Delta Pronunciation: (del-ta). Delta letter quick facts. Delta is the fourth letter (Greek letter #4) in the modern day Greek alphabet. The Delta letter appears before Greek letter Epsilon which is pronounced (ep-si-lon), and after the letter Gamma which is pronounced (gam-ah). Delta Letter Template size: 600 X 600 pixels. Greek letter set: #1 to #12 (12 color combinations).
The most common disease-causing agents are viruses, bacteria, protozoa, and parasitic worms. Viruses are not living, but do get transferred between living organisms. The West Nile Virus is transferred from mosquitoes to humans. Vaccines are a good way to prevent the spread of viruses.iruses are the disease-causing agent that most people are familiar with. They cause colds, the flu, HIV, meningitis, polio, chicken pox, rabies, West Nile, and a number of other diseases. Viruses themselves aren't living things, but they do get transmitted between living organisms.
Bacteria are known as pathogens as they are able to cause a disease in plants, insects, animals as well as humans. The ability of bacteria to cause disease is called pathogenicity. This pathogenicity is expressed in terms of virulence.