Vectorborne Transmission of<i>Leishmania infantum</i>from Hounds, United States

Schaut, Robert G.; Robles-Murguia, Maricela; Juelsgaard, Rachel; Esch, Kevin J.; Ramalho-Ortigão, Marcelo; Petersen, Christine A.

doi:10.3201/eid2112.141167

Cited by 29 publications

(33 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Infection progresses to the chronic severe visceralizing form, which is often fatal, in approximately 40 % of L. infantum -infected dogs. Both asymptomatic and symptomatic dogs can be infectious to competent vectors, and naturally infected US hunting hounds have been shown to be infectious to vectors present in the USA (Courtenay et al 2014; Schaut et al 2015). These dogs could potentially serve as domestic reservoirs for emergent human infection (Drahota et al 2014; Petersen 2009a; Schaut et al 2015).…”

Section: Introductionmentioning

confidence: 99%

“…Both asymptomatic and symptomatic dogs can be infectious to competent vectors, and naturally infected US hunting hounds have been shown to be infectious to vectors present in the USA (Courtenay et al 2014; Schaut et al 2015). These dogs could potentially serve as domestic reservoirs for emergent human infection (Drahota et al 2014; Petersen 2009a; Schaut et al 2015). Most US-trained health professionals do not have VL on their list of differential diagnoses, and even in endemic countries, discrimination of early symptoms of VL can be difficult (Ergen et al 2015; Herwaldt et al 1993).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Semi-quantitative measurement of asymptomatic L. infantum infection and symptomatic visceral leishmaniasis in dogs using Dual-Path Platform® CVL

Larson

Toepp

Scott

et al. 2016

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

Infection with Leishmania causes diseases with variable presentation. The most severe form is visceral leishmaniasis (VL), caused by either L. donovani or L. infantum. Despite efforts to eliminate VL, to date, molecular detection in resource-poor settings have lacked the accuracy and rapidity that would enable widespread field use and the need for accurate, sensitive assays to detect asymptomatic Leishmania infection has become apparent. The domestic dog serves as the primary reservoir host of L. infantum. Study of this reservoir population provides an opportunity to evaluate the sensitivity and specificity of diagnostics for well-defined, symptomatic, canine visceral leishmaniasis (CVL) and asymptomatic L. infantum infection. Blood samples from an L. infantum-endemic population of US hunting dogs were evaluated with Dual-Path Platform (DPP®) CVL compared to those obtained via direct detection methods (culture- and Leishmania-specific quantitative polymerase chain reaction, qPCR) and immunofluorescence anti-Leishmania antibody test (IFAT). Statistically significant correlations were found between DPP® CVL development time and clinical status, culture status, circulating DNA levels, and IFAT titer. DPP® CVL results correlated with both clinical severity of disease and serological evidence of asymptomatic L. infantum infection. By precisely documenting the minimum time required for the development of a clear positive result in DPP® CVL, this test could be used in a rapid, semi-quantitative manner for the evaluation of asymptomatic and symptomatic CVL. Our results also indicate that a similar test could be used to improve our understanding of human VL.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Semi-quantitative measurement of asymptomatic L. infantum infection and symptomatic visceral leishmaniasis in dogs using Dual-Path Platform® CVL

Larson

Toepp

Scott

et al. 2016

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

show abstract

“…While vertical transmission of L. infantum exists in endemic areas like Brazil (da Silva et al, 2009), we cannot study this transmission mode directly because vertically infected and vector-infected dogs are indistinguishable. Since vertical is the only known transmission mode in canines in the United States (Schantz et al, 2005;Duprey et al, 2006;Weng et al, 2012;Schaut et al, 2015), we have a unique opportunity to study not only the individual-level dynamics of the infection but also the potential implications for infection spread in the larger (naive) canine population, should vector transmission emerge in the United States. The vertically maintained reservoir is the initial infection source for the vector (Figure 1).…”

