Question: What infectious disease has had the most cases?
Paraphrase: What disease has had the most cases?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q18123741 . ?ent wdt:P1603 ?obj } ORDER BY DESC(?obj)LIMIT 5 
Answer: 1918-1920 flu pandemic, hepatitis B, hepatitis C, typhoid fever, hepatitis E