10 research outputs found
The mass use of deltamethrin collars to control and prevent canine visceral leishmaniasis: A field effectiveness study in a highly endemic area
<div><p>Background</p><p>Visceral leishmaniasis (VL) is a zoonosis of great importance. Limitations in current VL control measures compromise efficacy, indicating the need to implement new strategies. The aim of this study was to evaluate the effectiveness of the mass use of deltamethrin-impregnated collars in dogs as a public health measure to control and prevent canine visceral leishmaniasis (CVL).</p><p>Methodology</p><p>An interventional study was implemented in two endemic areas in the district of Monte Gordo (Bahia-Brazil): an intervention area, in which VL seronegative dogs were collared, and a control area in which only conventional CVL control measures were applied. At baseline, seropositive dogs were removed and seronegative dogs were included. Dogs were then reevaluated every 7–8 months for almost two years. At each time point, dogs in the intervention area that remained seronegative received new collars and newly identified seronegative dogs were included and collared. The local zoonosis control authorities were notified of any dogs that tested seropositive in both areas, which were subsequently marked for euthanasia as mandated by the Brazilian Ministry of Health.</p><p>Principal findings</p><p>In the first serological survey, seroprevalence was similar in both areas. At the second evaluation, significant reductions in seroprevalence were seen in both areas, while seroprevalence in the intervention area reduced to 6.0% during the final evaluation versus an increase of 11.0% in the control area. This significant increase and the estimated relative risk (RR = 0.55) indicated protection against CVL in the intervention area. Although CVL incidence did not differ significantly between the areas, an increased tendency was observed in the control area, which could be due to low seroconversion rates throughout the study or a high loss to follow-up.</p><p>Conclusions/Significance</p><p>Although our evaluation of the effectiveness of deltamethrin-impregnated collars as a community-wide public health control measure was inconclusive, this measure likely provides protection over time. In endemic areas of Brazil, this strategy represents an operational challenge for local zoonosis control authorities, indicating the need for adjustments, including improved collar design.</p></div
The mass use of deltamethrin collars to control and prevent canine visceral leishmaniasis: A field effectiveness study in a highly endemic area - Fig 2
<p>Identification of the intervention area (A) and control area (B) in the district of Monte Gordo–municipality of Camaçari (Bahia-Brazil). Source: USGS LandsatLook (<a href="https://landsatlook.usgs.gov/viewer.html" target="_blank">https://landsatlook.usgs.gov/viewer.html</a>).</p
Canine characteristics recorded at baseline in each study area located in Monte Gordo–Camaçari (Bahia-Brazil).
<p>Canine characteristics recorded at baseline in each study area located in Monte Gordo–Camaçari (Bahia-Brazil).</p
Estimated effect of deltamethrin collar intervention on CVL seroprevalence at the time of each serological evaluation.
<p>Estimated effect of deltamethrin collar intervention on CVL seroprevalence at the time of each serological evaluation.</p
The mass use of deltamethrin collars to control and prevent canine visceral leishmaniasis: A field effectiveness study in a highly endemic area - Fig 5
<p>Number of dogs, and serological and inclusion status of the closed cohort in intervention (A) and control (B) areas.</p
Estimated effect of deltamethrin collar intervention on CVL incidence.
<p>Estimated effect of deltamethrin collar intervention on CVL incidence.</p
Number of dogs in the intervention area that remained collared until the subsequent survey.
<p>Number of dogs in the intervention area that remained collared until the subsequent survey.</p
The mass use of deltamethrin collars to control and prevent canine visceral leishmaniasis: A field effectiveness study in a highly endemic area - Fig 3
<p>Number of dogs, and serological and inclusion status of the open cohort in intervention (A) and control (B) areas.</p
District of Monte Gordo in the municipality of Camaçari–Bahia–Brazil.
<p>Source: Terraview.</p
Seroprevalence of CVL in study intervention and control areas.
<p>Seroprevalence of CVL in study intervention and control areas.</p