Heartwater is an acute, often fatal tick-borne disease of ruminants caused by the bacterium Ehrlichia ruminantium. It is widespread in sub-Saharan Africa and some Caribbean islands, where it can cause high mortality rates, especially in young animals and non-native breeds. The disease is characterized by neurological signs, respiratory signs, and systemic signs such as fever and loss of appetite. Diagnosis involves microscopic identification of E. ruminantium in tissues or molecular detection by PCR. Treatment during early stages may involve tetracyclines or sulfonamides, but prognosis is generally poor in advanced cases. Control relies on vaccination of young stock and ectoparasite control to reduce tick vectors.

1. HEARTWATERAnother Potential Foreign Animal DiseasePrepared by : DebbraMarcelMonoclonal Antibody Section, Veterinary Research Institute (VRI)

2. •a.k.aCOWDRIOSIS,isnon-zoonoticdiseasebutoftenacute,fatal,infectiousandtick-borne(Amblyommaticks) rickettsialonruminants.
•causedbybacteriaEhrlichiaruminantium(Dumler,2001).
•widespreadinmostofAfrica,alsofoundonafewCaribbeanislandsandthreateningtheAmericanmainland. However,nocasereportedinAsiaregionsyet(OIE,2010).
•cancausehighmortality(upto90%)insusceptiblewildanddomesticruminants(cattle,sheep,goats,antelopeandbuffalo)esp.younganimalsandnon-nativebreeds
INTRODUCTION
Goatsandsheeparemoresusceptiblethancattle,andEuropeanbreedsaregenerallymoresusceptiblethan
indigenousAfricanbreeds.
Amblyommaticks
GoatSheepCattle

3. GEOGRAPHICAL DISTRIBUTIONAccording to OIE 2010, no case for this disease ever reported in SouthestAsia (including Malaysia)

4. CLINICAL SIGNS
•causedbyanincreasedvascularpermeabilityandconsequentoedemaandhypovolaemia.
•symptomsincludeneurologicalsignssuchastremorsandheadpressing, respiratorysignssuchascoughingandnasaldischarge,andsystemicsignssuchasfeverandlossofappetite.
•highdeathratesinacutestagewithoutmanyclinicalmanifestationswhileinthehigherrecoveryrateinperacutestage.
•physicalexaminationmayrevealpetechiaeofthemucousmembranes,tachycardiaandmuffledheartsounds.
EXTRA INFO:
•canalsocausereproductiveandgastrointestinaldisease.
•recoveredanimalsbecomecarriersofinfection
•certainwildanimalscanplayaroleasreservoir
fever and loss of appetite
coughing and nasal discharge
oedemaand hypovolaemiaa

5. DIAGNOSIS(POST-MORTEM EXAMINATION)
•Lightyellowtransudatewithinthethorax,pericardiumandabdomen.
•Pulmonaryoedemaandmucosalcongestionareregularlyseenalongwithfrothyfluidintheairwaysandcutsurfacesofthelungs.
•Hydropericardium,hydrothoraxandlungoedemaarecommonlyassociatedpost-mortemsigns.
HistopathologicalidentificationofEhrlichiaruminantium:
bypreparingthehippocampusunderGiemsastainingorby
Histopathology(brain/kidney).
stainedEhrlichiaruminantium

6. DIAGNOSTIC TECHNIQUES(based on OIE Terrestrial Manual)
1.Identificationoftheagent(IsolationofEhrlichiaruminantium)
a)usingin-vitroculture
b)usingin-vivoculture
2.Molecularmethods(detectionofEhrlichiaruminantium)
a)usingDNAprobes
b)usingPCRandnestedPCR
c)usingthereverselineblottechnique
d)usingreal-timePCR
3.Serologicaltests
a)IFATwithinfectedendothelialcelltissuecultureas
antigen(CIFAtest)
b)MAP1-Benzyme-linkedimmunosorbentassay
c)MAP1competitiveenzyme-linkedimmunosorbent
assayBacterial Isolation
FluorecenseTest
ELISA

7. TREATMENT AND CONTROL
TREATMENT
•Duringtheearlystages,animalsmaybetreatedwithsulfonamidesandtetracyclines.
•Inadvanceddisease,prognosisispoor.
CONTROL
•Tetracyclinescanalsobeusedprophylacticallywhenanimalsareintroducedintoanareaendemicwithcowdriosis.
•Alivebloodvaccineisavailableforprotectionofyoungstock, butanimalsmayrequiretreatmentforthediseasepost- vaccination.
•EctoparasiticidesdipssuchasRhipicephalus(Boophilus)andHyalommaspecieswillcontributetocontrolofvectorsofEhrlichiaruminantium.

8. REFERENCES
1.DumlerJS,BarbetAF,BekkerCP,etal.(2001)."ReorganizationofgenerainthefamiliesRickettsiaceaeandAnaplasmataceaeintheorderRickettsiales:unificationofsomespeciesofEhrlichiawithAnaplasma,CowdriawithEhrlichiaandEhrlichiawithNeorickettsia,descriptionsofsixnewspeciescombinationsanddesignationofEhrlichiaequiand'HGEagent'assubjectivesynonymsofEhrlichiaphagocytophila". Int.J.Syst.Evol.Microbiol.51(Pt6):2145–65.doi:10.1099/00207713-51-6-2145. PMID11760958.
2.http://www.ebi.ac.uk/2can/genomes/bacteria/Ehrlichia_ruminantium.html
3."Heartwater".AnimalandPlantHealthInspectionService.U.S.DepartmentofAgriculture.Retrieved2008-04-13.
4.CHAPTER2.1.6.HEARTWATER.OIETerrestrialManual(2008).
5.CFSPHTechnicalFactSheets.Heartwaterathttp://www.cfsph.iastate.edu/ DiseaseInfo/
6.Heartwater:AnotherPotentialForeignAnimalDisease.http://www.vetmed. ucdavis.edu/vetext/INF-DA/INF-DA_HEARTWATER.HTML
7.USDAAPHISfactsheet.Heartwater.http://www.aphis.usda.gov/lpa/ pubs/fsheet_faq_notice/fs_ahheartw.html
Prepared by :
DebbraMarcel
Monoclonal Antibody Section,
Veterinary Research Institute (VRI)