Pathogens Week 4 Flashcards
Intended learning outcomes
Describe the main marine mammal pathogens and their impact on the health and abundance
Why is monitoring of pathogens among marine mammals is necessary?
Marine mammal health is used as an indicator of population and ecosystem health
Viral pathogens in marine mammals
- Influenza:
- InfluenzaA
- InfluenzaB
- Morbillivirus:
- CanineDistemperVirus(CDV) *
- PhocineDistemperVirus(PDV)
- CetaceanMorbillivirus(CeMV)
- Herpesvirus
- Poxvirus
- Pestivirus
- Polyomaviruses
- Coronaviruses
- Caliciviruses
- Anellovirus
- Astrovirus
- Picobimaviruses
- Picornaviruses
- Rhabdovirus
- Reovirus
- Retrovirus
- Asfarviruses
- Circovirus
- Parvoviruses
- Arboviruses
Seal pox (transmission, symptoms, common areas…)
- Skin disease
- Transmission: physical
contact - Symptoms: Nodules or lumps, breaks open, ooze, heals but leaves scars and patches without fur
- Common areas: head and
neck - Zoonotic: Contact with infected skinàpainful swollen sores that may re-occur
Pestivirus - Family: Flaviviridae
Newly discovered virus (Jo et al., 2019)
Horizontal transmission:
* Acute disease
* Immunosuppression
* Inapparent infections
Vertical transmission:
* Myocarditis
* Congenital tremor
* Chronic wasting
* Intrauterine infections:
- Increased rates of abortions
- Fetal malformations
- Persistent infections (offspring)
Influenza A and B
- Respiratory disease
- Transmission: Direct contact, contaminated objects and aerosols
- Disease:
- Fever
- Coughing
- Respiratory distress
- Pneumonia
- Spillover from birds (and humans)
- Zoonotic
Morbillivirus
- Viruses:
- Phocine distemper virus (PDV)
- Cetacean morbillivirus (CeMV)
- Canine distemper virus (CDV)
- Transmission: Direct contact, contaminated objects and aerosols
- Respiratory disease
- Pneumonia
- Encephalitis (inflammation or the brain)
- Immunosuppression
- Zoonotic: No?
Mycoplasma (bacteria)
- Secondary infections during the 1988 PDV epizootic in harbour seals
- Pleomorphic
- Transmission: Airborne droplets
- Disease:
- Pneumonia
- polyarthritis
- Zoonotic: seal finger
Brucella Pinnipedialis (bacteria)
- Transmission:
- ingestion of infected meat
- body fluids
- droplets
- Disease: Brucellulosis
- Reproductive disorders
- Neurological disorders
- Osteomyelitis
- Zoonotic:
- Headache, lethargy, and severe sinusitis
Leptospira interrogates (bacteria)
- Transmission: unknown – body fluids – interspecific transmission (dogs, rats ?)
- Disease:
- Lethargy (pathological state of
inactivity) - Dehydration
- Convulsions
- Abortion, stillbirth
- Inflammation of the kidneys –>
Renal failure - Zoonotic: acute nephritis and renal failure
Sea lice and whale “lice” (ectoparasites)
- Effects on the host
- Irritation, anemia (heavy infections), transmission of heartworm in seals.
- Large numbers of lice indicate an unhealthy animal.
- Zoonotic potential
- None – parasites are often host specific
Heartworm (acanthocheilonema)
- A nematode (roundworm)
- Site:
- Right ventricle of the heart and arteries transporting blood to the lungs
- Life cycle
- Host species:
- harbour, harp, ringed and hooded seals
- Effect: Cause damage to the heart, arteries and lungs
- Not zoonotic
Lungworm
- A nematode (roundworm)
- Site: Lungs and airways
- Life cycle – unknown but fish play a role as intermediate hosts in harbour porpoises and seals (Lehnert et al., 2010)
- Hosts: seals and whales (different species)
- Young stranded animals are often heavily infected
- Effect:
- Poor condition
- Severe infections –> Difficulties breathing (coughing)
- Pneumonia
- Not zoonotic
Toxoplasma gondii (parasite)
- Protocoan
- Definitive host: Felids
- Infection has been assicioated with:
- Inflammation (brain, heart, placenta, thymus and adrenal gland, retina, lymph nodes)
- Pneumonia
- Hepatitis
- Abortion, stillbirth
- Zoonotic
Impacts of pathogens
Pathogens regulate the population size
Population health
Circulation of pathogens between terrestrial and marine ecosystems:
- Zoonoses
- Transmission ways: Sewage, runoff from big cities and the industry, ingestion of raw meat, etc
