Epidemiology module of practical skills for mbbs student

Where the disease is occurring?

Diseases tend to cluster in a particular area. Clustering indicates that a large number of similar cases have occurred in a limited geographical area or have occurred around the index case. This provides an idea of the causative and predisposing factors that may have played a role in the occurrence of the VPD. See Figure 10.2.

A Spot map is a tool that enables analysis across space (spatial). It shows the occurrence of the cases, high-risk areas, areas of poor immunization coverage or areas with vacancies of HWs.

A Spot map helps to identify:

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  ƒ Pockets from where cases are consistently reported
  
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  ƒ Pockets from where cases are expected but not reported
  
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  ƒ Disease trends in comparison to similar maps for the previous corresponding period.