Module 9d Mosquitoes Part 2 Flashcards Preview

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Flashcards in Module 9d Mosquitoes Part 2 Deck (23):
1

Malaria

kills 1 million per year
vector: Anopheles sp.
parasites:
1. Plasmodium falciparum (50%)
2. Plasmodium vivas (43%)
3. Plasmodium malariae (7%)
4. Plasmodium ovale (

2

malaria transmission cycle in mosquitoes

mosquito is definitive host (development occurs)
1. ingests parasite during blood meal
2. travels to gut then salivary glands
3. escapes through saliva at next blood meal

3

malaria transmission cycle in humans

human in intermediate host
1. receives parasite from saliva of mosquito
2. travels to liver (may hibernate)
3. enters bloodstream and RBCs where it multiplies
4. bursts RBC to get back into bloodstream

4

malaria disease information

-sudden periods of fever, chills, lethargy, and sweating (highly predictable)
-after rupture of RBCs, new plasmodium merozoites are released along with toxins, prompting chills/fever
-next episode occurs in 48 or 72 hours depending on species

5

Plasmodium falciparum

causes the most severe form of malaria because:
-attacks young and old RBC
-toxins from dead RBC cause toxemia and anemia
-infected RBC stick to epithelium of capillaries which impedes blood flow

6

Plasmodium vivax

invade only young RBC
on 48 hours cycle
less severe symptoms (death unlikely)
relapses possible (remain dormant for awhile)

7

Plasmodium ovale

causes malaria similar to P. vivas with milder symptoms

8

Plasmodium malariae

invades only old RBC
on 72 hour cycle
can stay dormant with no symptoms for up to 50 years

9

malaria drugs

Primaquine (for P. vivax)
Mefloquine (taken monthly)
Chloroquine (taken weekly)

10

subfamily Culicinae mosquito-borne viruses

1. Togaviridae virus family (Alphavirus)
-causes Chikungunya, Equine Encephalitis
2. Flaviviridae virus family (Flavivirus)
-causes yellow fever, dengue, west nile

11

chikungunya

parasite: togaviridae
vector: Culicinae
emerging US disease
symptoms: fever, joint pain, rash
not fatal
no treatment

12

yellow fever virus

parasite: flaviviridae
vector: Aedes aegypti (Culicinae)
primarily a zoonotic disease
hemorraghic disease: sudden high fever, headache, nausea, pain, jaundice, bleeding gums, black vomit
effective vaccine available

13

dengue virus

primarily zoonotic
virus: flaviviridae - 4 serotypes (DEN-1, etc)
vectors: Aedes aegypti, Aedes albopictus (Culicinae)

14

transmission cycle of dengue virus

1. mosquito ingests virus
2. travels from gut - salivary gland
3. reinfects thru saliva

15

symptoms of dengue fever

"Breakbone Fever": extreme pain, fever, headache, rash
severe in certain cases: dengue hemorrhagic fever and dengue shock syndrome
no vaccine/medication, can only treat symptoms
can be fatal

16

west nile virus

primarily zoonotic in birds
vectors: Culex sp. (Culicinae)
also transmitted thru blood transfusions, organ transplants, lab exposure, or mother to baby
most people don't show symptoms
death unlikely

17

prevention and control of mosquitoes

1. prevention of bite
2. keeping populations at acceptable densities
3. minimize contact
4. reduction of longevity of females

18

personal protection

-chemical repellants (DEET)
-avoid outdoors, use window screens
-heat nets/protective clothing
-bed nets with insecticides

19

biological control

use of predators, parasites, or pathogens
predators: Gambusia mosquito fish (feed on larva)
pathogen: Bacillus thuringiensis israelensis (Bti) (larvae die when they ingest toxin)

20

physical control

complete eradication of breeding sites by filling water sources

21

chemical controls : larvicide

apply chemicals to water sources
-oils: kills by poisoning/suffocation
-insecticides: DDT or organophosphates
-insect growth regulators: interfere w/ development

22

chemical controls : adulticide

apply to surfaces or air
-foggers drift chemicals thru areas
-DDT used on landing surfaces

23

surveillance

core of all effective mosquitos control programs
know the diseases/mosquito species in your area