On September 11, samples despatched to Calicut Medical College for testing have been confirmed as Nipah virus. But solely on September 20, after 323 samples have been examined for the virus, did ICMR allow Kerala to make use of Truenat for Nipah testing. Even the belated permission got here solely after Kerala “strongly demanded” for Truenat throughout discussions with ICMR, Health Minister Veena George stated throughout a press convention.
Truenat for Nipah virus testing was granted an emergency use authorisation (EAU) by the Indian regulator in September 2021 days after the third Nipah outbreak in Kerala. The EAU was primarily based on validation of the Truenat take a look at to detect the virus and the Trueprep AUTO lysis buffer (to inactivate the virus) by NIV Pune in 2018 in Kerala and exterior validation on the Institute of Epidemiology Disease Control and Research, Dhaka, Bangladesh. Both human and bat samples from Kerala have been used for validating the take a look at in 2018. In 2019, NIV put in Truenat on the Government Medical College, Ernakulam through the Nipah outbreak, and at two discipline websites in Punjab as a part of the Nipah virus surveillance in bats. Of the 120 human scientific specimens and 25 samples from bats examined in 2019, Truenat accurately identified all of the constructive and detrimental samples, besides for one constructive human pattern.
As per a 2021 paper revealed within the Indian Journal of Medical Research, the sensitivity of Truenat was 97% and specificity was 100%. It was capable of accurately diagnose Nipah even when different viruses have been current. The efficacy of the Trueprep AUTO lysis buffer for inactivating Nipah virus previous to virus detection was additionally examined and located to be excessive. The “inactivation of Nipah virus was evident by the absence of Ct value”, notes the paper. A examine was carried out at NIV in April 2020 utilizing SARS-CoV-2 virus to judge the virus inactivating effectivity of each the lysis buffer and the Trueprep AUTO transport medium. The examine, which is but to be revealed however shared with The Hindu, discovered excessive virus inactivating effectivity by each the lysis buffer and the transport medium.
“The Truenat test for Nipah virus was already developed and ready as our idea is to work on diseases that have the potential to become a pandemic if not diagnosed early,” says Dr. Chandrasekhar Nair, Director and Chief Technology Officer at Molbio Diagnostics Pvt Limited.
Despite the validation as a point-of-care take a look at by NIV and an EUA granted in September 2021, ICMR didn’t allow Kerala to make use of Truenat until September 2023. A senior scientist primarily based in Kerala tells The Hindu that it is the Indian regulator and never the ICMR that is authorised to approve the usage of Truenat for Nipah testing. With an EUA granted in 2021, States ought to have been free to make use of Truenat with none permission from ICMR, the scientist says.
BSL-2 amenities
“Truenat will be used for testing Nipah virus at five government medical colleges that have a BSL-2 facility with BSL-3 practices. Private medical colleges that have similar facilities will also be allowed to use Truenat,” says Hanish Mohammad, Principal Secretary (Health), Kerala.
“Testing for Nipah using Truenat is being considered only for hospital-based BSL-2 facilities and not in stand-alone labs,” says Dr. Aravind R, Head of Infectious Diseases, Government Medical College, Thiruvananthapuram. According to him, permitting solely hospital-based BSL-2 amenities to check for Nipah is to discourage folks from strolling in to get examined at stand-alone labs. “The decision to test for Nipah should be taken by doctors, not patients. There should be a pretest probability of a patient being positive for Nipah,” says Dr. Aravind.
“The lysis buffer inactivates the virus and the risk is reduced maximally. There is no need for a BSL-2 lab for Nipah virus testing when Truenat is used,” says Dr. Raman Gangakhedkar, who was the Head Scientist of Epidemiology and Communicable Diseases at ICMR and a co-author of the 2021 paper.
Explaining why a BSL-2 facility is important for testing Nipah virus, Dr. Rajiv Bahl, Director-General of ICMR says: “Even though in the diagnostic samples the virus may be inactivated by using lysis buffer, handling the initial samples before the addition to lysis buffer without strict containment measures may pose a risk of exposure to healthcare workers or any accidental environmental release if no proper decontamination is taken care of.”
