Institutionalising wastewater surveillance systems to minimise the impact of COVID-19: cases of Indonesia, Japan and Viet Nam

On 31 December 2019, China reported an outbreak of pneumonia of unknown aetiology occurring in Wuhan (WHO 2020a). This disease caused by a novel coronavirus was named coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO) on 11 February 2020 (WHO 2020b). On 2 March 2020, the coronavirus causing the outbreak was officially designated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the Coronaviridae Study Group of the International Committee on Taxonomy of Viruses (2020). COVID-19 was declared a global pandemic on 11 March 2020 (WHO 2020c). As of 26 July 2020, there have been 15,785,641 confirmed cases including 640,016 deaths globally (WHO 2020d).

Table 1 shows cases of COVID-19 in Indonesia, Japan and Viet Nam as of 26 July 2020. In each country, testing for COVID-19 has been performed in less than 1% of the total population. Considering that some individuals are tested multiple times, it is expected that the actual number of people tested is lower than the number of cases tested. For example in Japan, the number of people tested (606,403) is 61% of the total number of cases tested (999,883), and comprises 0.5% of the total population.

An estimated 18–31% of SARS-CoV-2-infected individuals within a population are likely to be asymptomatic (Mizumoto et al. 2020, Nishiura et al. 2020), but nevertheless still carry and contribute to the spread of the virus. This makes it difficult to ascertain the actual degree of viral circulation in a community based on clinical testing of symptomatic patients. Meanwhile, as asymptomatic patients can also excrete SARS-CoV-2 in faeces (Tang et al. 2020), wastewater surveillance could potentially provide a method of evaluating the spread of infection in a community, even where resources for clinical diagnosis and reporting are limited or unavailable. Moreover, wastewater monitoring can help to understand variations in strains of the virus through nucleotide sequencing and phylogenetic analysis, allowing for comparisons between geographic locations and helping to track the evolution of the viral genome over time (Nemudryi et al. 2020). Wastewater surveillance can thus be useful as an indication of whether the introduction or reintroduction of SARS-CoV-2 or other novel viruses has occurred in a community, or to evaluate the effectiveness of public health interventions (Kitajima et al. 2020).

Service coverage rates (shown here as percentage of population) of centralised wastewater treatment systems and decentralised or on-site wastewater systems are shown in Table 2. These were the three categories of wastewater we considered for monitoring the spread of COVID-19.

Figure 1 shows that raw domestic wastewater comes from three groups in the population: (i) known or documented cases of COVID-19, (ii) unknown or undocumented cases of COVID-19, and (iii) the non-infected. Wastewater flows into either a centralised treatment system or a decentralised system, or is discharged into the environment without any treatment. In the case of centralised wastewater treatment systems, it is possible to collect and monitor influent and effluent samples given the local authorities agree, with information fed back into society via national or local governments (Kitajima et al. 2020). Decentralised wastewater systems would be challenging to monitor, as it would be a resource-intensive process to collect samples from each household or facility. A possible solution would be to analyse sludge samples from the sludge treatment plants where septage or sludge from the decentralised systems are taken.

Untreated wastewater is an even greater challenge to monitor, and would require a whole-of-community approach to find a solution which best addresses the needs and risks of the community.

It is important to note that although decentralised treatment or untreated wastewater constitutes a larger challenge than centralised systems, communities with decentralised treatment or untreated wastewater may also have the most to gain from wastewater surveillance systems. These communities include informal settlements, evacuation shelters, and refugee camps, and in many cases face socio-economic challenges such as availability or affordability of clinical testing, in addition to being disproportionately affected by the health and economic risks (UNDP 2020).

Various stakeholders need to be involved in the cycle of a monitoring framework, which includes the sampling, analysis, information feedback and any subsequent action or decision-making. Table 3 shows the stakeholders responsible for each process. The Committee of COVID-19 Handling and National Economy Recovery in Indonesia is placed directly under the President, and has the authority to issue binding instructions to ministries. The Cabinet Office (CAO) of Japan is directly managed by the Prime Minister. The National Steering Committee for COVID-19 Prevention and Control in Vietnam was established by the Decision of the Prime Minister on 30 January 2020 and is headed by a Deputy Prime Minister. In Japan and Viet Nam, the jurisdiction of centralised and decentralised wastewater treatment systems falls under different ministries. The actual implementation and operation of wastewater treatment systems as well as COVID-19 countermeasures are managed by local governments in all countries. The analysis of samples and development of technological solutions including monitoring equipment are mainly carried out by academic/research institutions and private sectors. Therefore, it is critical to involve all agencies when building a national platform for wastewater surveillance systems. Furthermore, special care needs to be taken that the views of the disproportionately affected, including women (UN 2020), LGBTI (lesbian, gay, binary, transexual and intersex) people (OHCHR 2020), youth and children, and persons with disabilities (UNDP 2020), are taken into consideration when institutionalising such systems, for example through a consultative process to ensure that their rights and needs are not neglected, including their right to education.

Based on informal consultations with various stakeholders in each of the case study countries, challenges and opportunities for institutionalising wastewater surveillance systems for COVID-19 are listed in Table 4. This is not an exhaustive list, and does not reflect official views of any of the governments involved.

Multiple challenges exist before such wastewater surveillance systems can be formally institutionalised, or woven into the governance fabric at national or local government levels. Based on the preceding discussion, the following recommendations are proposed as a way forward in institutionalising wastewater surveillance as a tool to reduce risks from COVID-19 in Indonesia, Japan and Viet Nam.

• Build a multi-country or regional platform to exchange information and experiences, including discussion of post-pandemic collaboration.

• Develop a national platform for multistakeholder coordination and collaboration, especially including disproportionately affected communities and groups as active agents.

• Cultivate an environment of sharing knowledge and information across various stakeholders.

This study will benefit from further research into more countries with diverse backgrounds, as well as case studies at local levels.

This study was partly supported by the J-RAPID program of Japan Science and Technology Agency (JST), entitled ‘Real-time monitoring of novel coronavirus (SARS-CoV-2) infections using wastewater-based epidemiology approach’. The authors would also like to thank André Derek Mader (Institute for Global Environmental Strategies) and Nguyen Quoc Dinh (Vietnam Institute of Geosciences and Mineral Resources) for their valuable inputs.

All relevant data are included in the paper or its Supplementary Information.