The Effect of Removing Potentially Infectious Dogs on the Numbers of Canine Leishmania infantum Infections in an Endemic Area with High Transmission Rates

Grimaldi, Gabriel; Têva, Antônio; Santos, Claudiney Biral dos; Ferreira, Adelson Luiz; Falqueto, Aloísio

doi:10.4269/ajtmh.2012.12-0040

Cited by 31 publications

(35 citation statements)

References 42 publications

(62 reference statements)

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“…One control measure taken by the VLCSP that has had little impact is the elimination of the canine reservoir, and this failure has been ascribed to delays in detecting and eliminating infected dogs, the tendency to replace infected dogs with susceptible puppies, and the low sensitivity of the available serological methods [33]–[34]. Furthermore, the effectiveness euthanasia of seropositive dog in controlling VL is widely questioned [35]–[36].…”

Section: Discussionmentioning

confidence: 99%

Risk Factors for Seroconversion by Leishmania infantum in a Cohort of Dogs from an Endemic Area of Brazil

et al. 2013

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Visceral leishmaniasis (VL) has recently emerged in various urban and peri-urban areas of Brazil and other countries. Understanding the urbanization of VL requires identification of risk factors associated with human and canine infection. To determine the predictors of risk for canine VL, a survey was conducted of 1,443 dogs, from which a cohort was selected (n = 455) and evaluated for approximately 26 months. Serology was conducted with two enzyme-linked immunosorbent assays (ELISA): one conducted in the Laboratory of Zoonosis of the Belo Horizonte Health Department (LZOON) and the other in the Laboratory of Immunopathology of the Federal University of Ouro Preto (LIMP). A molecular diagnostic method (PCR–restriction fragment length polymorphism) and a structured questionnaire were also used. To identify the factors associated with seroconversion, two time-dependent Cox regression models were performed with different sensitivities (model 1, seroconversion by ELISA/LZOON; model 2, seroconversion by ELISA/LIMP). The overall incidences of seroconversion were 6.5/1000 dogs-months and 11.2/1000 dogs-months for ELISA/LZOON and ELISA/LIMP, respectively. Increased risk of seroconversion was associated with short fur (model 1: hazard ratio [HR] 1.9), the presence of dry leaves (model 1: HR 2.8) or manure (model 1: HR 3.5) in the backyard, dogs sleeping predominantly in the backyard (model 2: HR 2.1), the presence of symptoms (model 2: HR 2.0), and positive molecular results during follow-up (model 2: HR 1.5). Decreased risk was associated with insecticide spraying in the house (model 2: HR 0.5). These results indicate that more-vulnerable domiciles, certain dog behaviors, lack of vector control measures, and positive molecular results were associated with the occurrence of canine VL. Furthermore, it is important to emphasize that PCR-positive dogs should be monitored, owing to the possibility of seroconversion. Identifying risk factors for seroconversion in dogs is crucial for developing adequate strategies for VL prevention and control.

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Section: Discussionmentioning

confidence: 99%

Risk Factors for Seroconversion by Leishmania infantum in a Cohort of Dogs from an Endemic Area of Brazil

et al. 2013

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“…However, the efficacy of dog culling as a unique control measure for both human and canine visceral leishmaniasis remains controversial (Dietze et al 1997, Ashford et al 1998, Courtenay et al 2002, Grimaldi et al 2012. In endemic areas, fast dog replacement by owners in houses where infected dogs have been eliminated may play an important role for maintenance of the disease (Nunes et al 2008).…”

Section: Visceral Leishmaniais (Vl) Caused By Leishmania (Leishmania)mentioning

confidence: 99%

Outbreak of autochthonous canine visceral leishmaniasis in Santa Catarina, Brazil

Steindel

Menin

Evangelista³

et al. 2013

Pesq. Vet. Bras.

