Nepal Elephant TB Control and Mgt Action Plan.pdf - Elephant Care ...

Nepal Elephant Tuberculosis ulosisControl andManagement agemenAction Plan (2011-2015)2015)1.3 Descripon of DiagnoscMethodsa. The Elephant TB Stat-Pak ® test is a bloodanbody test. A reacve test indicatesprobable TB infecon. Confirmaon withother tests is ideal - when possible and asdiscussed above. A non-reacve test indicatesno infecon and a TB-free status at the meof tesng. The Elephant TB Stat-Pak ® test isused as the standard roune TB screeningtest for elephants in Nepal. The test isadministered by the TB Plan veterinarian.b. The DPP VetTB test is a blood anbody testused to confirm the Elephant TB Stat-Pak ® test.The Elephant TB Stat-Pak ® and DPP ® VetTBtests have been shown to be early predictorsof infecon and may be reacve monthsto years in advance of detecon by culture(Greenwald et al. 2009). This provides theopportunity to treat elephants before theyshed and infect other elephants, humans, orwildlife.c. Culture is used to detect elephants that areacvely shedding TB organisms. Respiratorysamples obtained by collecng trunkdischarges are submi!ed to a laboratorythat is qualified to test for mycobacteria(this requires specific procedures). A posiveculture confirms that an elephant is acvelyinfected. Posive isolates should be tested toconfirm if the organisms were M. tuberculosisor M. bovis. Drug sensivity tesng (DST) foran-tuberculosis drugs (isoniazid, rifampin,and ethambutol) should be performed.Note that culture has inherent limitaons.Failure to isolate the organism does notrule out infecon. False-negave resultsmay occur 1) if the elephant is infected butorganisms are not shed on the day of samplecollecon or 2) contaminated trunk washsamples cause other organisms to overgrow.False-negave results allow TB disease toprogress and the infected elephant is a sourceto spread TB to other elephants, humans,or wildlife. Culture is expensive and manysamples may be needed to detect infecon. InSweden, of 189 trunk wash cultures collectedfrom 5 elephants confirmed TB-infected onpostmortem, only 7 samples were posive(Moller et al. 2005).Newer technologies that prove to be morereliable, sensive, or cost effecve fordetecng TB organisms in trunk wash or othersecreons will be incorporated into this planas they become available.d. PCR (polymerase chain reacon) is a type ofnucleic acid amplificaon test (NAAT). NAATsfacilitate the idenficaon of pathogens byamplifying and detecng specific nucleicacid sequences. PCR assays to detect TB inelephants in Nepal are under invesgaon bythe Center for Molecular Dynamics-Nepal (seeKay et al. 2011).e. LAMP (loop-mediated isothermalamplificaon) assay is a type of NAAT thatallows detecon of trace amounts of DNAunder isothermal condions. It has been usedto diagnose TB in humans in Nepal (Pandey etal. 2008) and is under invesgaon for use inelephants.1.4 Segregaon ProceduresSegregaon is an important management tool.Segregaon from wild elephants and otherwildlife (e.g. rhino) is considered a priority toprevent TB transmission to endangered wildlifepopulaons. Segregaon can also minimizetransmission to other capve elephants and tohumans. The goal of segregaon is to preventhealthy animals from coming into contact withrespiratory droplets or other secreons frominfected elephants.10