Common Human Infectious Diseases: Symptoms and Overview

Major Infectious Diseases Affecting Humans

Infectious diseases are caused by bacteria, viruses, fungi, and parasites. Prevalence varies by region; prevention relies on vaccination, hygiene, and vector control.

Key Diseases

Disease	Pathogen	Key Symptoms
Influenza (Flu)	Influenza viruses	Fever, cough, sore throat, myalgia, fatigue
COVID-19	SARS-CoV-2	Fever, cough, fatigue; severe cases: respiratory failure
Tuberculosis	Mycobacterium tuberculosis	Persistent cough, fever, night sweats, weight loss
Malaria	Plasmodium spp. (mosquito-borne)	Cyclic fever, chills, sweats, fatigue
Measles	Measles virus	Fever, rash, cough, coryza, conjunctivitis
Dengue	Dengue virus (mosquito-borne)	High fever, severe headache, myalgia/arthralgia, rash
HIV/AIDS	HIV	Immunodeficiency → opportunistic infections, cancers
Pneumonia	Bacteria (e.g., S. pneumoniae) or viruses	Cough, fever, chest pain, dyspnea
Hepatitis A, B, C	Hepatitis viruses	Fatigue, nausea, abdominal pain, jaundice, dark urine
Food Poisoning	Bacteria (E. coli, Salmonella) or viruses	Vomiting, diarrhea, cramps, fever

Prevention Cornerstones

• Immunization (where vaccines exist).
• Safe water, food handling, sanitation.
• Hand hygiene, respiratory etiquette.
• Vector control (mosquito nets, repellents).
• Safe sex practices.