Tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran: A systematic review

Abstract

BackgroundTick-borne zoonoses in the Order Rickettsiales and Legionellales cause infections that often manifest as undifferentiated fevers that are not easy to distinguish from other causes of acute febrile illnesses clinically. This is partly attributed to difficulty in laboratory confirmation since convalescent sera, specific diagnostic reagents, and the required expertise may not be readily available. As a result, a number of tick-borne zoonoses are underappreciated resulting in unnecessary morbidity, mortality and huge economic loses. In Iran, a significant proportion of human infectious diseases are tick-borne, with anecdotal evidence suggesting that tick-borne zoonoses are widespread but underreported in the country. Epidemiological review is therefore necessary to aid in the effective control and prevention of tick-borne zonooses in Iran. The aim of this review is to provide an in-depth and comprehensive overview of anaplasmosis, ehrlichiosis, spotted fever group rickettsioses and coxiellosis in Iran.MethodsUsing the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, all relevant publications on tick-borne zoonoses in the Order Rickettsiales and Legionellales in Iran were searched using a number of search terms. The search was confined to authentic resources from repositories of popular data bases among them PubMed, Web of Science, Google Scholar, Science Direct, SpringerLink and SCOPUS. The search items included peer reviewed journals, books and book chapters published between 1996 and 2017.ResultsA total of 1 205 scientific publications and reports were sourced, of which 63 met the search criteria and were reviewed. Of the 63 articles reviewed, 36 (57.1%) reported on coxiellosis, 15 (23.8%) on anaplasmosis, 11 (17.5%) on ehrlichiosis and 1(1.6%) on spotted fever group rickettsiae in a large scale study involving four countries, among them Iran. The existence of tick-borne pathogens in the Order Rickettsiales and Legionellales was confirmed by molecular, serological and microscopic techniques conducted on samples obtained from sheep, cattle, goats, camels, poultry, animal products (milk and eggs), dogs, ticks and even human subjects in different parts of the country; pointing to a countrywide distribution.DiscussionBased on the review, coxiellosis, anaplasmosis, ehrlichiosis, and SFG rickettsiae can be categorized as emerging tick-borne zoonotic diseases in Iran given the presence of their causiative agents (C. burnetii, A. phagocytophilum, A. marginale, A. bovis, A. ovis, A. central, E. canis, E. ewingii, E. chaffeensis and R. conorii) collectively reported in a variety of domestic animals, animal products, arthropods and human beings drawn from 22 provinces in Iran.ConclusionGiven the asymptomatic nature of some of these zoonoses, there is a high likelihood of silent transmission to humans in many parts of the country, which should be considered a public health concern. Presently, information on the transmission intensity of tick-borne zoonoses caused by pathogens in...

Molecular-based Survey of Rickettsia spp. and Coxiella burnetii in Mosquitoes (Diptera: Culicidae) from Fars Province, Southern Iran, during 2017-18

“…They are transmitted to humans by vector arthropods such as ticks, fleas and lice [42 -47]. In the Middle East, a number of known species of Rickettsia genus have been reported, but some studies are suspicious [48]. Al-Deeb et al reported the first case of spotted fever group of Rickettsia sp.…”

“…Mediterranean Spotted Fever (MSF) is caused by Rickettsia conorii subsp. Israelensis is the main cause of fever and chills from spotted fever group rickettsiosis in collected ticks from mice, deers, goats, red foxes and wild boars [48,51].…”

“…According to conducted studies in the Middle East, the presence of different types of ticks, which can transmit Rickettsia in several countries including Yemen, Saudi Arabia, and Oman throughout the Middle East, can cause Rickettsial diseases in the Middle East [48,52,53]. Despite the evidence of the presence of Rickettsial SFG pathogens in the Middle East, there is no study on this disease in Iran.…”

“…Despite the evidence of the presence of Rickettsial SFG pathogens in the Middle East, there is no study on this disease in Iran. Therefore, it is necessary to study the SFG Rickettsiae to have a better understanding of the epidemiology of this disease in Iran [48]. There is only a paper on the spotted-fever group rickettsioses, and it investigates 40 samples of human serum collected from 4 countries, including Iran, for the presence of spotted fever group rickettsia antibodies among other pathogens by Kovacova et al From 40 human laboratory samples, 45% were positive in terms of SFG rickettsia by the ELISA test, and 27.5% were positive using the IFA test [48,54].…”

Molecular-based survey of Rickettsia spp. and Coxiella burnetii in mosquitoes (Diptera: Culicidae) from Fars province, southern Iran, during 2017-18

“…Israelensis as a main cause of fever and chills from spotted fever group rickettsiosis in collected ticks from mice, deers, goats, red foxes and wild boars(48,51).According to conducted studies in the Middle East, the presence of different types of ticks, which can Despite the evidence of presence of Rickettsial SFG pathogens in the Middle East, there is no study on this disease in Iran.Therefore, it is necessary to study the SFG Rickettsiae to better understand the epidemiology of this disease in Iran(48). There is only a paper on the spotted-fever group rickettsioses and it investigates 40 samples of human serum collected from 4 countries including Iran for the presence of spotted fever group rickettsia antibodies among other pathogens by Kovacova et al From 40 human laboratory samples, 45% were positive in terms of SFG rickettsia by the ELISA test, and 27.5% were positive using the IFA test(48,54).…”