1.
Which 4 worms have lifecycles involving migration to the lungs, being coughed up, swallowed, and down to the intestine?
Correct Answer
A. Strongyloides, hookworm, ascaris and paragonimus.
Explanation
The correct answer is Strongyloides, hookworm, ascaris, and paragonimus. These four worms have lifecycles that involve migration to the lungs, being coughed up, swallowed, and then reaching the intestine.
2.
Which larva can usually be found in fresh feces?
Correct Answer
C. Strongyloides
Explanation
Strongyloides is a type of parasitic nematode that commonly infests the intestines of humans and animals. The larvae of Strongyloides can be found in fresh feces. This parasite has a unique lifecycle where the larvae can infect the host through the skin, migrate to the lungs, and eventually reach the intestines where they mature into adults. The presence of Strongyloides larvae in fresh feces indicates an active infection and the potential for transmission to other individuals.
3.
How big is an infertile Ascaris egg?
Correct Answer
D. 85 - 90 microns
Explanation
The correct answer is 85 - 90 microns. This means that an infertile Ascaris egg is between 85 and 90 microns in size.
4.
What are the main reservoirs of Strongyloides?
Correct Answer
B. Dogs and primates
Explanation
Strongyloides is a genus of parasitic worms that commonly infects dogs and primates. These worms live in the intestines of their hosts and can cause various health issues. While other animals like bears, rats, and sheep can also be infected with different species of Strongyloides, the main reservoirs for this particular genus are dogs and primates.
5.
How many times do the Strongyloides L1 larvae have to molt to enter the free-living cycle?
Correct Answer
C. 4
Explanation
The Strongyloides L1 larvae have to molt four times to enter the free-living cycle. Moulting is the process of shedding the old cuticle and forming a new one. Each molt allows the larvae to develop and grow, eventually reaching the infective L3 stage. Once they reach this stage, they can infect a host and continue their life cycle. Therefore, the correct answer is 4.
6.
Parthenogenesis occurs in which worm?
Correct Answer
D. Strongyloides
Explanation
Parthenogenesis is a form of reproduction in which an organism can produce offspring without the need for fertilization. Among the given options, Strongyloides is the only worm that is known to exhibit parthenogenesis. This means that Strongyloides worms can reproduce without mating with a male worm, making them unique compared to the other worms listed. Ascaris, Enterobius, and Hookworms reproduce through sexual reproduction, requiring both male and female worms to mate. Therefore, the correct answer is Strongyloides.
7.
Ascaris is also called the whipworm?
Correct Answer
B. False
Explanation
Ascaris is the common round worm, trichuriasis is the whip worm.
8.
Loeffler's syndrome occurs which nematode infection?
Correct Answer
B. Ascaris lumbricoides
Explanation
Loeffler's syndrome is a reaction to the worm in the lungs. It is treated with prednisolone.
9.
Ascaris can be treated with albendazole.
Correct Answer
A. True
Explanation
True, and with mebendazole or pyrantel pamoate as well.
10.
Rectal prolapse can occur with which nematode infection?
Correct Answer
C. Trichuris trichiura.
Explanation
Rectal prolapse is a condition where the rectum protrudes out of the anus. Trichuris trichiura, also known as whipworm, is a nematode infection that can cause chronic inflammation of the large intestine. This chronic inflammation weakens the rectal muscles, making them more susceptible to prolapse. Enterobius, also known as pinworm, primarily affects the intestines but does not directly cause rectal prolapse. Capillaria philippinensis is a nematode that primarily affects the small intestine and does not cause rectal prolapse. Therefore, the correct answer is Trichuris trichiura.
11.
Nematodes are platyhelminths.
Correct Answer
B. False
Explanation
Cestodes and trematodes are platyhelminths.
12.
The eggs of Capillaria philippinensis are what size?
Correct Answer
A. 35 - 45 microns
Explanation
35- 45 with a striated shell and 2 polar plugs (non-protruding unlike trichuris).
