Infectious Lecture 5 PDF

INFECTIOUS Lecture 5 Dr: Abdelkareem Written by : Abdelrahman Sadawy Abortion Premature expulsion of fetus Still birth mean: fetus die after 2-3 days postpartum Causes specific...

INFECTIOUS Lecture 5 Dr: Abdelkareem Written by : Abdelrahman Sadawy Abortion Premature expulsion of fetus Still birth mean: fetus die after 2-3 days postpartum Causes specific Non-specific 1. Bacterial: Brucella, Leptospira, listeria 1. Genetic, (in sheep), vibriosis (5 month), salmonella 2. Traumatic (especially open system), (equine, sheep) 3. Fever, Heat stress 2. Parasitic: trichomoniasis (4), 4. Toxic material: silage (as contain toxoplasma(sheep) mycotoxin) 3. Mycotic: aspergillosis (late stage) 5. Drugs: parasympathetic drugs, cortisone, 4. Viral: BVD, IBR, RF, Acaban PGF2, Oxytocin 6. Live vaccines Brucella In man: Malta fever, Mediterranean fever, undulant fever In animal: Bangs disease, contagious abortion 1. Definition − Highly contagious diseased transmitted by direct and in direct contact − Characterized by late stage of abortion (calf drop) in cattle, − Orchitis, epididymitis in male Importance ▪ Zoonotic importance: the major route brucella can transmitted to man is by intact M.M or conjunctiva ▪ Also, it can be transmitted by ingestion of raw or unpasteurized milk (as it dies at 60 C0 ) ▪ Not transmitted by meat ▪ Cause late stage of abortion “calf drop” (occur only one time in the life of cow then stillbirth as its latent organism) ▪ Death of animal (as retention of placenta may cause toxemia) 2. Etiology − Gram -ve intracellluer organism stained by Z.N stain − Sensitive to sunlight and acidic PH − Affect all animals and man Brucella abortus(cattle) 9 Brucella Ovies(sheep) Man: abortus- biotypes Brucella Canis (dog) Meletinsis-Swis-Ovies Brucella Melitensis (goat) Brucella neotomae Brucella Swiss (pig) (dessert rat) ▪ 99% of affected cattle in Egypt is from Melitensis ABDELRAHMAN SADAWY 1 3. Susibtability All domestic animal and man especially sexually mature animal 4. Source of infection 1. All secretion and excretion of animal (semen, milk, feces, uterine discarded which contain huge number of organism) 2. Placenta and aborted fetus 3. Contaminated food and water 4. Cat and specially Dog 5. Transmission 1. Ingestion (is the most route of infection) and not venereal 2. Although it secrets in semen but the acidity of vagina kills it, only AI can transmit it 3. Intact skin or shaved skin 4. intact M.M or conjunctiva 5. intrauterine transmission 6. Pathogenesis Oral ingestion of brucella Blood causing bactermia without fever for about 10 Days male Female testicles Joints If pregnant If not pregnant migrate to Uterus due Go to lymphnode of mammary Orchities Lamness to eryhritol gland and mammary gland it self (mastitis) Epididmytis Placnetom Then migrate to internal organ like spleen, liver Necrosis Until pregnancy 7. Clinical signs Cattle Sheep and goat Equine rd 1. Storm of abortion 80-90% of animal gets 1. Abortion after 3 month Don’t cause abortion Brucella Abours 2. Orchitis and epididymitis in but fistulas wither 2. Sporadic abortion in cattle and occur 2-3 male (salmonella is causing months of gestation in case of Melitensis 3. Mastitis in cattle and sheep abortion) 3. Retention of placenta 4. Orchitis and epididymitis in male 5. Hygroma of knee joints ABDELRAHMAN SADAWY 2 8. Lesion ▪ Necrotic placenta and placentome ▪ Swelling of fetus (all cavities) 9. Clinical Diagnosis 1- Direct smear form placenta then stains with Z\N stain (red bacilli with blue background) 2- Isolation a. (sample from uterine discharge, stomach of fetus, milk) b. then inoculation on Albimi agar media or TSA c. incubation at 10% CO2 for 7-10 days at 37 C 3- Animal inoculation a. Male guineapig is preferred: if Ve+ Strauss Reaction occurs b. Female: strawberry like appearance of spleen 4- Serological diagnosis 1) Tube agglutination test a. Positive titer is 1/40 in cattle, 1/80 in sheep, 1/100 in human Disadvantage of this test 1. False negative: in early stage and late stage of infection 2. False positive: other organism that produce IgM like E. coli, Yersinia 2) Rose Bengal test a. Regent Ph adjusted at Ph 3.6 to inhibit IgM b. Give 99-98% accuracy 3) Complement fixation test (chronic infection) a. Can be used for detection between vaccinated and infected animal 4) Milk ring test using one of those Ag (tetrazolium‘red’or hematoxylin ‘blue’ ) 5) Semen agglutination test 6) Vaginal agglutination test 10. Control 1) Hygienic measure 2) Vaccination: 1. Strain19(calf hood): o Attenuated vaccine, o Used between 6-9 month of cow age given 2 cm S\C o It gives immunity for 5 years o If it was given: - ▪ Before 6 months (low calf immunity system) ▪ After 9 months ( +ve agglutination test so misdiagnosis between infected and vaccinated one) ▪ If cow is more than 9 months u can give it intra conjunctiva or give 1\3 the dose (immunity for 3 years) ABDELRAHMAN SADAWY 3  ▪ Disadvantage 1. Discharged in semen causing orchitis, epididymitis 2. May infect human when use (zoonotic importance) 3. May infected the cattle that vaccinated 4. May induce abortion 5. Systemic reaction in calf 2. S.RP51 − Attenuated vaccine − Non agglutinating vaccine − Confirmed immunity 2 year (not more than 1 year in reality) − Injected at any time 3. Brucella aborts strain 45\20 dead vaccine (abortix) − Dead vaccine − Non agglutinating vaccine − Injected 2 time with 1 month interval, repeated every year Sheep: 1. Rev 1 vaccine − Injected at 3-6 months of age one time − Give 5-6 years protection 2. H38 − Dead vaccine − Given at any time − Non agglutigenic vaccine TB Pearl's disease Cachexia 1- Definition It is chronic contagious disease of animals and man characterized by: − Emaciation, enlargement of lymph nodes and caseous nodules in different organs of the body. 2- Etiology: 3 types of tubercles bacilli: Mycobacterium bovis: bovine type (most etiological agent) It is the cause of bovine tuberculosis. The organism is an intracellular Gram-positive aerobic acid-fast bacillus. It is sensitive to sunlight and phenolic compounds. Occasionally M. avium and M.tuberculosis give rise to bovine TB and both of them make sensitization of animal to produce AB ABDELRAHMAN SADAWY 4 3- Susceptibility: ▪ Cattle and buffaloes are more susceptible. a. Dairy cattle are less affected than fattening one due to more stress ▪ Open system is less susceptible than closed one ▪ Goats, sheep and camels are less susceptible as they are in open yard 4- Sources of infection: Exhaled air and sputum. Milk, feces and urine. Vaginal and uterine discharges. Discharges from opened lymph nodes during examination. 5- Transmission: Inhalation (droplet infection). Ingestion Intrauterine infection. Intramammary infection may occur through teat siphons Skin abrasion, but it is very rare. Coitus and the use of infected semen. 6- Pathogenesis: Droplet infection results in caseous nodules in the lungs and associated lymph nodes. The lesion is called primary complex. Infection through ingestion leads to lesions in pharyngeal or mesenteric lymph nodes. Spread of infection from the primary complex occurs via blood or lymphatic resulting in milliary tuberculosis (discrete nodular lesions in various organs) Generalize TB (Millary TB) caseated and calcified nodules ▪ Clinical manifestations appear according to the site of localization e.g:- Pulmonary tuberculosis. Intestinal tuberculosis. Tuberculous mastitis. Tuberculous metritis. ▪ Incubation period: o 3-6 month ABDELRAHMAN SADAWY 5 7- Clinical signs: A. Respiratory form: Persistent cough occurs once or twice at a time. In advanced stages there is dyspnea as result of involvement of the bronchial lymph nodes which leads to constriction of air passages. B. Digestive Form: Recurrent or persistent ruminal tympany may occur due to enlarged mediastinal lymph node. Dysphagia due to enlarged retropharyngeal lymph node. Diarrhea may occur due to tuberculous ulcer of small intestine. C. Genital form: Tuberculous metritis Tuberculous vaginitis, Infertility. Tuberculous mastitis 8- Postmortem lesions: Caseous nodular at first then the lesions calcified with pus and greasy Sound as in Military TB 9- Diagnosis: 1. Clinical signs and lesions. 2. Laboratory diagnosis. a. Microscopical examination of smears of milk sediment or sputum stained by Ziehl Neelsen. 