Zoonosis Zoonoses: What can we get from our pets? Infectious disease that occurs principally in animals but which may spread to humans Bacteria, viruses, fungi, protozoans, helminths Toxocariasis (Visceral and Ocular Case 1 Larva Migrans) A 5yr.old autistic male, was brought to the ER due to seizures. On auscultation, you Develops when human ingest the eggs of canine ascarid Toxocara canis or, less commonly, the hear crackles and wheezing and physical feline ascarid Toxocara cati examination revealed hepatomegaly. Almost all puppies are naturally infected with CBC revealed leukocytosis (14.2/cu mm T.canis with 20 % eosinophils). The caregiver tells Infected animals shed millions of eggs per day you that the patient is fond of playing in that can survive for months in the soil the garden with soil where their pet dog runs and plays. Toxocariasis: Epidemiology Toxocariasis: Pathogenesis Larva hatches in Small children are Eggs in feces Ingested in GIT especially prone to GIT acquire VLM from intimate contact circulation with a family pet from contaminated sandboxes or playgrounds Larva migrates in liver, lung, brain, (+) history of other organs geophagia (pica) exposure to puppies Toxocariasis: Clinical Manifestations Toxocariasis: Clinical Manifestations (VLM) (VLM) Classic description involves a child Larvae migrating during a primary (usually between 1 -5 yrs.old) who infection may be better able to damage has: host viscera without being impeded by the Fever host inflammatory response Leukocytosis therefore, more likely to reach the CNS Eosinophilia Children with CNS involvement: frequently Hepatomegaly have either neuropsychiatric disturbances Pneumonitis with wheezing and or seizures hypergammaglobulinemia Toxocariasis: Clinical Manifestations Toxocariasis: Diagnosis (Ocular Larva Migrans - OLM) Typically occurs in older children VLM: usually established by clinical symptoms Often do not have eosinophilia or elevated EIA measures serum antibody against antigens from antibody titers T.canis High degree of sensitivity (78%) and specificity Larvae probably enter the anterior (92%) at a titer > 1:32 vitreous of the eye from the peripheral OLM: diagnosed on fundoscopy by characteristic branch of the retinal artery migratory tracts and granulomata on the retina; Common features: Unilateral vision loss larvae occasionally seen and strabismus, diffuse endophthalmitis Toxocariasis: Treatment Toxocariasis VLM: usually self - OLM: antihelminthic + Prognosis: excellent limiting corticosteroid therapy in children Anthelminthic of albendazole, choice: albendazole mebendazole, Prevention: control (10 mg/kg/day in 2 thiabendazole, and anthelminthic levamisole , and divided doses x 5 levamisole , and treatment of animal days) ivermectin reservoirs; elimination With surgery when For severe symptoms, appropriate (e.g., of dog feces from or for CNS and eye appropriate (e.g., involvement: vitrectomy, membrane environment peeling) add corticosteroids Other Major Helminthic Zoonotic Infections Case 2 Disease Causative Common Modes of agent Animal transmission Reservoir A 12 yr.old female was brought to your Cutaneous larva Ancylostoma Cats, dogs Direct contact migrans braziliense, A. clinic with complaints of fever for 5 days, caninum associated with arthralgia, calf muscle Echinococcosis Echinococcus Dogs, Ingestion of eggs granulosus, carnivores, or food pain, headache, chills, nausea and Echinococcus livestock contaminated multilocularis (especially with fecal vomiting. The patient recently came from sheep) material the province for the summer and spent Cysticercosis Taenia solium pigs Ingestion of uncooked or her vacation lounging in the town ’s pond. partially cooked pork Leptospirosis: Leptospirosis Clinical manifestations A disease of wild and domestic animals Leptospires penetrate the circulation Localized ischemia of infected blood skin, mucous membranes vessels of renal tubules, liver, meninges, Caused by Leptospira interrogans muscles, eyes, placenta Incubation period of 1-2weeks: Leptospires live for years in renal tubules of Initial or Leptospiremic Phase infected mammals (rats, dogs, cattle, swine, Secondary LEPTOSPIRURIC or (4-7days): goats, mice) Immune Phase (>4-30 days): • profound myalgias Become infected when on contact with 1-5 days •Aseptic meningitis •Conjunctival suffusion asymptomatic leptospiruric animals, contaminated soil, or •Fever, headache, vomiting •Nausea/vomiting bodies of water •Isolated from the urine •Abdominal pain •Anti-leptospira agglutinating antibodies •Fever, headache, chills are present •Neck stiffness •Disappearance of leptospires from blood •Leptospires isolated from blood & CSF Leptospirosis: Leptospirosis: Diagnosis Clinical