key: cord-0887518-7ntp7x8d
authors: Street, Renée; Malema, Shirley; Mahlangeni, Nomfundo; Mathee, Angela
title: COVID-19 wastewater surveillance: An African perspective
date: 2020-07-03
journal: Sci Total Environ
DOI: 10.1016/j.scitotenv.2020.140719
sha: 5892abd17f25bae03e07b1bf3df8eb830cc66344
doc_id: 887518
cord_uid: 7ntp7x8d

Abstract The COVID-19 pandemic has once again highlighted the importance of access to sufficient quantities of safe water and sanitation in public health. In the current COVID-19 pandemic, an early warning wastewater system has been proposed as a platform for SARS-CoV-2 surveillance, and a potentially important public health strategy to combat the disease. This short communication on wastewater surveillance in sub-Saharan Africa highlights challenges, opportunities and alternatives taken into account the local context.

The COVID-19 pandemic has once again highlighted the importance of access to sufficient quantities of safe water, and sanitation in public health. Well managed water, sanitation and hygiene (WASH) are critical for protection of human health during disease outbreaks [1] . Wastewater contains viruses, bacteria and parasites and inadequate treatment of, or exposure to, wastewater and fecal sludge plays a role in spreading disease [2, 3] . On the other hand, tracking of wastewater has historically played a key role in the development of early warning systems (EWS) for various enteric viruses, including poliovirus, norovirus and hepatitis [4] [5] [6] . In 2011, Kano State of Nigeria was the first on the African continent to introduce environmental surveillance for poliovirus and many other regions in Africa have since included wastewater surveillance to supplement polio eradication efforts [7] [8] [9] . To date, the screening of wastewater is recognized as an important tool for monitoring wild poliovirus and vaccine-derived polioviruses [7, 10] .

In the current COVID-19 pandemic, tracking of wastewater has been proposed as a platform for SARS-CoV-2 surveillance, and a potentially important public health strategy to combat the disease [11, 12] . Diarrhea is a frequent presenting symptom in patients with COVID-19, and SARS-CoV-2 RNA has been detected in stool samples from both adults and children [13] [14] [15] [16] . Thus SARS-CoV-2 surveillance through water-based epidemiology (WBE) is a potential complimentary and cost-effective approach to enable wide scale screening which would reduce labor intensive and costly personal COVID-19 testing and tracings [11, 17, 18] . To date, the detection of SARS-CoV-2 RNA has been demonstrated in the wastewater of a growing number of countries including Australia, J o u r n a l P r e -p r o o f France, the Netherlands and the United States of America [13, [19] [20] [21] [22] . Notably most of this work has been carried out in high-income countries.

Like most epidemics, the rapid spread of COVID-19 is likely to disproportionately affect the most disadvantaged and vulnerable communities [18, 23, 24] . Currently COVID-19 prevalence is influenced by regions supporting high frequency screening and testing, compared with poorly resourced regions where low prevalence may be linked to underreporting [18, 25] . Therefore, wastewater surveillance systems may prove critical in many low-and middle-income countries where health systems infrastructure, testing systems, personal protective equipment (PPE) and human resource capacity are constrained [25, 26] . Nonetheless, the proposed opportunities presented by wastewater surveillance need to be understood in the local context which will in turn give rise to locally relevant, evidence-informed solutions. A study of 100 households in a low-income urban settlement of Nakuru, Kenya revealed that all pit latrines were shared by more than one family, and the average number of people sharing a pit latrine was 23 individuals (ranging between 4 and 56) [37] . To date, no cases of transmission via the fecal-oral or waterborne routes have been reported for SARS-CoV-2, and it has been suggested that infection via this route is improbable during quarantine or while under self-isolation [21, 38] . However, this may not be the case for shared spaces and potential fecal-oral transmission might pose an increased risk in contained living premises such as hostels and similar places of overcrowding [21] . The sampling of non-sewered systems such as pit latrines has been proposed as a 

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