Article

Risk factors for visceral leishmaniasis in a new epidemic site in Amhara Region, Ethiopia. Am J Trop Med Hyg

Malaria & Other Vector Borne Diseases, Prevention and Control Program, Ministry of Health, Addis Ababa, Ethiopia.
The American journal of tropical medicine and hygiene (Impact Factor: 2.74). 08/2009; 81(1):34-9.
Source: PubMed

ABSTRACT We conducted a case-control study to evaluate risk factors for visceral leishmaniasis during an epidemic in a previously unaffected district of Ethiopia. We also collected blood and bone marrow specimens from dogs in the outbreak villages. In multivariable analyses of 171 matched case-control pairs, dog ownership, sleeping under an acacia tree during the day, and habitually sleeping outside at night were associated with significantly increased risk. Specimens from 7 (3.8%) dogs were positive by immunofluorescent antibody test (IFAT) and both enzyme-linked immunosorbent assays (ELISAs), whereas Leishmania DNA was detected in 5 (2.8%) bone marrow aspirates (from 3 seropositive and 2 seronegative dogs). Insecticide-treated nets may only protect a portion of those at risk. Further research on the vectors, the role of the dog in the transmission cycle, and the effect of candidate interventions are needed to design the best strategy for control.

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    • "Nevertheless, there is evidence for the possible involvement of zoonotic transmission with uncertain reservoir hosts (Ashford, 2000). Recently, natural infections of dogs (Bashaye et al., 2009), domestic animals (Rohousova et al., 2015) and rodents (Kassahun et al., 2015) with L. donovani complex were reported in Ethiopia. "
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    • "Nevertheless, there is evidence for the possible involvement of zoonotic transmission with uncertain reservoir hosts (Ashford, 2000). Recently, natural infections of dogs (Bashaye et al., 2009), domestic animals (Rohousova et al., 2015) and rodents (Kassahun et al., 2015) with L. donovani complex were reported in "
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    ABSTRACT: The leishmaniases, a group of diseases with a worldwide-distribution, are caused by different species of Leishmania parasites. Both cutaneous and visceral leishmaniasis remains important public health problems in Ethiopia. Epidemiological cycles of these protozoans involve various sand fly (Diptera: Psychodidae) vectors and mammalian hosts, including humans. In recent years, Leishmania infections in bats have been reported in the New World countries endemic to leishmaniasis. The aim of this study was to survey natural Leishmania infection in bats collected from various regions of Ethiopia. Total DNA was isolated from spleens of 163 bats belonging to 23 species and 18 genera. Leishmania infection was detected by real-time (RT) PCR targeting a kinetoplast (k) DNA and internal transcribed spacer one (ITS1) gene of the parasite. Detection was confirmed by sequencing of the PCR products. Leishmania kDNA was detected in eight (4.9%) bats; four of them had been captured in the Aba-Roba and Awash-Methara regions that are endemic for leishmaniasis, while the other four specimens originated from non-endemic localities of Metu, Bedele and Masha. Leishmania isolates from two bats were confirmed by ITS1 PCR to be L. tropica and L. major, isolated from two individual bats, Cardioderma cor and Nycteris hispida, respectively. These results represent the first confirmed observation of natural infection of bats with the Old World Leishmania. Hence, bats should be considered putative hosts of Leishmania spp. affecting humans with a significant role in the transmission. Copyright © 2015. Published by Elsevier B.V.
    Acta tropica 07/2015; DOI:10.1016/j.actatropica.2015.07.024 · 2.52 Impact Factor
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    • "The main potential vectors of VL include Phlebotomus orientalis, Phlebotomus martini, and Phlebotomus celiae (Hailu et al., 1995; Gebre-Michael and Lane, 1996). The transmission dynamics of VL in Ethiopia and neighboring East African countries is generally believed to be anthroponotic (Chappuis et al., 2007); however DNA of L. donovani complex has recently been detected in both wild and domestic animals (Bashaye et al., 2009) and in certain districts of Sudan, rodents are suspected to be reservoirs of the parasite (Chance et al., 1978; Le Blancq and Peters, 1986; Elnaiem et al., 2001). The Fig. 1. "
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    ABSTRACT: Human visceral (VL, also known as Kala-azar) and cutaneous (CL) leishmaniasis are important infectious diseases affecting countries in East Africa that remain endemic in several regions of Ethiopia. The transmission and epidemiology of the disease is complicated due to the complex life cycle of the parasites and the involvement of various Leishmania spp., sand fly vectors and reservoir animals besides human hosts. Particularly in East Africa, the role of animals as reservoirs for human VL remains unclear. Isolation of Leishmania donovani parasites from naturally infected rodents has been reported in several endemic countries; however, the status of rodents as reservoirs in Ethiopia remains unclear. Here, we demonstrated natural Leishmania infections in rodents. Animals were trapped in 41 localities of endemic and non-endemic areas in eight geographical regions of Ethiopia and DNA was isolated from spleens of 586 rodents belonging to 21 genera and 38 species. Leishmania infection was evaluated by real-time PCR of kinetoplast (k)DNA and confirmed by sequencing of the PCR products. Subsequently, parasite species identification was confirmed by PCR and DNA sequencing of the 18S ribosomal RNA internal transcribed spacer one (ITS1) gene. Out of fifty (8.2%) rodent specimens positive for Leishmania kDNA-PCR and sequencing, 10 were subsequently identified by sequencing of the ITS1 showing that five belonged to the L. donovani complex and five to L. tropica. Forty nine kDNA-positive rodents were found in the endemic localities of southern and eastern Ethiopia while only one was identified from north-western Ethiopia. Moreover, all the ten ITS1-positive rodents were captured in areas where human leishmaniasis cases have been reported and potential sand fly vectors occur. Our findings suggest the eco-epidemiological importance of rodents in these foci of leishmaniasis and indicate that rodents are likely to play a role in the transmission of leishmaniasis in Ethiopia, possibly as reservoir hosts. Copyright © 2015. Published by Elsevier B.V.
    Acta Tropica 02/2015; 13. DOI:10.1016/j.actatropica.2015.02.006 · 2.52 Impact Factor
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