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

This mini review describes the current status and challenges regarding institutionalisation of wastewater surveillance systems against COVID-19. Monitoring SARS-CoV-2 in wastewater has been proposed to be a potential tool to understand the actual prevalence of COVID-19 in the community, and it could be an effective approach to monitor the trend during the COVID-19 pandemic. However, challenges to institutionalise wastewater surveillance systems are still abundant and unfolding at a rapid rate given that the international understanding regarding the scientific knowledge and socio-political impacts of COVID-19 are in the developing stages. To better understand the existing challenges and bottlenecks, a comparative study between Japan, Viet Nam, and Indonesia was carried out in the present study. Through gaining a better understanding of common issues as well as issues specific to each country, we hope to contribute to building a robust multistakeholder system to monitor SARS-CoV-2 in wastewater as an effective disease surveillance system for COVID-19.

• Challenges and opportunities to institutionalise wastewater surveillance of COVID-19 are proposed.
• Although wastewater monitoring is contextualised to each locality, all countries will benefit from an international or regional network to exchange information and experiences.  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.

WASTEWATER SURVEILLANCE OF COVID-19
An estimated 18-31% of SARS-CoV-2-infected individuals within a population are likely to be asymptomatic (Mizumoto et al. , Nishiura et al. ), 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. ), 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. ). 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. ).

WASTEWATER MANAGEMENT IN INDONESIA, JAPAN AND VIET NAM
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. ). 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 ).

STAKEHOLDERS FOR WASTEWATER MONITORING
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 decisionmaking. 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 ), LGBTI (lesbian, gay, binary, transexual and intersex) people (OHCHR ), youth and children, and persons with disabilities (UNDP ), 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.

CHALLENGES AND OPPORTUNITIES
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.

RECOMMENDATIONS
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. • Cross-organisational collaboration to share the burden between organisations/individuals with too much work and those with too little work as a result of COVID-19 • Diverse financing mechanisms to support needs • Peer competition leading to non-disclosure of information until publication/patent • Incentivise sharing of outputs with high social benefit • Creation of an overarching platform at international/ regional levels to share information Civil society • Limited formal mechanisms for inclusive decisionmaking • Lack of effective coordination, weak financial base, lack of transparency, and lack of commitment • Formalise inclusive processes during institutionalisation • Sharing of good practices regarding inclusivity at international/regional levels