Evidence for a long-term increase in the incidence of Leishmania tropica in Aleppo, Syria

Abstract

We report the results of a short study of the epidemiology of Leishmania tropica in the Sheikh Maksoud District of Aleppo, Syria. The present and past status of infection in a community of about 100,000 people are assessed from prevalence and incidence data obtained by active and passive case detection, and from a skin test survey. L. tropica has apparently been endemic for at least 2-3 human generations in Aleppo, and incidence has increased over the past decade. The current estimated force of infection is 0.174/year, the incidence is about 5%, and the average age of infection is 14 years. L. tropica has the essential characteristics of a cyclic infectious disease, and the recent rise in incidence could be part of a long period cycle. A survey of leishmanial scars seriously underestimated the fraction of persons immune, as scar surveys usually do. We estimate that a passive case registration scheme, which has been established in response to growing concern about leishmaniasis in Aleppo, succeeds in recording and treating about one in 4 cases.

Leishmaniaspecies and zymodemes isolated from endemic areas of cutaneous leishmaniasis in Jordan

“…L. major was also isolated from four Psammomys obesus , the principle reservoir host caught in endemic foci in Jordan [14]. CL is also known to be endemic in the neighboring countries where nine patients contracted the disease [24-26]. L. major was the predominant species (75%) that was isolated from all localities in this study and in previous studies [13,14].…”

“…L. tropica was mainly isolated from the north, few cases from the central region, and one case in the south. It was also isolated from cases imported from Saudi Arabia and Syria where it is endemic [24,29]. …”

Cutaneous leishmaniasis in Syria: A review of available data during the war years: 2011–2018

“…The main findings of our data analysis exercise suggest that the progressive increase in the number of CL cases was already evident between 2007 and 2010. The surge observed since the onset of the war, which led to doubling the number of cases between 2010 and 2018, therefore adds to a progressively increasing trend that was already in place and that fits into a pattern observed in other Middle Eastern countries, whereby cyclic increases and decreases in the number of cases occurs every 7 to 10 years [38][39]; with regard to the Aleppo governorate, for example, a progressive increase in incidence of CL had been documented since the mid-1980s [2,40], in spite of extensive vector control efforts [41]. The significant increase in CL incidence between 2010 and 2011 cannot be attributed to the conflict, due to its still limited impact on infrastructures and populations; in our view it is largely due to the ongoing, increasing epidemiological trend.…”

Trends in the epidemiology of cutaneous leishmaniasis in a young adult population in Israel: a long-term survey

“…An analysis of the recently activated IDF computerized medical record system suggests that the actual incidence rates in 2006 may have been as high as 234 per 100,000. These rates are still considerably lower than those witnessed in other eastern Mediterranean countries 11,12 …”