Background: Tuberculosis caused by Mycobacterium Tuberculosis is detected by smear microscopy, molecular tests like CBNAAT (Cartridge based nucleic Acid Amplification test) or Truenat, Line Probe assays (LPA) and phenotypic tests like solid Culture and liquid Culture. Yet every year there are many cases which go undiagnosed due to lack of information, availability, and accessibility to these tests. Presumptive examination rate helps us to understand the scenario of existing individuals having any one of the symptoms of TB diagnosing TB and thus helping in detecting Tuberculosis cases much earlier.

Interventions: A quality analysis and assessment were conducted to identify the reasons for the high and low Presumptive Examination Rates across all districts in Telangana, India. The availability of CBNAATs and truenats machines at the periphery level helped in increasing the number of tests in the year 2022. The state ensured the availability of logistics such as CBNAAT cartridges and Truenat chips. Extensive IEC efforts were carried out at both district and block levels to promote the availability of NAATs, aiming for optimal utilization of the machines for patients seeking care in both the public and private sectors.

Results: The Presumptive examination rate, which was significantly lower in the year 2015 gradually, increased in the year 2023 with adequate availability of logistics in the NAAT facilities. This intervention not only increased the presumptive examination rate but also boosted TB detection rates and utilization of the public sector NAAT facilities by the private sector.

Conclusion: Analyzing the presumptive examination rate provides insights into the availability and accessibility of facilities, the sufficiency of logistics, and the utilization of services across all sectors. This understanding aids in developing more effective strategies to make TB diagnostics more accessible.

Keywords: quality analysis, diagnostics, global health, resources

PER, presumptive examination rate; TB, tuberculosis; NAAT, nucleic acid amplification test, LPA, line probe assays

Tuberculosis (TB) remains a significant global health challenge, with India bearing one of the highest burdens of the disease. Timely and accurate diagnosis is crucial for effective management and control of TB. Various diagnostic methods such as smear microscopy, molecular tests like CBNAAT and Truenat, Line Probe assays (LPA), and phenotypic tests like solid and liquid culture are available to diagnose TB. However, despite these advancements, many TB cases go undiagnosed each year due to factors like lack of awareness, limited access to diagnostic facilities, and insufficient logistics. In this article, we delve into the significance of presumptive examination rate as a metric for understanding TB diagnosis and discuss interventions undertaken in Telangana, India, to improve TB diagnosis rates.

Research question

1. Why is it important to understand the presumptive examination rate?
2. What is the influence of presumptive TB examination rate over TB diagnosis and notification?
3. What factors help in improving Presumptive TB examination rate?

Aims and objectives

1. To analyse factors affecting Presumptive examination rate.
2. To understand district wise issues for the time of the nine years from 2015 to 2023) in the state of Telangana, India to improve Presumptive examination rate.

Data was collected for last nine years i.e. from 2015-to 2023.The data included the monthly indicators of smear microscopy, Cartridge Based Nucleic Acid Amplification Test (CBNAAT) and Truenat: The data collected was analyzed to understand the availability of the NAAT resources and its logistics at the periphery, its optimal utilization and knowledge of the field staffs on these equipment.

Time period-2015-2023

Place- reports from all districts of Telangana, India

Study Period-January 2024-March 2024.

The data collected was analyzed against the number of new TB cases diagnosed in that particular year and occurrence of the positivity rate with the technology used.

The trend showed an increase in the presumptive examination rate from 584 tests/lac/year in 2015 to 1721 tests/lac/year in 2023.

The picture (Figure 1) shows an increase in Presumptive examination rate from 584 test/ lac/ year in 2015 to 1712 tests/ lac/year in 2023.

Figure 1 Bar diagram showing trend of presumptive examination rate from 2015-2023.

The availability of TB diagnostic resources in State of Telangana is as follows (Table 1).

The availability of resources is present pictorially in the diagram below (Figure 2).

Figure 2 Resources and presumptive examination rate.

The average Presumptive Examination Rate (PER) in 2015 across all districts of Telangana was 584 tests per lakh per year. Over the next nine years, the PER increased threefold compared to 2015 (Figure 3).

Figure 3 Line diagram showing presumptive examination rate and notification of TB achieved from 2015-2023.

The notification achieved and represented in graph is number of TB cases diagnosed in that particular year. Notification of TB against targets were in rise in 2019, but there was dip in both PER and Notification in the year 2020 &2021 (Figure 4).

Figure 4 Line and bar diagram showing samples testing from private sector and public sector along with presumptive TB examination rate from 2015-2023.

The Number of cases diagnosed with TB gradually increased and number of tests to be done for TB increases from 41343 (55%) to 71951 (91%).

Over the years, the utilization of the available TB diagnostic services from public and private sector increased gradually and thus improved in the of presumptive examination rate and thus overall increasing the TB notification (Figure 5–7).

Figure 5 Line and bar diagram showing notification from both the public and private sector and presumptive examination rate.

Figure 6 Showing NAAT samples testing in private, pediatric and EP samples.

