Affect is a psychological term for an observable expression of emotion. A person's affect is the expression of emotion or feelings displayed to others through facial expressions, hand gestures, voice tone, and other emotional signs such as laughter or tears. Individual affect fluctuates according to emotional state.
There are over 3,000 different species of cockroaches-some are considered pests while others are beneficial in their natural environment. The three main types of cockroaches commonly found in homes in South Africa include the German cockroach, Oriental cockroach and American cockroach.
Diseases Spread By Cockroaches. Cockroaches are persistent and troublesome pests of homes, restaurants, hospitals, warehouses, offices, and other structures with food handling areas.These insects contaminate food and utensils, destroy fabric and paper products, and impart stain and odor to surfaces they contact. These may include: 1  Aeromonas species cause wound and other infections, diarrhea. 2  Alcaligenes faecalis causes of gastroenteritis, urinary tract infections. 3  Bacillus cerreus causes food poisoning. 4  Bacillus subtilis causes conjunctivitis. 5  Campylobacter jejuni causes enteritis.