Helminthology Module 1 LT

t or f: roundworms are also called cestodes

false (roundworms = nematodes)

t or f: tapeworms are cestodes

true

t or f: flukes are nematodes

false (flukes = trematodes)

leaf-shaped helminths with dorso-ventrally flattened body

trematodes (flukes)

helminths that are flattened, elongated, and consist of segments called proglottids

tapeworms (cestodes)

the anterior attachment organ of adult worms

scolex

the body of adult worms that consists of a chain of segments called proglottids

strobila

t or f: roundworms are platyhelminths

false

refers to soil-transmitted nematodes

geohelminths

t or f: geohelminths require intermediate hosts

false (have a direct life cycle and involves NO intermediate hosts)

helminths that require an intermediate, definitive, or a reservoir hosts to complete their life cycle

biohelminths

this is the only zoonotic schistosome species

S. japonicum

reservoir hosts of S. japonicum

dogs and water buffaloes

host where parasite sexually matures (can release eggs)

definitive host

host in which the parasite undergoes larval development but does not reach sexual maturity

intermediate host

present in immature tapeworm, has invaginated scolex into fluid-filled bladder, and is ovoidal, milky white in color

cysticercus

refers to animals that harbor an infection that can be transmitted to humans

reservoir host

host where the parasite does not develop further to later stages but remain infective to another host and widen parasite distribution

paratenic host

main approach for STH control

regular distribution of deworming drugs to individuals living in endemic areas

a strategy that aims at the large-scale use of safe, single-dose medicine as well as the availability of the drug which will reduce morbidity and interrupt parasite transmission

preventive chemotherapy

a strategy that focuses on better access to the healthcare system through improved case detection and clinical management of the disease and aims to prevent mortality, reduce morbidity, and interrupt parasite transmission

intensive disease management

a strategy aimed at improving the efficiency and sustainability of disease control measures against vector-borne diseases including the management of pesticides

vector and intermediate host control

a strategy aimed at improving the prevention and control of neglected zoonotic diseases

Veterinary public health at the human-animal interface

strategy aimed at providing access to safe drinking water

Provision of safe water, sanitation, and hygiene

refers to the reduction of disease incidence, prevalence, morbidity, and mortality

control

refers to the reduction to zero on the incidence of infection

elimination

refers to the permanent reduction of NTD to zero

eradication

helminths that have unsegmented, small, dorso-ventrally flattened body and have a tough snycytial tegument

trematodes

this is the infective stage of S. japonicum

cercaria stage

considered the gold standard for the detection of parasite egg in stool sample

Kato-Katz Technique (involves microscopy)

repeating sequences of 2-6 base pairs of DNA whose polymorphism is based on their variation in the number of repeats

microsatellites

t or f: the no. of cercariae that infect the host and mature to lay eggs determine the severity of infection

true

t or f: S. japonicum can multiply in the definitive host

false (cannot multiply)

this results from the obstruction of the intrahepatic portal branches brought about by granuloma formation

splenomegaly and ascites

Elongated, oval in shape, cuticle is covered with fine, scale-like spines that are most numerous toward the anterior end

Heterophyes heterophyes

Morphologically characterized by the median location of the ventral sucker and the presence of a genital sucker ,which may lie within the acetabulum

Heterophyes heterophyes

primary intermediate hosts of most heterophyids

members of Thiarid or Melaniid