In the FoodSmartphone project, we are developing rapid on-site food safety analyzers. One of our major challenges is to develop a device providing high reliability and accuracy while keeping it cost-effective and simple enough to be used by untrained users. This is a common challenge in the field of on-site testing whether in food safety or the diagnostic domain. Considering the urgent need for the Covid-19 reliable rapid testing now, in this blog, I am going to explain why the accuracy and reliability play such a vital role in the wide-spread applicability of rapid analysis.
The reliability and accuracy of any test can be measured in terms of sensitivity and specificity. The sensitivity value shows how many times a test result is positive correctly. For example, if the sensitivity of a test is 70%, this means that in 30% of the actual positive cases the result of the test is negative (false negative). This would lead to the underdiagnose of the infected people which in the case would lead to the spread of the virus. The other factor is specificity, which shows how many times a test result is negative correctly. For example, if the specificity of a test is 90%, this means in 10 % of the actual negative cases the result of the test is positive (false positive). This would lead to assuming those people have potential immunity since they contracted the virus while that is not the case.
The best test would have the highest sensitivity and specificity and a near-zero false negative and false positive rate. There are mainly two types of tests available for COVID -19 disease. The reverse-transcription polymerase chain reaction (RT-PCR) test is based on detecting the RNA of the virus. This test is the one recommended by the World Health Organization (WHO), and the most widely used. Although the RT-PCR test is considered the gold standard and shows excellent performance, it is a lab-based technique, in need of expensive equipment and trained personnel. Therefore, the number of tests would widely depend on the number of equipped central labs. Also, it is time-consuming, it might take several days to have the results having considered the sampling, delivery of the sample, and conducting the test. Most importantly, the high sensitivity and specificity of the test are about 66 to 80 % in real sample analysis.
On the other hand, the rapid test provides a simple and cost-effective alternative for testing at home. They work based on detecting the antibody produced against the virus and look like the pregnancy test. The positive result is a visual detection of two lines on the test strips. However, unlike the RT-PCR test, not all of them are validated and verified by standard methods. The ones which are, are not as strictly validated due to the easier regulations because of the lack of time. Although it won’t be possible to develop a perfect test, the innovations focused on increasing the sensitivity and specificity in real sample analysis will provide a good enough test either in the diagnostic or food safety domain.
As for my Ph.D. project, the good news is, as the lock-down restriction is easing up, I feel excited to resume my experiments and start working in the Lab again. This past two months was quite a challenge to cope with the lock-down restrictions and the home-office working conditions. To stay productive, I was trying to dress up for the work and keep the same schedule. But soon I realized why not enjoy the flexibility that it brings, so I tried to make my schedule a bit more colorful with cooking, gardening, and going for a walk now and then. And for the productivity, it wasn’t all bad, I found out that it is much easier to focus on some tasks working from home, such as writing and reading. Till my next blog,