Motivation

Problems with current methods of detection

Current diagnostic methods, though highly advanced, are not without their inherent limitations. Antibody-based tests such as ELISA and Rapid Antigen Tests, designed even for high-profile cases like COVID-19, are plagued by a significant drawback - a propensity for producing false positives or false negatives. These tests rely on the immunogenicity of the pathogen, which can vary greatly between different microbes. Antibodies, as proteins, are exquisitely sensitive to factors like pH, temperature, and contaminants. Moreover, the production of antibodies involves substantial costs and consumes considerable time.

On the other hand, PCR techniques offer a faster and more accurate means of detection, but they demand a skilled professional, a resource that is often scarce in remote regions of developing countries. The multi-step nature of PCR-based detection also results in the extensive use of consumables and plasticware, limiting automation possibilities. The COVID-19 pandemic underscored this challenge, with developing nations like India facing testing constraints due to limited access to equipment and trained personnel for PCR-based testing.

The Pandemic

During the pandemic, India faced several challenges in its detection efforts:

1. Initially, a conclusive and robust test was not available promptly to curb the initial spread of COVID-19 before it evolved into a nationwide pandemic.
2. At the peak of the pandemic, there was a shortage of testing kits to meet the high demand for patient testing.
3. As patient testing numbers dropped, laboratories encountered a dilemma. They couldn't utilize new kits until they had a sufficient number of samples due to batch testing. With fewer samples, the cost of the kits outweighed the revenue generated, leading to a delay in testing until a suitable sample count was achieved.
4. The absence of reliable self-diagnostic kits failed to alleviate the burden on testing centers.

These issues collectively resulted in delays in delivering accurate results, which could have otherwise enabled better control of the pandemic's spread and reduced associated fatalities. Some limitations of RT-PCR are long-term nucleic acid extraction, requirement of trained staff, errors during sample preparation, and high cost for large volumes1. A few RT-PCR kits can also fail to differentiate between influenza virus and SARS-CoV-2. A faster development of more robust testing kits could have significantly improved the situation.

In our region and the country as a whole, the majority of the population, being low-income, is exposed to less-than-ideal sanitary conditions, contaminated food, and poor-quality potable water. According to WHO, 110 billion USD is lost yearly in productivity and medical expenses resulting from unsafe food in low- and middle-income countries like India. Our location being Punjab, an agricultural, dairy, and food industry hub, gives us first-hand exposure to these problems. Thus, we have chosen the bacteria E. coli and S. typhi and the fungus Penicillium all of which commonly contaminate food and water.

Diseases vs Detection

In our region, and indeed across the entire country, the majority of the population belongs to the low-income bracket and is exposed to suboptimal sanitary conditions, contaminated food, and low-quality drinking water. This predicament fosters the prevalence of diseases such as malaria, seasonal flu, and various other illnesses. While detection methods for these diseases exist, they are not readily accessible to the masses, contributing significantly to the high fatality rates. In 2017, the World Health Organization had estimated6 Ref6 that India only reports 8% of its malaria cases to the surveillance system. Today “even if we give a best case scenario, it will not be very different than 12%, 15%”, said Lahariya. “We need to remember that in two years of Covid-19, almost all other non-Covid services had suffered.”

Situated in Punjab, a hub for agriculture, dairy, and the food industry, we gain first hand exposure to issues related to plant and water-based diseases, exemplified by challenges like E. coli and Salmonella contamination.

Sustainable detection

Antigen-antibody methods of detection also present sustainability challenges due to potential specificity issues, resulting in false-positive results and resource overuse. The production of antibodies, a crucial component, raises concerns about resource consumption and animal welfare. Moreover, these assays often depend on single-use disposable kits, contributing to plastic waste. The transportation and storage requirements further contribute to their carbon footprint. Complex manufacturing processes involving chemicals and energy-intensive techniques compound their environmental impact, with some components relying on non-renewable resources.

Furthermore, the existence of various techniques for different types of detections increases the operational costs for laboratories and demands more lab space, consumables, and technical expertise to perform all necessary tests effectively.