With the recent rise in Covid-19 cases, a number of people have contacted me for advice on what to do after being exposed to someone who tested positive for SARS-CoV-2. At the height of the pandemic, these rules were ingrained in the minds of most people.
We’ve been fortunate to have had a long stretch of time where cases remained low even as mask mandates were lifted, which has now led to many people no longer remembering what to do if they are exposed or infected. The previous guidance on quarantine and isolation from the Department of Health (DOH) updated last February 2024 has not changed, and now is a good time to review these for our peace of mind.
Quarantine
Quarantine, defined as a period of confinement to home or a facility after exposure to a confirmed or suspected case of Covid-19, is no longer required. The rationale for quarantine early in the pandemic was the high mortality rate associated with Covid-19 prior to the availability of effective vaccines and treatments, as well as the emergence of more dangerous variants such as Delta when vaccination programs were still under way. It was imperative that the spread of these variants be mitigated so that hospitals had a chance to breath even as our government tried to vaccinate as many people as possible.
With the continued shift of Covid-19 to endemicity and with the widespread vaccination of the population, the impact of Covid-19 on our society has been substantially mitigated. Quarantine is not innocuous and can have significant impacts on economic productivity and material resources as well as on mental health. Quarantining people who were recently exposed to a Covid-19 case can no longer be justified in the current endemic state of Covid-19 since the public health risk of the circulating variants is low. There may be emergency scenarios when it might be considered if a highly virulent and immune-evasive variant emerges, but this is very unlikely to occur. The near hysterics accompanying the so-called FLiRT variants don’t count since there is no evidence these variants cause any more severe disease than previous variants. The old vaccines, even without recent boosters, continue to protect against severe disease. Despite having done away with quarantine, wearing a mask for at least ten days from the time of exposure to a known or suspected case of Covid-19 is a prudent measure, especially for those who live with people who are in the vulnerable population. There is no need to test for Covid-19 in an exposed person unless he or she develop respiratory symptoms.
Isolation
Isolation, on the other hand, refers to the period of confinement to home or a facility after someone develops symptoms and tests positive for SARS-CoV-2. Testing can be done by either antigen or RT-PCR. In the presence of symptoms, a positive Covid-19 antigen test need not be further confirmed with an RT-PCR. However, antigen-negative persons can be tested with an RT-PCR if Covid-19 is still suspected, since antigen tests are less sensitive than RT-PCR tests. Confirmed Covid-19 cases are most contagious within the first three days of the start of symptoms. For asymptomatic cases, there is a lot of uncertainty regarding infectiousness, but we do know that transmission can occur even without symptoms. There does not seem to be much appetite for testing now that Covid-19 testing is no longer mandatory. Nonetheless, there is some utility in testing people who are in the vulnerable group, especially among those who can lower their risk of severe disease with antivirals. Testing also helps detect the emergence of outbreaks and informs the public health response.
For patients with mild symptoms or who are asymptomatic, the current rules recommend undergoing home isolation for five days or until fever-free for at least 24 hours without using antipyretics (like paracetamol) along with improvement of respiratory symptoms, whichever is earlier. This recommendation preceded the downgrade of the US CDC guidelines to isolation for at least 24 hours after being fever free, and so our guidelines do reflect the latest understanding of Covid-19 from a public health context. It also gives physicians the discretion to stop isolation earlier, depending on their clinical assessment. Wear a good quality mask for at least ten days from the end of isolation is recommended, because residual shedding can occur beyond the recommended isolation period.
Patients with moderate or severe symptoms should be tested for Covid-19 since they will likely need antiviral medication and ancillary treatments. The period of isolation for this subset of patients is ten days from the onset of symptoms. For immunocompromised patients, regardless of severity of symptoms, discontinuation of isolation should only be done upon the advice of a doctor. Those who develop severe disease should also only discontinue isolation upon the advice of a doctor. Masks should continue to be worn for at least ten days from the end of isolation to mitigate residual shedding.
What about antivirals? The three antivirals that are currently available in the country are remdesivir, nirmatrelvir-ritonavir (also known by its brand name Paxlovid), and molnupiravir. All three medications are still expected to work against all known variants of SARS-CoV-2, including the latest ones.
Not everyone, however, needs to be treated with antivirals. For those with mild symptoms, only those at risk for developing severe disease should be treated. These include the elderly, those with significant comorbid conditions, and those who are immunocompromised. Molnupiravir and Paxlovid are oral agents that should be started within five days of symptoms. Remdesivir is only available as an intravenous drug and so it is usually used in the hospital. It can be started up to seven days from the start of symptoms. Remdesivir, when used in patients at risk for progression for severe disease is given only for three days. It is given for five days in those with severe symptoms. Molnupiravir and Paxlovid should not be used for those with severe symptoms as these have not been shown to work well in these patients.
We are still waiting for news on the availability of updated vaccines. A new monovalent vaccine based on the JN.1 variant is planned for September this year, but it is not known whether this will be brought into our country. The last locally available booster was the bivalent vaccine in 2022. The updated XBB.1.5 monovalent booster that was released in 2023 never made it to our country. These updated vaccines, if they do get here, will likely only be offered to the most vulnerable. In the meantime, our original shots and boosters do still protect most of us from severe Covid-19. As long as we continue to judiciously use the tools that help mitigate spread of Covid-19 such as masking, good ventilation and appropriate isolation, we will be okay.