Some hospitals in the national capital have said they are are seeing recovered coronavirus patients returning to them with recurrence of the infection.
Earlier this month, the Delhi government-run Rajiv Gandhi Super Speciality Hospital saw two instances of patients with relapse of coronavirus, almost one-and-a-half months after they were cured of the infection.
In both the instances of relapse, the patients had moderate symptoms.
Aakash Healthcare in Dwarka had also reported a case where a cancer patient recovered from coronavirus and contracted the disease again after a couple of months.
The second time proved fatal for the patient who succumbed to the virus.
Last month, the case of a Delhi policeman having a relapse of the novel coronavirus had emerged which had left experts baffled.
In the same month, a similar case had surfaced in the national capital after a nurse employed at a civic-run dedicated COVID-19 hospital had tested positive again after recovering from the contagious disease.
According to Dr BL Sherwal, medical director of the Delhi government-run hospital, unless the virus is cultured or gene sequencing done, it will be difficult to determine whether it is a different strain of the virus that has infected the person the second time.
"There can be a relapse. The virus can be isolated from the body particularly from the sputum. We have the evidence that after ninth or tenth day the virus becomes non-infectious and the patients are not tested again," he said.
"However, the virus has been reported to be living in patients who have recovered around 39 to 40 days back," he added.
Dr Chandragouda Dodagoudar, director of medical oncology at Aakash Healthcare in Dwarka, shared the case of a 65-year-old patient who had stage 2 lymphoma. The patient first visited the health facility in March and was advised chemotherapy but was very apprehensive due to the coronavirus disease.
"The patient delayed the treatment for two and a half months and took alternative medicines and when that medication did not work and she started having pain, she visited the hospital. She had contracted COVID-19 by then and the lymphoma had progressed from Stage 2 to Stage 4. We could not administer chemotherapy while she was undergoing COVID treatment," he said.
The doctor said after the patient recovered from coronavirus, she was administered a slight dose of chemotherapy and became better and was discharged. But after a month, she had a relapse of COVID and ended up in a critical condition and succumbed last month.
The senior doctor said the patient did not have any other co-morbidities but called cancer a ''co-morbidity''.
Sherwal said patients with weak immunity are likely to get reinfection.
"It can be there in any of the patients, cancer patients, HIV patients, etc," he said.
He added that immunocompromised patients are at more risk if they do not take precautions like wearing of masks and washing hands frequently.