Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants.Not included are ectoparasites like insects, mites, vertebrate, or other pests that affect plant health by consumption of plant tissues.rganisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants.
Erectile dysfunction (impotence) facts. 1  Erectile dysfunction (ED), also known as impotence, is the inability to have a hard erection initially and/or to have a hard erection that lasts long enough for sexual activity. Symptoms of erectile dysfunction include lack of an erection hard enough for penetration and/or lasting long enough for completion of sexual activity.
As can be understood from the mechanisms of a normal erection, impotence may develop due to hormonal deficiency, disorders of the neural system, lack of adequate penile blood supply or psychological problems. Spinal cord injury causes sexual dysfunction including ED.