What were main infectious diseases during the elizabethan era?

what were easily transmitted diseases during the elizabethan era???

Very interesting question. (I assume you mean "in England". That would elimate tropical diseases.)

Tuberculosis would be right up there. Dysentery (noted above) would be correct. Malaria also, to my surprise. The web tells me, "From 1564 to the 1730s鈥攖he coldest period of the Little Ice Age鈥攎alaria was an important cause of illness and death in several parts of England. "

Of course, there were the less-serious infectious diseases that have been common into modern times: measles, mumps, chicken pox.

Some that seem NOT to have been a major problem:
-- Black Death (bubonic plague) had been signicifant earlier, but that was before Elizabethan times.
-- Typhus and cholera seem to have mostly have come later (but see site listed below).
-- Smallpox wasn't too bad, for Europeans had developed immunities. (It was disasterous when brought to the Americas, however.)

Many people died of dysentery due to poor sanitation and the lack of personal hygiene.

Probably STD's

The bubonic plague existed in that time, however there wasn't a big outbreak until around the 1660's which is after that era.

Mostly, the diseases were things that we now have vaccines for, or bacterial infections that they had no treatment for so here are some common ones that it would make sense for them to have back then:
Viral:
Small pox, chicken pox, whooping cough, diphtheria, tetanus, measles, rubella, mumps, etc
Bacterial:
Polio, Strep throat, staph infections, eye infections(could be viral or bacterial), tuberculosis (consumption), syphilis, clamydia (not sure how to spell that)
Parasites:
Malaria (if travelling to exotic places), cholera, etc.