Frequently Asked Questions

Community-based surveillance
When and where is CBS useful?

CBS can be useful in contexts where the existing surveillance system is not able to capture health risks/events from the community level that can lead to outbreaks. This is often due to lack of access to health care facilities, which is where traditional public health surveillacne systems are often based. These gaps can also occur during conflicts, emergency situations such as natural disasters, large outbreaks, due to lack of resources or other challenges and are particularly relevant in remote or marginalized communities.

CBS can help fill the surveillance gap by getting information from the community level to the level necessary to trigger an early response. Implementing CBS should be done in collaboration with the national health authorities, and as an addition to complement existing surveillance systems. CBS provides information about people, animals or the environment with signs and symptoms of health risks or other events which can indicate diseases or lead to disease outbreaks. It does not report on confirmed cases and can thus not replace a regular surveillance system for diseases.

CBS can be used both in emergency response, and in everyday routine preparedness. You can learn more about what CBS is here, and take a look at how it looks in different implementations and contexts here

When CBS is used as a component of a community health programme, it helps link the communities to the closest existing health clinic which can then support in investigation of a report. In some cases, if the National Societies has mobile/fixed clinics (e.g. Somaliland) these components can be supported by the Red Cross Red Crescent National Society. 


What if the word "surveillance" is not appropriate in my context?

The term “surveillance” alone can sometimes have a negative connotation in some communities and may make it more difficult to discuss the potential opportunities CBS may have for a community or health district. However, public health surveillance is not conducted with the purpose to name, shame or blame any one person or group, rather it is designed to strengthen rapid response to a health risk or potential disease outbreak based on following health trends. The goal of CBS is to contribute to this goal by strengthening the early warning system for potential outbreaks. Referring to CBS as “early warning” may be an alternative way to talk about the concept without using the terminology “surveillance.” 

How does CBS work?

The decision to implement CBS as a component of a community health, WASH, risk reduction or global health security programme, and which health risks/events to include, is decided together with the Ministry of Health/ Ministry of Agriculture/ National CDC and the National Society. The community volunteers, who are most often existing National Society volunteers, should be identified by the community. CBS can be done in different ways using different tools, but the core purpose is for community members to share information about health risks or events directly from their community to trigger investigation and responses when needed. They report to their assigned supervisor in their National Societies (or District Health Offices if MOH CHWs) on health risks/events, while providing a first level community response (such as community-level epidemic control measures and first aid). For CBS to be implemented, it is necessary to have a mechanism in place to ensure there is a response and investigation to the reports coming from the community. 

How do I know if CBS is the right approach for the context I am working in?

Before starting any planning for CBS it is important to complete an assessment. An assessment will tackle the questions of whether CBS is needed and justified, how it would fit into the surveillance landscape, and if it is feasible. An assessment will also help address whether there is a clear response mechanism in place. It is crucial to ensure action can be taken when needed from CBS alerts, such as investigation of suspected cases, laboratory confirmation or vaccination campaigns. 

It is important to know if there is a gap in the existing surveillance system and what the key public health challenges are. This allows you to answer the question if CBS could be an appropriate strategy to fill in the gaps and if CBS would help to adapt the response. 

Have a look through the IFRC CBS Assessment Template to get an overview of the CBS assessment process. 

How do volunteers report from the community?

CBS reporting can be done in different ways including the use of paper forms, SMS and or mobile apps. Mobile technology has been used widely in recent years to ensure data is shared in real-time. A digital platform called Nyss, has been developed by and for the Red Cross Red Crescent Movement. Nyss works to directly aggregate SMS reports from volunteers, as well as automatically analyzes and visualizes data and triggers alerts to supervisors who shares appropriate data with health authorities to facilitate a response.

The Red Cross Red Crescent CBS technical working group has developed a global list of community case definitions for health risks/events in collaboration with partners like WHO, CDC, and Ministries of Health. These are based on signs, symptoms and events which can indicate that there is a possible transmittable disease in the community.