manifestations Suspected from the clinical manifestations + Anicteric leptospirosis history of possible exposure Aseptic meningitis Confirmed by serologic testing: MAT; ELISA st Weil ’s disease: During 1 week: leptospires can be isolated from blood and CSF Classic hepatorenal disease occuring in 5 -10% of cases During Leptospiruric phase: More severe illness Urine is source of positive cultures and dark -field examinations consisting of an initial phase of fever + azotemia, jaundice, hemorrhage, anemia, mental status Mild proteinuira, granular casts, microscopic hematuria changes, and shock CSF analysis Leptospirosis: Treatment Leptospirosis: Prevention Self -limiting in >90% of untreated Self -limiting in >90% of untreated Avoidance of potentially patients infected areas near streams High -dose penicillin G 300,000 and ponds U/kg/day (max 12 -24 MU) q4 IV for 7 Vaccinated domestic animals days is recommended for serious and livestock may still infection excrete the organism in the urine doxycycline 4mg/kg/day (max Doxycycline: prophylaxis for 200mg/day) q12 PO x 7days for those persons working in highly >9 y/o endemic areas; long -term use is not advised Case 3 An 8 yr.old female was brought to you because of enlarged right axillary lymph nodes of 3 weeks duration. You noticed a suppurative papule along her right forearm. Cat Scratch Disease CSD: Clinical Manifestations Wheal/papule formation at 50-80% of cases Caused by Bartonella inoculation site have fever, henselae spread by either a 1-4wks later headache, malaise, Incubation up and anorexia cat bite or scratch to 3wks Unresolving Transmission from cat to cat lymphadenopathy is believed to be from fleas, (axillary, anterior cervical, Resolves spontaneously Ctenocephalides felis inguinal regions) Worldwide, most common in 5-10 yrs. of age Suppuration, fistula formation Symptoms: local swelling and swelling of the lymphatic system and flu like malaise CSD: Other Clinical Manifestations CSD: Diagnosis Hepatosplenic CSD Suspected on the basis of: CNS: seizures, encephalopathy in 2% of patients clinical presentation Onset: few days to months after lymphadenopathy regional lymphadenopathy formation regional lymphadenopathy (+) recent direct contact with a cat Abnormal EEG (+) recent direct contact with a cat CSF: lymphocytic pleocytosis confirmed by serologic test Parinaud ’s syndrome Antibody titers (IFA, ELISA >1:64) Bulbar conjunctivitis, conjunctival granuloma usually peaks at 4 -6 wks after Preauricular lymphadenopathy development of lymphadenopathy, In AIDS and cancer patients, bacillary angiomatosis, peliosis persists for 4 -5 months Organism grows slowly, takes 10 - 40 days CSD: Diagnosis CSD: Treatment Antimicrobial therapy should be considered for patients with: PCR: highly sensitive and specific Lymphadenopathy that does not resolve within diagnostic tool 6-8weeks Detects Bartonella at sites of skin inoculation, Lymphadenopathy associated with significant lymph nodes, bone, eye, conjunctivae, pain, limitation of movement, or persistence of paraspinal lesions, liver, spleen, brain debilitating symptoms Majority of cases resolves in 1 -2 months Severe systemic disease: encephalopathy, osteomyelitis, neuroretinitis; without any antimicrobial therapy osteomyelitis, neuroretinitis; Underlying medical disorder complicated by CSD CSD: Treatment CSD: Prognosis and Prevention Some clinical response may be achieved with Completely resolves in 1-2months even rifampin (20 mg/kg/day in 2 divided doses x without antimicrobial 14 days), azithromycin, cotrimoxazole, therapy gentamicin, and ciprofloxacin No deaths have been directly attributed to Proposed treatments regimens for directly attributed to CSD bacteremia and endocarditis includes Attentiveness towards combinations of gentamicin + ceftriaxone, avoidance of erythromycin or a macrolide, and a quinolone scratches and bites from cats & kittens CSD: Prognosis and Prevention Case 4 No data exist to support A 10 yr.old male was brought to your clinic usefulness of antimicrobial because of diarrhea and abdominal pain. There prophylaxis for persons after cat was associated low -grade fever. On PE the contact OR use of flea abdomen was tympanitic with increased bowel sounds. According to the mother, the child was eradication measures eradication measures often seen playing with his older brother ’s pet Declawing is unnecessary iguana. Nontyphoidal Salmonella Salmonella: Clinical Manifestations Associated with pet reptile or amphibian Most Salmonella infections are asymptomatic or contact mild Many reptiles are Oral ingestion of at least 100,000 viable colonized with organisms is required to cause enteritis Salmonella , intermittently shed in their feces Short incubation