ICAR AICE-JRF/SRF Veterinary Protozoology: practice questions

Question 1 · hard

The feature of Theileria parva and T. annulata schizonts that underlies their pathogenicity is that they:

1. Live free in plasma and evade antibody by antigenic variation of their surface coat
2. Lyse red cells synchronously every 48 hours
3. Transform the host leucocyte so that it proliferates, and divide in step with it
4. Produce a potent exotoxin that damages the lungs directly

Question 2 · medium

The infection-and-treatment method of immunising cattle against East Coast fever involves:

1. Using a schizont-infected cell line attenuated by long passage in culture
2. Inoculating live T. parva sporozoites together with a long-acting tetracycline
3. Injecting a killed whole-parasite vaccine with an oil adjuvant into calves at weaning
4. Giving buparvaquone monthly throughout the tick season

Question 3 · hard

Which test is most suitable for identifying carrier cattle persistently infected with Anaplasma marginale before export?

1. A single Giemsa-stained blood film
2. Competitive ELISA based on major surface protein 5, or PCR
3. The Sabin-Feldman dye test
4. Faecal flotation for oocysts

Question 4 · hard

Why is a low faecal oocyst count not sufficient to rule out clinical coccidiosis in a calf with bloody diarrhoea?

1. Severe damage from late meronts and gamonts can occur before, or just as, oocyst shedding starts
2. Oocyst counts are only valid in poultry, where species have been calibrated against lesion scores
3. Pathogenic species never produce oocysts
4. Oocysts of the pathogenic species usually float poorly in standard salt solutions and are missed

Question 5 · medium

Which feature explains why Cryptosporidium causes waterborne outbreaks in people and persistent contamination of calf pens?

1. Oocysts are infective when passed and resist chlorine at drinking-water concentrations
2. Oocysts must sporulate for about two weeks in moist soil before they become infective to calves
3. Transmission requires an intermediate host snail
4. Oocysts are killed by drying within minutes

Question 6 · hard

Cryptosporidium andersoni in adult cattle differs from C. parvum in that it:

1. Causes haemorrhagic typhlitis in adult cows kept on wet pasture
2. Is the main zoonotic species acquired by students and farmers handling young scouring calves on dairy farms
3. Infects the respiratory tract of chickens
4. Infects the abomasal glands and is linked to reduced milk yield rather than neonatal diarrhoea

Question 7 · hard

Why is there no approved drug treatment for bovine trichomonosis in the EU and USA?

1. The effective nitroimidazoles are prohibited in food-producing animals
2. Treatment is unnecessary because bulls clear infection within days
3. The parasite is resistant to every known drug class
4. Cattle cannot absorb oral drugs

Question 8 · hard

Which statement best describes the current treatment situation for histomonosis in food-producing turkeys in the EU and USA?

1. A live attenuated vaccine is universally licensed and routinely used in all commercial flocks
2. Ionophores are licensed for turkeys and are fully effective in treating outbreaks once signs appear
3. Tetracyclines in water are the approved first-line treatment
4. The former nitroimidazoles and arsenicals are no longer available, so control relies on prevention

Question 9 · hard

Why is canine leishmaniosis by L. infantum a One Health concern in the Mediterranean and Brazil, whereas dogs are not central to kala-azar control in India?

1. L. infantum (the Mediterranean species) does not infect people
2. Kala-azar in India is transmitted by triatomine bugs that never feed on dogs, so dogs cannot act as a source of infection
3. Dogs are the main reservoir of zoonotic L. infantum, whereas Indian kala-azar (L. donovani) is anthroponotic
4. Indian sand flies cannot feed on dogs

Question 10 · medium

Why does bovine trichomonosis often go undetected on a farm for a long time?

1. Infected cows abort in late pregnancy with obvious foetal lesions
2. It affects only calves, which are rarely examined
3. Bulls show no signs, and in cows the main effect is early embryonic death that looks like infertility
4. It causes sudden death in adult cows, which is usually attributed to bloat, clostridial disease or lightning