A mosquito-borne viral disease transmitted by Aedes aegypti and Aedes albopictus mosquitoes. Causes sudden onset fever and severe joint pain. First identified in Tanzania in 1952. Name means 'that which bends up' describing the stooped posture from joint pain.

Mosquito-borne viral infection caused by dengue virus (4 serotypes). Transmitted by Aedes aegypti and Aedes albopictus. 100-400 million infections annually. Can progress to severe dengue (dengue hemorrhagic fever/shock syndrome).

An autoimmune condition where the pancreas produces little or no insulin. Previously known as juvenile diabetes, it typically appears during childhood or adolescence but can develop in adults. Requires lifelong insulin therapy.

A chronic metabolic disorder characterized by high blood sugar, insulin resistance, and relative lack of insulin. The most common form of diabetes, accounting for 90-95% of cases. Often preventable and sometimes reversible with lifestyle changes.

A rare but severe, often fatal hemorrhagic fever caused by Ebola virus. Zoonotic disease transmitted from wild animals to humans, then human-to-human. Case fatality rate 25-90% depending on outbreak. West Africa 2014-2016 outbreak: 28,000+ cases.

A condition in which excess fat builds up in the liver, not due to alcohol use. The most common chronic liver disease worldwide, affecting 25% of the global population. Ranges from simple steatosis to nonalcoholic steatohepatitis (NASH) which can progress to cirrhosis.

Inflammation of the stomach lining. Can be acute (sudden onset) or chronic (long-term). Common causes include H. pylori infection, NSAID use, and excessive alcohol consumption. Can lead to ulcers and increased stomach cancer risk if untreated.

A chronic digestive disease where stomach acid or bile irritates the food pipe lining. Occurs when the lower esophageal sphincter relaxes abnormally or weakens. Affects approximately 20% of adults in Western countries. Can lead to serious complications if untreated.

Diabetes diagnosed for the first time during pregnancy. Affects approximately 2-10% of pregnancies worldwide. Increases risk of complications for both mother and baby but usually resolves after delivery. Women with GDM have 50% lifetime risk of developing type 2 diabetes.

The most common enzyme deficiency worldwide, causing hemolytic anemia with oxidative stress. X-linked. Affects 400 million people, most commonly in malaria-endemic regions (protective against malaria). Triggers include fava beans, certain drugs, infections.

Human Immunodeficiency Virus attacks CD4+ T cells, progressively weakening the immune system. Without treatment, progresses to Acquired Immunodeficiency Syndrome (AIDS). Transmitted through blood, sexual contact, and mother-to-child. First described in 1981.

A condition where the thyroid gland produces too much thyroid hormone (T3 and T4). Accelerates the body's metabolism, causing unintentional weight loss, rapid heartbeat, sweating, and nervousness. Graves' disease is the most common cause.

A condition where the thyroid gland doesn't produce enough thyroid hormones. Slows down many of the body's functions. Hashimoto's thyroiditis is the most common cause in developed countries. Can occur at any age but is more common in older women.

Parasitic disease transmitted by infected Anopheles mosquitoes. Caused by Plasmodium species (falciparum, vivax, ovale, malariae, knowlesi). Major public health problem in tropical regions, causing ~600,000 deaths annually, mostly children under 5.

Open sores that develop on the inside lining of the stomach (gastric ulcers) and the upper portion of the small intestine (duodenal ulcers). Most common cause is H. pylori infection or NSAID use. Affects approximately 4% of the global population.

Infection causing inflammation of lung air sacs (alveoli). Can be bacterial, viral, or fungal. Leading cause of death in children worldwide and serious illness in elderly.

A fatal viral disease affecting the central nervous system, transmitted through saliva of infected animals. Once clinical symptoms appear, rabies is virtually 100% fatal. Preventable through post-exposure prophylaxis (PEP) if administered before symptom onset.

An autosomal recessive hemoglobinopathy caused by a point mutation in the HBB gene (Glu6Val). Red blood cells become rigid and sickle-shaped, causing vaso-occlusion, hemolysis, and multi-organ damage. Most common inherited blood disorder in the US.

Carrier state of sickle cell disease (HbAS), usually asymptomatic but associated with rare complications including exercise-related sudden death, rhabdomyolysis, renal medullary carcinoma, and splenic infarction at high altitude.

Bacterial infection caused by Mycobacterium tuberculosis, primarily affecting lungs but can involve any organ. Leading infectious cause of death worldwide. Latent infection common; active disease in 5-10% of infected.

A mosquito-borne flavivirus most commonly transmitted by Culex species mosquitoes. Can cause neurological disease in humans. Birds are primary hosts. First identified in Uganda in 1937; emerged in North America in 1999.

The most common type of anemia, caused by insufficient iron leading to decreased hemoglobin production. Can result from inadequate dietary intake, blood loss, or malabsorption. Affects all age groups globally.

