Psittacosis — also known as parrot fever or ornithosis — is a zoonotic infectious disease caused by the bacterium Chlamydia psittaci. It is primarily transmitted to humans through inhalation of aerosolized secretions, droppings, or feather dust from infected birds, particularly parrots, pigeons, and poultry. The disease predominantly affects the respiratory system, with common symptoms including … Read more
Leprosy, also known as Hansen’s disease, is a chronic infectious disease caused by the slow-growing bacterium Mycobacterium leprae. It primarily affects the skin, peripheral nerves, mucous membranes, and eyes, leading to symptoms such as hypopigmented or reddish skin lesions, numbness, muscle weakness, and nerve damage. In advanced cases, untreated leprosy can result in deformities of … Read more
Botulism is a rare but potentially life-threatening paralytic illness caused by botulinum toxin, a neurotoxin produced by Clostridium botulinum and related species. The toxin interferes with normal nerve function by inhibiting the release of acetylcholine, leading to muscle weakness that can progress to respiratory failure if untreated. The disease occurs in several distinct forms, including … Read more
Yersinia pestis is a type of bacteria that causes plague, a serious and highly contagious disease that spreads from animals to humans. It belongs to a group of bacteria called Enterobacteriaceae and has a short, rod-like shape. This bacterium has been responsible for several major pandemics in history, including the Justinian Plague in the 6th … Read more
Anthrax is a serious infectious disease that affects both humans and animals. It is caused by exposure to the spores of Bacillus anthracis, a bacterium capable of surviving in the environment for long periods under harsh conditions. Anthrax is primarily a zoonotic disease, occurring most commonly in livestock such as cattle, sheep, and goats, but … Read more
Legionnaires’ disease is a severe and potentially fatal form of pneumonia caused by infection with Legionella bacteria, most frequently Legionella pneumophila. The disease is typically acquired through the inhalation of aerosolized water droplets that contain the bacteria. These aerosols can originate from various sources where Legionella thrives, such as improperly maintained or contaminated water systems. … Read more
Pertussis, also known as whooping cough, is a highly contagious acute respiratory illness caused by Bordetella pertussis. The infection primarily targets the mucosal lining of the respiratory tract and is characterized by a prolonged paroxysmal cough, often accompanied by a high-pitched “whoop” sound during gasping inhalation following coughing fits. The disease has a global distribution … Read more
Shigellosis is an acute, highly contagious infectious disease caused by gram-negative bacteria of the genus Shigella, which includes four major species: S. dysenteriae, S. flexneri, S. boydii, and S. sonnei. It primarily affects the intestines, leading to inflammation of the colon (colitis), and is characterized by diarrhea that may range from mild to severe, often … Read more
Diphtheria is an acute and highly contagious bacterial infection caused by Corynebacterium diphtheriae. It primarily affects the mucous membranes of the upper respiratory tract, including the throat and nose. A characteristic feature of the disease is the formation of a thick, gray or white pseudomembrane, which can obstruct the airway and lead to breathing difficulties. … Read more
Lyme disease is an infectious disease caused by the bacterium Borrelia burgdorferi, transmitted to humans through the bite of infected black-legged ticks (Ixodes scapularis in North America). Early symptoms typically include fever, fatigue, and a characteristic skin lesion known as erythema migrans. If left untreated, the infection can spread to joints, the nervous system, and … Read more