What is the difference between CBS, contact tracing and surveys?

CBS is the systematic detection and reporting of an observed health risk/event in the community to ensure a rapid response. It is often used for immediate reporting as an early warning. CBS typically tries to collect the minimal amount of personal identifying information needed for early warning. Contact tracing is identification and follow up of contacts when a confirmed case is identified. This often includes line listing and more collection of personal identifying information such as names, addresses, phone numbers, etc. Surveys are structured method for infromation gathering from a sample of people, often done once, or on a regular basis to obtain specific information. You can also learn more in IFRC’s Epidemic Control Toolkit for response managers here.

Process  Purpose  Who  How 
CBS  Immediate reporting of observed health risks that meet the COVID-19 criteria  Trained CBS volunteers within the NS  Volunteers can report health risks matching COVID-19 during their regular health promotion or key messaging  activities. 
Contact Tracing  The identification and follow-up of persons who may have come into close contact with an infected person with COVID-19  Officials, VHWs or CHWs (NS volunteers when requested) typically with special request, support and training from National or local government 

Close contacts to be isolated and monitored for 14 days following potential exposure. This entails: 

  1. Finding people who meet the definition of a close contact, and 
  2. Following-up on whether contacts develop symptoms (daily by phone if possible) 
Active Case Finding  Systematic searching and screening for COVID-19 within targeted groups or locations believed to be at risk  Epidemiologists, CHWs or others based on the Health System Capacity  Requires rapid diagnostic testing capabilities and human resources, may include checkpoints, door-to-door, or searching within hospitals wards for people who may have been misdiagnosed. 
Reporting Hotline  Communication network allowing community members to call and report if they believe COVID-19 is an issue in their community and provide information on symptoms for follow-up  Community members, health facility workers, RCRC Volunteers (population/ community)  Requires a national or local hotline established and maintained with referral connections 
Point of Entry Screening  Screenings that are put in place at points of entry to assess whether symptoms are present in travelers  Government officials (HWs, army, police, etc.), based on mandate can also be RCRC NS  Based on National government requirements. Typically screening for symptoms aligned with WHO or National case definition 
How is animal health included?

Many diseases pass from animals to people (zoonotic), plus the burden of animal diseases has important impacts on the livelihoods and wellbeing of families. Volunteers can be trained to report early signs of potential animal zoonotic or epizootic threats to trigger early action and disease control. 

It is important to consider the capacity for response. National Society should not report on more than what they can respond to in collaboration with National Authorities and partners, such as Ministry of Health, and must connect with local veterinary service providers if they choose to include animal health in their CBS system. In many locations both animal health (including abortions and unusual deaths) is easily reported alongside human health risks in the same CBS system. 

How is personal information protected when doing CBS?

The Red Cross Red Crescent CBS approach is designed in such a way that personal or identifiable information is not sent out from the community. The volunteers will know who they are sending the report about to ensure the response can reach the right person if necessary. However, the information sent by SMS or on paper only contains the health risk/event they have seen, the sex and age group of the person. This is all the information needed to be able to determine if and which response is needed. All volunteers have RC/RC supervisors who are the link between the community and the authorities, who are responsible for the response. It is essential to have trust within the community and agreement among community members about how CBS should be conducted in their community, because a CBS alert may require a response/ follow-up from local health authorities.

For the CBS platform Nyss, the volunteers are registered with their personal information, but they are informed about what this means and must give consent. Personal identifying information is only visible for the supervisors and the National Society staff involved in CBS.  

How many volunteers are needed for a CBS system?

The number of volunteers required depends on the context – factors such as the scope of the CBS program, workload to be distributed, the terrain and geographic accessibility to households, density of population, and security. It can also be very difficult to define community and determine the true population of a village. For example, some villages may have unclear geographical boundaries or moving populations.  

