LA Infectious Diseases of Hemolymphatics PDF

LA Infectious Diseases of Hemolymphatics Clare Ryan, DVM, DACVIM Learning Objectives For the following infectious agents affecting the hemolymphatic system, describe: type of organism, means of transmission (and related preventive measures), clinical significance, treatments if...

LA Infectious Diseases of Hemolymphatics Clare Ryan, DVM, DACVIM Learning Objectives For the following infectious agents affecting the hemolymphatic system, describe: type of organism, means of transmission (and related preventive measures), clinical significance, treatments if reportable Equine Infectious Anemia Bovine Leukemia Virus Anaplasma Piroplasma (Babesia/Theilaria) Corynebacterium pseudotuberculosis (horses and small ruminants) Streptococcus equi ssp. equi (Strangles)  Equine Infectious Anemia- EIA Retrovirus (like FIV, BIV, SIV, HIV) Simple RNA genome (8 kb) gag, pol, env Macrophage/monocyte cell lines Systemic effects from cytokine secretion http://permanent.access.gpo.gov/lps3025/eia.html  Coggins Coggins test Required for sale/movement in US Performed yearly: ✓ USDA Category II-accredited vet  Coggins AGID (Agar Gel Immunodiffusion) gold standard for testing Detects Antibodies  Prevalence is low in US (Gulf Coast region) 2016 52 positive horses, 34 positive premises Annual total number of equine cases of EIA and number of affected premises in each State, 2001 - 2016. USDA Infection: Transfer of Blood Insect Vectors: Flies, Mosquitoes http://www.idph.state.il.us/envhealth/pcbitingflies.htm Iatrogenic: Needles, Surgical instruments, Dental floats, Bits, etc Equine Infectious Anemia Clinical Signs: Acute form Sudden, high fever: 104-108F Anorexia, depression Weight Loss Petechiae (thrombocytopenia) Jaundice (hemolytic anemia) Ventral edema From Sellon DC, Long MT: Equine infectious diseases. St. Louis, WB Saunders, 2007 Abnormalities: Acute 1. Thrombocytopenia Earliest and most consistent abnormality 2. Anemia http://www.merckmanuals.com/media/vet/photos/media/photos/genei01.jpg Intravascular and Extravascular hemolysis Also affects erythropoiesis 3. Glomerulonephritis/ Vasculitis: Antibody/Antigen complexes  EIA: Cyclical alterations in viremia, platelet counts, temperature Acute/Subacute: most common Chronic: Ill- thrift Acute/subacute attacks Inapparent carrier: No clinical signs Managing Positive Horses Causes lifelong infection Reactor and all horses within 200 yards are quarantined Euthanasia or life- long quarantine for positive animals Bovine Leukemia Virus Deltaretrovirus genus Retroviridae family Lifelong infection Blood-borne infection of lymphocytes 3 stages of disease https://www.canr.msu.edu/news/research-drilldown-the-fyi- on-blv-what-you-need-to-know-to-keep-your-herd-healthy  5% cattle will develop signs Mostly- lymphosarcoma Uterus, heart, abomasum, spinal canal, retrobulbar lymphatic tissue, sometimes LN enlargement. 10-20%- persistent lymphocytes BLV Significance High prevalence in US Dairy (up to 90% of herds) Beef (up to 40%). Carcasses of affected animals are condemned BLV: about 1/2 of condemned carcasses https://edis.ifas.ufl.edu/publication/VM253  Testing If no clinical disease, test for antibodies AGID, ELISA (higher sensitivity) Reportable If clinical disease, can sample LN https://edis.ifas.ufl.edu/publication/VM253 BLV Transmission Blood/fluids with blood cells milk in utero (only about 1/20) nasal secretions(?) insects that take blood meal Iatrogenic spread Don’t reuse needles  Babesia and Theileria in LA Tick- transmitted hematic protozoa https://doi.org/10.3390/pathogens11020168  Babesia/Theileria: LA different than dogs Pathogen Tick Vectors Affected Hosts References Babesia microti Ixodes scapularis Humans [7,8,9] Cattle (bovine sadness complex): B. duncani B. divergens-like Dermacentor albipictus ND Humans Humans Babesia bigemina, B. bovis B. bigemina Rhipicephalus microplus, Cattle [12,13,14] Theileria orientalis B. bovis R. annulatus R. microplus, R. Cattle [12,13,14] Tx: Imidocarb, diminazene aceturate annulatus B. gibsoni R. sanguineus * Dogs B. vogeli R. sanguineus Dogs B. Conradae ND Dogs Equine piroplasmosis: B. Vulpes ND