Figure 7 Positivity for smear microscopy and NAAT.

As the number of tests increased, the positivity in both smear and NAAT decreased.

Tuberculosis is an age-old disease, and its diagnosis is important for early detection and prompt treatment to cut the chain of Transmission. There are many diagnostic methods for detection of Tuberculosis and few of them are as follows (Table 2).

However, the National Strategic plan for TB elimination 2020-2025 did special mention about an important indicator on Presumptive examination rate (PER).¹

Presumptive examination Rate is calculated as number of presumptive TB tests done per lac per year for a particular geography.

Presumptive TB² as per Technical Operational guidelines 2016 of Revised National TB Elimination program of India (RNTCP) is defines any person suffering from one or more of the following symptoms

1. Cough more than two weeks’ duration
2. Fever more than two weeks’ duration
3. Weight loss
4. Hemoptysis
5. Any abnormality in chest X-ray.

In 2015, when molecular techniques were not available in large number, the diagnosis of TB was limited with utilization of smear microscopy and chest x-ray.

The differences in the microscopy are charted as follows³ (Table 3).

Sputum smear microscopy accounts for a limited sensitivity of 5000–10,000 AFB/ml. Around 45% below the CFU count is missed. However culture techniques are comparatively better and scores over smear microscopy.⁴

In the year 2015, The State had only resource of sputum smear microscopy either by LED-FM or ZN microscopy to diagnose TB n the year 2015. The availability of Molecular technologies like CBNAAT (cartridge Based Nucleic Acid Amplification Test) and Line Probe assays were accessible only at Culture and Drug susceptibility labs (C&DST labs). The Presumptive examination rate calculated during the year 2015 is based only on smear microscopy.

In the year 2016, 15 CBNAAT sites were identified the state and policy of offering upfront NAAT in Children, PLHIV (people living with HIV) and Extra-pulmonary (EP) paved path and improved the diagnosis of Tuberculosis in people living with HIV and Ea Pulmonary TB cases.

The utilization of NAAT services across the state increased, however due difficulty in the sample extraction in Children less than 6 years, obtaining a EP sample for all presumptive TB cases posed a challenge. Obtaining an organ specific sample in case of EP TB case is a challenge and sputum sample testing may not be appropriate as it is not mandatory to have pulmonary involvement in all the cases. Moreover, lower sensitivities CBNAAT/ Xpert MTB Rif Assay were reported for cerebrospinal fluid, pleural, pericardial and synovial fluid samples.⁵

In a study by Akanbi et al in Nigeria, the use of upfront NAAT in symptomatic People living with HIV (PLHIV) demonstrated early detection of Tuberculosis with rifampicin resistance status. As part of intensified case finding in PLHIV group, upfront NAAT was offered to all symptomatic (current cough or fever or night sweats or weight loss).⁷

Microbiological diagnosis of TB enables confirmation of disease and initiation of appropriate treatment, and this is challenging in children because they often have pauci bacillary disease, and most young children cannot voluntarily produce good quality sputum specimens, the standard sample collected in adults.⁸ The testing of pediatric samples increased from 2016 to 2023 in NAAT which is supported by Non-Government organizations, public and private partnerships in the state of Telangana.

The testing of extra pulmonary and samples from Private sector increased over the years The increase in number of Tuberculosis tests and Presumptive examination rat can be categorized as follows (Figure 8).

Figure 8 Categorization of factors for increased PER.

1. Increase in number of machines and resources

As observed in Table 1, the availability of resources like Designated Microscopy Center, CBNAAT and Truenat increased from 2015 to 2023.

The availability of CBNAAT machines increased from 15 in 2016 to 42 in 2023.The availability of Truenat machines rose from 40 machines in 2021 to 95 machines in 2023.

However, low, presumptive examination rate was noticed in the year 2020, 2021 due to COVID-19 pandemic, and lack of availability of CBNAAT cartridges.

Yadadri, Bhongir, Nagarkurnool, Jogulamba Gadwal, Wanaparthy, Kamareddy, Jayasankar Bhupalpally and Medchal-Malkajiri did have CBNAAT till the year 2020.When state purchased four 16 module CBNAAT machines, few CBNAAT machines were relocated to where these services were not available. As on 2023, Narayanpet district did not CBNAAT facility. All the districts were equipped with more than 2 truenat machines and thus helped improving TB testing. A CBNAAT machine offered by Public service units like railways at Railway Hospital also helped in increasing PER in Hyderabad. Establishing a Truenat lab at ESI Medical College, under ministry of labour in Hyderabad also facilitated testing of TB.

2. Increase in awareness about tuberculosis

Awareness about Tuberculosis increased from 2015 to 2023. This was possible by offering upfront NAAT to all the Private samples. The awareness of TB increased by having community involvement, having TB clubs at the level of gram panchayat who were constituted by village heads, school teachers, religious heads, local health workers, etc.

