Spread by: Contact with blood or body fluids.
Symptoms: Fever, headache, weakness, vomiting, jaundice, joint pain, or there may be no symptoms.
Disease complications: Chronic liver infection, liver failure, liver cancer.

Spread by: The mouth
Symptoms: Diarrhea, fever, vomiting
Disease complications: Severe diarrhea, dehydration

Spread by: Air and direct contact (diphtheria and pertussis); exposure through cuts in skin (tetanus).
Symptoms: Sore throat, mild fever, weakness, swollen glands in neck (diphtheria); stiffness in neck and abdominal muscles, difficulty swallowing, muscle spasms, fever (tetanus); severe cough, runny nose, apnea (a pause in breathing in infants) (pertussis).
Disease complications: Swelling of the heart muscle, heart failure, coma, paralysis, death (diphtheria); broken bones, breathing difficulty, death (tetanus); pneumonia, death (pertussis).

Spread by: Air and direct contact
Symptoms: There may be none unless bacteria enter the blood.
Disease complications: Meningitis, intellectual disability, epiglottitis, pneumonia, death.

Spread by: Air and direct contact.
Symptoms: There may be none, or pneumonia can develop.
Disease complications: Bacteremia, meningitis, death.

Spread by: Air, direct contact, and the mouth
Symptoms: Sore throat, fever, nausea, headache, or there may be no symptoms.
Disease complications: Paralysis, death.

Spread by: Air and direct contact.
Symptoms: Fever, muscle pain, sore throat, cough, extreme fatigue.
Disease complications: Pneumonia.

Spread by: Air and direct contact.
Symptoms: Rash, fever, cough, runny nose, pinkeye (measles); swollen salivary glands, fever, headache, fatigue, muscle pain (mumps); rash, fever, swollen lymph nodes (rubella).
Disease complications: Encephalitis, pneumonia, and death (measles); meningitis, encephalitis, inflammation of testicles or ovaries, deafness (mumps). Rubella is very dangerous for pregnant women: It can lead to miscarriage, stillbirth, premature delivery, and birth defects.

Spread by: Air and direct contact.
Symptoms: Rash, fatigue, headache, fever.
Disease complications: Infected blisters, bleeding disorders, encephalitis, pneumonia.

Spread by: Direct contact and contaminated food or water.
Symptoms: Fever, stomach pain, loss of appetite, fatigue, vomiting, jaundice, dark urine, or there may be no symptoms.
Disease complications: Liver failure, joint pain, and kidney, pancreatic, and blood disorders.

Spread by: Air and the mouth.
Symptoms: Nausea, vomiting, confusion, sensitivity to light.
Disease complications: Limb loss through amputation, hearing loss, problems with the nervous system, intellectual disability, seizures, strokes.