Post Covid-19, patients’ focus should be on boosting immunity: Health experts

A study has found that Covid-19 leads to an increase in infectious diseases such as tuberculosis. Representation pic

Even as Omicron is considered as a milder Covid-19 variant, health experts are concerned about the long-term health issues, including suppressed immune system which many are exposed to, causing other serious infections viz. tuberculosis, chikungunya, herpes, etc. They advise recovered patients to focus on strengthening their immune system through a healthy lifestyle including yoga.

Existing conditions

Dr Wiqar Shaikh, professor of medicine, Grant Medical College and Sir J J Group of Hospitals, said that the infection requires a robust response from the immunity system of the affected person. He also mentioned cytokines which work as messenger molecules and transmit instructions to the immune system. In a viral infection, the immune system responds through a "cytokine storm" in which there is a massive surge in cytokines leading to inflammation, which may lead to damage to multiple organs and even death. Dr Shaikh quoted a study from the journal Infections Microbes and Disease, which explained that the main culprit is a cytokine called IL-6 (Interleukin-6) which triggers release of other cytokines such as IFN-gamma, TNF-alpha and IL-10, which cause local tissue damage.

The other mechanism causing damage to an infected person is the production of autoantibodies which attack the patient's own body, leaving the body without any defence against the virus. This, Dr Shaikh explained, is like knocking down a "castle's gate". He quoted a study from the National Institute of Health in the USA which concluded that half of the hospitalised Covid patients had autoantibodies.

Dr Shaikh warned that people with comorbidities such as diabetes, high blood pressure, chronic kidney failure, cancer, HIV-AIDS, and other infections have a risk of facing severe Covid infection and being hospitalised. He added that lung failure and multiorgan failure are the main causes Covid fatalities. He also quoted a study by the British Society for Immunology which concluded that Covid-19 also causes scarring of the lungs, clotting in the blood vessels and an increase in infectious diseases such as tuberculosis.

Rise in active TB cases

"Amid the pandemic, the medical fraternity has been observing a sudden increase in the number of active cases of TB, herpes zoster, severe forms of herpes, and severe episodes of diarrhoea among new patients of Covid, but little has been reported about these changing patterns. The clinical research reports of cases are less prominent. As a result, the immune suppression caused by coronavirus has also not been highlighted. For example, people with latent (inactive) TB carry the bacilli but have no symptoms and do not transmit the infection under normal conditions. India has 360 million people with latent TB. But when people suffer from active Covid, the immune suppression activates latent or dormant TB. Hence, recovered Covid patients should undergo a TB skin test after 4-6 weeks," said Dr Subhash Hira, professor of global health at University of Washington-Seattle and advisor to WHO-TDR-Geneva.

He added, "During the lockdowns, Mumbai has seen a surge of new TB cases among women facing low immunity due to anaemia, repeated deliveries or undernourishment. This gender shift has further altered the trend of TB, which was majorly seen in men earlier." "Several studies across the world have revealed increased incidence of TB in patients who suffered from Covid. In high burden HIV/TB countries, the spread of Covid-19 among people living with HIV is a well-founded concern. TB was a risk factor for Covid-19 both in terms of severity and mortality irrespective of HIV status in various studies from the African subcontinent. Individuals with the so-called long Covid type of outcomes need to be investigated for tuberculosis. Whether it is latent TB which becomes manifest due to an immunocompromised state is under investigation," said Dr Ketan Vagholkar, professor of surgery at D Y Patil Medical College.

May lead to other infections

"Low immunity can cause other infections too. In India TB is the most common infection to get in low immunity patients. Since Covid is a new disease, we don't clearly know about its long-term impacts on our body. As days will pass, various researches will make our idea clear about its long-term impacts. If any patient who had Covid in the past gets fever or any other symptoms, we must screen that patient for various common diseases as well as diseases we can get because of low immunity," said Dr Santosh Bansode, head of the department, Emergency Medicine, Wockhardt Hospitals, Mumbai Central.