COVID-19

• Causative Organism: SARS-CoV-2.
• Mode of Transmission: Droplet and airborne.
• Virulence Factors: Attachment to ACE-2 host cell protein; induction of autoimmunity.
• Culture/Diagnosis: RT-PCR, antibody (Ab), and antigen (Ag) tests.
• Prevention: Vaccination and mitigation efforts (masks, social distancing).
• Treatment: Antivirals such as Paxlovid™.
• Signs and Symptoms: Respiratory symptoms, "cytokine storm" leading to hyperinflammation, skin rashes, muscle/joint pain, heart damage, and loss of taste and smell

Acute Endocarditis

• Causative Organism: Staphylococcus aureus, Streptococcus pyogenes, S. pneumoniae, Enterococcus, Pseudomonas aeruginosa, and others.
• Mode of Transmission: Parenteral (e.g., via injections).
• Virulence Factors: Not explicitly listed in the source table.
• Culture/Diagnosis: Blood culture.
• Prevention: Aseptic surgery and sterile injections.
• Treatment: Vancomycin or surgery.
• Signs and Symptoms: Fever, anemia, abnormal heartbeat, symptoms of heart attack, shortness of breath, chills, Janeway lesions, and Osler’s nodes

Subacute Endocarditis

• Causative Organism: Alpha-hemolytic streptococci and others.
• Mode of Transmission: Endogenous transfer of normal biota to the bloodstream.
• Virulence Factors: Not explicitly listed.
• Culture/Diagnosis: Blood culture.
• Prevention: Prophylactic antibiotics before invasive procedures.
• Treatment: Broad-spectrum antibiotics or surgery.
• Signs and Symptoms: Similar to acute endocarditis but with a slower onset; includes enlarged spleen and clubbed fingers/toes

Sepsis (Septicemia)

• Causative Organism: Various bacteria or fungi.
• Mode of Transmission: Parenteral or endogenous transfer.
• Virulence Factors: Cell wall or membrane components (e.g., endotoxin).
• Culture/Diagnosis: Blood culture and deep sequencing.
• Prevention: No specific prevention listed.
• Treatment: Broad-spectrum antibiotics until susceptibility is tested.
• Signs and Symptoms: Fever, altered mental state, shaking chills, gastrointestinal symptoms, increased breathing rate, and low blood pressure leading to septic shock

Plague (Bubonic, Pneumonic, and Septicemic)

• Causative Organism: Yersinia pestis.
• Mode of Transmission: Biological vector (flea), droplet contact (pneumonic), and direct contact with body fluids.
• Virulence Factors: Capsule and plasminogen activator.
• Culture/Diagnosis: Rapid genomic methods.
• Prevention: Flea and animal control; vaccines for high-risk individuals.
• Treatment: Streptomycin or ciprofloxacin.
• Signs and Symptoms: Inflammation and necrosis of lymph nodes (buboes), respiratory distress (pneumonic), and purpura/necrosis (septicemic).

Tularemia

• Causative Organism: Francisella tularensis.
• Mode of Transmission: Biological vector (tick), direct contact with infected animal fluids, or airborne.
• Virulence Factors: Intracellular growth.
• Culture/Diagnosis: Serology (culture is dangerous to lab workers).
• Prevention: No specific prevention listed.
• Treatment: Gentamicin or streptomycin.
• Signs and Symptoms: Headache, backache, fever, chills, malaise, ulcerative skin lesions, and swollen lymph glands

Lyme Disease

• Causative Organism: Borrelia burgdorferi and related species.
• Mode of Transmission: Biological vector (tick).
• Virulence Factors: Antigenic shifting and adhesins.
• Culture/Diagnosis: Acute and convalescent sera testing.
• Prevention: Tick avoidance.
• Treatment: Doxycycline and/or amoxicillin.
• Signs and Symptoms: Characteristic bull’s eye rash, fever, headache, stiff neck, and dizziness; progresses to cardiac, neurological, and polyarthritis symptoms

