Vector-borne diseases constitute around 23% of the infections. Although arboviruses
can be transmitted by awide range of arthropods, mosquitoes are the most important
from a veterinary and medical point of view and may have been parasitizing on
mammalian blood for 100 million years. Disease from vector-borne pathogens often
occurs as spillover events, as the pathogens generally circulate between reservoir
hosts and the invertebrate vectors without causing apparent disease.
1.1List any two ways of spreading of communicable or infectious diseases.
1.2 Name the target organs for the following diseases.
(a) Hepatitis .
(b) Tuberculosis .
1.3 Write one difference between chronic &
acute diseases.
1.4 Define health asper WHO.