Schistosomiasis (bilharziasis) is a major human disease caused by three species of the genus Schistosoma, known collectively as blood flukes. Africa and western Asia (e.g., Iran, Iraq) are endemic centres for S. haematobium; S. mansoni also is found in these areas, as well as inâ¦
How Alcohol Damages Sperm. Alcohol can reduce the quantity of sperm a man produces (his sperm count) and the quality of that sperm. One way in which alcohol does this is by preventing the body from absorbing zinc in the normal way. Zinc is found in high quantities in sperm.
Other causes of low sperm count include: 1  Drug use. Anabolic steroids taken to stimulate muscle strength and growth can cause the testicles to shrink and sperm production to decrease. Use of cocaine or marijuana might reduce the number and quality of your sperm as well.  Alcohol use.