India's test positivity rate for Covid-19 down to 15%; Centre ups caution

India’s test positivity rate for Covid-19 has fallen to 15.2 per cent between May 13 and May 19 after reaching nearly 22 per cent in the first week of May, revealed the health ministry data. 

Positivity rate had been consistently increasing for 10 weeks since February and started to decline in the past 10 days. 

The central government has also increased the caution level in its latest advisory by recommending double masking, wearing masks at home, and also stating that aerosols - one of the key transmission modes of the novel coronavirus - can be carried in the air for up to 10 metres. 

The advisory, released by the office of the Principal Scientific Advisor K VijayRaghavan, while suggesting proper airflow and ventilation in indoor spaces, has also cautioned against surface transmission, advising frequent disinfecting of high contact points, such as door handles, light switches, tables, and chairs. 

“Even one infected person showing no symptoms can release enough droplets to create a ‘viral load’ that can infect many others,” said the advisory. 

The health ministry, quoting an international study, said one person can infect up to 406 people in 30 days if he does not follow any physical distancing. This number can be brought down to 2.5 by reducing physical exposure. 

Eight states continue to have more than 100,000 active cases. Of these, all - except Tamil Nadu - are seeing a declining trend in active cases. 

There are 22 states reporting a positivity rate of more than 15 per cent. Seven have a positivity rate exceeding 25 per cent, including Goa, West Bengal, Puducherry, Kerala, Karnataka, Sikkim, and Lakshadweep. 

There is decreased positivity and decline in cases in 123 districts, observed the health ministry. The decline in positivity rate is being reported in 303 districts in the country in the last week, compared to 214 districts in the week earlier.

The number of districts reporting more than 100 daily cases has also come down from 531 during April 28-May 4 to 430 in the last week. 

“India has witnessed a consistent upward trend in weekly tests since mid-February, with average daily tests increasing 2.3x in the past 12 weeks,” said Lav Agarwal, joint secretary, health ministry.

However, the government is concerned about the dual challenge of rising daily cases and increased positivity in seven states, including Tamil Nadu and the Northeast states of Meghalaya, Tripura, Manipur, Sikkim, Mizoram, and Nagaland. 

The Indian Council of Medical Research (ICMR) is expecting to increase the testing capacity to 2.5 million per day, from nearly 2 million a day currently by the end of May and to 4.5 million by the end of June. This capacity will be a mix of rapid antigen test (RAT) and reverse transcription–polymerase chain reaction (RT-PCR). 

The ICMR is planning to increase RAT capacity fourfold - from 700,000 per day to 2.7 million a day - and RT-PCR from 1.2 million to 1.8 million a day by the end of June. 

The government’s strategy would be to ramp up testing using RATs in rural areas, so that there is one mobile testing van for every 10 villages.