3. Allergic test (tuberculin test): Purified protein derivative "PPD" prepared from M. bovis as it is more potent and specific than that prepared from M. tuberculosis human type a. Single intradermal test (SID): Clip the hair at site of injection Wash with water By caliper measure the thickness of skin before injection Inject 0.1 ml of tuberculin The result of the test is read by measuring of skin fold thickness using skin caliper after 72 hours. Disadvantages of the test: 1. Lack of specificity and the presence of non-visible lesion reactors (False positive cases) a. With some organisms like i. Nocardia ii. Vaccination with BCG iii. Actinomyces pyogenes iv. Para TB ABDELRAHMAN SADAWY 6 To overcome this, we use: b. Signal intradermal comparative − Use mammalian in one side and avian type in other side − Then take the read if:- Avian mammalian 5 3 Sensitized 3 4 infected Failure to detect cases of minimal sensitivity (false negative cases) 1. Early stages of infection 2. Recent parturition 3. Old cases (senility) c. To overcome use Stormont test: The test is used to detect poorly sensitized animals. The test is done as in SID test in the neck with a second injection at the same site seven days later. An increase in skin thickness of 5 mm or more 24 hours after second injection is a positive result. 10- Differential diagnosis: The disease confused with diseases causing enlargement of lymph nodes like: Bovine farcy: It is an infectious disease of cattle and buffaloes caused by nocardia farcinicus. Characterized by purulent lymphangitis and lymphadenitis with pulmonary signs. The tuberculin test gives positive result with bovine farcy. The film from unopened nodules should be done to differentiate between them using Ziehl- Neelsen stain: - o the nocardia appear as acid fast long filament bacilli stained evenly o But TB appear as short acid-fast bacilli 11- Control 1. Hygienic measures 2. Vaccination: BCG vaccine is an attenuated vaccine of mycobacterium tuberculosis bovine type injected intradermally. Advantages of BCG vaccine in children: 1. Given immunity life time 2. Increase the phagocytic power of the body 3. Give nonspecific immunity against babesiosis, Rift Valley Fever and Salmonellosis. 4. Enhance the production of AB ABDELRAHMAN SADAWY 7 In animal we gave BCG for: - 1. Give nonspecific immunity against babesiosis, Rift Valley Fever and Salmonellosis. 2. Increase weight by 10% Not used in animal for TB protection due to Vaccination should be carried out by i\v injection of 100 ml. which may led to anaphylactic shock And if animal not die, the immunity is short (6 month) 12- Treatment: 1. Chemotherapy of tuberculosis in domestic animals is of little value because of: The chronic nature of the disease. The high costs. Ineffective nature of treatment because microorganism surrounded by vascular capsulated connective tissue. The disease has a zoonotic importance. 2. Chemotherapy in human using: Streptomycin and Para aminosalicylic acid. Johne's disease Paratuberculosis Woody Cow Disease It is a chronic wasting disease of ruminants characterized by emaciation, intermittent foamy diarrhea, thickening and corrugation of intestinal mucosa. 1- Etiology: The disease caused by Mycobacterium paratuberculosis. It is a Gram-positive aerobic acid fast intracellular small rod 2- Susceptibility: Cattle, buffaloes are more susceptible. Parturition, transportation and nutritional deficiencies increase susceptibility (risk factors). 3- Sources of infection: ❖ Infected bulls: o Feces are the main source of infection: o Semen 4- Transmission: ❖ Infection occurs by: o Ingestion of contaminated food by feces of infected animals. ABDELRAHMAN SADAWY 8 5- Pathogenesis: After ingestion of the organism localization occurs in the mucosa of the small intestine. the organism multiplies and infiltrates the intestinal submucosa this will result in: a. Decreased absorption and chronic diarrhea. b. Leakage of protein leading to hypoproteinemia and edema (Bottle jaw) ❖ incubation periods: o 2 years or more 6- Clinical signs: Cattle Sheep Emaciation inspite of a normal appetite Shedding of wool. Intermittent diarrhea (foamy) Diarrhea is not common. Intermandibular edema. bottle jaw 7- Postmortem lesions: Cattle Sheep Thickening of the intestinal wall of small Yellow pigmentation of the intestinal intestine. wall. Corrugation of rectal mucosa. Thickening of the intestinal wall. 8- Diagnosis: 1. Clinical signs and lesions. 2. Laboratory diagnosis. a. microscopical examination of rectal scraping stained by Zeihl Neelsen stain for demonstration of acid-fast bacilli scattered as match like structure. 9- Treatment − Hygienic measure − Vaccination: o Live attenuated vaccine used after 1 month in calf o Killed vaccine. ABDELRAHMAN SADAWY 9