Diagnostics in Developing Countries
Science & Technology › Biotechnology – Principles and Techniques · Topic 10.18
Diagnostics in developing countries are tests and tools designed to find disease accurately at a low cost, in places with limited laboratories, electricity and trained staff. The World Health Organization describes the ideal test with the ASSURED criteria: affordable, sensitive, specific, user friendly, rapid and robust, equipment free and delivered to those who need it. Examples include rapid test strips for malaria, dengue and HIV, the CBNAAT cartridge test for tuberculosis, paper based tests, smartphone readers and point of care devices. Cheap, accurate diagnosis matters because treatment depends on it and wrong or late diagnosis fuels drug resistance and deaths.
5 min read · UPSC Prelims · Science & Technology · Biotechnology – Principles and Techniques
At a Glance
- Standard ASSURED criteria
- Main type Point of care rapid tests
- TB test CBNAAT and Truenat
- Aim Low cost, accurate, quick
- Link Public health
- Exam link UPSC Prelims, Science & Technology: Biotechnology – Principles and Techniques
Where Does It Fit?
This is the last topic of the macro on biotechnology principles and techniques. It brings together probes, antibodies and PCR and asks how they can be made cheap and simple enough for poorer settings. Previous topic: Pharmacogenetics. Next topic: Genetically Modified Plants and Pest-Resistant Crop Technologies.
What Makes a Good Diagnostic for Low Resource Settings?
| Criterion | Meaning |
|---|---|
| Affordable | Cost within reach of patients and health systems |
| Sensitive | Few false negatives. Catches true cases |
| Specific | Few false positives. Avoids wrong treatment |
| User friendly | Simple steps that a health worker can do after short training |
| Rapid and robust | Result within minutes to hours, and stable in heat and humidity without a cold chain |
| Equipment free | Minimal need for power, water or complex machines |
| Deliverable | Reaches those who need it, including remote villages |
Which Tools Are Used?
- Lateral flow strips: antibody based paper tests for malaria, HIV, dengue, hepatitis and pregnancy, giving results in 10 to 20 minutes
- CBNAAT or GeneXpert: a cartridge based PCR test that detects tuberculosis and rifampicin resistance in about two hours
- Truenat: an Indian chip based real time PCR test from Molbio Diagnostics, used for tuberculosis and other infections in peripheral laboratories
- Microscopy: sputum smear and blood film remain the cheapest, but need skilled staff
- Paper microfluidics: tests on printed paper that move fluid by capillary action
- Smartphone readers: phones capture and read colour or fluorescence for result recording and reporting
- Isothermal amplification: methods like loop mediated amplification that work at one temperature without a thermal cycler
- Telemedicine and artificial intelligence: remote reading of X-rays and slides when specialists are scarce
What Else Should You Remember?
- Sensitivity and specificity: sensitivity is the share of sick people correctly found, and specificity is the share of healthy people correctly cleared
- Point of care: testing at or near the patient, so treatment can start at the same visit
- Tuberculosis: India has the largest number of tuberculosis cases in the world, and molecular testing is being scaled up under the National TB Elimination Programme
- Malaria: rapid tests help to separate malaria from other fevers, so that antimalarials are used only when needed
- Sickle cell: a low cost point of care test for sickle cell disease has been developed and is used in screening programmes in tribal areas
- Free Diagnostics Service Initiative: a National Health Mission programme that provides free tests at public health facilities
- Health and Wellness Centres: Ayushman Arogya Mandirs offer screening for common non-communicable diseases and infections
- Quality assurance: rapid tests must be validated, and poor quality kits can give false results
- Regulation: diagnostics in India are regulated as medical devices under the Medical Devices Rules, 2017
- Make in India: Indian firms now make many kits, which lowers the cost compared with imports
- ICMR role: the Indian Council of Medical Research validates test kits and supports diagnostic research
- Link: these tests use ideas from Enzyme-Linked Immunosorbent Assay (ELISA) and Polymerase Chain Reaction (PCR)
- Antimicrobial resistance: accurate tests stop needless antibiotic use, because treatment can be matched to the cause of infection
- Cold chain problem: many tests need cool storage, so heat stable reagents and dried reagents make delivery easier in hot regions
- Training and reporting: health workers need training, and results must be recorded in digital systems so that programmes can track disease
- Local innovation: Indian start-ups and institutes have developed low cost devices for anaemia, sickle cell and cervical cancer screening that are designed for field use
Why Does It Matter for the Exam?
