In numbers: The COVID-19 pandemic

Data | India's COVID-19 testing declines sharply despite rising positivity rate

File photo of a medical team conducting COVID-19 test in East Godavari district.   | Photo Credit: S. Rambabu

The number of new COVID-19 cases in India recorded a significant fall in the last five days after consistently breaching the 90,000 mark on several days in early September. The drop in cases could be due to a significant decrease in the number of tests conducted.

In at least 10 States, there was a sharp fall in the number of tests conducted in the last 10 days despite an increase in the share of people testing positive.

Rapid fall in tests

Over the last 10 days, the number of new COVID-19 tests conducted per million people in India has been declining rapidly. While the share of people testing positive (positivity rate) has remained high and even increased a little over the last five days, the number of tests per million people dropped from 811 to 722 over the last 10 days. The share of positive tests is hovering around the 8.5% mark.


Chart appears incomplete? Click to remove AMP mode

Among States

Not all States recorded a decline in tests. They can be classified into three types based on their recent testing levels.

The bad: In Maharashtra and Assam, tests are going down, while the share of positive cases is going up. Using such a strategy would mean missing a lot of positive cases.


Other States in this category include Arunachal Pradesh, Goa, M.P., Nagaland, Sikkim, Tripura, Chhattisgarh and Karnataka.

The good: In T.N., tests are going up, while the positivity rate is going down. Other States include Delhi, Bihar, Jharkhand, Mizoram and W.B.


This is the ideal strategy. Despite the positivity rate going down, tests need to be scaled up or maintained at a certain level. Such an approach is required as sero-surveys show that for every confirmed case, there were 82-130 undetected infections in India.

Thus, the more the tests, the better, regardless of the positivity rate

Middling States: In Gujarat and Telangana, tests are dropping, but the share of positives is also going down. In these States, tests should be maintained at a certain level, if not increased, to ensure that the share of positives does not necessarily go down due to decreasing testing levels.

In Andhra Pradesh, tests as well as the share of positives are rising. Such States need to increase their testing levels to capture more positives. Nine other States are following this trend: Haryana, J&K, Punjab, Rajasthan, Uttarakhand, Manipur, Meghalaya, U.P. and Kerala.

Last word

The positivity rate varies widely based on the method of testing. For instance, over the past seven days, 81% of tests in Delhi were Rapid Antigen Detection Tests (RADT), which are not as reliable as RT-PCR tests. RADTs can register as many as 50% 'false negatives'.

The Hindu In Focus podcast | Do rapid antigen tests provide reliable enough data to track the pandemic?

In Tamil Nadu, RADTs are not used. Thus, while the positivity rate in T.N. may be closest to the actual rate, the same cannot be said about Delhi. The share of RADTs in select States is as follows: A.P. (54%), Chhattisgarh (68%), Karnataka (42%), W.B. (55%), Mizoram (25%), Nagaland (7%).

