Field evaluation of a 0.005% fipronil bait, orally administered to Rhombomys opimus, for control of fleas (Siphonaptera: Pulicidae) and phlebotomine sand flies (Diptera: Psychodidae) in the Central Asian Republic of Kazakhstan

<div><p>Plague (<i>Yersinia pestis</i>) and zoonotic cutaneous leishmaniasis (<i>Leishmania major</i>) are two rodent-associated diseases which are vectored by fleas and phlebotomine sand flies, respectively. In Central Asia, the great gerbil (<i>Rhombomys opimus</i>) serves as the primary reservoir for both diseases in most natural foci. The systemic insecticide fipronil has been previously shown to be highly effective in controlling fleas and sand flies. However, the impact of a fipronil-based rodent bait, on flea and sand fly abundance, has never been reported in Central Asia. A field trial was conducted in southeastern Kazakhstan to evaluate the efficacy of a 0.005% fipronil bait, applied to gerbil burrows for oral uptake, in reducing <i>Xenopsylla</i> spp. flea and <i>Phlebotomus</i> spp. sand fly abundance. All active gerbil burrows within the treated area were presented with ~120 g of 0.005% fipronil grain bait twice during late spring/early summer (June 16, June 21). In total, 120 occupied and 14 visited gerbil colonies were surveyed and treated, and the resulting application rate was minimal (~0.006 mg fipronil/m²). The bait resulted in 100% reduction in <i>Xenopsylla</i> spp. flea abundance at 80-days post-treatment. Gravid sand flies were reduced ~72% and 100% during treatment and at week-3 post-treatment, respectively. However, noticeable sand fly reduction did not occur after week-3 and results suggest environmental factors also influenced abundance significantly. In conclusion, fipronil bait, applied in southeastern Kazakhstan, has the potential to reduce or potentially eliminate <i>Xenopsylla</i> spp. fleas if applied at least every 80-days, but may need to be applied at higher frequency to significantly reduce the oviposition rate of <i>Phlebotomus</i> spp. sand flies. Fipronil-based bait may provide a means of controlling blood-feeding vectors, subsequently reducing disease risk, in Central Asia and other affected regions globally.</p></div

Molecular Study of Theileria&nbsp;annulata and Anaplasma spp. in Ixodid Ticks from Southern Regions of the Republic of Kazakhstan

Ixodid ticks are vectors of pathogens that cause dangerous infectious and parasitic diseases in animals, leading to reduced productivity and, in some cases, mass mortality. In Kazakhstan, information on tick fauna and their epizootological role in the transmission of hemoparasites is limited. This study aimed to determine the species composition of ixodid ticks parasitizing cattle in the Almaty, Zhambyl, and Turkistan oblasts, and to assess their potential role in the transmission of Theileria and Anaplasma spp. A total of 3121 ixodid ticks were collected from cattle, belonging to the genera Hyalomma (86.9%; 2711/3121), Rhipicephalus (8.5%; 266/3121), Dermacentor (3.2%; 101/3121), and Haemaphysalis (1.4%; 43/3121). Morphological identification revealed that ticks of the genus Hyalomma, including Hyalomma scupense (31.7%), Hyalomma asiaticum (27.9%), and Hyalomma anatolicum (19.6%), were the predominant species. Rhipicephalus annulatus was recorded for the first time in the Almaty and Zhambyl oblasts. Partial sequencing of the cox1 gene confirmed the species identification obtained by morphological examination. A total of 113 representative ticks were subjected to DNA extraction for the identification of Theileria and Anaplasma species using conventional PCR with primers targeting the 28SrRNA and GroEL genes, respectively. No Anaplasma spp. were detected in the analyzed tick samples. Theileria annulata DNA was identified in seven nymphs of Hy. scupense (6.1%) collected in the Zhambyl oblast, and for the first time in Kazakhstan, in one female Rhipicephalus annulatus (0.9%) collected in the Almaty oblast. The overall infection prevalence of Theileria annulata was 7.0% (8/113)

A wooden great gerbil trap positioned in the entrance of an active gerbil burrow.

<p>A wooden great gerbil trap positioned in the entrance of an active gerbil burrow.</p

Map of boundaries and gerbil colony locations with the treatment (bottom) and control (top) plots.

<p>Red and blue dots indicate selected colony locations within the treatment and control plots, respectively. Small squares surrounding the treatment and control plots indicate the plot boundaries. The larger boundary surrounding the treatment plot indicates the buffer zone. Map was generated in ArcGIS using ArcMap with a World Imagery base layer (Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community).</p

The average number of sand flies per trap-night (+SD), efficacy of bait (0.005% fipronil) against female <i>Phlebotomus mongolensis</i> sand flies (non-gravid and gravid), and average minimum temperature, maximum humidity, and precipitation (+SD) recorded during all study periods.

<p>The average number of sand flies per trap-night (<u>+</u>SD), efficacy of bait (0.005% fipronil) against female <i>Phlebotomus mongolensis</i> sand flies (non-gravid and gravid), and average minimum temperature, maximum humidity, and precipitation (<u>+</u>SD) recorded during all study periods.</p

Total <i>Phlebotomus</i> spp. sand flies collected in CDC light traps set 17 times from June 1-July 29, 2016.

<p>Total <i>Phlebotomus</i> spp. sand flies collected in CDC light traps set 17 times from June 1-July 29, 2016.</p

The efficacy of bait (0.005% fipronil) in reducing the flea index of <i>Xenopsylla gerbili minax</i>.

<p>The efficacy of bait (0.005% fipronil) in reducing the flea index of <i>Xenopsylla gerbili minax</i>.</p

<i>Xenopsylla gerbili minax</i> fleas collected within the treatment and control plots from wild-caught great gerbils during the pre-treatment, treatment, and post-treatment periods.

<p><i>Xenopsylla gerbili minax</i> fleas collected within the treatment and control plots from wild-caught great gerbils during the pre-treatment, treatment, and post-treatment periods.</p

Adult great gerbils (<i>Rhombomys opimus</i>) consuming fipronil-based grain bait (red).

<p>Adult great gerbils (<i>Rhombomys opimus</i>) consuming fipronil-based grain bait (red).</p

The location and occupancy status of all 134 gerbil colonies within the treatment area upon which two fipronil bait applications were performed June 16 and June 21, 2016.

<p>Map was generated in ArcGIS using ArcMap with a World Imagery base layer (Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AeroGRID, IGN, and the GIS User Community).</p