13.
Trichuris trichiura are adults are found in the small intestine?
Correct Answer
B. False
Explanation
They mature to adults and oviposit in the caecum and ascending colon (both large intestine).
14.
Older dogs are a greater source of environmental Toxocara contamination then puppies.
Correct Answer
B. False
Explanation
In puppies, the larvae migrate to the lungs, bronchial tree, and esophagus to become adults that oviposit, therefore passing eggs in their feces. In older dogs, the larvae encyst rather than becoming adults, so eggs are not passed as much in their feces.
15.
Trichinella spiralis has a high transmission rate in the UK?
Correct Answer
B. False
Explanation
Trichinella is found worldwide, but there is little or no transmission in the UK. There are much higher rates in Eastern Europe, Asia, and Japan.
16.
Nurse-cell larval complexes are found in which worm's lifecycle?
Correct Answer
B. Trichinella spiralis
Explanation
The female worms in the mucosa of the small intestine release larvae that migrate to striated muscle and encyst. The lifecycle is continued when this is eaten by other animals.
17.
Graham's test can be used for which infection diagnosis?
Correct Answer
D. Enterobius
Explanation
Graham's test is the sellotape method for pinworm eggs.
18.
Ground itch occurs with which worm infection.
Correct Answer
D. Hookworm
Explanation
Ground itch is a skin condition caused by the larvae of hookworms. These parasites can penetrate the skin, usually through bare feet, and cause an itchy rash and inflammation. The larvae migrate through the skin and eventually reach the intestines, where they mature into adult worms. Hookworm infection is commonly found in areas with poor sanitation and can be transmitted through contaminated soil or feces. Symptoms of hookworm infection may include anemia, abdominal pain, and diarrhea. Treatment typically involves medication to kill the worms and alleviate symptoms.
19.
Do L3 hookworm larvae have longer buccal cavities than Strongyloides?
Correct Answer
A. True
Explanation
L3 hookworm larvae have longer buccal cavities than Strongyloides. This means that the hookworm larvae have larger and more developed mouthparts compared to Strongyloides larvae. The length of the buccal cavity is an important characteristic that distinguishes different species of parasites.
20.
Cutaneous larval migrans occurs in Toxocara infection?
Correct Answer
B. False
Explanation
This occurs with hookworm when the larvae are migrating through the skin. It is caused by Ancylostoma caninum or braziliense and is treated with oral albendazole or topical thiabendazole. Visceral and ocular larval migrans occurs in Toxocara.
21.
Autoinfection can occur with Capillaria philippinensis.
Correct Answer
A. True
Explanation
Some eggs hatch in the intestine and re-invade the mucosa, whilst others are passed in the feces to be eaten by fish, which are then eaten by humans or birds (the definitive hosts).
22.
Ancylostoma duodenale has no teeth.
Correct Answer
B. False
Explanation
Anycylostoma does have teeth, necator americanus doesn't (it has plates).
23.
Trichuris eggs are passed into the soil embryonated.
Correct Answer
B. False
Explanation
They are passed unembryonated and embryonated in the soil.
24.
Visceral and ocular larval migrans are caused by:
Correct Answer
C. Toxocara
Explanation
Visceral and ocular larval migrans are caused by Toxocara. Toxocara is a parasitic roundworm that commonly infects dogs and cats. Humans can become infected by accidentally ingesting the eggs of the parasite, usually through contact with contaminated soil or objects. Once inside the body, the larvae migrate through various organs, including the liver, lungs, and eyes, causing inflammation and damage. This can lead to symptoms such as fever, abdominal pain, cough, and vision problems. Therefore, Toxocara is the correct answer for the cause of visceral and ocular larval migrans.
25.
Properly cooking fish is a control method for which worm?
Correct Answer
D. Capillaria pHilippinensis
Explanation
Capillaria philippinensis is transmitted by eating fish (brackish or freshwater). Birds are the definitive host.