Our code of editorial values

Related Topics
This article is closed for comments.
Please Email the Editor

Printable version | Jul 27, 2021 5:56:50 AM |

In This Series
Data | What is the COVID-19 vaccine policy of countries across the world?
Data | U.K. variant of the novel coronavirus spreads at least 50% faster than old variants
Data | U.S. bears the brunt of global COVID-19 deaths in December; Delhi, W.B. and Punjab record spurt in fatalities
Data | How India fared in various COVID-19 parameters since March, compared with other countries
You are reading
Data | India's COVID-19 testing declines sharply despite rising positivity rate
From 0 new COVID-19 cases to 10,000 in six months: dissecting Kerala's second wave
Data | COVID-19 infections continue to grow at a constant pace in India
Data | Lower COVID-19 fatality rate in rural areas not necessarily due to lower share of co-morbidities among rural population
The Hindu Explains | Is COVID-19 intensifying in rural India?
Data | What's afoot on the COVID-19 vaccine front?
Data | COVID-19 deaths in India are rising third fastest in the world
Puducherry's pandemic trajectory shows the need for more testing
Data | India's COVID-19 cases are the fastest growing in the world
Data | Less reliable rapid antigen tests ramped up in many States
Coronavirus | In contrast to initial stages, districts now push tally in Tamil Nadu
Data | COVID-19 resurges in Kerala as migrants return, testing rate drops
Data | Overcrowded jails and the COVID-19 contagion
Data | Among nations with a high case load, infections continue to double in less than 20 days only in India
Understanding Chennai’s COVID-19 trend
Data | How do States fare on reporting COVID-19 data?
Data | Not just Mumbai and Chennai, COVID-19 cases are starting to swell in Cooch Behar and Ayodhya too
Data | Major uptick in COVID-19 cases in the past week and it's not just the usual suspects
Data | Coronavirus deaths increasing significantly in several States
Data | Domestic violence complaints at a 10-year high during COVID-19 lockdown
Data | A study of India's coronavirus cases: symptoms to secondary transmission
Data | Karnataka, Telangana, A.P. see sharp spike in COVID-19 cases; burden easing in Delhi
Data | COVID-19 has affected higher share of men in India, difference relatively lesser in other countries
Data | An estimated 12.2 crore Indians lost their jobs during the coronavirus lockdown in April: CMIE
Data | Sudden spike in cases results in fastest COVID-19 doubling rate in Punjab in the past week
Data | States which tested more in the initial days of the coronavirus outbreak found it easier to contain the spread
Data | Why handwashing and physical distancing are a privilege to the poor
Data | Migrant workers' distress continues as nationwide lockdown extended for the second time
Data | The variable impact of the novel coronavirus across different countries
Data | A State-wise comparison of coronavirus infection doubling rates and testing
Data | Kerala flattens the coronavirus curve but must remain vigilant as 'import' cases still dominate
Data | Why has Mumbai seen the most coronavirus cases in Maharashtra?
Data | Where are the coronavirus hotspots in India?
Data | The lockdown effect on jobs in India
Data | How quickly are coronavirus infections and deaths increasing in India, compared to the rest of the world?
Data | 96% migrant workers did not get rations from the government, 90% did not receive wages during lockdown: survey
Data | How fast are India's coronavirus cases doubling since the lockdown?
Data | Who gets tested for coronavirus determines infection rates better than how many are
Data | How many doctors and nurses have tested positive for coronavirus in India?
Data | India's coronavirus infection rates are among the highest in Asia
Data | From 129 to 430 districts in a month: how coronavirus cases are spreading thick and fast
COVID-19 | Under which zone does your district lie?
Data | In the battle against COVID-19, severity of lockdown matters less than testing rates
Data | Are States testing enough compared to the size of their coronavirus outbreaks?
Data | Is India undercounting its COVID-19 deaths?
Data | The curious case of Gujarat's COVID-19 curve: remained flat throughout May
Data | Why is it necessary to test more to reduce the impact of COVID-19?
Data | The path to 5 lakh coronavirus cases: infections, fatalities spiralling; testing rate consistently coming down
Data | Most COVID-19 deaths occurred within two days of hospital admission in Chennai, Karnataka
Data | India's COVID-19 situation worst among Asian countries
Data | Japan's limited testing strategy for coronavirus does not yield in the long run
Data | Which States recorded the most coronavirus cases, deaths, and the best testing rates?
Data | To reduce coronavirus spread, India needs to test more, lockdown notwithstanding
Data | Who are the most vulnerable to the lockdown among urban dwellers
Coronavirus | Patient data from Singapore and South Korea shows physical distancing is the only option
Data | How prepared are India's States in health infrastructure to tackle COVID-19
Data | Kerala leads States in testing for coronavirus, Maharashtra in infections
Data | Where does India stand on the coronavirus curve?
Data | COVID-19 is deadliest for the elderly
Data | 5,680 flights cancelled: the coronavirus impact on global air travel
Data | Coronavirus death rates peak in Italy and Spain
Data | India's coronavirus testing rates are among the lowest in the world
Data | Govt. rarely passes on the benefit of falling crude oil price to consumers
The Disaster Response Force teams of Greater Hyderabad Municipal Corporation wearing protective gear and spray disinfectant chemical at medical shop amid concerns over the spread of the novel coronavirus, in Hyderabad on March 23, 2020.
COVID-19 | Interactive map of confirmed coronavirus cases in India
Data | Where does the March 9 market crash rank among the biggest falls in Sensex history?
Data | Is COVID-19 spreading faster outside mainland China?
Data | The wide, rapid spread of the novel coronavirus
Next Story