The results the vaccine coverage surveywere reviewed

Learning Objectives
After completing this case study, the participant should be able to:
GDefine incidence, prevalence, and case-fatality rate;
GDefine surveillance and identify the key features of a surveillance system;
GList the types of information that should be collected on a surveillance case report form; GList the factors that can account for a change in the reported incidence of a disease; GDefine sensitivity of a surveillance system, and the effect of different case definitions on sensitivity.

This case study was originally developed by Nancy Binkin (EIS '80) in 1989. The current version was revised and edited by Richard Dicker with input from EIS Summer Course instructors and students over the years

CDC / EIS, 2003: Paralytic Polio in Ababo (891-903) – Student's Guide	Page 2

One measure of the polio situation in a children, since lameness is a common sequela

Question 4: What are the key elements included in the definition of public health surveillance?

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Table 1. Polio Morbidity and Mortality, Ababo District, 1986-1990

Question 6a: What is a case-fatality rate? What does it measure?

Question 9: What might account for the increase in the number of new cases observed during the two most recent years?

Question 10: How might you explain the discrepancy between the hospital cases and reported cases?

the following tables.

Table 2. Seasonal Distribution of Polio, Ababo District Hospital, 1989 and 1990

Month	1989		Month
January	5	7	July	2
February	19	16	August	0	2
March	4	8	September	1
April	9		October	2
May	4	8	November	4
June	4	5	December	7	5

Table 3. Age Distribution of Po Age (in years)
<1	34	5	2
1	50	6	3
2	25
3	27
4	7

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Table 4. Sex and Ethnic Distribution of Polio Cases, Ababo District Hospital, 1989 and 1990

Sex

Zanu	Male
Zanu
Hanzu
Other
Other	93	57	150

Table 5. Lameness by Vaccination Status among Children 12-23 Months of Age, Ababo District, 1991

Polio	$1 dose	Lame
Polio	$1 dose
Vaccine				676
Vaccine		10	909	919

The District Health Officer plans to review the polio surveillance data each month. Knowing

disseminating the information to "those who need to know," the District Health Officer begins

Officer. She has seen 12 and 34 cases in the months of January and February of 1991,

pediatric service called the District Health respectively.

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EPILOGUE

In 1988, the World Health Assembly launched a global initiative to eradicate polio by the end of the year 2000. This initiative was not without controversy. Some public health officials argued that polio, a potentially fatal or crippling disease, could be eradicated, so it should. In the long run, eradication would save billions of dollars.

2. PAHO. Polio Eradication Field Guide, 2nd ed. Washington, DC, PAHO, 1994.

3. WHO. Poliomyelitis (Fact Sheet no. 114). Geneva: WHO, April 2003.