Infectious Mononucleosis

• Causative Organism: Epstein–Barr virus (EBV).
• Mode of Transmission: Direct or indirect contact; parenteral.
• Virulence Factors: Latency and the ability to incorporate into host DNA.
• Culture/Diagnosis: Differential blood count, Monospot test for heterophile antibody, and ELISA.
• Prevention: No specific prevention listed.
• Treatment: Supportive care.
• Signs and Symptoms: (Common symptoms mentioned in context: fatigue, sore throat, and night sweats

Anthrax

• Causative Organism: Bacillus anthracis.
• Mode of Transmission: Vehicle (air, soil, food) or indirect contact (animal hides).
• Virulence Factors: Triple exotoxin (edema factor, protective antigen, and lethal factor).
• Culture/Diagnosis: Culture and direct fluorescent antibody tests.
• Prevention: Vaccination for high-risk populations and post-exposure antibiotics.
• Treatment: Consultation with the CDC.
• Signs and Symptoms: Varies by site (cutaneous lesions, pulmonary involvement, or GI symptoms)

Yellow Fever (Hemorrhagic)

• Causative Organism: Yellow fever virus.
• Mode of Transmission: Biological vector (the Aedes mosquito).
• Virulence Factors: Disruption of clotting factors.
• Culture/Diagnosis: ELISA or PCR.
• Prevention: Live attenuated vaccine.
• Treatment: Supportive care.
• Signs and Symptoms: Fever, internal hemorrhaging, and jaundice

Dengue Fever (Hemorrhagic)

• Causative Organism: Dengue fever virus.
• Mode of Transmission: Biological vector (Aedes mosquito).
• Virulence Factors: Disruption of clotting factors.
• Culture/Diagnosis: A rise in IgM titers.
• Prevention: A vaccine is approved for children (ages 9–16) with previous infections living in endemic areas.
• Treatment: Supportive care.
• Signs and Symptoms: Fever and severe pain, leading to the name “breakbone fever”

Chikungunya (Hemorrhagic)

• Causative Organism: Chikungunya virus.
• Mode of Transmission: Biological vector (Aedes mosquito).
• Virulence Factors: Disruption of clotting factors.
• Culture/Diagnosis: PCR.
• Prevention: Not available.
• Treatment: Supportive care.
• Signs and Symptoms: Fever, internal hemorrhaging, and arthritic symptoms

Ebola and/ or Marburg (Hemorrhagic)

• Causative Organism: Ebola virus or Marburg virus.
• Mode of Transmission: Direct contact with body fluids.
• Virulence Factors: Disruption of clotting factors.
• Culture/Diagnosis: PCR or viral culture (conducted at the CDC).
• Prevention: A new Ebola vaccine is used for epidemic situations.
• Treatment: New drugs have been developed for ongoing outbreaks.
• Signs and Symptoms: Massive hemorrhage; patients may bleed from orifices and mucous membranes

Lassa Fever (Hemorrhagic)

• Causative Organism: Lassa fever virus.
• Mode of Transmission: Droplet contact (aerosolized rodent excretions) or direct contact with infected fluids.
• Virulence Factors: Disruption of clotting factors.
• Culture/Diagnosis: ELISA.
• Prevention: Avoiding rats and maintaining safe food storage.
• Treatment: Ribavirin.
• Signs and Symptoms: Chest pain and long-term deafness

Brucellosis (Non-hemorrhagic)

• Causative Organism: Brucella melitensis, B. abortus, or B. suis.
• Mode of Transmission: Direct contact, airborne, or parenteral (needlesticks).
• Virulence Factors: Intracellular growth and the ability to avoid destruction by phagocytes.
• Culture/Diagnosis: Gram stain of biopsy material or PCR.
• Prevention: Animal control and pasteurization of milk.
• Treatment: Doxycycline plus gentamicin or streptomycin.
• Signs and Symptoms: An undulating fever pattern and muscle aches

Q Fever (Non-hemorrhagic)

• Causative Organism: Coxiella burnetii.
• Mode of Transmission: Airborne, direct contact, or food-borne.
• Virulence Factors: Endospore-like structure.
• Culture/Diagnosis: PCR or serological tests for antibodies.
• Prevention: Vaccine available for high-risk populations.
• Treatment: Tetracycline or TMP/SMZ.
• Signs and Symptoms: Fever and variable disease presentation

