Pure Science 9: Infectious Diseases - Blood Parasites PDF

# Pure Science 9: Infectious Diseases ## Blood Parasites - **Theoretical:** Dr. Ahmed Magdi (online & lecture explanation) - **Practical:** Dr. Peter ## I. Bovine Babesiosis ### Synonyms: - Texas fever - Red water fever - Cattle tick fever - Enzootic hemoglobinuria - Splenic fever ### Definiti...

# Pure Science 9: Infectious Diseases ## Blood Parasites - **Theoretical:** Dr. Ahmed Magdi (online & lecture explanation) - **Practical:** Dr. Peter ## I. Bovine Babesiosis ### Synonyms: - Texas fever - Red water fever - Cattle tick fever - Enzootic hemoglobinuria - Splenic fever ### Definition: A group of tick-borne seasonal diseases of domestic, wild, laboratory animals, and humans caused by protozoa (genus _Babesia_). ### Host and Etiology: - **Host-specific** - **Intra-erythrocyte** - **Pear-shaped and pyriform bodies** - **Arranged in pairs forming acute or wide angle** | Species | Shape | Susceptible host | |----------------|----------------------------------|-------------------| | _B. bigemina_ | Large in size; pairs forming acute angle | Cattle & buffalo | | _B. major_ | Pairs of _Babesia_ forming acute angle | | | _B. bovis_ | Small in size; pairs forming wide angle | | | _B. divergen_ | Small in size; pairs forming acute angle | | ### Cattle are more susceptible than buffalo. ### All ages are susceptible, but clinical signs and pathological changes are mild and short-lived in animals under 6 months old, while severity of signs increases with age. **Why is the common age of infection 6-12 months of age?** Endemic stability. - **Calf from previously immune (infected) dam takes maternal immunity from colostrum (passive immunity) → provides protection for 3 months of age → followed by age resistance to 9 months of age.** - **When a calf is exposed to infection during this time they rarely show clinical signs and develop long-lasting immunity (endemic stability).** ### Life Cycle: 1. **First phase:** Multiply sexually by binary fusion in RBCs of a vertebrate host. 2. **Second phase:** In female ticks by sporogony ­­-sporozoites (infective stage) in the salivary gland of female ticks. ### Hard ticks have 4 life stages: - Adult - Egg - 6-legged larva - 8-legged nymph ### Most ticks prefer to feed on different hosts at each life stage. ### Ticks can feed on: - Mammals - Birds - Reptiles - Amphibians ### Transmission: **Infected Ticks (mainly)** 1. **Biologically:** - **Transovarian** - **Trans-stadial (stage to stage)** 2. **Mechanical:** Contaminated needles, surgical instruments, and blood transfusions ### Pathogenesis: - **Protozoa multiply in peripheral or visceral circulation by binary fusion → destruction of RBCs → hemolysis, anemia (hemolytic anemia)** - **Some metabolized in the liver → producing unspecific toxic substance → affects the thermoregulatory center in the brain → ↑ fever (41-42°C)** - **Death occurs due to anemic anoxic (destruction of RBCs → ↓ O2 infusion for tissues)** ### If animals survive, they become carriers and resist reinfection with the same species. ## Signs (Depend on the amount of parasite in blood) - **High fever (41-42°C) + Complete off food (in the early stage)** - **Sudden onset of high fever (41-42°C) + inappetence (in the early stage)** - **Bloody urine** ### Signs indicate death (cases of bad prognosis): - **Foreign breeds (as they take severe infestation form)** - **Subnormal temperature (hypothermia) + cold extremities** - **Recumbency** - **Panting and difficult breathing** (due to destruction of RBCs and ↓ O2) - **One-year-old infection** - **Late pregnancy** - **Nervous signs** ### PM: - **Presence of ticks on carcass skin** - **Marked jaundice** - **Liver** → hepatomegaly and dark brown - **Gall bladder** → distended and contains thick granular bile - **Spleen** → splenomegaly (can reach one meter in length) - spleen has a soft and pulpy consistency - **Kidney** → dark and enlarged - **Red urine in the urinary bladder** - **Pericardium and endocardium** → ecchymotic hemorrhages ### Diagnosis: #### Field Diagnosis: - **History** - Ticks (in summer seasons) and coffee colored urine - **Clinical signs and PM** #### Lab Diagnosis: - **Thin blood sample** → peripheral blood smear from ear vein puncture (during febrile stage) using Giemsa stain. _Babesia_ are pyriform in shape. - **Hemolymph and egg smear from ticks** ### Treatment: #### Specific Treatment: 1. **Acaprine 5%** (no longer in use due to side effects) 2. **Diminazene Aceturate 7%** (Berenil / Batrynil / Intropar) → 3.5 mg/kg I/M (drug of choice in bloody urine) 3. **Imizol** (Imidocarb dipropionate) → The best drug for mixed infection (_Babesia + Anaplasma_) and for early stages before bloody urine (fever only), but use with caution: - Has a load effect on the liver, so give liver tonic such as Ornipural. - Has mild cholinergic signs (parasympathomimetic effect) such as salivation, nasal drip and panting, coughing and colic. So use atropine as a parasympatholytic (the same dose as Imizol). #### Differential Diagnosis: - Disease causing red urine #### Prevention and Control: 1. **Tick control:** - **Acaricides:** Diazinon, Bac dip, Neguvon powder, Ivermectin products, Buotox, Sepacil - **Pasture change:** - Remove fecal matter and remove 10 cm of top soil. - Treat with lime and add fresh soil. - **Resistant cattle:** Breed for tick resistance. - **Immunization:** Inject tick brain vaccine. 2. **Treatment of infected animals:** 3. **Chemo-immunization (premunization):** - Pool blood from splenectomized donor calves during the acute stage of babesiosis. - Inject 2 ml IM to each animal on the same day of collection and treatment. 4. **Vaccination:** (not present in Egypt) - **Live vaccine:** Monovalent (B. bovis), bivalent (B. bovis & B. bigemina) or trivalent with _Anaplasma_ - Give 1-2 ml I/M or S/C to any age (best at 3-9 months of age). - Provides immunity after 8 weeks and lifelong. ### II. Bovine Theileriosis #### Synonyms: - Tropical Theileriosis - Egyptian fever - Mediterranean Coast fever #### Definition: Peracute, acute, subacute, or chronic tick-borne protozoal disease of cattle and buffalo caused by _Theileria annulata_. #### Characterized by: - Fever - Progressive anemia - Wasting - Enlargement of LN - Corneal opacity - Abomasal ulcer #### Etiology: _Theileria_ species #### The parasite occurs in two forms: 1. **Erythrocytic (Piroplasm) form:** Parasite is found inside RBCs. 2. **Lymphocytic (Koch's blue bodies) form:** Schizont phase of the parasite occurs inside lymphocytes. #### Transmission: Mainly through **ticks** (_Hyalomma_ spp.) by: 1. **Stage to stage (trans-stadial) transmission only** (3 host ticks or 2 host ticks) 2. **Contaminated needle or syringe** 3. **Transplacental transmission** #### Pathogenesis: - **Ticks must feed for 2-4 days before sporozoites (infective to cattle) become mature (infective to cattle).** - **Sporozoites enter blood during blood meal then go to lymphocytes (develop schizonts) in L.N in area of tick attachment → lymphocytes transformed to lymphoblast → infected lymphoblast disseminated through lymphoid system.** - **Some schizonts differentiate to merozoites → invade RBCs.** - **In RBCs, the parasite transforms to piroplasm which are infective to ticks.** #### Susceptibility: - **Cattle and water buffaloes** - **Highly virulent for European dairy cattle and may be subclinical in local cattle** - **Water buffaloes** - can be infected and be a carrier #### Clinical Signs: - **IP:** 6-21 days - **Morbidity:** 60% - **Mortality:** 60% **A) Peracute form:** - **Foreign susceptible animals entering endemic areas.** - **Fever, anorexia, weakness, and die within 2-3 days** **B) Acute form:** - **Fever persists for several days, inappetence, and a drop in milk production.** - **Enlargement of L.Ns** (parotid, pre-scapular, and precrural/pre-femoral) due to rapid division of infected lymphoblast and accumulation of infected fluid - **Skin lesion** (reported in Tunisia) found schizonts in skin nodules subcutaneously. - **Eye proptosis** → massively protruding of eye balls out of their sockets (due to pressure of accumulating fluid in the membrane of the orbit and may be combined with Pink eye disease). May progress to complete removal of eye ball. - **Difficult breathing and cough** (respiratory signs): - **Due to pulmonary edema and secondary bacterial infection (pasteurella → BRD)** - **Die due to asphyxia** - **Nasal and ocular discharge and swollen eyes** - **Corneal opacity** within 2-3 days after fever (central to peripheral) **C) Subacute form:** - **Intermittent fever for 2-4 weeks.