111
Causative agent
Mode of transmission
Symptoms
Major reservoir
Required
environmental
intervention
Onchocerciasis
(river blindness)
Onchocerca volvulus
(parasitic worm)
Black flies
Skin nodules as well as
itching may develop; eye
infections may result in
vision damage
Water resource
management
projects
(particularly
dams); infected
people
Vector control
Leishmaniasis
Protozoa of the genus Leishmania
Sand flies
Fever, loss of appetite, low
blood counts, malaise, or
night sweats; eruption of
skin sores weeks/months
after the person is infected
Infected people/
dogs/cats/rodents
Vector control;
control of dogs/
cats/rodents;
proper solid waste
management
Dengue fever
Dengue virus
Mosquito
High fever, headache, rash,
and muscle and joint pain
Infected people/
monkey
Management of
mosquito-breeding
places
Japanese
encephalitis
Japanese encephalitis virus
Mosquito
Mosquito
Infected people/
pigs/birds
Management of
mosquito farm
animals; personal
protection
Source:
Baron (1996) and WHO (1990, 2016, 2019a)
3.4 Interrelation Between Environment and Human/Animal Health