Is poliomyelitis a serious problem in developing countries?--lameness in Ghanaian schools

Area of Science:

• Public Health
• Epidemiology
• Infectious Diseases

Background:

• Poliomyelitis remains a significant public health concern in tropical endemic countries.
• Official incidence rates often fail to capture the true burden of paralytic poliomyelitis.
• Lameness in school-aged children can serve as an indicator of undiagnosed polio cases.

Purpose of the Study:

• To estimate the prevalence of lameness attributable to poliomyelitis in Ghanaian school children.
• To determine the mean annual incidence of paralytic poliomyelitis in Ghana.
• To compare reported versus estimated incidence rates and assess the impact of polio vaccination.

Main Methods:

• A postal survey was conducted among schools across Ghana.
• Data on lameness prevalence and reported polio cases were collected.
• Estimated prevalence and incidence rates were calculated and compared to official figures.

Main Results:

• An estimated 5-8 per 1000 school-aged children experienced lameness due to poliomyelitis.
• The estimated mean annual incidence of paralytic poliomyelitis was 23 per 100,000 population.
• At least 90% of polio cases appear to be unreported, significantly exceeding official rates.
• The global reduction in paralytic poliomyelitis cases since vaccine introduction is only 25%.

Conclusions:

• Poliomyelitis incidence in tropical endemic countries may be as high or higher than historical epidemic rates in temperate regions.
• Current polio vaccination coverage and reporting mechanisms in Ghana are insufficient.
• Immunization against poliomyelitis should be a high priority in Ghana and other endemic tropical nations.