As general guidance, 2-7 volunteers per village depending on the size of the community. Remember to engage community members in the CBS system, not only Red Cross Red Cresent volunteers – provide orientation to certain key community members, such as teachers, community leaders, traditional healers, religious leaders etc, to serve as ‘Community Informants’ – they can notify the volunteer, when they see or hear of a potentially serious illness or death. In some cases these community informants can also later become community volunteers or official Red Cross and Red Crescent volunteers as well.

The right selection of volunteers is crucial.  This should be done with the community leaders and based on trust, likelihood of retention, activeness of the person, etc. Also ensure that gender and age balance is considered according to context.  

How many supervisors / team leaders are needed in a CBS system? Who should I choose to be the supervisors?

The number of supervisors / team leaders required depends on the context and the scope of their role and task-load, the geographic accessibility to the volunteers, their capacity, the location of Red Cross Red Crescent branch offices but it is a very important consideration.  

You must have enough supervisors / team leaders to easily reach the volunteers within their catchment area to support them with weekly, 2-weekly or monthly supervision according to their need.

We typically recommend a maximum ratio of one supervisor to 25-35 volunteers. 

What systems and tools do I need for implementation of CBS?

CBS system should be timely. The key advantage of CBS is that community illnesses are alerted quickly to authorities, or to a response agency. To achieve that, your CBS tools should feed alerts into a system as fast as possible. All CBS tools have advantages and limitations.  

Some things should be considered when deciding what method of communication to use. This can include the number of community member and volunteers have access to phones, the recharge costs, battery failures, security threats, reach of the network signal, and who is in place to receive the SMSs and manage the incoming alerts data. The Red Cross Red Crescent CBS Technical Working Group can support you when deciding what tool would be the best fit. Paper can also be used for CBS, but it may lead to delays in alerting the authorities.

CBS should be a low-resource system, but realistically any program requires investment to achieve results. Aim for a CBS program which may have start-up costs (such as training and resources) but has minimal ongoing routine costs.  

How long should a CBS project continue for? When should I stop the CBS program?

Use the IFRC CBS Assessment Template to review your CBS program. A clear need, and the capacity to continue the CBS system is key to deciding on how long it should continue.  

Some CBS programs are needed only for a short time for an emergency response to control a defined outbreak, other CBS programs are useful in epidemic preparedness as ongoing early detection.  

CBS can be flexible to the situation. Because of this flexibility you have the option to:  

i) Continue CBS as an ongoing epidemic preparedness program integrated into other community activities

ii) Handover CBS to another agency for ongoing management, such as a RC National Society Branch, development partner, or local Government

iii) Close the CBS program and exit once the urgent outbreak has been controlled. 

How do I select health risks?

The health risks chosen should have a significant potential for a high impact on morbidity, disability and/ or mortality. It should also have a potential for sudden epidemics or ongoing transmission with seasonal epidemics. It is important the information provided by CBS will enable significant, rapid, and cost-effective public health action. The health risks should be chosen in coordination with the local health authorities and ministry of health as they understand the local context, and it enables sustainability of the projects.  

Additional considerations are discussed in the CBS Protocol tool

What is an alert threshold and how do I set one?

The alert thresholds are the number of reports which combine to trigger an alert. The threshold for reports is set at a specific number, which when exceeded will trigger an alert. For some health risks, the alert threshold will be one single report, which must trigger prompt follow-up and cross-checking by supervisors.  

For health risks that are endemic and/or may be predicted, the alert threshold is based on the historical trend – it is a calculated number which signifies a greater than usual number of cases during a certain period of time and distance.  

In emergencies, where prior data in the area may not be available to indicate the trend, this needs to be calculated using moving averages over a short period of time.  

Decide on the alert threshold together with Ministry of Health. 

What is a CBS Protocol and what is included in it?

A CBS protocol is a structured guidance for comprehensive planning and design of CBS, based on findings of the assessment. Its purpose is to support the design of a comprehensive CBS system and rapid preparation of a draft prior to inputs by stakeholders. It also can act as a living document to be revised based on feedback during implementation and therefore supports future expansion or scale-up. You can see the CBS Protocol guideline here.  

