JOIN USGovernment develops own model for estimating TB cases in India
India has become the first country in the world to have developed a country-level mathematical model to estimate the prevalence of TB cases, official sources said on Tuesday.
Using this model, TB incidence and mortality estimate data for India will be available by March every year, months before the annual WHO estimates are released in October, they said, adding that India can also prepare similar estimates at the state level in future.
The model was presented before the delegates from 40 countries taking part in the 36th Stop TB Partnership Board meeting in Varanasi last week. Most of them lauded it saying they would want to implement it in their countries, the sources said.
According to WHO estimates, the TB incidence rate (per 10,000) in India in 2021 was 210. Using the Indian mathematical model, it was estimated to be 196 in 2022. The WHO estimated that the TB incidence absolute number to be 29.50 lakh in 2021. The Indian model suggested it was 27.70 lakh in 2022.
According to WHO, the TB mortality rate (per 10,000) in 2021 was estimated to be 35, which reduced to 23 in 2022 as per the Indian model. WHO's TB mortality absolute numbers were estimated to be 4.94 lakh in 2021. The Indian model suggested it was 3.20 lakh in 2022, officials said.
They said a total of 21.5 lakh cases were notified on the Nikshay portal last year and 93,000 deaths were reported.
In 2022, a total of 23,58,664 patients were diagnosed with drug-susceptible TB (DSTB). Of them, 22,48,816 (95.3 per cent) were initiated on treatment. Among notified DSTB cases, 14,33,922 (60.8 per cent) were male, 9,22,649 (39.1 per cent) were female, and 1,34,001 (5.7 per cent) were below 14 years of age, according to India TB Report 2023.
Among the persons diagnosed with DSTB in 2021, 85 per cent had been successfully treated, 4.20 per cent died during treatment, 2.60 per cent were lost to follow-up, 1.9 per cent were assigned treatment failure outcome and 1.6 per cent were not evaluated (including still on treatment).
The treatment success rate of patients notified from public and private sector were 85 per cent and 87 per cent respectively, the report said.
It said 2022 marks a milestone year for TB surveillance efforts in India, with a record high notification of 24.20 lakh cases, an increase of over 13 per cent as compared to 2021. This translates to a case notification rate of about 172 cases per lakh population.
The treatment initiation rate among the notified cases for 2022 was 95.5 per cent. The highest case notification rate among States was seen in Delhi (546 per lakh population) and the lowest among States was seen in Kerala (67 per lakh population).
The new mathematical model was developed based on natural history of disease, individual status of infection, disease, healthcare seeking, missed or correct diagnosis, treatment coverage and outcomes including cure and death.
Listing the efforts taken over the last 9-10 years to increase the National TB Elimination programme coverage, find missing cases and generate more evidence, officials said laboratory services have been decentralised and scaled up with high quality rapid diagnostic tests such as Nucleic Acid Amplification Test (NAAT).
With scale-up of private sector engagement and mandatory notification, the coverage of private sector notification has increased over seven times since 2014. Besides, introduction of active case finding has helped the country in community screening of vulnerable and giving an opportunity for early diagnosis, thereby reducing per capita transmission rate in the community.
India has also introduced daily regimen for first-line treatment of tuberculosis in 2017, harmonizing the regimens in public and private sector harnessing universal access to TB care.
Also, drug resistant TB patients have been provided injection-free, shorter and better second-line treatment and with Ni-kshay, tracking of patients has also helped in improving the treatment outcomes of all types of patients in both public and private sector, including those which otherwise who would have been loss-to follow-up.