The TrueNat test was originally developed to quickly and accurately diagnose Tuberculosis (TB) but has since been adapted for other infectious diseases, including COVID-19. It is a portable, chip-based, battery-operated device that offers a cost-effective, rapid alternative to traditional RT-PCR tests. Here’s an in-depth look at what the TrueNat test is and how it works for both TB and COVID-19.

What is the TrueNat TB Test?

TrueNat was developed to detect TB in just one hour. The TrueNat Xpert MTB and TrueNat Xpert MTB Plus are the versions used for TB detection. Created by a Goa-based company, TrueNat has been approved by the World Health Organization (WHO) due to its high accuracy, affordability, and efficiency. It’s often described as a miniaturized PCR test, making it accessible even in resource-limited settings.

TrueNat Test for COVID-19

Given the versatility of the TrueNat system, it was quickly adapted to detect COVID-19 when the pandemic began. The Indian Council of Medical Research (ICMR) approved TrueNat for conducting COVID-19 tests due to its portability, allowing it to be used in remote areas to screen patients.

For the COVID-19 test, nasal and throat swabs are collected by trained technicians wearing personal protective equipment (PPE). The SARS-CoV-2 virus, which causes COVID-19, contains RNA, not DNA. The TrueNat machine uses a reverse transcription process (RT) to convert the virus’s RNA into DNA before it is analyzed.

Initially, TrueNat could only detect the E-gene in the SARS-CoV-2 virus, which is responsible for forming the envelope of the virus. However, newer versions of the TrueNat test can now also detect the RdRp gene, which plays a role in the replication of the virus, making the test even more accurate.

Revised Guidelines for TrueNat for COVID-19

ICMR has outlined three types of TrueNat assays for COVID-19 detection:

1. TrueNat Beta CoV E Gene Screening Assay: Initial screening for the presence of the E-gene.
2. TrueNat SARS CoV 2 RdRp Gene Confirmatory Assay: Used for confirmation if the screening is positive.
3. TrueNat COVID-19 Multiplex Assay: A one-step test that screens for both the E-gene and the Orf1a gene for confirmation.

Negative results are considered true negatives, and positive results are treated as true positives.

How Long Does the TrueNat Test Take?

The TrueNat test takes about one hour to detect TB, and for diagnosing resistance to the drug Rifampicin, an additional hour is required. For COVID-19, the test is a two-step process that takes around two hours to screen and confirm the presence of the virus.

Accuracy of the TrueNat Test

For TB detection, TrueNat tests show:

• 99% specificity compared to sputum microscopy.
• 89% sensitivity for TB detection.

For COVID-19, the TrueNat test demonstrates similar levels of accuracy and specificity to other RT-PCR tests, such as Genexpert.

TrueNat Test Procedure for COVID-19

The TrueNat test for COVID-19 consists of the following steps:

1. Sample Collection: A nasal or throat swab is collected and placed in a viral lysis buffer.
2. Step 1: TrueNat Beta CoV E Gene Screening: If the sample tests negative at this stage, it is deemed COVID-negative.
3. Step 2: TrueNat SARS CoV 2 RdRp Gene Confirmation: If the sample is positive, the presence of COVID-19 is confirmed.

Advantages of TrueNat Over Other Tests

1. Portable: The battery-operated machine can be easily transported to remote areas, making it ideal for rural healthcare settings.
2. Cost-Effective: The TrueNat test costs significantly less than a traditional RT-PCR test.
3. Quick Turnaround Time: TrueNat delivers results in two hours for COVID-19 and one hour for TB, making it faster than many other molecular diagnostic methods.
4. High Accuracy: TrueNat has shown high levels of accuracy and specificity, both for TB and COVID-19, comparable to other leading molecular diagnostic tests.

Conclusion

The TrueNat test is a game-changer for diagnosing diseases like TB and COVID-19 in India, especially in remote or resource-limited settings. Its portability, speed, and cost-effectiveness make it a highly valuable tool in public health. The Indian Council of Medical Research (ICMR) has approved its use for COVID-19 detection, and it continues to play a vital role in screening and confirming cases in the ongoing pandemic.

TrueNat is a reliable, quicker, and more affordable alternative to traditional RT-PCR tests, and with minimal training, healthcare workers can collect and analyze samples efficiently.

FAQs

1. What is the difference between TrueNat and other COVID-19 test kits?
TrueNat is portable, making it ideal for use in remote locations. It is also cheaper than larger RT-PCR test kits.

2. How long does the TrueNat machine operate on a full charge?
TrueNat machines can function for 10 hours on a full charge and can run 24/7 if necessary.

3. How many samples can be tested in a day?
In an eight-hour shift, TrueNat can complete 45 tests.

4. What diseases can TrueNat detect?
TrueNat is primarily used for detecting TB, COVID-19, and HIV. The machine can be programmed to detect multiple diseases.

5. How accurate is the TrueNat test for COVID-19?
The TrueNat test has shown high accuracy and specificity for COVID-19, comparable to other molecular diagnostic tests like Genexpert.