Experts say this could be because when a person contracts a virus, it takes time for it to replicate within the body to trigger noticeable symptoms.

New Covid variant EG.5 has been spreading fast in different parts of the world and while the strain is good at escaping immunity, the symptoms remain mild, and experts say it doesn't pose a significant threat. EG.5 has been declared as a variant of interest and will be monitored for its mutations. The strain may become dominant in many countries with its rapid spread. As the Eris and other Omicron variants are being detected, people are also reporting a 'pre-Covid' phenomenon that was even being reported in the initial days of pandemic. This means that people are showing signs of Covid even with a negative test and upon being tested again after a week or so, the result comes positive.

Experts say this is because when a person contracts a virus, such as Covid-19, it takes time for the virus to replicate within the body to trigger noticeable symptoms. The initial test comes negative due to low viral load and the same increases with each passing day. If you too are facing this 'pre-Covid' phenomenon, get tested again after a week for correct diagnosis.

The incubation period effect

"This phenomenon can be attributed to the virus's incubation period. When a person contracts a virus, such as Covid-19, it takes time for the virus to replicate within the body to levels that trigger noticeable symptoms. This period between exposure to the virus and the appearance of symptoms is known as the incubation period. Eris is one of the two latest sub-variants of Corona virus. The symptoms of Eris variant start about a week before it could be detected by tests. The symptoms are nearly the same as those of Covid illness," says Dr Anurag Saxena, HOD-Internal Medicine, Primus Super Speciality Hospital.

"In the case of Eris and similar illnesses, symptoms may manifest roughly a week before a positive test because the virus or pathogen has been present in the body long enough to cause noticeable symptoms, but it might still take a little more time for the viral load to reach a level detectable by the testing methods in use," adds Dr Saxena.

Go for RT-PCR tests

"In some patients, they continue to test negative for Covid illness, because they don't have it. In some cases, initial tests can be negative due to low viral load initially, i.e., load below the limit of detection of that particular test. In such cases, repeating a test after few days usually helps to confirm the diagnosis. In other patient, use of rapid antigen tests, improper sampling technique (when performed by self) etc. can be cause of negative result despite having Covid illness. In such cases, RT-PCR tests, a more accurate test than rapid antigen tests, should be performed, and sampling performed preferably by trained personnel. As of now, there is very limited data to suggest any significant difference compared to previously circulating variants with respect to transmissibility, immune evasiveness, severity, diagnostic modalities, or response to available treatment. Furthermore, more robust, large cohort-based data is needed, on viral dynamics of new emerging variants, and performance characteristics of various tests in such scenarios to ascertain such phenomenon and its plausible explanation," says Dr Rohit Garg, Consultant, Dept of Infectious Disease, Amrita Hospital, Faridabad.

"Symptoms such as nasal congestion, sneezing, cough, fever and fatigue is commonly seen in the 'pre COVID' period. This can last upto first 7 days of the infection. It is seen with Eris variant as the transmissibility of this virus is higher than the previous variants. However, there is no need to panic and it becomes imperative to follow Covid appropriate behaviour, especially hand hygiene, during the monsoon season when the rate of airborne and droplet infections are already high," says Dr Charu Dutt Arora, Infectious Disease Specialist, Consultant Physician, AmeriHealth, Asian Hospital.

"Understanding this timeline helps in both managing the illness and preventing further transmission, as individuals with symptoms can take appropriate precautions and seek medical attention promptly, reducing the risk of spreading the illness to others," says Dr Saxena.

Eris symptoms

Dr Saibal Chakravorty, Senior Consultant - Internal Medicine, Metro Hospital Noida says the symptoms of the new variant as of now are same as we have seen and witnessed previously, though more research on this is being done.

As per limited evidence, the symptoms are:

• Cough
• High Fever
• Severe Headache
• Body ache
• Weakness and Fatigue
• Decreased Appetite