title: Occult Dirofilariosis in Dogs of North Eastern Region in India.
abstract: BACKGROUND
  The North Eastern Region in India is endemic for canine heartworm disease but in clinics accurate diagnosis is some times difficult. The aim of the present study was to determine the prevalence of occult infections for heartworm disease in canine in two geographical regions of North Eastern India.
  
  
  METHODS
  A total of 782 numbers of three categories of dogs namely, working dogs of military and paramilitary forces, pet dogs and stray dogs were screened for the presence of heartworm infection from August 2011 to July, 2012 in Guwahati (Assam) and Aizawl (Mizoram). Conventional, immunological and molecular techniques were followed for this epidemiological study. The criteria to determine the occult heartworm cases were based on the differences between heartworm positive cases in PCR test and antigen ELISA test.
  
  
  RESULTS
  The findings revealed an overall 22.69 percent occult case. The working dogs had highest prevalence (60%) followed by pet (29.16%) and stray dogs (17.75%).
  
  
  CONCLUSIONS
  The highest percentage of occult heartworm infection was present in working dogs maintained under military or paramilitary forces.
authors.affiliation: Department of Parasitology, College of Veterinary Sciences and AH, Central Agricultural University, Selesih, Aizawl, Mizoram, India.
authors.forename: Sonjoy Kumar
authors.initials: SK
authors.lastname: Borthakur
authors.affiliation: Department of Parasitology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781 022, Assam, India.
authors.forename: Dilip Kumar
authors.initials: DK
authors.lastname: Deka
authors.affiliation: Department of Parasitology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781 022, Assam, India.
authors.forename: Saidul
authors.initials: S
authors.lastname: Islam
authors.affiliation: Department of Parasitology, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati-781 022, Assam, India.
authors.forename: Prabhat Chandra
authors.initials: PC
authors.lastname: Sarmah
keywords: Dirofilaria immitis; India; Occult infection