This was evident in tribal districts like Khammam, Bhadradri, Kothagudem, Mulugu, Adilabad, Jayashankar Bhupalpally. The awareness of TB increased when strategic plans constituted the involvement of corporates, public sector units like railways, involvement of ministry of labor, panchayat raj, etc.

3. Public Private partnerships

The samples were linked to and from the private sector to the public sector through various schemes like Public Private Support Agencies (PPSA) under the program for early diagnosis and testing.

This increased the private sample testing from 1749 in 2016 to 21479 in 2023. The private sector in India is fragmented and its involvement in TB control is a key step. The Urban districts like Hyderabad, Rangareddy, Sangareddy, Medchal -Malkajgiri had performed more TB tests with the help of partnerships. There are many studies showing the impact of involving the private sector for offering molecular tests enhanced Presumptive examination rate.⁹

4. Memorandum of Understanding (MoU) between medical colleges and districts for pediatric and extra pulmonary sample

Extra pulmonary TB was unrecognized due to varied and non-specific symptoms and lack of access to diagnostic services.¹¹ Delay in diagnosis of extra pulmonary TB results in morbidity, increased mortality and disease sequelae.¹² The samples which are difficult to obtain especially in extra pulmonary cases has increased after having a MoU with medical colleges as a part of Public private Partnership scheme in Tb program. The difficult samples like biopsies, getting a gastric aspirate in pediatric presumptive TB cases was made easier. The number of extra pulmonary samples tested increased three times from 2016 to 2023.This was noticed in districts of Rangareddy and Sangareddy.

5. Involvement of professional bodies

Involvement of professional bodies like Indian Medical Association (IMA), Indian Academy of pediatricians (IAP) and other bodies helped the TB program realize the advantage of engaging professional associations at the initial planning stages of policy development and revisions especially building strategies to find out the missing cases.¹⁰

The involvement of professional bodies helped increasing private sample testing and also providing the microbiological evidence of disease even in EP cases.

6. Establishing the External Quality Assurance(EQA) mechanism for NAAT

External Quality Assurance for CBNAAT and Truenat is an important step for providing a more promised results for the molecular tests offered. In 2020, only 2 private sector CBNAAT labs were involved in EQA, where a dried tube may contain sample sent by National laboratories. The number of private CBNAAT facilities involving EQA mechanism is more than five in 2023.

The positivity of samples tested decreases both in smear microscopy and NAAT.

The presumptive examination rate in the state of Telangana increased from 584 in 2015 to 1721 in 2023.The increase in PER was because of many factors like increase in the number of resources, logistics for TB testing, involvement of private sector, professional bodies, involvement of public private partnerships schemes.

1. All staff of National TB Elimination Program (NTEP), Telangana, India
2. Mr. Prakash Reddy, Deputy Statistical Officer for data analysis

The authors declare that there are no conflicts of interest.

1. National strategic plan for elimination of tuberculosis in India. 2020-2025.
2. Technical operational guidelines –revised National TB elimination control program of India, Tbc, India. 2016.
3. Surani C, Kumar S, Chauhan M, et al. Comparison between ziehl-neelsen staining and fluorescent staining of sputum samples to detect acid fast bacilli in suspected case of pulmonary tuberculosis at tertiary care hospital, Amreli, Gujarat. India J Microbiol Res. 2021;8(4):302–307.
4. Leung E, Minion J, Benedetti A, et al. Microcolony culture techniques for tuberculosis diagnosis: a systematic review. Int J Tuberc Lung Dis. 2012;16:16–23.
5. SO Friedrich, F von Groote-Bidlingmaier, AH Diacon. Xpert MTB/RIF assay for diagnosis of pleural tuberculosis. J Clin Microbiol. 2011;49(12):4341–4342.
6. Akanbi MO, Achenbach C, Taiwo B, et al. Evaluation of gene Xpert for routine diagnosis of HIV-associated tuberculosis in Nigeria: a prospective cohort study. BMC Pulm Med. 2017;17(1):87.
7. Guidelines for prevention and management of TB in PLHIV at ART Center. Central Tb Division, India. 2016:4.
8. Perez-Velez CM, Roya-Pabon CL, Marais BJ. A systematic approach to diagnosing intra-thoracic tuberculosis in children. J Infect. 2017;74(Suppl 1):S74–S83.
9. Salje H, Andrews JR, Deo S, et al. The importance of implementation strategy in scaling up Xpert MTB/RIF for diagnosis of tuberculosis in the Indian health-care system: a transmission model. PLos Med. 2014;11(7):e1001674.
10. Lal SS. The role of private health sector engagement in TB control in India, Universities Leiden, Netherlands. 2019.
11. Nishal N, et al. Diagnostic yield of CBNAAT in the diagnosis of extrapulmonary tuberculosis: a prospective observational study. Lung India. 2022;39(5):443–448.
12. Solovic I, Jonsson J, Korzeniewska-Koseła M, et al. Challenges in diagnosing extrapulmonary tuberculosis in the European Union, 2011. Euro Surveill. 2013;18(12):20432.