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  • Writer's pictureASAR Blog Team

Exploring the outbreak data numbers in India: An ASAR Data Story

Updated: Dec 5, 2023

By ASAR Blog Team

Ideation & Drafting

Padmavathy Krishna Kumar, Pubali Biswas, Sweta Dubey, Parth Sharma, Shreyas Patil

Calculations & Visualisations

Shreyas Patil

Data Extraction

Shreyas Patil, Padmavathy Krishna Kumar, Pubali Biswas

Review & Editing

Siddhesh Zadey, Parth Sharma, Shreyas Patil

‘Health system development is a key to effective detection, response, and control of any outbreak.’

- Margaret Chan

The world has witnessed numerous events where tiny, invisible organisms around us have wreaked havoc and led to great suffering. The plague epidemic in the Middle Ages, the Spanish flu pandemic in the 1910s, and, most recently, the COVID-19 pandemic were unexpected events for which the world was unprepared. These events are called disease outbreaks which are defined by the WHO as “the occurrence of cases of disease over what would normally be expected in a defined community, geographical area, or season.“

Overcrowding, rapid unplanned urbanisation, and poor communal hygiene are some factors related to an increased incidence of infectious diseases. With India becoming the most populous country in the world, controlling these potentially explosive contagious disease outbreaks becomes all the more challenging. To tackle this, the Integrated Disease Surveillance Programme (IDSP) was initiated under the National Health Mission (NHM) in India.

The IDSP reports and maintains digitised surveillance systems for diseases susceptible to outbreaks. The data collected helps in tracking a rapid rise in cases and mitigating any potential outbreak. Under the IDSP, health workers and medical officers at health facilities report outbreaks of various diseases at the district level weekly. A cumulative weekly outbreak report is then generated at the state level.

In this ASAR data story, we use the IDSP data on infectious disease outbreaks in India for 2022 to understand general reporting trends of outbreaks with a closer look into diarrheal disease, measles, and vector-borne disease outbreak reporting at the district level.

1) How did reporting infectious disease outbreaks in India vary over 5 years from 2018-2022?

Reporting of disease outbreaks was the highest in 2019 at 1667 and its lowest in 2020 with only 563 outbreaks reported. (Figure 1) This fluctuation in reporting could be attributed to the COVID-19 pandemic, wherein health system resources were diverted towards containing the viral disease. However, the reporting recovered slightly post-COVID, with 726 outbreaks reported in 2021 and 1072 outbreaks reported in 2022.

2) How did the percentage of weekly outbreak reporting (including nil reporting) by the States/Union Territories (UT) of India vary in 2022?

All states/UTs must report to the IDSP portal weekly mandatorily and, in the absence of a disease outbreak, a nil report needs to be submitted. The percentage of reporting for each week was calculated by dividing the number of states/UTs submitting a weekly report (including nil reports) by the total number of states/UTs in 2022 (36 at the time) multiplied by 100.

A lapse in reporting was noticed as less than half the states/UTs reported (including nil reporting) to the IDSP portal for most of 2022 (36 out of 52 weeks). (Figure 2) The highest proportion of reporting was observed in the 19th and 22nd weeks, with about 6 out of every 10 states/UTs submitting a report. Data on reporting was missing for weeks 24, 45, 46, 48 and 52.

3. How did the reporting of diarrheal disease outbreaks vary across the districts of India in 2022?

We included the outbreaks reported under the following IDSP categories in diarrheal disease: Acute diarrheal disease (ADD), Food poisoning, Cholera, Typhoid, Dysentery, and Norovirus.

In 2022, 582 diarrheal disease outbreaks were reported in India. The districts that reported the highest number of diarrheal disease outbreaks were Ernakulam, Kerala (14), Mirzapur, Uttar Pradesh (13), Thiruvananthapuram, Kerala (11), Kalaburagi, Karnataka (9) and Kottayam, Kerala (9). However, over 500 districts nationwide reported no diarrheal disease outbreaks in 2022. (Figure 3) Whether these zeroes are true nulls or due to deficiencies in reporting necessitates a deeper look. It is also evident from the data that two districts from Kerala had some of the highest number of reported diarrheal disease outbreaks compared to several bigger states which have none. This might be the result of better reporting and must be interpreted cautiously.