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The present study reports the first outbreak of autochthonous canine visceral leishmaniasis in Florianópolis, Santa Catarina, southern Brazil. Following the report of two cases of CVL, the Control Center of Zoonotic Diseases conducted a serological survey by ELISA and IFAT assays in seven districts of the Santa Catarina Island. Eleven seropositive dogs of autochthonous transmission were used in the present study. Infection by Leishmania sp. was confirmed by parasitological examination of bone marrow, liver, spleen and lymph nodes, culture in Schneider's medium and PCR. Leishmania sp. isolates were characterized by PCR-RFLP and hybridization with specific probes, allowing for the identification of Leishmania infantum. Autochthonous transmission of this disease in an area with high tourist traffic presents a major public health concern and signifies the emergence of an important zoonosis in southern Brazil. Therefore, the implementation of surveillance and control measures is imperative to prevent the spread of the disease among the canine population as well as transmission to the human population. infecção por Leishmania sp. foi realizada pelo exame parasitológico da medula óssea, fígado, baço e linfonodos, cultura em meio Schneider e PCR. Os isolados de Leishmania sp. foram caracterizados por PCR-RFLP e hibridação com sondas específicas, permitindo a identificação de Leishmania infantum. A transmissão autóctone da LCV em uma área com grande fluxo turístico como Florianópolis representa um preocupante risco à saúde pública e o surgimento de uma importante zoonose no sul do Brasil. Neste contexto, a implementação de medidas de vigilância e controle da doença são fundamentais para evitar a propagação da doença entre a população canina, bem como a transmissão para a população humana.TERMOS DE INDEXAÇÃO: Leishmaniose visceral canina, Leishmania infantum, zoonose, doenças negligenciadas, saúde pública.

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“…The VLCSP mainly relies on the euthanasia of seropositive dogs to control VL; however, this measure is controversial and some reports suggest that it has little impact on the reduction of human and canine cases [11]–[13]. This failure has been attributed to delays in detecting and eliminating infected dogs, the tendency to replace infected dogs with susceptible puppies, and the low sensitivity of the serological methods used [14]–[19].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Change in Canine Diagnosis Protocol Adopted by the Visceral Leishmaniasis Control Program in Brazil and a New Proposal for Diagnosis

et al. 2014

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The techniques used for diagnosis of canine visceral leishmaniasis (CVL) in Brazil ELISA and IFAT have been extensively questioned because of the accuracy of these tests. A recent change in the diagnosis protocol excluded IFAT and included the Dual-Path Platform (DPP). We evaluated the prevalence and incidence rates of Leishmania spp. before and after the change in the protocol. In addition, based on our results, we propose a new alternative that is less expensive for the screening and confirmation of CVL. Plasma samples were obtained from a serobank from dogs evaluated in a cross-sectional study (1,226 dogs) and in a cohort study of susceptible animals (n = 447), followed for 26 months. Serology testing was performed using ELISA, IFAT, and DPP. The incidence and prevalence of CVL were determined by using the protocol of the Visceral Leishmaniasis Control and Surveillance Program until 2012 (ELISA and IFAT using filter paper) and the protocol used after 2012 (DPP and ELISA using plasma). The prevalence was 6.2% and the incidence was 2.8 per 1,000 dog-months for the protocol used until 2012. For the new diagnosis protocol for CVL resulted in an incidence of 5.4 per 1,000 dog-months and a prevalence of 8.1%. Our results showed that the prevalence and incidence of infection were far greater than suggested by the previously used protocol and that the magnitude of infection in endemic areas has been underestimated. As tests are performed sequentially and euthanasia of dogs is carried out when the serological results are positive in both tests, the sequence does not affect the number of animals to be eliminated by the Control Program. Then we suggest to municipalities with a large demand of exams to use ELISA for screening and DPP for confirmation, since this allows easier performance and reduced cost.

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The Effect of Removing Potentially Infectious Dogs on the Numbers of Canine Leishmania infantum Infections in an Endemic Area with High Transmission Rates

Cited by 31 publications

References 42 publications

Risk Factors for Seroconversion by Leishmania infantum in a Cohort of Dogs from an Endemic Area of Brazil

Risk Factors for Seroconversion by Leishmania infantum in a Cohort of Dogs from an Endemic Area of Brazil

Outbreak of autochthonous canine visceral leishmaniasis in Santa Catarina, Brazil

Evaluation of Change in Canine Diagnosis Protocol Adopted by the Visceral Leishmaniasis Control Program in Brazil and a New Proposal for Diagnosis

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