1 Animal pathogens: viruses Topic 11 Ms Sherina Kamal

2 Types of diseases  Foot and mouth  Hog Cholera  New Castle  Avian Influenza

3 Foot and mouth disease (FMD)  an infectious disease affecting cloven-hoofed animals Cattle Sheep Pigs Goats Deer Other ruminants: deer and some zoo animals- camelids (camels, llamas, alpacas, guanaco) and elephants can also be affected

4 Foot and mouth disease (FMD)  serious for animal health and for the economics of the livestock industry  not normally fatal to adult animals it is debilitating and causes significant loss of productivity  milk yields may drop or the animals may become lame  In young animals it can be fatal on a large scale

5 Foot and mouth disease (FMD)  A picornavirus is a virus belonging to the family Picornaviridaevirus family

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9 Laboratory analysis

10 Hog cholera/Swine fever/Classical swine fever  serious and often fatal viral disease of swinedisease  Characterized by high fever and exhaustionfever  The disease is transmitted from infected pigs via numerous carrier agents including vehicles in which pigs are conveyed from place to place dealers who journey from farm to farm farm attendants  The virus may be present in garbage used for swine feed but is destroyed by cookingvirus  It affects no other species

11 Hog cholera/Swine fever/Classical swine fever

12 Hog cholera/Swine fever/Classical swine fever

13 Diagnosis  CSF is a rapid spreading disease with high mortality  There are characteristic post-mortem changes with haemorrhagic lymph nodes, dead patches in the spleen, multiple small haemorrhages in the kidneys and so-called "button ulcers" in the gut  Laboratory tests identification of viral antigen isolation of the virus and the presence of antibodies in serum In most countries CSF is notifiable

14 Hog cholera/Swine fever/Classical swine fever  Larynx of pig with swine fever, note haemorrhaging (red and dark black areas)

15 Hog cholera/Swine fever/Classical swine fever  Kidneys showing small pinpoint heammorrahges

16 Hog cholera/Swine fever/Classical swine fever  Haemmorrhaging inside chest cavity

17 Hog cholera/Swine fever/Classical swine fever  Haemorrhaging in bladder of pig with swine fever

18 New Castle disease  viral disease that can affect a wide variety of avian species wild birds domestic fowl  The disease is of great concern throughout much of the world's agricultural community it is highly contagious can cause severe disease in poultry

19 New Castle disease  Strains that produce mild and moderate forms of the disease are sometimes found in domestic poultry pigeons  The most severe forms- velogenic Newcastle disease (VND) caused by highly pathogenic strains of the virus can cause severe mortality in chickens

20 New Castle disease  conjunctiva

21 New Castle disease  signs of the disease in wild birds occur mainly in the young and include: clenched toes high number of sudden deaths in wild birds, particularly cormorants (wild aquatic, migratory birds) inability to walk or fly lack of muscular coordination muscle tremors paralysis of one or both legs or wings twisting of the head and neck walking in circles

22 New Castle disease  Prevention Vaccines are available  Chickens Turkeys Pigeons  used to induce an antibody response  so vaccinated bids must be exposed to a larger dose of NDV to be infected

23 Avian influenza  refers to the disease caused by infection with avian (bird) influenza (flu) Type A viruses  A(H5N1)  A(H7N9)  occur naturally among wild aquatic birds worldwide and can infect domestic poultry and other bird and animal species  Avian flu viruses do not normally infect humans  However, sporadic human infections with avian flu viruses have occurred

24 Avian influenza  outbreaks of AI in poultry may raise global public health concerns due to their effect on poultry populations can seriously impact local and global economies and international trade  The majority of human cases of A(H5N1) and A(H7N9) infection have been associated with direct or indirect contact with infected live or dead poultry

25 Avian influenza  avian influenza A viruses are very contagious among birds some of these viruses can sicken and even kill certain domesticated bird species:  Chickens  Ducks  Turkeys

26 Avian influenza  Infected birds can shed avian influenza A viruses in their: Saliva nasal secretions feces  Susceptible birds become infected when they have contact with the virus as it is shed by infected birds  They can also become infected by coming in contact with surfaces that are contaminated with virus from infected birds

27 Avian influenza  Laboratory analysis Direct RNA  RT-PCR techniques  Preferred rRt-PCR (modification of RT-PCR that reduces the time for both identification of virus subtype and sequencing) Antigen detection  AC-ELISA kit (immunoassays; use antibody against the nucleoprotein) Can detect the presence of influenza A viruses in poultry

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