** - **Moderate progressive anemia and jaundice.** - **Animals may recover or develop an acute form after stress and die.** **D) Chronic form:** - **More prolonged form of subacute disease.** - **Recovery is rare and some cases suddenly develop an acute form and die.** - **In Egyptian buffalo** → chronic diarrhea, emaciation with normal temperature and appetite. #### PM: - **Pin-headed infarct (foci) in kidneys' cortex** → due to aggregation of lymphocytes - **Abomasal and intestinal mucosa** → ulcerated (at Payer's patches) 2-12 mm surrounded by a zone of inflammation → black diarrhea - **Emaciation, icterus, and infected with ticks** → pale M.M and yellowish discoloration of tissues. - **Lungs** → pulmonary edema, hyperemia, and congestion. - **LNs** → enlarged and edematous and hyperemic. - **Liver and spleen** → enlarged and friable and pale brown or yellow. - **Heart** → epicardial and endocardial hemorrhages. #### Diagnosis: **1. Field diagnosis:** - **History** → suspected from area - **Clinical signs & PM** - **Presence of ticks** **2. Lab diagnosis:** - **Thin blood film** (during febrile) from ear vein puncture → examine under oil immersion and look for: - **Echinocytes** : red blood cells that are star-shaped with projections. - **Smears from enlarged LN, liver, kidney, and spleen** → look for Koch's blue bodies (diagnostic). - **Blood for hematology (CBC and PCV)** → anemia, leukopenia - **Liver function tests** → ALT, AST, and Gamma-glutamyl Transferase (GGT) test - **Kidney function test** → creatinine and BUN (blood urea nitrogen) - **Serum for serology** → IFAT, CFT, ELISA - **PCR** for carrier animals **3. Differential diagnosis:** - _Babesia_, _Anaplasma_ #### Treatment: **A) Specific treatment:** - **Imizol** (Imidocarb dipropionate) → 2.5 ml / 100 kg S/C (to prevent latent carriers, which eliminates carries). - **Long-acting tetracycline** → 1 ml / 10 kg I/M (to prevent latent carriers). - **Marbocyl (marbofloxacine)** #### Supportive treatment for blood parasite: - **Fluid therapy with Duphalyte, phosphorus, and vitamin B.** - **Give animals boiled barley water (diuretic).** - **Vitamins and electrolytes.** - **Iron dextran** → 7 ml / 100 kg I/M - **Fercobsang for anemia** (Cobalt + vitamins) → 20 ml / cow I/M - **Duphalyte or Ornipural** (sorbitol + electrolytes) → 100 ml / cow I/M #### Prevention and Control: - **Tick control:** - **Acaricides:** - **Pasture change** - **Resistant cattle** - **Immunisation** 2. **Detection of carriers by PCR.** 3. **Restriction of cattle movement.** 4. **Vaccination:** - **Live _Anaplasma_ marginale** → Creation of large numbers of carrier animals. - **Attenuated vaccine** (Frozen _Anaplasma_ marginale) - **Killed _Anaplasma_ marginale vaccine:** 2 injections 4-6 weeks apart. The last dose is given 2 weeks before the vector season (summer). ### III. Anaplasmosis #### Synonyms: - Gall sickness - Yellow cow disease #### Definition: Tick-borne disease of ruminants caused by rickettsia (anaplasma). _Characterized by:_ - Fever - Anemia - Jaundice - Enlarged superficial LN #### Etiology: _Anaplasma_ spp. (rickettsia) - **_A. marginale_** → causes severe disease and locates on the margins of RBCs - **_A. centrale_** → causes mild disease and locates on the central region of RBCs - **_Anaplasma_ are obligate intracellular and multiply by binary fission of RBCs.** #### Susceptibility: - **Cattle and Buffalo** - **Sheep and goats** (subclinical) - **Young age usually resistant to disease (cattle over 3 years of age are commonly affected).** - **Any immune depressing as live attenuated vaccine of _Anaplasma_.** - **Animals recovered become carriers for life.** #### Transmission: 1. **Ticks (mainly):** - **Stage to stage and transovarian:** e.g., Boophilus spp., Hyalomma spp. - **Mechanical transmission:** Contaminated needles, syringes or hemophilic diptera flies (e.g., _H. irritans_, _Tabanus_, _Stomoxys_) and blood transfusions. #### Pathogenesis: - **Infective initial bodies enter the host along with the saliva of a vector → capillaries of visceral organs then peripheral circulation → ↑ in size and multiply by binary fission in RBCs into 2-8 new initial bodies.