Section: Population Sir Model: Vector Transmissionmentioning

confidence: 99%

Bayesian compartmental models and associated reproductive numbers for an infection with multiple transmission modes

et al. 2019

Self Cite

View full text Add to dashboard Cite

Zoonotic visceral leishmaniasis (ZVL) is a serious neglected tropical disease that is endemic in 98 countries. ZVL is primarily transmitted via a sand fly vector. In the United States, it is enzootic in some canine populations; it is transmitted from infectious mother to pup transplacentally, and vector‐borne transmission is absent. This absence affords a unique opportunity to study (1) vertical transmission dynamics in dogs and (2) the importance of vertical transmission in maintaining an infectious reservoir in the presence of a vector. In this paper, we present Bayesian compartmental models and reproductive number formulations to examine (1) and (2), providing a mechanism to plan and evaluate interventions in regions where both transmission modes are present. First, we propose an individual‐level susceptible, infectious, removed (SIR) model to study the effect of maternal infection status during pregnancy on pup infection progression. We provide evidence that pups born to diagnostically positive mothers during pregnancy are more likely to become diagnostically positive both earlier in life, and at some point during their lifetime, than those born to diagnostically negative mothers. Second, we propose a population‐level SIR model to study the impact of a vertically maintained reservoir on propagating infection in a naive canine population through emergent vector transmission using simulation studies. We also present reproductive numbers to quantify contributions of vertically infected and vector‐infected dogs to maintaining infection in the population. We show that a vertically maintained canine reservoir can propagate infection in a theoretical naive population in the presence of a vector.

show abstract

“…[16][17][18] Because of vaccination practices in endemic countries, in both Europe and South America, asymptomatic, seronegative, infected dogs are frequently vaccinated. Based on our previous studies, 8,12,19,20 asymptomatically infected dogs may have altered vaccine responsiveness, leading to increased inflammation after vaccination. Assessing the safety of vaccine use within asymptomatic dogs is necessary to assure that vaccination is safe within a population including infected animals.…”

Section: Introductionmentioning

confidence: 98%

“…[8][9][10][11] Naturally infected U.S. hounds were shown to be infectious to sand flies; thus, if these dogs were bitten by competent vector(s), they could serve as domestic reservoirs to emergent human infection. [12][13][14] Dogs born to infected dams are infected, but remain asymptomatic, through the first 2 or 3 years of life and often test negative by serological screening.…”

Section: Introductionmentioning

confidence: 99%

Safety Analysis of Leishmania Vaccine Used in a Randomized Canine Vaccine/Immunotherapy Trial

Toepp

Larson

Grinnage-Pulley

et al. 2018

The American Journal of Tropical Medicine and Hygiene

View full text Add to dashboard Cite

In -endemic countries, controlling infection within dogs, the domestic reservoir, is critical to public health. There is a need for safe vaccines that prevent canine progression with disease and transmission to others. Protective vaccination against requires mounting a strong, inflammatory, Type 1 response. Three commercially available canine vaccines on the global veterinary market use saponin or inflammatory antigen components (Letifend) as a strong pro-inflammatory adjuvant. There is very little information detailing safety of saponin as an adjuvant in field trials. Safety analyses for the use of vaccine as an immunotherapeutic in asymptomatically infected animals are completely lacking. , the causative agent of canine leishmaniasis, is enzootic within U.S. hunting hounds. We assessed the safety of LeishTec after use in dogs from two different clinical states: 1) without clinical signs and tested negative on polymerase chain reaction and serology or 2) without clinical signs and positive for at least one diagnostic test. Vaccine safety was assessed after all three vaccinations to quantify the number and severity of adverse events. Vaccinated animals had an adverse event rate of 3.09%, whereas placebo animals had 0.68%. Receiving vaccine was correlated with the occurrence of mild, site-specific, reactions. Occurrence of severe adverse events was not associated with having received vaccine. Infected, asymptomatic animals did not have a higher rate of adverse events. Use of vaccination is, therefore, likely to be safe in infected, asymptomatic animals.

show abstract

Vectorborne Transmission ofLeishmania infantumfrom Hounds, United States

Cited by 29 publications

References 13 publications

Semi-quantitative measurement of asymptomatic L. infantum infection and symptomatic visceral leishmaniasis in dogs using Dual-Path Platform® CVL

Semi-quantitative measurement of asymptomatic L. infantum infection and symptomatic visceral leishmaniasis in dogs using Dual-Path Platform® CVL

Bayesian compartmental models and associated reproductive numbers for an infection with multiple transmission modes

Safety Analysis of Leishmania Vaccine Used in a Randomized Canine Vaccine/Immunotherapy Trial

Contact Info

Product

Resources

About