A genetic condition where a person inherits one sickle cell gene and one normal hemoglobin gene. Usually asymptomatic but can cause complications under extreme conditions. Different from sickle cell disease.

Inflammation of the stomach and intestines caused by viruses (norovirus, rotavirus, adenovirus). Commonly called 'stomach flu.' Highly contagious, causing diarrhea, vomiting, and abdominal cramps. Major cause of morbidity worldwide.

A highly contagious viral disease causing fever, cough, runny nose, conjunctivitis, and characteristic rash. One of the most contagious infectious diseases. Can cause serious complications including pneumonia, encephalitis, and death. Vaccine-preventable.

A mild viral infection causing rash and fever, but devastating to developing fetuses (congenital rubella syndrome). Usually mild in children and adults but can cause miscarriage, stillbirth, or severe birth defects if contracted during pregnancy. Vaccine-preventable.

A serious bacterial infection causing painful muscle spasms and lockjaw. Caused by Clostridium tetani spores found in soil. Not transmitted person-to-person. Fatal in 10-20% of cases even with treatment. Entirely vaccine-preventable.

A highly contagious viral infection causing itchy blister-like rash, fever, and fatigue. Caused by varicella-zoster virus (VZV). Usually mild in children but more severe in adults. Can reactivate later as shingles. Vaccine-preventable.

A contagious skin infestation caused by the Sarcoptes scabiei mite. Causes intense itching and rash as the mites burrow into skin to lay eggs. Spreads through close skin-to-skin contact. Common in crowded conditions and healthcare settings.

A life-threatening bacterial infection caused by Salmonella typhi. Spread through contaminated food and water. Causes sustained high fever, abdominal pain, and rose-colored spots. Endemic in areas with poor sanitation. Vaccine-preventable.

An acute diarrheal infection caused by Vibrio cholerae bacteria. Causes severe watery diarrhea and dehydration, can kill within hours if untreated. Spread through contaminated water. Major public health problem in areas with poor sanitation.

A mosquito-borne viral hemorrhagic fever endemic to tropical Africa and South America. Causes fever, jaundice, bleeding, and organ failure. Named for yellowing of skin and eyes. Can be fatal. Vaccine-preventable and provides lifelong immunity.

Also known as delta hepatitis, caused by the hepatitis D virus (HDV) which requires hepatitis B virus to replicate. The most severe form of viral hepatitis with rapid progression to cirrhosis. Occurs as coinfection (with HBV) or superinfection (in chronic HBV).

Inability to fully digest lactose, the sugar in milk and dairy products, due to deficiency of lactase enzyme in the small intestine. Very common worldwide, especially in certain ethnic groups. Not dangerous but can cause uncomfortable symptoms.

A pregnancy complication characterized by high blood pressure and signs of damage to other organ systems, typically liver and kidneys. Usually begins after 20 weeks of pregnancy. Can lead to serious complications for both mother and baby including eclampsia (seizures). Leading cause of maternal and perinatal morbidity worldwide.

A potentially life-threatening condition where a fertilized egg implants and grows outside the main cavity of the uterus, most commonly in a fallopian tube. The pregnancy cannot proceed normally and can cause the fallopian tube to rupture, leading to severe internal bleeding. Requires immediate medical intervention.

A chronic inflammatory lung disease causing obstructed airflow from the lungs. Includes emphysema (destruction of lung air sacs) and chronic bronchitis (inflammation of bronchial tubes). Progressive disease that makes breathing increasingly difficult over time. Primarily caused by smoking.

A tropical parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma. Acquired through contact with contaminated freshwater. Affects over 240 million people worldwide, primarily in Africa. Second most devastating parasitic disease after malaria.

A parasitic disease caused by the nematode worm Onchocerca volvulus, transmitted through the bites of infected blackflies. Leading cause of infectious blindness worldwide. Affects approximately 20-25 million people, primarily in sub-Saharan Africa. WHO goal is elimination by 2030.

A neglected tropical disease caused by filarial worms transmitted by mosquitoes. Damages lymphatic system causing abnormal enlargement of body parts. Affects over 120 million people in 72 countries. WHO goal is elimination by 2030.

A parasitic disease transmitted by tsetse flies, caused by Trypanosoma brucei parasites. Affects rural populations in sub-Saharan Africa. Two forms exist: T.b. gambiense (West/Central Africa, chronic) and T.b. rhodesiense (East/Southern Africa, acute). Without treatment, fatal.

A severe, often fatal hemorrhagic fever caused by Marburg virus, related to Ebola virus. Transmitted through contact with infected animals (primarily fruit bats) or person-to-person through bodily fluids. First recognized in 1967 in Germany and Yugoslavia. Case fatality rate 23-90%.

A viral respiratory illness caused by Middle East Respiratory Syndrome Coronavirus (MERS-CoV). First reported in Saudi Arabia in 2012. Transmitted from camels to humans and person-to-person in close contact. Case fatality rate approximately 35%. Most cases in Arabian Peninsula.