Infectious Diseases

Question 1

You have been graduated several years and are working in a large mixed practice in southern England. Your Boss has agreed to participate in a study with the University of Nottingham on the prevalence of pathogens in urine from domestic animals. Neither your boss nor the students involved in the project have much of an idea about biosafety and the academic involved has come from a background in human medicine. Your boss has delegated the responsibility of filling out the risk assessment form from UoN to you though he has helpfully filled in the section on potential hazards in the material with a list of pathogens that he thinks have something to do with the kidneys (some of which may not be appropriate)

What is the likelihood that the pathogens listed will be excreted in the urine?

What is the prevalence of these diseases in the UK?

Answer 1

Leptospirosis - Uncommon in the UK, more common in tropical areas. Common animal reservoirs include rodents, cattle, and pigs.

Babesia - does present in Europe but is generally prevalent in more tropical regions.

MCF - not common in UK but is present, outbreaks are usually sporadic

Pulpy kidney (clostridium perfringens type D) - Common in unvaccinated animals. The incidence of pulpy kidney declined over the past 25 years due to the widespread use of clostridial vaccines, but the condition is becoming a problem again as complacency reduces the use of vaccination.

Bacillary haemoglobinuria (Clostridium haemolyticum) - very rare but can be found in UK

E.cuniculi - Very common in the UK

Question 2

Malignant Catarrhal Fever

1. How would you recognise if the animal had the infection?
2. What is the risk to humans?
3. What is the risk to other animals?
4. Is there an effective treatment?
5. Is there an effectice prophylaxix?
6. What would be appropriate to minimise the risk (for instance do you need to wear gloves?)
7. Is it notifiable?

Answer 2

1.

Erosive stomatitis

Gastroenteritis

Erosions in the upper RT

Keratoconjunctivitis

Cutaneous exanthema

LN enlargement

2. It is not zoonotic
3. Risk for cattle and farmed deer if in contact with lambing ewes
4. No - supportive treatment
5. • not available
6. control measures to reduce cattle contact with lambing sheep
7. No

Question 3

Bacillary haemoglobinuria (Clostridium haemolyticum)

1. How would you recognise if the animal had the infection? (this increases the risk) (11)
2. What is the risk to humans?
3. What is the risk to other animals?
4. Is there an effective treatment?
5. Is there effective prophylaxis (vaccination) available and how widespread is its use in the UK?
6. What would be appropriate to minimise the risk (for instance do you need to wear gloves?)
7. Is it notifiable?

Answer 3

1.

Sudden death with no clinical signs.

Sudden onset clinical signs:

Abdominal pain – arched back posture, grunting on walking.

Respiration – shallow, laboured

Pulse -weak/rapid

Pyrexia (but temperature decreases just before death)

Edema of the brisket

Diarrhoea – with mucous and blood

Dark red urine (due to presence of haemoglobin from intravascular haemolysis)

Jaundice

Abortion in pregnant cows

2. no
3. Through ingestion of contaminated material, it is a soil-borne anaerobe. Occurs in summer and autumn in endemic areas, which are usually irrigated or subirrigated fields.

4.

Antibiotics (penicillin or tetracyclines at high doses)

Antiserum (antitoxic)

Supportive treatment – blood tranfusion, parenteral fluids, electrolyte solutions.

5. Yes, 4-6 week before expected occurrence of the disease. Annual revaccination of all animals over 6 months of age is necessary in enzootic areas. Vaccination of cattle that have been in contact with animals from endemic areas also necessary.
6. Dispose of the animal carcasses appropriately to minimise spread of infection.
7. No

Question 4

Babesia:

1. How would you recognise if the animal had the infection? (this increases the risk)
2. What is the risk to humans?
3. What is the risk to other animals?
4. Is there an effective treatment?
5. Is there effective prophylaxis (vaccination) available and how widespread is its use in the UK?
6. What would be appropriate to minimise the risk (for instance do you need to wear gloves?)
7. Is it notifiable?

Answer 4

1. Babesia Divergens causes dark red urine – from the haemoglobin due to the haemolysis of the red blood cells. Blood in the urine occurs with most species of babesiosis. Anaemia, jaundice. Flu-like symptoms.
2. Yes it is zoonotic, can be infected by a ixodes ticks (bite). Babesia microti in humans.
3. Yes
4. For humans – give oral Azithromycin and Atovaquone or in severe cases IV Clindamycin and oral Quinine. Blood transfusion.
5. There is currently no vaccine for babesiosis? Babesia is transmitted via ticks and so best to use anti-tick medication such as Frontline and to remove ticks manually if you see them on your pet.
6. Humans only infected when bitten by an infective tick. Best to treat animals for ticks.
7. yes

Question 5

E. Cuniculi:

1. How would you recognise if the animal had the infection? (this increases the risk)
2. What is the risk to humans?
3. What is the risk to other animals?
4. Is there an effective treatment?
5. Is there effective prophylaxis (vaccination) available and how widespread is its use in the UK?
6. What would be appropriate to minimise the risk (for instance do you need to wear gloves?)
7. Is it notifiable?

