Babesiosis

Introduction Synonyms: Piroplasmosis, Cattle tick fever, Red water fever, Texas Fever, Splenic Fever. It is an acute, subacute or chronic tick borne infectious disease of cattle and buffalo. Acute form of disease is characterized by fever, hemolytic anemia, hemoglobinuria jaundice and frequent death. The term Babesiosis refer to the acute form. During this peroid rapid growth and multiplication of the parasite occurs in blood. The term Babesiasis refers to the subacute and chronic form of infection that usually persist following recovery form the initial attack by parasite The term Piroplasmosis refers to the both Babesia and theileria infection (mixed infection). First description of Babesia bovis by Babes in Romania in 1888

Etiology Babesia species Babesia bigemina Babesia bovis (more pathogenic) Babesia major Babesia divergens Babesia sps are intraerythrocytic and appear as pear shaped, pyriform bodies May be either single or double and may be oval, amoeboid or take multiple forms. With Romanowesky stains (Giemsa or Leishman stain), cytoplasm is stained bluish with chromatin staining red.

Transmission and mode of infection Infected ticks are the only source of infection Mechanical transmission via contaminated needles and instruents also possible Blood transfusion Intrauterine transmission

Pathogenesis Bite of infected ticks Reaches to blood stream Parasite attach to erythrocytes, is engulfed via endocytosis Matures inside erythrocytes and starts asexual reproduction, producing merozoites Infected erythrocytes eventually rupture (intra vascular hemolysis) and released merozoites. Released merozoites again invade other erythrocytes. Infected RBC relaease proteolytic enzymes which increase erythrocytes fragility leading to hypotensive shock, hemolytic anemica and jaundice.

Clinical Signs Incubation period: 8 – 15 days Sudden onset of high fever ( C) In appetence, depression, weakness and reluctance to move. Hemoglobinuria Blood appear thin and watery Pale icteric mucous membrane Cerebral babesiosis: Hyperesthesia, nystagmus, circling, head pressing, aggression, convulsions and paralysis

PM findings Mucous membrane and carcass paler then normal Blood: light red, thin and watery Spleen: Enlarged and has pulpy consistency (severe congestion) Liver: Swollen, friable, and yellowish brown in colour; heapatic surface has mottled appearance with lighter coloured periacinar areas Gall bladder: Distended with viscous bile which often contains dark brown granules up to 1mm in diameter. Intestinal content: diminished and yellowish in colour. Kidney: Mildly to moderately swollen and dark reddish-brown in colour. Accumulation of exudate in body cavity.

Microscopic findings Presence of pear shaped Babesia organism in erythrocytes Presence of haemosiderin and phagocytosed red blood cells in cells of reticuloendothelial system (Liver, spleen and lymph nodes) Kidney: degeneration and necrosis of epithelium of convoluted tubules in the kidneys and presence of hyaline casts in the tubular lumen Liver: Centrilobular and midzonal hepatic necrosis and bile stasis. Spleen: Hemosiderosis, marked congestion of the sinusoids of the spleen and reduced ratio of white to red pulp with germinal centers containing few cells Hemorrhages in myocardium and hyaline degeneration of some myocytes Brain: Markd distension of the capillaries of the brain by parasitized RBCs

Diagnosis Demonstration of protozoan parasite in blood smear.

Diagnosis Hematological studies reveals – Macrocytic and hypochromic anemia; Decreased PCV and ESR value; Anisocytosis, polychromasia; Punctate basophilia, macrocytosis and reticulocytosis Blood Biochemistry reveals-n Increase in levels of BUN and plasma creatinine levels Marked increase in unconjugated bilirubin levels, plasma creatinine. Serological tests- CFT, ELISA, IFAT, Indirect haemaggluin

Differential diagnosis Bacillary Hemoglobinuria Leptospirosis Postparturient Hemoglobinuria, Enzootic Bovine Pyelonephritis and chronic cupper Poisoning Rabies, Copper poisoning

Prognosis Little chance to survive without treatment.