- Criteria: ASSURED and its meaning
- Tests: CBNAAT, Truenat and lateral flow
- Concepts: sensitivity and specificity
- Current affairs link: new tests for tuberculosis and sickle cell
- Common errors: confusing sensitivity with specificity
As an analytical point, accurate and fast diagnosis is the base of every disease control programme. Indian innovation in low cost, field ready tests can serve the country and other developing countries.
Why Is This Topic Important?
- Criteria ASSURED
- Tools Strips and cartridges
- Policy Free diagnostics
What Came Next?
The next macro covers applications of biotechnology, beginning with genetically modified plants. Next topic: Genetically Modified Plants and Pest-Resistant Crop Technologies.
Key People and Terms
- Point of care Test at patient site
- Sensitivity Catches true cases
- Specificity Avoids false alarms
- Cold chain Chilled storage
- Lateral flow Strip test
- Cartridge Self-contained test unit
Exam Corner
Points to Remember
- ASSURED: affordable, sensitive, specific, user friendly, rapid and robust, equipment free, deliverable.
- CBNAAT gives result in about two hours.
- Truenat is an Indian test.
- Sensitivity: few false negatives.
- Medical Devices Rules: 2017.
Do Not Confuse With
- Sensitivity and specificity False negatives versus false positives
- CBNAAT and Truenat GeneXpert system versus Indian chip based system
- Screening and diagnostic tests Find possible cases versus confirm disease
Memory Hook
ASSURED means low cost, quick and sure; strips and cartridges take the test to the door.
Mains Angle
Questions ask about the features of good tests and about Indian efforts. These points help.
- Need Access in villages
- Tools Strips and cartridges
- Policy Free tests and quality
A Question You May Face
An original practice question, not a past paper question.
“Discuss the importance of low cost point of care diagnostics for developing countries and the initiatives taken in India.”
How to Answer
- Need Scarce labs.
- Tools Rapid tests.
- Initiatives Free diagnostics, Make in India.
- Way Quality and training.
GS Relevance
Frequently Asked Questions
What are the ASSURED criteria?
The ASSURED criteria were set out by the World Health Organization for ideal diagnostics in low resource settings. The letters stand for affordable, sensitive, specific, user friendly, rapid and robust, equipment free, and deliverable to those who need them. A test that meets these criteria can be used in villages without a laboratory.
What is CBNAAT?
CBNAAT, or cartridge based nucleic acid amplification test, is a rapid molecular test that detects the tuberculosis bacillus and resistance to the drug rifampicin from a sputum sample in about two hours. It works as a closed cartridge, so it needs little training, and it is widely used in India under the National TB Elimination Programme.
What is Truenat?
Truenat is an Indian chip based real time PCR test developed by Molbio Diagnostics. It is battery operated and portable, so it can be used in peripheral health centres to detect tuberculosis, and has been adapted for other infections. It is an example of low cost diagnostics made in India.
What is a point of care test?
A point of care test is performed at or near the patient, such as at a clinic or in a village, and gives results quickly so that treatment can start at the same visit. Examples are rapid strip tests for malaria and HIV, blood glucose meters and cartridge based molecular tests.
What is the difference between sensitivity and specificity?
Sensitivity is the ability of a test to correctly identify people who have the disease, so a highly sensitive test gives few false negatives. Specificity is the ability to correctly identify people without the disease, so a highly specific test gives few false positives. Good diagnostics need both.
PYQ Practice — Statement Analysis
1 A highly sensitive test gives few false negatives.
It catches true cases.
2 CBNAAT detects tuberculosis and rifampicin resistance.
Using a PCR cartridge.
3 Truenat is a diagnostic platform developed in India.
By Molbio Diagnostics.
4 In the ASSURED criteria the letter S stands for sustainable.
S stands for sensitive and specific.
Past Mains Questions on This Topic
This topic comes under Biotechnology – Principles and Techniques. UPSC Mains questions asked on the matching syllabus topic, year-wise with marks:
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