Characterization of breeding sites of Phlebotomus orientalis – The vector of visceral leishmaniasis in northwestern Ethiopia

Moncaz, Aviad; Kirstein, Oscar D.; Gebresellassie, Araya; Lemma, Wossenseged; Yared, Solomon; Gebre-Michael, Teshome; Hailu, Asrat; Shenker, Moshe; Warburg, Alon

doi:10.1016/j.actatropica.2014.06.013

Cited by 32 publications

(45 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…orientalis was largely associated with such soil type in East Africa [9, 37]. Such type of soil is characterized by high contents of clay minerals that enhance swelling when hydrated and shrinkage upon desiccation, thereby, causing extensive cracking during the dry season [10]. Furthermore, a study conducted in Humera area by Shabtai et al [38] indicated that vertisols from farm fields have high swelling capacity upon wetting than vertisol in a nearby forest.…”

Section: Discussionmentioning

confidence: 99%

“…donovani in eastern Sudan [6] and the suspected vector in the northwestern Ethiopia [7, 8]. In these areas, it is strongly associated with Acacia-Balanites forest and deeply cracking ‘black cotton soil’, which the species may use as breeding and resting sites [9, 10]. Previous studies on population dynamics and distribution of this species in Sudan revealed that P .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Studies on sand fly fauna and ecological analysis of Phlebotomus orientalis in the highland and lowland foci of kala-azar in northwestern Ethiopia

et al. 2017

Self Cite

View full text Add to dashboard Cite

BackgroundVisceral leishmaniasis (VL) also known as kala-azar is a growing health problem in Ethiopia with an estimated annual VL incidence between 3700 and 7400. The disease is mainly endemic in northwestern parts of the country. The aim of the current study was to determine the sand fly fauna and ecology of Phlebotomus orientalis in two endemic and ecologically distinct areas of northwestern Ethiopia.MethodsSand flies were collected using CDC light traps, sticky traps and pyrethrum spray catches from peri-domestic, mixed forest, farm field and indoor habitats from both Libo-Kemkem (May 2011-April 2012) and Metema (October 2012-September 2013) districts.ResultsA total of 51,411 sand fly specimens were collected and identified (10,776 from highland and 40, 635 from the lowland areas). Seven species were found in the highland area: two Phlebotomus spp. (P. orientalis and P. rodhaini) and five Sergentomyia species. Whereas 19 species were found in the lowland area: six Phlebotomus (P. orientalis, P. rodhaini, P. bergeroti, P. duboscqi, P. papatasi and P. martini) and 13 Sergentomyia species. Of the Phlebotomus spp., P. orientalis was the predominant species in both the highland (99.9%) and lowland (93.7%) areas. Indoor collections using pyrethrum spray catches and sticky traps indicated that P. orientalis has a strong exophilic and exophagic behaviors in both districts. In both areas, this species showed seasonal occurrence and showing abundance during the dry months (March-May/June) of the year and increasing in numbers till the rain season, when numbers dropped dramatically. Mean density of P. orientalis in the two areas had positive and significant correlation with mean temperature in light trap collections (P<0.05). However, mean density of P. orientalis in the two areas in sticky trap collections had positive and insignificant association with the temperature (P>0.05). Regarding the rainfall pattern, density of P. orientalis had negative and statistically insignificant correlation (for light trap collections for both areas) and significant correlation (for sticky trap collections for lowland area).ConclusionsThe current study indicated the variation in sand fly fauna between the highland and lowland districts, wherein, P. orientalis was found to be the most abundant Phlebotomus species. The study also determined that P. orientalis exhibits distinct seasonality, where its abundance increases during the dry season and disappears when the rainy period starts in both study areas. This entomological observation on the bionomics of P. orientalis provides significant evidence for considering vector control or preventive measures in the areas studied.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Studies on sand fly fauna and ecological analysis of Phlebotomus orientalis in the highland and lowland foci of kala-azar in northwestern Ethiopia

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…They cook and sleep under the shade of B. aegiptiaca trees . The big cracks in the agricultual fields and sparse thickets of A. sayal are the breeding habiatats of P. orientalis [22,23]. Rarely, labour migrants come from areas outside Amhara and Tigray region.…”

Section: Methodsmentioning

confidence: 99%

Sero-prevalence of Leishmania donovani infection in labour migrants and entomological risk factors in extra-domestic habitats of Kafta-Humera lowlands - kala-azar endemic areas in the northwest Ethiopia

