availability and recommended uptake since the onset of the pandemic. There has been less of an urgent push for serology testing because it does not tell you if you are currently infected and there is lacking evidence on how protective the antibodies are and their length of protection. Additionally, there is a chance that a positive result could be due to antibodies from an infection with a virus from the same coronavirus family (eg. the one that causes the common cold). The U.S. CDC has also issued warnings about the risk of high false positive rates in antibody tests. While antibody tests are an integral part of routine surveillance and particularly understanding disease prevalence and the frequency of asymptomatic infection, they should not be seen as a silver bullet to virus control.
COVID-19 access to viral testing (diagnostic tests that tell you if you are currently infected with the virus) has varied significantly during the course of the pandemic. In the US, testing was largely unavailable except for those with acute symptoms until recent months. According to the U.S. Centers for Disease Control and Prevention (CDC), specimens tested by both the CDC and public health labs multiplied by more than 12 times from the beginning of March to the beginning of May. Limited testing early in the pandemic has left gaps in the data, particularly with regards to asymptomatic cases; however, because testing was initially (and in some regions still is) limited, there has been confusion about the benefits. While viral testing is not perfect in terms of accuracy and will not alone slow the pandemic, it is a crucial piece of the response effort. If one can get regularly tested, one should. In the initial months of the pandemic, countries that rapidly scaled up viral testing capacity, such as South Korea, were able to better contain the spread of COVID-19 in comparison to countries that were slow to increase testing, such as the United States.
Serology (antibody) testing has also varied in availability and recommended uptake since the onset of the pandemic. There has been less of an urgent push for serology testing because it does not tell you if you are currently infected and there is lacking evidence on how protective the antibodies are and their length of protection. Additionally, there is a chance that a positive result could be due to antibodies from an infection with a virus from the same coronavirus family (eg. the one that causes the common cold). The U.S. CDC has also issued warnings about the risk of high false positive rates in antibody tests. While antibody tests are an integral part of routine surveillance and particularly understanding disease prevalence and the frequency of asymptomatic infection, they should not be seen as a silver bullet to virus control.
