Q Fever (Coxiella burnetii)

Rabies

Rat Bite Fever

Relapsing Fever

Respiratory syncytial virus infection

Rift Valley Fever

Rheumatic fever and rheumatic heart disease

Rhinoscleroma

Rhinosporidiosis

Rocky Mountain Spotted Fever

Rotavirus diarrhea

Rubella

Rubeola

Salmonellosis (Gastroenteritis and Septicemia)

Scarlet fever

Schistosomiasis (Snail Fever)

Scrub Typhus

Shigellosis

Skin infections- (Histo-pathological patterns)

Sleeping Sickness

Smallpox

Sporotrichosis

St.Louis Encephalitis 

Staphylococcal Infection

Streptococcal Infection

Strongyloidiasis

Swine Influenza

Syphilis

Syphilitic Gumma

Tetanus

Tick-borne Encephalitis

Toxic Shock Syndrome

Toxoplasmosis

Trachoma

Trematode(Flukes)

Trichinosis

Trichosporonosis

Trichuriasis

Tuberculosis

Tularemia

Typhoid fever

Varicella

Variola

Venezuelan equine encephalitis

Verruga peruana

Viral hemorrhagic fevers

Viruses in Leukemia and Lymphoma

Visceral Larva Migrans

Western equine encephalitis

West Nile Virus disease

Whipple's disease

Whooping Cough (Pertussis)

Yaws

Yersiniosis

Yellow  Fever

Zygomycosis