Efforts are underway to estimate its potential size and impact in the third wave of Covid-19’s Omicron fuel, which is sweeping major cities in India.
Many state governments make internal forecasts. Maharashtra expects the number of cases recorded in the second wave to double, with Chhattisgarh three times and West Bengal 1.5 times, state officials said. Scroll.in.
The mathematical model by scientists at the Institute of Indian Science and the Institute of Statistics of India is based on South African data and, according to various assumptions, three scenarios (3 easy, 6 easy, 10 easy) for the number of cases per day. Is predicting.
However, what is difficult to estimate is the size of hospitalization and death.
The only model to enter this area was created by the Tata Institute of Fundamental Research in Mumbai. Hospitalization is estimated to be 50-70% of the peak seen in the second wave and death is predicted to be 30-50%. The number of deaths recorded in Mumbai in the second wave from March to June was about 4,000, which corresponds to an estimated 1,200-2,000 deaths in the city in the current wave.
One of the convergence points for all estimates is that the peak of the third wave is earlier. This raises concerns for health authorities in some states, as hospitals can be overwhelmed, even if the majority of cases are mild or asymptomatic.
Already, in Mumbai, where cases have increased 33-fold in two weeks, 12% of beds are occupied. In Delhi, hospital occupancy is currently low, but in anticipation of an increase, the state government has requested private hospitals to reserve 40% of beds for covid care.
Moreover, the extreme toxicity of Omicron means that doctors and medical staff are at high risk of infection.The labor shortage is already imminent Bihar When West Bengal Hundreds of doctors have infections.of Mumbai, A quarter of doctors residing in large public hospitals cannot go to work because they are infected.
Hospital burden
The Omicron variant was first reported on November 24 in Gauteng, South Africa. Within two weeks, the number of Covid-19 cases in the country exceeded previous records and the variants spread to 60 countries. This is a testament to its surprisingly high infectivity.
However, the silver lining is found in some studies to cause mild illness in healthy and vaccinated people compared to other variants of the coronavirus.
For example, according to a study in Houten, those admitted to the hospital with Covid-19 were more severe during the Omicron-led waves from November to December 2021 compared to the May 2021 delta waves. We found that we were 73% less likely to get sick.
The study also noted that only 4.9% of Covid-positive people needed to be hospitalized in Houten during the Omicron-led wave, compared to 13.7% of the Delta-led wave. However, in absolute numbers, the size of the Omicron wave was so large that it was converted to 6,510 inpatients, more than the 4,574 seen in the delta wave.
In India, this seems to be the main concern of officials. Omicron’s high contagiousness can mean a much higher number of cases in a much shorter time than the second wave. Health officials fear that this can overwhelm hospitals, especially in areas with poor medical capacity.
Maharashtra predicts that cumulative infections in the third wave will be nearly double the number of Rs. 450,000 reported in the second wave. Vyas. He said the case is expected to peak and taper faster than previous waves.
Similarly, experts advising the Chhattisgarh state government estimate that the number of cases in the third wave could be three times the number of cases in the second wave. Their rationale: Data from South Africa peg that Omicron variants are approximately three times more infectious than Delta.
One expert said he expected the waves to be significantly shorter than before, perhaps between 4 and 6 weeks. A sector with a population of 500,000 rupees could witness cases of 10,000 to 20,000 rupees in a week, he said. Even with a modest 5% hospitalization rate, he added, this could correspond to 12,000-37,500 patients requiring inpatient treatment when the wave peaks.
Meanwhile, in West Bengal, where cases are on the rise, especially in Kolkata, health services director Dr. Ajay Chakraborti said the state has not prepared its own model. However, based on central government data, it is estimated that the third wave could result in 1.5 times the cases recorded in the second wave. In West Bengal, 22,000 cases were seen daily at the peak of the second wave. If this trend continues, this time it could increase to 33,000 to 35,000 per day.
Two modeling exercises
But mathematical models are throwing mixed predictions. Based on South African data, a model by scientists from the Institute of Indian Sciences and the Institute of Statistics of India creates three scenarios, each taking into account different proportions of the vulnerable population of the new variant: 30%, 60%, 100%.
“The effects of past infections, vaccinations, and weakened immunity” are related to the size of the vulnerable population, the study authors say.
According to the model, a 30% vulnerability assumption leads to a lower peak than the delta wave. In other words, it is a case that slightly exceeds 30,000 rupees per day. However, assuming that the sensitive population is 60%, cases of 6 or more racs per day peak and surge by nearly 60% compared to the second wave. The worst scenario of 100% vulnerability depicts an ominous situation of about 100,000 rupees per day.
The model does not estimate hospitalization.
However, the Mumbai-centric model by the Tata Institute of Fundamental Research casts a more detailed prediction of the city. With some caveats, the city’s daily number of cases is widely estimated to range from 12,000 to 16,000 cases between January 6th and 13th, when cases are likely to peak. increase. In the second wave, the largest increase on April 4th was 11,206.
The model simulated by TIFR student Daksh Mittal is based on trends in South Africa and the United Kingdom. In calculating factors for both case spread and reinfection and breakthrough infections in vaccinated people, Omicron is assumed to be twice as infectious as Delta. This model is based on the assumption that 35% of the population is vulnerable to reinfection.
“The peak of hospitalization is about 50-70% of the peak seen under the Delta,” said Professor Sandeep Juneja of TIFR’s Faculty of Technology and Computer Science. Due to the increase in deaths a few days after the increase in infectious diseases, Geneja said the death toll in Mumbai was about 30 to what the city saw under the delta wave in the first week of February. He said it shows a peak at 50%.
Maharashtra health official Vyas said the hospitalization rate is expected to be much lower than the delta wave, but the peak number of cases is expected to exceed the previous wave. “I don’t think there will be a strain on the oxygen supply or a shortage of hospital beds for critical care centers,” he said. “Looking at the recent surge in South Africa and France, it seems that Mumbai will peak by at least mid-January.”