Dogs D. albipictus, D. Babesia caballi B. caballi variabilis, D. nitens Equids [18,19] White-tailed deer, Theileria equi B. Odocoilei I. scapularis reindeer, and elk D. nitens; Amblyomma Tx: Imidocarb Theileria equi mixtum Horses T. Haneyi ND Horses T. orientalis genotype Haemaphysalis Cattle ikeda longicornis White-tailed deer, elk, T. Cervi A. americanum [23,24] Reportable and mule deer https://doi.org/10.3390/pathogens11020168  Anaplasma Obligate intracellular bacteria coccoid to ellipsoidal Reside/replicate in vacuoles in cytoplasm of eukaryotic cells https://eclinpath.com/hematology https://eclinpath.com/hematology/inf /infectious-agents/anasplasma/ ectious-agents/anasplasma/a- phagocytophilus-003/  Anaplasma Transmission Ixodid ticks Eastern USA: I. scapularis Western USA: I. pacificus, I. spinipalpis  Anaplasma phagocytophilum formerly Erlichia Equi Horses: Equine granulocytic anaplasmosis Infects neutrophils, eosinophils Form mulberry-like colonies called “morulae” Fever, lethargy, inappetence, limb edema, icterus, ataxia, stiff gait Clinical signs worse in adults than young horses (< 1 year of age)  Anaplasma marginale Infects erythrocytes extra-vascular hemolytic anemia Clinical signs: fever, pale mucous membranes, lethargy, icterus, gastrointestinal signs, weight loss, decreased milk production, abortion and death Younger = milder clinical signs https://publications.ca.uky.edu/files/VET36.pdf Anaplasma Testing: Blood smear (intracellular organisms) Antibodies PCR Reportable disease in LA Treatment: Antibiotic: Tetracyclines Cattle vaccine available in some states  Corynebacterium pseudotuberculosis Gram positive, facultative intracellular coccobacillus Goats and Sheep Horses Caseous Lymphadenitis (CL) Pigeon fever https://www.fairfieldsuntimes.com/news/local/equine-pigeon- fever/article_f23f9606-6de3-11ed-8f1f-8b2307dfca19.html CL Pathogenesis Enters body via: Wounds on skin (shearing, needles, puncture wounds, etc) Mucous membranes (resp or GI) https://www.theshearerspost.com.au/blog /can-a-farmer-shear-their-own-sheep Virulence factors Exotoxin- phospholipase D, damages endothelium (promotes hematogenous spread) Lipid coating- protects from digestion in the cell (promotes persistence of infection) https://doi.org/10.1016/j.smallrumres.2009.10.008 CL: clinical signs https://www.merckvetmanual.com/circulatory-system/lymphadenitis-and-lymphangitis-of-large- animals/caseous-lymphadenitis-of-sheep-and-goats  CL Diagnosis Presumptive diagnosis: Abscessed LNs Serology (also for screening herd) Definitive diagnosis: Bacterial culture of pus* *Other abscess-causing bacteria: Trueperella pyogenes, Staphylococcus aureus, Pasteurella multocida, and Fusobacterium necrophorum, https://doi.org/10.1016/j.smallrumres.2009.10.008 CL treatment options Immature Caseous Liquefactive Fibrosis fibrosis necrosis necrosis 1. Cull 2. Surgical: Lance/drain abscess, lavage Mineralization Resect LN 3. Antimicrobials: Long- term penicillin + rifampin Tulathromycin (systemic and intralesional) https://doi.org/10.1016/j.jcpa.2007.07.002 Because recurrence rates are high, CL is not considered a “curable” disease  CL prevention Strict biosecurity and isolation measures Ideally, cull affected animals If cannot cull, separate affected from unaffected Vaccinations available Must use on the species they are labeled for Reduce disease prevalence but does not fully prevent disease  Streptococcus equi ssp. Equi aka Strangles Gram positive β-hemolytic bacteria M- protein resists phagocytosis immunogenic Polysaccharide capsule attachment, resist phagocytosis  Strangle: VERY CONTAGIOUS Fever Nasal discharge (unilateral or bilateral) Regional lymphadenopathy Parotid region swelling and/or pain Stertor or stridor Coughing Dyspnea Strangles: Retropharyngeal abscess Vetbook.com Metastatic Strangles Aka Bastard Strangles https://doi.org/10.1053/j.ctep.2006.03.016 https://ecampusontario.pressbooks.pub/pathologyoftherespi ratorysystem/chapter/respiratory-diseases-of-horses/  Strangles treatment and prevention Lance and drain abscesses Treat symptomatically (includes tracheostomy if needed) Antimicrobials: Penicillin Ceftiofur TMS/rifampin