This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of disease causation, Subject name: Social & Preventive Medicine
Accidents happening during weekends is - 
Select and explain. 
A. Cyclic trends, B. Seasonal trends, C. Secular trends, D. Point source epidemic
A: Cyclic trends
Answer: A: Cyclic trends 
Explanation: Ans. (a) Cyclic trendsRef : K. Park 23rd ed. / 65-66, 21st ed / 61,62Time Distribution of Disease* Secular trend: it implies changes in occurrence of a disease over a period of long time, generally several years or decade.# Ex: Polio, Diphtheria, Pertusis are the diseases which are reducing in India in fast few decades; and diseases like DM, Obesity and hypertension has increased in past few decades.* Epidemic: Short term fluctuation of a Disease occur in few days, week, or months. E.g. food poisoning, Bhopal gas tragedy* Cyclic trends: some diseases occur in cycles spread over a period of time which means days, weeks, months, or years. Non-infectious condition may also show periodic fluctuations ex: automobile accidents in US are more frequent on weekends, esp: Saturday. Other examples can be measles occurring every 2-3 years, Rubella every 6-9 years.* Seasonal trend: It is seasonal variation/fluctuation in occurrence of a disease. Ex: measles, URI, GIT infection.