NCDC Weekly Epidemiological Report: Volume 7, No. 49 - 22 December 2017



Response to disease outbreaks in recent past has highlighted evidence of weakness in integration between disease surveillance and laboratories. In this week’s editorial, we review the roles of the laboratory before and during an outbreak.

  1. Before an outbreak: The laboratory carries out two specific roles

• Early warning signals: This involves detecting pathogens that have the potential to spread. This will ensure early control measures are put in place.

• Outbreak Detection: The laboratory is responsible for confirming a diagnosis and providing guidance for a more specific case definition, detection of a new pathogen and providing additional information on the pathogen.

  1. During an Outbreak

• Laboratory confirmation of early cases

• Identification of new pathogens

• Typing of the pathogen-this can help with linking clusters is situations when epidemiological data is insufficient

• Antimicrobial susceptibility testing to guide treatment of cases

• Environmental investigations -This is applicable for disease conditions that are food and vector-borne e.g. Cholera, Yellow fever

• Detection of Carriers, if any

• Post-outbreak Surveillance

  1. In-between outbreaks

• Monitoring Endemic Disease Trends-This is achieved through confirmation of diagnosis (for case definitions that include laboratory criteria), monitoring resistance patterns of isolates and subtypes of a pathogen

• Monitoring eradication/elimination measures - Usually require more specific testing as positive predictive value decreases. Typing helps to identify the origin of a pathogen which will inform how eradication/elimination measures will be carried out.

It is very important that all States identify a public health laboratory – preferably in the State capital- to ensure laboratory confirmation of diseases, especially during outbreaks. Laboratory confirmation provides a stronger response structure to any outbreak.

Irrespective of the stage of the outbreak, it is important that good communication is established between the Epidemiologists and the laboratory. This also helps to increase on effective participation of the laboratory in surveillance