** - **Eventually, initial bodies are liberated from RBCs and the process is repeated.** - **Anemia results from phagocytosis of RBCs in the spleen (not hemolytic).** - **So animals are anemic without Hb.uria (no bloody urine).** - **_Anaplasma_ destruction of RBCs occurs in the spleen.** #### Clinical Signs: - **IP** → 3-4 weeks **Peracute:** - **In cattle over 3 years → often fatal** - **High fever** (40.5°C-41.5°C) - **Anemia and pale M.M** → rapid breathing, excessive salivation - **Occasionally nervous manifestations** → death **Acute form:** - **Animals develop fever over a few days (reaching 41°C-41.5°C).** - **Enlargement of LN.** - **Anemia, severe jaundice without Hb.uria, icterus (yellow cow disease).** - **Petechial hemorrhage** → Indicates liver dysfunction (↓ prothrombin), so use vitamin K in treatment. - **Emaciation and weakness.** - **Abortion (nonspecific) and temporarily infertility in bulls.** - **Affected animals usually have dark brown (bloody) feces containing mucus with an offensive odor** (due to ↑ unconjugated bilirubin) - **However, the urine is not usually red like babesiosis, but urine will be a dark yellow color.** **In Severe cases:** - **By auscultation → You can hear heart sound from rumen (flank region)** - **Indicates severe anemia with tachycardia.** #### PM: - **Icteric tissues, pale and icteric tissues.** - **Thin and watery blood.** - **Enlargement of LN** (congested and edematous), Hepato-splenomegaly. - **Heart** → flabby and petechial hemorrhages on endocardium and pericardium. #### Diagnosis: **1. Field Diagnosis:** - **History:** Endemic _Anaplasmosis_, signs and PM/animals with jaundice without Hb.uria. - **Lab Diagnosis:** - **Blood:** Giemsa stain blood smears → hematology, PCV, and CBC. - **Serum:** Serum biochemistry. - **Liverr function test:** ALT, AST, GGT #### Treatment: **A) Specific treatment:** 1. **Imidocarb (Imizol)** → 2.5 ml / 100 kg S/C (to prevent latent carriers, which helps eliminate carriers), or 2 doses 2 weeks apart or daily for 3 days (to prevent latent carriers). 2. **Long-acting tetracycline** → 1 ml/ 10 kg IM, or daily dose 10 mg/kg for 10 days (to prevent latent carriers). 3. **Marbocyl** (marbofloxacine) **B) Supportive Treatment for blood Parasite: - **Fluid therapy with Duphalyte, phosphorus and vit B.** - **Give animal boiled barley water (diuretic).** - **Vitamins and electrolytes.** - **Iron dextran** → 7 ml / 100 kg I/M. - **Fercobsang for anemia** (Cobalt + vitamins) → 20 ml / cow I/M. - **Duphalyte or Ornipural** (sorbitol + electrolytes) → 100 ml / cow I/M. #### Prevention and Control: 1. **Tick control (as for babesiosis).** 2. **Detection of carriers by PCR.** 3. **Restriction of cattle movement.** 4. **Vaccination:** - **Live _Anaplasma_ marginale** → creation of large numbers of carrier animals. - **Attenuated vaccine** (Frozen _Anaplasma_ marginale). - **Killed _Anaplasma_ marginale vaccine:** 2 injections 4-6 weeks apart. The last dose is given 2 weeks before the vector season (summer). **How to differentiate between causes of red urine:** - **By centrifugation of urine sample or even leave it for 1-2 hours.** **If RBCs precipitate with clear supernatant (hematuria = intact RBCs in urine) in cases like:** - **Pyelonephritis** - red urine with mucus secretion - **Cystitis** - red urine with straining and frequent urination - **T.T.T.** - Cephalosporins, amoxicillin-clavulanate ("Synulox") or sulpha-trimethoprim ("Borgal") **If there is no separation and the whole sample is still red (hemoglobinuria = destructed RBCs in urine) in cases like:** - **Blood parasites** - **Leptospirosis** - bloody urine + bloody milk from 4 quarters and flaccid udder - **Bacillary Hemoglobinuria** (Clostridia) - sudden death, associated with fasciola infection, no ticks. **To avoid the adverse effects of atropine, you must give:** - **Parasympatholytic drugs** - **Neostigmine** - **Parasympathomimetic drugs** - **Levamisole**