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.
Infectious diseases are the invasion of a host organism by a foreign replicator, generally microorganisms, often called microbes, that are invisible to the naked eye. Microbes that cause illness are also known as pathogens.The most common pathogens are various bacteria and viruses, though a number of other microorganisms, including some kinds of fungi and protozoa, also cause disease. An infectious disease is termed contagious if it is easily transmitted from one person to another.nfectious disease requires an agent and a mode of transmission (or vector). A good example is malaria, which is caused by Plasmodial parasites, chiefly Plasmodium falciparum but does not affect humans unless the vector, the Anopheles mosquito, is around to introduce the parasite into the human bloodstream.