Cat-scratch Disease (Non-hemorrhagic)

• Causative Organism: Bartonella henselae.
• Mode of Transmission: Parenteral (cat scratch or bite).
• Virulence Factors: Endotoxin.
• Culture/Diagnosis: ELISA or biopsy of lymph nodes plus Gram staining.
• Prevention: Thoroughly cleaning wound sites.
• Treatment: Azithromycin or rifampin.
• Signs and Symptoms: Small papules at the inoculation site and swollen, pus-filled lymph nodes

Trench Fever (Non-hemorrhagic)

• Causative Organism: Bartonella quintana.
• Mode of Transmission: Biological vector (lice).
• Virulence Factors: Endotoxin.
• Culture/Diagnosis: ELISA.
• Prevention: Avoiding lice.
• Treatment: Azithromycin plus or minus doxycycline.
• Signs and Symptoms: 5-day fever, leg pains, and a macular rash; endocarditis is common

Ehrlichiosis and Anaplasmosis (Non-hemorrhagic)

• Causative Organism: Ehrlichia or Anaplasma species.
• Mode of Transmission: Biological vector (tick).
• Virulence Factors: Not applicable.
• Culture/Diagnosis: PCR or indirect antibody test.
• Prevention: Avoiding ticks.
• Treatment: Doxycycline.
• Signs and Symptoms: Acute febrile state, headache, and muscle pain

Babesiosis (Non-hemorrhagic)

• Causative Organism: Babesia species.
• Mode of Transmission: Biological vector (tick).
• Virulence Factors: Not applicable.
• Culture/Diagnosis: Blood smear.
• Prevention: Avoiding ticks.
• Treatment: Combination therapy with antibacterial and antiprotozoal drugs.
• Signs and Symptoms: Fever, headache, and muscle pain

Spotted Fever Rickettsiosis (Non-hemorrhagic)

• Causative Organism: Rickettsia species (specifically R. rickettsii for Rocky Mountain Spotted Fever).
• Mode of Transmission: Biological vector (tick).
• Virulence Factors: Induces apoptosis in cells lining blood vessels.
• Culture/Diagnosis: PCR or fluorescent antibody tests.
• Prevention: Avoiding ticks.
• Treatment: Doxycycline.
• Signs and Symptoms: Fever, chills, and a distinctive spotted rash that appears 2 to 4 days after the prodrome

Chagas Disease

• Causative Organism: Trypanosoma cruzi.
• Mode of Transmission: Biological vector (triatomine bug) or vertical transmission.
• Virulence Factors: Antioxidant enzymes and induction of autoimmunity.
• Culture/Diagnosis: Blood smear (acute phase) or serological methods.
• Prevention: Insect control.
• Treatment: Consultation with the CDC.
• Signs and Symptoms: Acute fever, nausea, and "chagoma" at the bite site; chronic disruption of the heart, brain, and GI tract

Malaria

• Causative Organism: Plasmodium species (P. falciparum, P. vivax, P. ovale, P. malariae, P. knowlesi).
• Mode of Transmission: Biological vector (mosquito) or vertical transmission.
• Virulence Factors: Multiple life stages/antigenic types, glucose scavenging, and cytoadherence.
• Culture/Diagnosis: Blood smear or serological methods.
• Prevention: Mosquito control, bed nets, and prophylactic antiprotozoal agents; vaccine for children.
• Treatment: Artemisinin and combination therapy.
• Signs and Symptoms: Cyclic chills, fever, and sweating; anemia and organ enlargement

HIV Infection and AIDS

• Causative Organism: Human immunodeficiency virus 1 or 2.
• Mode of Transmission: Direct sexual contact, parenteral, or vertical transmission.
• Virulence Factors: Attachment, syncytia formation, reverse transcriptase, and a high mutation rate.
• Culture/Diagnosis: Immunoassay to detect antibodies and antigens.
• Prevention: Avoidance of contact with infected fluids; PreP for high-risk individuals.
• Treatment: Early antiretroviral regimen.
• Signs and Symptoms: Initial fatigue and weight loss; progresses to severe immune deregulation and opportunistic infections