viruses of gastrointestinal infections. hand drawn set of microorganisms. scientific in sketch style

virus bacteria gastroenteritis gastrointestinal norovirus astrovirus rotavirus adenovirus coronavirus gut stomach digestion digestive system diarrhea vomiting symptoms poisoning microorganism sketch hand drawn engraving pen pencil etch drawing doodle set type germ bacterium epidemic cell molecule biology microbiology microbe micro organism disease vector science microscopic bacillus pathogen isolated black white element pandemic viruses infections microorganisms scientific style infections microorganisms style