Viruses of the genital tract + pregnant uterus Flashcards

Question

PRRS - prevention + control

Answer 1

PRRS is endemic in UK SPF, all in – all out or quarantine of new stock Separate pregnant sows from rest of herd and avoid transfer of fomites Screening of semen for AI by PCR Vaccination (reduces clinical signs) with inactivated vaccine rapidly mutates - circulation of many genetic + antigenic variants diagnosis and control by vaccination difficult

Answer 2

Stillbirths, mummification,embryonic death + infertility (SMEDI) Abortion uncommon Transmission: faecal oral Replicates in GIT without clinical signs transplacental infection of foetus (rapidly dividing cells) Early embryonic death (< 30 days) leads to resorption (infertility) Infection at later stages causes death of foetus with mummification Death at late stages leads to stillbirths If infected >70 days, foetal death less frequent due to immune response

Answer 3

PCR on liver (or heart) tissue if CRL is < 70 days (not immunocompetent) or foetal fluid serology in older foetuses. Diagnosis by immunofluorescence on frozen foetal liver (viral antigen FAT) Virus isolation (expensive and doesn’t always work – viable virus and fresh tissue) Vaccination

Answer 4

Type A Influenza virus (H1N1, H3N2) Predominately respiratory signs Pyrexia >41°C Abortions predominately due to disease in sows Transplacental infections considered rare Diagnosis - PCR/ (virus isolation) in acutely infected animals Paired serology

Answer 5

Abortions, mummification, stillbirths – not confirmed in UK birth of weak piglets, congenital tremor – not confirmed in UK Post-weaning multisystemic wasting syndrome (PMWS) Porcine dermatitis and nephropathy syndrome (PDNS) PCV-2 associated disease Probably multifactorial aetiology (other viruses and bacteria) and/ or predisposes to other diseases e.g. PRRS but also able to cause disease by itself

Answer 6

Histopathology (heart), IHC – not PCR! SPF, all in- all out Optimised management conditions Vaccination

Answer 7

``` Family Herpesviridae Notifiable Entry via respiratory tract CNS signs and high mortality in piglets In pregnant sows: haematogenous spread to foetus Abortions/stillbirths Eradicated from UK infectious to cats + dogs - fatal ```

Answer 8

``` Pestivirus in family Flaviviridae Notifiable: Last outbreak in UK in 2000 High mortality Diarrhoea Haemorrhages in skin and other organs such as kidneys Abortion, mummification, stillbirths ```

Answer 9

``` Family Asfaviridae Notifiable So far never occurred in the UK Clinical signs very similar to classical swine fever including reproductive failure ```

Answer 10

Canine herpesvirus (CHV) Infection of pups during birth (via birth canal) or shortly after birth (contact) can lead to systemic herpesvirus infection immature immune system + poor regulation of body temperature allows infection to establish Organ necrosis and death Diagnosis by gross + histopathological findings Vaccine now available for pregnant bitches

Answer 11

Feline Leukaemia virus - Can cross placenta and lead to reproductive failure (resorption of foetuses or abortion) • Diagnosis: antigen test (queen) or immunofluorescence/ PCR on aborted foetuses • Prevention: vaccination Feline parvovirus (feline panleucopenia virus) - Can lead to reproductive failure or cerebellar hypoplasia • Prevention: vaccination

Answer 12

Samples from foetal organs or whole foetus as well as placenta Virus isolation, PCR or antigen detection Problems: if samples are not fresh - viruses lose infectivity, nucleic acids and proteins degrade

Answer 13

Antibody detection in foetal fluids: indicates infection of foetus only useful once foetus is immunocompetent Serology of the dam showing rising antibody titres Problems: Possible delay between - infection of dam and infection of foetus + Infection of foetus and reproductive failure becoming apparent Seroconversion may therefore have occurred earlier and will not be detected