Causes of viruses ?

1. Human behavior: Viruses can be spread through close contact with infected individuals, such as through coughing, sneezing, or touching contaminated surfaces.

2. Animal-to-human transmission: Some viruses originate in animals and can be transmitted to humans through direct contact or consumption of infected animal products.

3. Environmental factors: Viruses can survive in the environment for extended periods of time, allowing for transmission through contaminated water, soil, or air.

4. Poor sanitation and hygiene: Lack of proper sanitation practices and hygiene measures can contribute to the spread of viruses, especially in crowded or unsanitary conditions.

5. Global travel and trade: Increased international travel and trade can facilitate the spread of viruses across borders and continents.

6. Mutation and adaptation: Viruses have the ability to mutate and adapt to new environments, allowing them to evolve and potentially become more infectious or virulent.

7. Lack of vaccination: Failure to vaccinate against certain viruses can lead to outbreaks and epidemics, as individuals remain susceptible to infection.