4. How did the reporting of vector-borne diseases (VBD) outbreaks vary across the districts of India in 2022?

The National Vector Borne Diseases Control Programme (NVBDCP) of India focuses on six diseases: Malaria, Dengue, Chikungunya, Japanese Encephalitis, Kala Azar, and Lymphatic filariasis. A total of 141 VBD outbreaks were reported in India in 2022. Pune, Maharashtra (9); Ernakulam, Kerala (7); Chandrapur, Maharashtra (6); Nalanda, Bihar (4); Akola, Maharashtra (4) and Gadchiroli, Maharashtra (4) were among the districts with the highest number of reported VBD outbreaks for the year. In the case of VBDs as well, over 700 districts reported no outbreaks in 2022, which merits further investigation to determine if these are true nulls or due to issues in reporting. (Figure 4) As for the individual VBDs, the number of outbreaks reported was highest for Dengue at 84, followed by Malaria and Chikungunya with 19, and Japanese Encephalitis with 15 outbreaks. Three outbreaks for Kala Azar and one for Lymphatic filariasis were also reported in 2022.

Various differences have been noted while comparing IDSP outbreak data with the data provided by the NVBDCP. For example, Bihar and Jharkhand reported 550 and 188 cases of Kala Azar respectively as per the NVBDCP data but no outbreaks were reported to the IDSP. Similarly, none of the 257 districts endemic for filariasis reported an outbreak in 2022, but Tuensang in Nagaland was the sole district to report an outbreak of filariasis to the IDSP. With respect to dengue, the largest number of cases in the country was reported from West Bengal with 67,271 cases. However, only one outbreak was documented from Jalpaiguri district in West Bengal on IDSP. Similarly, Delhi, Chhattisgarh, and Odisha showed a disparity between cases and outbreaks reported.

5. How did the reporting of measles outbreaks vary across the districts of India in 2022?

Measles is a vaccine-preventable disease, and its presence connotes poor immunisation status of the children within that country. India reported 46 outbreaks of measles in 2022. Godda district in Jharkhand had the highest number in 2022, with 9 outbreaks, followed by Nuh, Haryana, with 7 outbreaks. Malappuram in Kerala and Nainital in Uttarakhand reported 3 outbreaks each. The district of Panipat in Haryana, Jamtara, and Pakur districts of Jharkhand, and Almora district of Uttarakhand reported two measles outbreaks each in 2022. Sixteen other districts reported one outbreak each, as depicted in the bar plot below. (Figure 5)

In 2022, Maharashtra reported about 2,692 cases of measles followed by Gujarat with 1,672 cases. However, according to the IDSP weekly outbreak data for 2022, just 36 cases of measles in Maharashtra and 15 cases in Gujarat were reported. These indicate an element of under-reporting, which warrants a deeper look to find out the causes behind this and devise solutions to fix them.

India’s preparedness for disease outbreaks is an important and evolving part of its public health system. However, several areas require attention to ensure better preparedness for future disease outbreaks. Underreporting and lack of NIL reporting by states raise concerns about the completeness and timeliness of the outbreak reporting system. For instance, the NVBDCP data for state-level cases for the VBDs shows a large variation from the respective IDSP reporting data. This re-emphasizes the need to cross-verify and further analyse the IDSP data with other sources like the NVBDCP for its accuracy.

A swift response and containment of outbreaks is possible only when accurate and real-time surveillance data is available. It is imperative that our country invests greater efforts and also thoroughly monitors the functioning of our data reporting systems with proper quality check mechanisms in place.

Cite this article as:

Krishna Kumar P, Biswas P, Patil S, Sharma P, Dubey S. Exploring the outbreak data numbers in India: An ASAR Data Story. 2023 Sep 26; Available from:



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