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Table 2 Operational definition of case detection and key surveillance activities

From: Challenges in early phase of implementing the 1-3-7 surveillance and response approach in malaria elimination setting: A field study from Myanmar

Key surveillance activities

Operational definition

Case detection

 Passive case detection

Detection of malaria cases among people who go to a health facility or a community health worker (CHW) on their own initiative to get treatment, usually for fever

 Active case detection

Detection by health workers of malaria cases in the community and in households, sometimes among population groups who are considered to be at high risk

 Reactive case detection (RACD)

RACD is triggered by the identification and notification of an index case. After the investigation and classification of the index case, RACD may be implemented within the household of the index case, or over a radius around the household or within the whole focus.

Malaria cases

 Indigenous case

A case contracted locally with no evidence of importation and no direct link to transmission from an imported case

 Introduced case

A case contracted locally, with strong epidemiological evidence linking it directly to a known imported case (first-generation local transmission)

 Imported case

Malaria case or infection in which the infection was acquired outside the area in which it is diagnosed

 Relapse case

Malaria case attributed to activation of hypnozoites of Plasmodium vivax or P. ovale acquired previously.

 Induced case

A case the origin of which can be traced to a blood transfusion or other form of parenteral inoculation of the parasite but not to transmission by a natural mosquito-borne inoculation

 Recrudescent case

Recurrence of asexual parasitemia of the same genotype(s) that caused the original illness, due to incomplete clearance of asexual parasites after antimalarial treatment

Type of foci

 Active foci

A focus with ongoing transmission

 Residual non-active foci

Transmission interrupted recently (1–3 years previously)

 Cleared foci

A focus with no local transmission for more than 3 years and which is no longer considered residual non-active

  1. Source: “malaria-surveillance-monitoring-and-evaluation---a-reference-manual” (link: https://www.who.int › docs › default-source › documents › publications › gmp)