Brucellosis is a disease that people can catch from animals, and it’s caused by bacteria called Brucella. These bacteria are tiny, rod-shaped germs that live inside the cells of animals and sometimes humans. The disease is found all over the world, but it’s especially common in places where people live closely with livestock like cows, goats, sheep, and pigs.
## How Do People Get Brucellosis?
People usually get brucellosis in a few main ways:
– **Eating or drinking contaminated food:** The most common way is by consuming unpasteurized milk or dairy products from infected animals. Pasteurization kills the bacteria, but raw milk can carry them.
– **Direct contact with animals:** Farmers, veterinarians, slaughterhouse workers, and others who handle animals or their tissues (like blood or placenta) can get infected if they have cuts or scratches on their skin.
– **Breathing in the bacteria:** In rare cases, people working in labs or slaughterhouses might inhale tiny droplets containing Brucella.
The bacteria enter the body through these routes and then start to multiply inside human cells.
## What Happens Inside the Body?
Once inside a person’s body, Brucella bacteria are very clever at hiding from the immune system—the body’s defense against germs. They sneak into white blood cells called macrophages that normally eat up invaders. Instead of being destroyed there like most germs would be, Brucella actually uses these cells as a safe place to grow and spread.
The immune system tries to fight back by sending more white blood cells to attack the infection. This battle causes inflammation—redness, swelling, heat—which leads to many of brucellosis symptoms.
## Why Does Brucellosis Cause Symptoms?
Brucellosis doesn’t always cause obvious symptoms right away; sometimes it starts slowly with mild signs that could be mistaken for other illnesses. Common symptoms include fever (which may come and go), sweating (especially at night), feeling tired all over (fatigue), loss of appetite (not wanting to eat), muscle aches (myalgia), joint pain (arthralgia), headache
