Veterinary Public Health


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Veterinary Public Health Program
313 N Figueroa St. Rm 1127
Los Angeles, CA 90012
Tel (213) 989-7060
Fax (213) 481-2375
vet@ph.lacounty.gov
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Heartworm Disease - Case Definition

This case definition is used to evaluate and categorize cases of heartworm disease reported in animals to the Los Angeles County Department of Public Health. It was developed by public health veterinarian by reviewing published published literature and reported cases of heartworm in LA County animals. Earlier case reports of this disease were reviewed and a few reclassified to meet this 2015 case definition. 

Learn more about animal disease surveillance in LA County, and about cases of heartworm in animals in LA County

CASE DEFINITION - Heartworm Disease - 2015
  CONFIRMED  
  • Two positive antigen tests on two separate blood samples, or

  • Positive antigen AND positive microfilaria test, or

  • Parasites seen on echocardiography

  PROBABLE  
  • Positive antigen test, or

  • Positive microfilaria test

  SUSPECTED  
  •  Positive antibody test (feline)
  •  Positive antigen test, followed by a negative antigen test
  NOT A CASE  
  • No testing for heartworm performed, or

  • Positive Antigen test followed by two negative antigen tests (i.e. false positive)

  EXPOSURE LOCATION  

1n general, cases are considered to be "Other" or "Unknown" unless the history indicates no travel outside of area.

  • UNKNOWN- Less than 2 years of travel history available.

  • LA COUNTY - Minimum of 2 years of history available, animal did NOT travel outside of LA County.

  • SO CAL - Minimum of 2 years of history available. Animal did NOT travel outside of southern California.

  • OTHER - Animal DID travel outside of southern California.

For the purpose of this case definition Southern California includes the following counties: Los Angeles, Orange, San Luis Obispo, Kern, Santa Barbara, Ventura, San Bernardino, Riverside, San Diego & Imperial.

  RATIONALE FOR SURVEILLANCE IN ANIMALS   Animals cases are sentinels for the risk of mosquito borne disease in general.
Wherever there are more cases, mosquito borne disease risk is higher.
       
  REFERENCES  

Last updated: September 28, 2017

 
Public Health has made reasonable efforts to provide accurate translation. However, no computerized translation is perfect and is not intended to replace traditional translation methods. If questions arise concerning the accuracy of the information, please refer to the English edition of the website, which is the official version.
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