However, Dr. Nair of Molbio Diagnostics confirms to The Hindu that for Truenat, the virus is inactivated on the website of pattern assortment and never when the pattern reaches the BSL-2 facility. Therefore, the inactivated virus is inert and non-infectious when the pattern reaches the lab for testing. “The Trueprep AUTO transport media is a proprietary medium that has reagents to inactivate the virus. The transport media inactivates the virus while the lysis media in Trueprep AUTO completely breaks open the pathogens to release nucleic acids,” he explains. The April 2020 examine at NIV discovered each the lysis buffer and the transport medium extremely environment friendly at inactivating the SARS-CoV-2 virus.
Virus confirmation
ICMR and NIV are very clear that for an official confirmation, the pattern should be examined solely in a BSL-3/4 facility, says Mr. Mohammad. The insistence on a BSL-3 facility for virus confirmation is primarily based on the 2021 authorities of India memorandum, he provides.
However, India’s guidelines on a BSL-3 facility for Nipah virus confirmation run counter to the WHO’s draft excessive precedence diagnostics for Nipah. The WHO doc mentions that Nipah will be confirmed by detection of the virus RNA or viral tradition. For a reference laboratory setting, the “diagnostic options for confirmation can include laboratory NAT, NPT/POC NAT assays, virus isolation (if BSL-3/4 available), and serum neutralisation assays”. Of the diagnostic choices for Nipah confirmation, WHO has included each near-patient testing (NPT) and point-of-care (POC) NAT testing; Truenat is a POC NAT take a look at. The WHO additionally clearly mentions that BSL-3/4 facility is wanted solely when virus isolation is undertaken; isolation of viruses is solely for analysis functions.
“Viruses are sometimes cultured [for detection]. This used to be done a lot before nucleic acid-based amplification became available… Used much less now (and viral culture experts and lines are hardly available),” says microbiologist Dr. Gagandeep Kang, former professor at CMC Vellore. Dr. E. Sreekumar, Director of the Institute of Advanced Virology, Thiruvananthapuram says: “All labs in India, including the NIV’s, use only RT-PCR for Nipah diagnosis, be it for initial detection or confirmation. No other methods are used now.”
Usually, it is the identical specimen that has been used for testing that is despatched for virus confirmation, says Dr. Aravind. Dr. Sreekumar provides: “At present, ICMR encourages collection of only live samples so that they can do both diagnostic testing and research by virus isolation in the same sample. This [collection of live samples] prevents early detection as local labs are prevented from doing testing.”
But now, by default, all samples despatched for Truenat testing are collected in a transport medium, which inactivates the virus on the website of pattern assortment. Since inactivated viruses aren’t viable, they can not infect folks; genomes will be sequenced utilizing inactivated viruses. This makes a BSL-3 facility redundant for virus confirmation. Relying on BSL-2 labs for testing and confirmation can velocity up the method as many such amenities in Kerala will be roped in.
Inactivated viruses aren’t solely used for testing and genome sequencing but in addition for creating diagnostics, reminiscent of Truenat. “For any nucleic acid tests (NAT), the U.S. FDA accepts synthetic DNA. That is precisely how the U.S. and other countries developed COVID tests and the U.S. FDA authorised for emergency use even before outbreaks happened in those countries,” says Dr. Vinod Scaria, Senior Consultant on the Vishwanath Cancer Care Foundation, Bengaluru. “Even for drug discovery, live viruses are needed only for screening molecules and understanding the infection and immune processes. Even here, many scientists use pseudoviruses, which are better amenable and easier to use, for studying antibody escape.”
Responding to a query on why ICMR insists on a BSL-3 facility for Nipah virus confirmation regardless of the virus being already inactivated, Dr. Bahl, ICMR Director-General says: “BSL-3 facilities have specialised equipment and containment protocols to prevent the release of infectious materials. This is essential in case the virus is not fully inactivated or if there are any procedural errors during diagnosis.” But NIV had validated the Trueprep AUTO lysis buffer and the transport medium and located it to be actually efficient in inactivating the virus.
