Continuation of 5.1.

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5.1.1. Epidemiological surveillance model for disaster situations

The epidemiological surveillance model for disaster situations includes the operation of the crisis situation room (see section 1 of this Module), assessment of potential risks, and the evaluation of the public health response. This involves:

  • Activating the health situation room as a crisis room within the first hours of the disaster. The Health Emergency Operations Committee will use the crisis room to process and analyze information processing for decision-making.
  • Assessing the risk of potential health problems as a basis for deciding what surveillance to implement.
  • Implement the epidemiological surveillance system and begin the process of collecting, analyzing, and interpreting data to assess the population’s health problems and living conditions, examine possible interventions jointly with the Health Emergency Operations Committee, and propose lines of action for a health response plan.

5.1.2. Implementation of epidemiological surveillance in disasters

When implementing surveillance, consideration must be given to certain conditions that will prevail in the period after the impact. These include scarce time or tolerance for procedures and filling out forms on the part of personnel, difficulty communicating with information sources, limited ability to develop and evaluate large quantities of data, damage to health facilities responsible for surveillance, and so forth.

Surveillance should be functioning within five days of the disaster event. The basic steps for implementation are as follows:

a. Select the diseases, tracer events, and reporting criteria to be used, bearing in mind that:

  • The number of diseases and events monitored should be limited.
  • Determination should be based on clinical syndromes, because laboratory access may be limited.
  • Be tracers for the type of event that has occurred and potential risks involved.
  • The diseases selected should be endemic, or of which there have previously been outbreaks in the area.
  • Non-communicable disorders that are common in disaster situations should be considered. These include: injuries, mental health problems, and chronic pathologies that require patients to take drugs on an ongoing basis and may lead to setbacks if therapy is interrupted.

All data on the diseases and/or syndromes selected should be broken down, to the degree possible, by sex and age.

b. Select the surveillance methods

The most commonly used temporary surveillance methods are:

  • Sentinel surveillance: This is surveillance conducted in selected data sources, such as primary care facilities, hospitals, laboratories, or individual providers. This widely used method makes it possible to detect early signs of problems in specific places, such as those most impacted by the event. It can be useful when the existing surveillance system has been damaged or slowed down, and when time and resource constraints prevent collecting data through population studies. It is also useful to ensure uninterrupted monitoring of non-communicable health problems that are not subject to compulsory reporting. The advantages of sentinel surveillance are its timeliness, flexibility, and acceptability to local teams.
  • Monitoring at temporary shelter sites: Due to the presence of multiple risk factors in these locations, it is advisable to set up an early detection system based on defined syndromes and on environmental conditions. This form of surveillance is conducted by health teams on their rounds, and it calls for actively involving people in the shelter community who have appropriate training.
  • Monitoring rumors: Every rumor from nonofficial sources, such as the mass media, community, or health teams in the field, should be investigated immediately by a professional member of the epidemiology team to rule out or confirm the rumor, to implement control measures, and to report the findings. Such investigations will sometimes require field presence, although at other times telephone contact with local health teams will suffice.
  • Comnunity-based surveillance: This can be particularly useful in small and isolated communities and depends on the presence of trained community members, who detect and report early stages of illness based on a set of symptoms or syndromes. In addition to having training in early detection of diseases or syndromes, a community member involved in this work must be trusted by the community and coordinate closely with the local health team to provide for immediate diagnosis and treatment and streamline the implementation of measures to control contact or environmental factors as necessary.
  • Environmental surveillance: This type of surveillance helps to collect information for evaluating, detecting, and acting quickly on deficient living conditions in the population. It utilizes tracers of problems in sanitation, water, food, and vectors. It can also actively involve the community in the systematic detection of problems.
  • Surveillance of reportable diseases: Local teams should continue this type of surveillance in areas less affected by the event. They should continue to report on any reportable diseases they detect. It is important not to create a parallel surveillance system if the system is functioning correctly in less affected areas.

There are two other approaches that, although they are not strictly surveillance, can be used to detect and learn about health problems stemming from a disaster. They are:

  • Rapid epidemiological assessment: In the phase immediately following impact, a rapid epidemiological assessment is needed to estimate the general magnitude and location of the event, its impact on health, the functionality of the health care system, and damage to other public services that can jeopardize the health of the population or prevent addressing specific health needs. This information, collected and reported on in the first hours after the disaster and up through the 48-hour point, will contribute to an assessment potential public health risks. Visual inspections by public health teams will be used to complete forms.
  • Special investigations: In addition to rapid evaluations and the implementation of temporary surveillance systems, investigations of specific problems may be necessary. In disaster situations, populations in selected areas may be exposed to risks resulting from damaged or collapsed sanitation services, damaged or nonfunctioning final disposal sites, overflowing canals, and ash-contaminated air or water.