THIRUVANANTHAPURAM: In a major breakthrough, the Rajiv Gandhi Centre for Biotechnology (RGCB) here has developed self-testing tool for Covid-19, a first of its kind in the country. The Covid Anosmia Checker, a strip-based screening tool, will confirm the infection by checking signs for temporary loss of smell (anosmia), considered to be one of the earliest and most commonly reported indicators of Covid-19. If approved by the agencies concerned, it will also become the first-of-its kind for testing anosmia.
Meanwhile, RGCB, which comes under the Department of Biotechnology, said the tool can be used as an alternative to RT-PCR and rapid antigen tests in the first-line mass screening, as the latter is resource-intensive and requires expert personnel resulting in higher costs and reduced testing frequency. Another merit is that the new tool could replace the current method of ‘smelling the coffee powder’ test which is rather unscientific.
It is learnt that the screening using the Covid Anosmia Checker will take less than two minutes and the odorised test strip has a shelf life of around one month. At the same time, a scientific report, which has not been peer-reviewed but published in Medrxiv, a pre-print server for health sciences, says that the loss of smell can be used as a reliable marker for screening for Covid-19.
According to the authors, the effectiveness of the tool has been assessed through an epidemiological study carried out among 160 participants in the 20-60 age group. “The test strip consists of six black-printed regions where positions 1, 3, 4, 5 contain different concentrations of coffee oil respectively, meant for odour threshold/quantitative smell assessment. Position 2 was intentionally kept blank (to identify odour discrimination), and Position 6 contained lemon grass oil. This combination is ideal for assessing the quantitative reduction and qualitative changes in smell. Coffee oil and lemon grass oil is used since these two odours are very common to households,” says the study.
As part of the study, the person subjected to the test has to cut each position and smell separately along the dotted lines immediately and report the smell and intensity before proceeding to the next position. Interpretation of the data showed that almost 95 per cent of the Covid-19 positive patients showed some degree of olfactory dysfunction ranging from a partial to complete loss of smell and the remaining five per cent showed normal smell perception indicating the possibility of recovery from the disease.
Jackson James, scientist at RGCB and one of the authors of the study, said, “Covid Anosmia Checker is not a confirmatory test. It is a screening tool. Along with this, we have developed a mobile application, which takes the input response from the user and can readily categorise the user in the appropriate risk groups (low, medium or high). It is designed for self-screening and community screening.”