Analysis of Outbreak, Essay Example

Interpretation for Epidemic Curve Exercise

Source:  Centers for Disease Control and Prevention (1971).  MMWR 20:26

Review the following material from Association of Faculties of Medicine in Canada about varying types of epidemics and epidemic curves:

http://phprimer.afmc.ca/Part2MethodsStudyingHealth/Chapter7ApplicationsOfResearchMethodsInSurveillanceAndProgrammeEvaluation/Patternsofdiseasedevelopmentinapopulationtheepidemiccurve

Look at the epidemic curve pictured on the facing page. It is from a measles epidemic in South Dakota in 1970-71 (published in MMWR too long ago to be available on line).  Using the information in the Canada article and its examples to help you interpret, answer the following questions:

What term describes the case in the South Dakota outbreak that occurred on approximately October 16^th?

This is an index case.

Of the five types of outbreaks outlined in the Canada article, which is this?

Propagated is the type of outbreak because the infection occurs from one person to the next. The affected individual becomes an independent reservoir for the organism

From the South Dakota outbreak, what is your estimate of the incubation period of measles?

12 -14 days is the estimated incubation period

Supposing the South Dakota outbreak occurred primarily in persons 5-15 years of age, give two possible explanations as to why the epidemic may have waned after the third week of December.

From an individual perspective antibody build up is a factor to be considered, but from a broader perspective they vaccination program involving children from birth to adolescence is a major criteria influencing waning of the epidemic in the population along with adequate surveillance of measures taken by public health authorities. After the third week in December children would have been involved in the Christmas holiday celebrations. This could turn attention away from the epidemic itself towards the festivity effects on the community.

What feature of the epidemiology of measles is responsible for the occurrence of most outbreaks and (fortunately) is quite different in the case of Ebola virus?

The feature of measles epidemiology regarding outbreaks, which is fortunately different in Ebola, is the affect on children mainly between the ages of 5 -15 whereby Ebola affects adults primarily.