Answer 5

1. Neurological disease (head tilt, unsteadiness, urinary incontinence)/ kidney disease/eye disease. Diagnosis is via a blood test which indicates exposure.
2. Yes it is zoonotic, especially to immunosuppressed individuals.
3. No
4. Antiinflammatory medication (steroids) and anti-paraciticide (Panacur) for 28 days.
5. All rabbits entering a large group should be given panacur for 28 days first.
6. The more rabbits kept together the greater the risk of infection. Keep the hutch clean, regularly disinfect.
7. No

Question 6

Leptospirosis:

1. How would you recognise if the animal had the infection? (this increases the risk)
2. What is the risk to humans?
3. What is the risk to other animals?
4. Is there an effective treatment?
5. Is there effective prophylaxis (vaccination) available and how widespread is its use in the UK?
6. What would be appropriate to minimise the risk (for instance do you need to wear gloves?)
7. Is it notifiable?

Answer 6

1.

Subclinical infections- common, particularly in the maintenance host. Incidental hosts- acute, systemic, often febrile illness characterized by renal and/or hepatic damage. There may be effects on other body systems resulting in clinical problems such as uveitis, pancreatitis, bleeding, haemolytic anaemia, muscle pain, or respiratory disease.

In both incidental and maintenance hosts that are pregnant at the time of infection, localization and persistence of the organism in the uterus may result in fetal infection, with subsequent abortion, stillbirth, birth of weak neonates, or birth of healthy but infected offspring.

Serologic assays are the most commonly used technique to diagnose leptospirosis in animals- microscopic agglutination test or FAT. Also culture of organisms in blood, urine etc.

2. Zoonotic disease. People are susceptible to infection with most of the pathogenic serovars of Leptospira but are incidental hosts and, therefore, not important reservoirs of infection.
3. Essentially all mammals are susceptible to infection with pathogenic Leptospira, although some species are more resistant to disease. Among common companion animals and livestock, leptospirosis is most frequently recognized in cattle, swine, dogs, and horses. Cats have historically been considered to be resistant to disease but have been shown to seroconvert on exposure to leptospires.
4. Treatment with antibiotics to treat the acute infection and eliminate Leptospiruria.
5. Yes- widespread use in the UK.
6. Leptospirosis can be transmitted to humans through cuts and abrasions of the skin, or through the mucous membranes of the eyes, nose and mouth with water contaminated with the urine of infected animals- wear gloves, protective clothing.
7. No

Question 7

Pulpy Kidney (Clostridium Perfringens type D):

1. How would you recognise if the animal had the infection? (this increases the risk)
2. What is the risk to humans?
3. What is the risk to other animals?
4. Is there an effective treatment?
5. Is there effective prophylaxis (vaccination) available and how widespread is its use in the UK?
6. What would be appropriate to minimise the risk (for instance do you need to wear gloves?)
7. Is it notifiable?

Answer 7

1.

Pulpy kidney can affect unvaccinated sheep of all ages. However, it is most common in 4-10 week old lambs, and fattening lambs between 6 months and 1 year of age.

A presumptive diagnosis of pulpy kidney can be made on the basis a history of sudden deaths in lambs recently introduced to carbohydrate-rich feed. If animals are seen before they die, certain clinical signs may be suggestive of pulpy kidney, and post-mortem examination may also aid diagnosis. However, histopathology of the brain is the most useful diagnostic test.

Signs are typically neurological and include hyperaesthesia, ataxia, circling or head-pressing, with rapid progression to recumbency, opisthotonus, convulsions and death. Diarrhoea may also be seen, and hyperglycaemia or glycosuria is frequently reported.

2. Is not known to affect humans.
3. Can occur in cattle but this is rare. Goats can be affected- typically young animals.
4. Due to the short course of the disease, treatment is generally not possible or practical. Valuable animals can be treated with intravenous fluids and intravenous antibiotics.
5. Ewes should receive the primary vaccination course before entering the breeding flock and an annual booster approximately six weeks before lambing. A UK survey revealed that almost 20 per cent of sheep farmers did not vaccinate their sheep on a regular basis.
6. Not a human health risk.
7. No