Page 519 - The Veterinary Laboratory and Field Manual 3rd Edition

chapter 14

Arthropod vectors and

arthropod-borne diseases

Regula Waeckerlin and Susan C. Cork

Arthropods (phylum Arthropoda) have gained is observed. For successful insect monitoring,
increasing significance in the transmission of the following questions have to be answered to
viral, bacterial and parasitic (protozoan) diseases decide on the trap type used, the length of the
to humans and animals. In many cases, patho- trapping season, the duration of single trapping
gens undergo part of their replication cycle in events, and methods of sample collection and
the arthropod. At other times, invertebrates can storage.
be merely mechanical vectors. Mosquitoes (class
Insecta, order Diptera, family Culicidae) are the Ecological questions to consider when
most common transmitters of arthropod-borne setting up arthropod sampling:
diseases, followed by ticks (class Arachnida,
order Ixodida), midges (order Diptera, family • Which species will be sampled?
Nematocera) and phlebotomid sandflies (order • What are its life stages (eggs, larvae, pupae,
Diptera, family Psychodomorpha). However, any nymphs, adults)?
blood-feeding insect has the potential for dis- • Where does the arthropod breed?
ease transmission, for example Rhodnius prolixus • Are there special requirements for each life
(‘kissing bug’) transmitting Trypanosoma cruzi stage (temperature, humidity, plant cover-
(the protozoan causing Chagas disease) or the age)?
genus Glossina transmitting T. conglolensis and • When (life stage/season of the year/time of
T. vivax (the agents causing hagana). day) does it bite?
• Does it bite only one or several hosts?
• Which vertebrate species are affected?
14.1 Monitoring of disease vectors • Where is the highest density of affected spe-
cies?
arthropod monitoring • What will the collected samples be used for
(ecological studies, pathogen isolation)?
Monitoring the presence, abundance and phenol-
ogy (seasonal variation) of arthropods that can Variable components of trapping
function as disease vectors can provide valuable
information on the risk of disease transmission • type of trap
in a certain area, even before the actual disease • determination of trapping season

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