How can I ensure that the CBS project is sustainable?

Firstly, not all CBS projects need to be sustainable. For example, a short-term emergency implementation of CBS for a particular outbreak may no longer be needed after the outbreak has ended.  

If CBS is being used as a preparedness measure, then the sustainability of the project becomes important. To ensure a CBS project is sustainable community engagement and ownership is very important. It is crucial to include community leaders and local health workers in the training, planning and system. If presented with simple, low-cost solutions these community leaders can maintain CBS structures even after departure. Also, you must ensure a retention plan is in place when recruiting staff and volunteers. Ensuring there is capacity for continued training of supervisors and volunteers is also crucial  

CBS must be coordinated with health authorities and relevant stakeholders. It is also ideal to start small and be scaled up once shown to be functional and effective. As well health risk control actions by the community, and response by authorities is clear and agreed on from the beginning.  

Using Nyss
What do I need to start implementing CBS using Nyss?

After the initial assessment period, there will be a joint discussion with the National Society and Ministry of Health to decide how and where CBS will be implemented. If it is decided to use Nyss, trainings to facilitate the use of Nyss will be required. For the volunteers to be able to send reports to the Nyss platform, the National Society needs to have configured an SMS Eagle (a physical device that turns SMS into electronic reports). This device will be configured with the help of Norwegian Red Cross. Nyss is supported by software developers based at Norwegian Red Cross. It requires continuous connection to the internet and a reliable power source. The National Society has the ownership of the platform. Ministry of Health and other external partners can have access to the dashboard which contains the epidemiological data. 

The platform can also be used by Ministry of Health or other partners for their CBS programmes. Contact IFRC or Norwegian Red Cross CBS focal points to get more information. They will also support the advocacy of the NS with Ministry of Health to use the Nyss platform if decided relevant.

You can find more information about the CBS platform Nyss here.  

Do volunteers need internet access to send reports when using Nyss?

The volunteers do not need internet access for the reports to be sent. This is done through a short-coded SMS, describing the health risks, gender and age. Therefore, the only necessity for volunteers is a relatively stable mobile signal. 

What type of SIM card do I need to use Nyss?

The only requirements are the SIM card can send and receive SMS messages. Ideally the volunteers would be able to send messages to the SIM card free of charge, but this is NOT a requirement for Nyss to work. To enable this, we recommend you make an agreement with the telecom provider. There are different ways to do this, and one is not better than the other. A common option is to use a short code service. 

How do I configure the SMS Eagle?

The Nyss team at Norwegian Red Cross will assist you in configuring the SMS Eagle. When this is done remotely, the team needs the following to ensure it goes smoothly:

  • The SMS Eagle and your computer are connected to internet using the same connection, preferably using a cable. This way we can access the local network to find the SMS Eagle device and connect to it. If you are unsure how to connect the two devices to the same network, ask an IT person in your office for help.

  • Remote access to your computer through TeamViewer. We kindly ask you to download and install TeamViewer prior to meeting the Nyss team for configuration.

  • A SIM card to test sending SMS messages when the configuration is done.

Where is the Nyss database located and why?

The Nyss server is in Ireland at the Microsoft Azure data center for Northern Europe. This server uses state-of-the-art security features to provide secure storage. Through this security we can adhere to the European General Data Protection Regulation and provide a high standard of data protection for our users. Our aim is to have Nyss globally available, and by using Microsoft as our server provider we ensure extremely high availability, while still having resources to focus on usability and the improvement of Nyss as a tool. Having an in-country server where the CBS project is being implemented would lead to additional costs and potential security issues. 

Although we use Microsoft as our service provider, we are the legal owners of the data and Microsoft is not allowed access. Additionally, we have developed a data protection agreement that every Head Manager needs to accept. This agreement passes the legal rights of the data from Norwegian Red Cross on to each implementing country. In short, as an implementor of CBS with Nyss, you are the legal owner of your own data.

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