Local researchers are hoping they will soon be able to provide some of the poorest communities on the planet with cheap and effective tools to monitor Covid-19.
The University of Otago is collaborating with Western University of Canada on an investigation into monitoring wastewater to provide population level data on both the spread of the virus and which variants are present.
Prof Miguel Quinones-Mateu of the University of Otago microbiology and immunology department said researchers were collecting samples in Uganda, Ghana, Colombia, Venezuela and Fiji.
Preliminary processing to extract RNA from samples was taking place in the test cities, with the processed material shipped to New Zealand and Canada for full sequencing.
The results of this process could be shared with public health authorities to give them data on the prevalence of Covid-19 in their communities, with other enteric viruses also able to be detected by the sequencing.
‘‘[It could also] identify variants which is really important right now, with the delta and the beta ... now we’re talking about an epsilon [variant] which has come in.’’
Large-scale nasal swab testing was not practical in low and middle income countries, with testing costs and a lack of laboratory facilities limiting their ability to effectively monitor spread of disease.
Wastewater testing could provide these countries with a cheaper way of gathering data to help make public health decisions.
Part of the investigation was proving that wastewater systems that did not have expensive treatment plants could still provide accurate data.
Samples taken from Kampala, Uganda, were taken from an open stream into which sewers drained.
‘‘We know [wastewater testing] works in higher income countries ... with well-established wastewater systems, but we want to show that we are able to make it work in low and middle income countries too.’’
Prof Quinones-Mateu said he hoped that the method could be scaled up to be used as an early warning system for future viral outbreaks and epidemics.