et al. 2015

Self Cite

View full text Add to dashboard Cite

BackgroundVisceral leishmaniasis (VL) or kala-azar cases in seasonal labour migrants from highland areas are addressed to travel history to the Metema–Humera lowlands, northwestern Ethiopia. Factors that affect the incidence of VL in extra-domestic habitats were not evaluated. The aim of this study was to evaluate sero-prevalence of Leishmania donovani infection in randomly selected labour migrant workers and entomological risk factors which might affect the incidence of kala-azar.MethodsSero-prevalence of L. donovani infection in labour migrants was obtained from Direct Agglutination Test (DAT) using blood samples. Logistic regression analysis was used to correlate the possible risk factors with L. donovani infection. The season for L. donovani infection or Phlebotomus orientalis bite was estimated from the study of population dynamic of P. orientalis in areas where the blood was sampled.ResultA total of 7, 443 P. orientalis (1,748 female and 5,695 male) were collected from agricultural fields and thickets of Acacia seyal using 461 CDC light traps. The highest mean number of P. orientalis/trap in the thickets of A. seyal and agricultural fields were 46.9 and 43.9 in March and April respectively. The mean P. orientalis/trap for November – May dry season in agricultural fields (11.39) and thickets of A. seyal (25.30) were higher compared to 0.66 in fields and 3.92 in thickets during June – August weeding season. Of the total 359 labour migrants screened using DAT, 45 (12.5%) were DAT-positive (≥1:800) for L. donovani infections. Very high titers (1:12800) were found in 3 (0.8%) individuals who had the risk of kala-azar development. Statistically significant p-values and odd ratio (OR) for staying in the areas both in the weeding and harvesting seasons (p = 0.035; OR = 2.83) and sleeping in the agricultural fields (p = 0.01; OR = 15.096) were positively correlated with L. donovani infection. Night harvest (p = 0.028; OR = 0.133) and knowledge about sign or symptoms (p = 0.042; OR = 0.383) were negatively associated with this infection.ConclusionsSleeping in open agricultural fields was related with L. donovani infections in labour migrants during June-August weeding season.

show abstract

“…This species is frequently associated with Acacia-Balanite s- Ziziphus woodlands and vertisols (black cotton soils) [6,7]. …”

Section: Introductionmentioning

confidence: 99%

The influence of moonlight and lunar periodicity on the efficacy of CDC light trap in sampling Phlebotomus (Larroussius) orientalis Parrot, 1936 and other Phlebotomus sandflies (Diptera: Psychodidae) in Ethiopia

Gebresilassie

Yared

Aklilu

et al. 2015

Parasites & Vectors

Self Cite

View full text Add to dashboard Cite

BackgroundPhlebotomus orientalis is the main sandfly vector of visceral leishmaniasis in the north and northwest of Ethiopia. CDC light traps and sticky traps are commonly used for monitoring sandfly populations. However, their trapping efficiency is greatly influenced by various environmental factors including moonlight and lunar periodicity. In view of that, the current study assessed the effect of moonlight and lunar periodicity on the performance of light traps in collecting P. orientalis.MethodsTrapping of P. orientalis and other Phlebotomus spp. was conducted for 7 months between December 2012 and June 2013 using CDC light traps and sticky traps from peri-domestic and agricultural fields. Throughout the trapping periods, collections of sandfly specimens were carried out for 4 nights per month, totaling 28 trapping nights that coincided with the four lunar phases (viz., first quarter, third quarter, new and full moon) distributed in each month.ResultsIn total, 13,533 sandflies of eight Phlebotomus species (P. orientalis, P. bergeroti, P. rodhaini, P. duboscqi, P. papatasi, P. martini, P. lesleyae and P. heischi) were recorded. The predominant species was P. orientalis in both trapping sites and by both methods of collection in all lunar phases. A significant difference (P < 0.05) was observed in the mean numbers of P. orientalis and other Phlebotomus spp. caught by CDC light traps among the four lunar phases. The highest mean number (231.13 ± 36.27 flies/trap/night) of P. orientalis was collected during the new moon phases, when the moonlight is absent. Fewer sandflies were attracted to light traps during a full moon. However, the number of P. orientalis and the other Phlebotomus spp. from sticky traps did not differ in their density among the four lunar phases (P = 0.122).ConclusionResults of the current study demonstrated that the attraction and trapping efficiency of CDC light traps is largely influenced by the presence moonlight, especially during a full moon. Therefore, sampling of sandflies using light traps to estimate population density and other epidemiological studies in the field should take the effect of moonlight and lunar periodicity into account on the trapping efficacy of light traps.

show abstract

Characterization of breeding sites of Phlebotomus orientalis – The vector of visceral leishmaniasis in northwestern Ethiopia

Cited by 32 publications

References 28 publications

Studies on sand fly fauna and ecological analysis of Phlebotomus orientalis in the highland and lowland foci of kala-azar in northwestern Ethiopia

Studies on sand fly fauna and ecological analysis of Phlebotomus orientalis in the highland and lowland foci of kala-azar in northwestern Ethiopia

Sero-prevalence of Leishmania donovani infection in labour migrants and entomological risk factors in extra-domestic habitats of Kafta-Humera lowlands - kala-azar endemic areas in the northwest Ethiopia

The influence of moonlight and lunar periodicity on the efficacy of CDC light trap in sampling Phlebotomus (Larroussius) orientalis Parrot, 1936 and other Phlebotomus sandflies (Diptera: Psychodidae) in Ethiopia

Contact Info

Product

Resources

About