A zoonotic focus of cutaneous leishmaniasis in Addis Ababa, Ethiopia

Abstract

BackgroundCutaneous leishmaniasis (CL) is endemic in the highlands of Ethiopia, and almost always caused by Leishmania aethiopica. Hitherto, Addis Ababa (the capital city of Ethiopia) was not considered endemic for CL, mainly due to absence of epidemiological and field ecological studies. This report summarizes the preliminary epidemiological investigation that proved the existence of active transmission in southeastern Addis Ababa.ResultsActive case finding surveys were conducted in 3 localities, Saris, Kality, and Akaki, which are found in and around Bulbula-Akaki river gorges. During the surveys conducted in January 2005 - May 2006, a total of 35 cases with 9 active and 26 healed skin lesions were identified. Eighteen of the cases (51.4%) were found in Saris; while 10 (28.6%) and 7 (20%) cases were from Kality and Akaki respectively.Ten colonies of rock hyraxes (Heterohyrax brucei) were identified in the vicinities of the 3 localities. Three of the 48 hyraxes (6.3%) trapped from the surroundings harbored natural infections of Leishmania aethiopica. Confirmation of the Leishmania species of the 3 isolates was achieved by PCR amplification and RFLP analysis of the ribosomal DNA internal transcribed spacer (ITS) sequences. Based on sandfly species composition and proximity of resting sites to human settlements, Phlebotomus longipes is circumstantially proven to be the vector of CL in south east Addis Ababa.ConclusionThe study proves the existence of isolated zoonotic foci of CL in south eastern Addis Ababa, with P. longipes as the likely vector and H. brucei as the natural reservoir host.

Risk map for cutaneous leishmaniasis in Ethiopia based on environmental factors as revealed by geographical information systems and statistics

“…The human cases of CL, sand fly vectors and reservoir hyrax species responsible for L. aethiopica transmission are known to commonly occur at altitudes similar to our prediction: the previously characterised CL foci in Ethiopia lie between 1,400 and 2,700 m above MSL (Ashford et al, 1973;Ashford, 1977;Negera et al, 2008;Lemma et al, 2009). Considering geographical and individual variables, Morrone et al (2011) documented clustering of CL cases in males living at altitudes above 2,000 m above MSL in the Tigray regional state.…”

Leishmaniasis recidivans in Ethiopia: cutaneous and mucocutaneous features

“…Our patients all came from the Ethiopian highlands around Mekelle. It has been demonstrated that CL on the Ethiopian highlands (> 2,000 meters) is caused by L. aethiopica, which was the only species isolated from patients living in the highlands of different regions including Tigray in several studies [16][17][18][19][20][21].…”

“…Here we report the presence of LR in Ethiopia, where L. aethiopica is to date still the only species found in the highlands causing CL [16][17][18][19][20], and describe the mucosal involvement in this uncommon clinical variant.…”

Population Size and Diet of Bush Hyrax <i>Hetrohyrax brucei</i> (Gray 1868) in the Isolated Romanat Michael Church Forest in Northern Ethiopia, Implication for Conservation

“…For species like bush hyrax, which has a relatively long (24-30 weeks) gestation period (Barry and Hoeck, 2013) and reproduction synchronized with seasonal rainfall (Barry and Mundy, 1998), the loss of five adult individuals in just one season, raises a worrisome sustainability concern. Note that bush hyraxes are susceptible to viral pneumonia and tuberculosis (Sale, 1966), they harbour Leishmania (Lemma et al, 2009), nematode and different arthropod ectoparasites (Barry and Shoshani, 2000). Even though we did not investigate this topic, the small hyrax population might have suffered genetic stochasticity that could be explained by compromised resistance to diseases and parasites, as some of the adult individuals looked unusually weak during the dry season a few days before the population count dropped.…”

“…Studies on population status and diet are also scarce. From a human health point of view, several reports explained the reservoir role of hyraxes in the epidemiology of cutaneous leishmaniasis, a form of Old World leishmaniasis occurring in the highlands of Kenya and Ethiopia (Ashford et al, 1973;Lemma et al, 2009). …”