Multiple sclerosis; its frequency and distribution, with special reference to San Francisco

Area of Science:

• Epidemiology
• Neurology
• Public Health

Background:

• Multiple sclerosis (MS) is a chronic neurological disease.
• Understanding the geographic distribution and incidence of MS is crucial for public health initiatives.

Purpose of the Study:

• To conduct epidemiologic surveys of multiple sclerosis (MS) in five North American cities in 1949.
• To determine the incidence, prevalence, and mortality rates of MS.
• To investigate potential geographic variations in MS rates.

Main Methods:

• Conducted surveys in San Francisco, Winnipeg, Boston, New Orleans, and Denver in 1949.
• Collected case reports from 1939-1948 from various medical record sources.
• Calculated average annual incidence, prevalence on January 1, 1949, and mortality rates per 100,000 population.

Main Results:

• In San Francisco, the average annual incidence was 2.1 per 100,000 (1.5 male, 2.6 female).
• Prevalence in San Francisco was 29.7 per 100,000 (21.2 male, 38.1 female).
• Mortality was 0.7 per 100,000 (0.6 male, 0.9 female).
• Comparison with other cities suggested a north-to-south decrease in MS incidence and severity.

Conclusions:

• The study provides baseline epidemiologic data for multiple sclerosis in selected North American cities in 1949.
• Findings suggest a potential latitudinal gradient in MS incidence and severity.
• Further research is warranted to explore the factors contributing to geographic variations in MS.