4. The Camallanina are a suborder of nematodes.
Species: Dracunculus medenensis (human as final host)
Parasites of terrestrial and aquatic vertebrates
Copepods as obligatory secondary hosts
5. Thelazioidea is a superfamily of spirurian nematodes in the
large order Spirurida. Like all nematodes, they have neither a circulatory nor a
respiratory system.
Species: Gnathostoma spinegerum
8. Live in tissues or body cavities of a vertebrate host
Slender, threadlike worm usually 2 to 1 cm
Common habitat: circulatory system, lymphatic system, connective tissue and
serous cavities
These are transmitted by blood sucking insects
Requires two hosts to complete the cycle.
9. Produces less differentiated microfilariae
Microfilariae- are highly motile, threadlike pre larva that in some species may retain egg
membrane as SHEATH or it raptures to become naked or UNSHEATHED
Microfilaria are capable of living a long time in the vertebrate host, but cannot develop further until
ingested by an intermediate host.
Microfilariae transforms into infective larvae in the insect and are deposited in the next host when
insect takes its blood meal
• Female worms are viviparous
• Males are smaller than females
10. Sheathed Unsheathed
• Burgia malayi,
• Wuchereria bancrofti
• Loa loa
• M. Perstans
• M. Ozzardi
• M. Streptocerca
• O. volvulus
11.
12. Infective third stage larvae are transmitted to man by infected biting arthropods
during a blood meal
Inside the arthropod, the microfilariae develop in 1 to 2 weeks into infective
filariform (third stage larvae)
The adults dwell in various human tissues where they can live for several years
Larva migration and development takes place in the tissue
Definitive host: man
13. Nocturnal- largest no. of microfilariae found in peripheral blood is at night
Diural- Largest no. of microfilariae found in peripheral blood during day
Non periodic- largest no. of microfilariae circulating at some what constant levels
during day and night
Sub periodic- Microfilariae detected throughout the day but are detected in a
larger number during late afternoon
14. Parasites Adult Microfilaria Periodicity Vector
LYMPHATIC
W. bancrofti Lymphatic blood Nocturnal culex, aedes, anopheles
B. malayi Lymphatic blood Nocturnal Aedes, anoph, mansoni
B. timori Lymphatic blood Nocturnal Anopheles
SUBCUTANEOUS
L. loa Connective blood Diurnal chrysops
O. volvulus Connective skin Non periodic Simulium
M. streptocerca Dermis skin Non periodic Culicoides
SEROUS CAVITY
M. perstans Body cavity blood Non periodic Culicoides
M. ozzardi Body cavity blood Non periodic Culicoides
L o c a t i o n i n b o d y
18. Clinical manifestations mainly by the adult worms
Immunologic responses, both humoral and cell-mediated
Dead or dying worms elicit the most severe inflammation
Calcification of necrotizing granulomas with dead worms lead to lymphatic
obstruction
19. Acute filarial disease “acute attacks”
Episodes of febrile lymphangitis and lymphadentis
Adenolymphangitis (ADL) dermatoadenolyphangitis (DADL)
Pain, tenderness and swelling of affected areas (limbs, genitals, breast) w/ or
w/out fever
Epididymo-orchitis in males may occur
20. Lymphedema- An abnormal
accumulation of lymph in tissues
causing swelling of legs , arms, breasts,
or genitals
Elephantiasis- disabling and
disfiguring lymphedema of the limbs,
breast and genitals, accompanied by
marked thickening of the skin
PRESENCE OF PARASITE IN LYMPHATIC
SYSTEM CAN LEAD TO:
21. Hydrocele- Fluid-filled
ballon-like enlargement of
the sacs around the testes
Kidney damage- leading to
blood and protein loss in
urine
PRESENCE OF PARASITE IN LYMPHATIC
SYSTEM CAN LEAD TO:
23. MAJOR FILARIAL INFECTIONS OF HUMANS
Lab.
diagnosis
vectorLocation of
microfilaria
Location of
adult in
humans
Geographic
distribution
Diseasespecies
Blood filmmosquitoesBlood
(nocturnal
periodicity)
Lymphatic
vessels
Tropical
and
subtropical
areas
elephantiasisWuchereria
bancrofti
Blood filmmosquitoesBlood
(nocturnal
periodicity)
Lymphatic
vessels
AsiaelephantiasisBrugia
malayi
Skin snipSimulium
spp. (black
fly)
Skin, eyes,
no
periodicity
Subcutaneous
nodules
Africa,
Central
and South
America,
Yemen
Onchocerciasi
s (river
blindness)
Onchocerca
volvulus
Blood filmChrysops
spp. (deer
fly)
Blood
(diurnal
periodicity)
Moving in
subcutaneous
tissues
Central
Africa
loiasisLoa loa