infectious disease

Tuberculosis

Caused by Mycobacterium tuberculosis a slow-growing acid-fast bacterium infecting lungs via inhalation. It survives in macrophages causing granuloma formation leading to cough hemoptysis and weight loss. Treated with prolonged multi-drug antibiotics including isoniazid rifampin pyrazinamide and ethambutol

HIV/AIDS

Human immunodeficiency virus, a retrovirus targeting CD4+ T cells causing progressive immune suppression. Leads to opportunistic infections and malignancies. Treatment involves antiretroviral therapy to suppress viral replication

Malaria

Protozoan parasites of genus Plasmodium transmitted by Anopheles mosquitoes infecting liver and red blood cells causing cyclical fevers anemia and splenomegaly. Treated with antimalarials such as chloroquine or artemisinin-based therapies

Influenza

RNA virus infecting respiratory epithelial cells causing fever cough myalgia and potential secondary bacterial pneumonia. Mechanism includes viral replication and immune-mediated damage. Treatment includes supportive care and antivirals like oseltamivir

COVID-19

Caused by SARS-CoV-2, a coronavirus infecting respiratory tract cells via ACE2 receptor leading to fever cough ARDS and multi-organ involvement. Treated with supportive care antivirals, steroids, and monoclonal antibodies in severe cases

Streptococcal pharyngitis

Group A Streptococcus bacteria infecting throat mucosa causing sore throat fever and tonsillar exudate. Complications include rheumatic fever. Treated with penicillin or amoxicillin

Sepsis

Systemic inflammatory response to infection caused by bacteria, fungi or viruses leading to organ dysfunction. Mechanism involves widespread cytokine release causing hypotension and shock. Treated with antibiotics fluids and supportive care

Clostridium difficile infection

Anaerobic spore-forming bacterium causing antibiotic-associated colitis via toxin-mediated mucosal damage leading to diarrhea and pseudomembranous colitis. Treated with oral vancomycin or fidaxomicin

Herpes simplex virus infection

HSV-1 and HSV-2 viruses infect epithelial and neuronal cells causing painful vesicular lesions and latency in sensory ganglia. Reactivation causes recurrent sores. Treated with acyclovir and related antivirals

Human papillomavirus infection

DNA virus infecting epithelial cells causing warts and oncogenic strains leading to cervical and other cancers via integration and oncogene expression. Prevented by vaccination and treated by lesion removal

Lyme disease

Borrelia burgdorferi spirochete transmitted by Ixodes ticks infecting skin and disseminating causing erythema migrans arthritis and neurologic symptoms. Treated with doxycycline or amoxicillin

Hepatitis B

DNA virus infecting hepatocytes causing acute and chronic hepatitis leading to cirrhosis and hepatocellular carcinoma. Transmitted sexually and perinatally. Treated with antivirals like entecavir and tenofovir

Hepatitis C

RNA virus infecting liver causing chronic hepatitis and cirrhosis. Transmitted via blood exposure. Treated with direct-acting antivirals achieving high cure rates

Measles

Highly contagious paramyxovirus infecting respiratory tract and causing fever cough Koplik spots and rash with risk of pneumonia and encephalitis. Prevented by MMR vaccine and treated supportively

Rabies

Neurotropic virus transmitted by animal bites infecting peripheral nerves and CNS causing fatal encephalitis. Post-exposure prophylaxis includes rabies immunoglobulin and vaccine

Tetanus

Caused by Clostridium tetani producing neurotoxin blocking inhibitory neurotransmitters causing muscle spasms and lockjaw. Treated with antitoxin antibiotics and supportive care

Dengue fever

Flavivirus transmitted by Aedes mosquitoes causing fever rash and hemorrhagic manifestations due to vascular leakage. No specific treatment supportive care essential

Cholera

Vibrio cholerae bacterium producing enterotoxin causing massive watery diarrhea and dehydration. Treated with rehydration and antibiotics

Typhoid fever

Salmonella typhi infecting intestinal lymphoid tissue causing fever abdominal pain and rose spots. Treated with antibiotics such as ceftriaxone

Zika virus

Flavivirus transmitted by mosquitoes infecting skin and nervous system causing rash fever and congenital microcephaly. Supportive treatmen