Diversity of rodent-borne zoonotic pathogens at the human-animal-environment interface in Qatar.

Abstract

Rodents are the most diversified terrestrial mammals in the world. These animals assist with maintaining a healthy ecosystem through the soil structure modification, aeration, and hydration, although 5-10% are regarded as pests and carry zoonotic pathogens. Besides consumption and damage of our food and property, they are responsible for the transmission of several diseases, including plague, typhus, and leishmaniasis. Commensal rodents are the primary source of these pathogens because of their close proximity to humans. Qatar is a small country in the Arabian Peninsula. Four rodent species have been recorded in this country, that includes three commensal (Mus musculus, Rattus norvegicus, and Rattus rattus) and one wild (Jaculus jaculus) species. The zoonotic importance of rodents is yet to be explored. Knowing the pathogens originating from rodents is essential for early preparedness, prevention, and control. Therefore, the current study was undertaken on commensal rodents, rodentborne zoonotic pathogens, and the factors that are associated with pathogen prevalence among rodents, such as rodent sex, age, and trapping location in Qatar. A cross-sectional study was conducted between August 2019 and February 2020, which trapped rodents from different facilities, such as livestock and agricultural farms, bachelor and family accommodations, and industrial and commercial areas of Qatar. After studying the morphological and morphometric characters, blood samples, ectoparasites and visceral samples were collected from the captured rodents. Parasitic, bacterial, and viral pathogens were identified and characterized using gross, necropsy, microscopic, culture, biochemical, immunologic, and molecular methods. Descriptive statistics and univariate analysis were conducted to detect rodents, rodent-borne pathogens abundance, and the related risk factors. The study trapped 148 rodents, most of which were adults (n = 138, 93.2%, 95% CI: 87.92–96.71), and from livestock farms (n = 79, 49%, 95% CI: 41.02–57.65). R. norvregicus was the most prevalent (n = 120, 81%, 95% CI: 73.83–87.05), followed by R. rattus (n=24, 16%, 95% CI:10.68–23.16) and M. musculus (n=4, 3%, 95% CI: 0.74– 6.78) with an average body weight of 18.8 ± 2.2 gm, 264.3 ± 87.5 gm, and 130 ± 71.3 gm, respectively. This is the first morphologic and morphometric study of commensal rodents in Qatar and the Arabian Peninsula that detected the Qatari rodents are relatively smaller than those of Turkey, Tunisia, and Iran. About 63.5% of the rodents were infected with at least one of the 9 species of parasites, viz. Xenopsylla astia, Ornithonyssus bacoti, Hymenolepis diminuta, Taenia taeniaeformis, Capillaria annulosa, Strongyloides spp., Giardia spp., Toxoplasma gondii, Trypanosoma lewisi, and Leishmania spp. Helminths were the most prevalent (46.0%), followed by ectoparasites (31.8%) and protozoa (29.1%). Going by individual species prevalence, X. astia ranked the highest (31.8%), where the lowest prevalent parasite was C. annulosa (0.7%). The prevalence of H. diminuta was positively correlated (OR=4.13; p = 0.00) with the prevalence of X. astia. The study also identified thirteen bacterial species, namely Acinetobacter baumannii, Aeromonas salmonicida, Citrobacter freundii, Citrobacter koseri, Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Hafnia alvei, Klebsiella pneumoniae, Providencia stuartii, Proteus mirabilis, Pseudomonas aeruginosa, and Salmonella enterica, from the intestine samples. The majority of the bacteria were E. coli (54.63%, 95% CI: 44.76-64.24), followed by P. mirabilis (17.59%, 95% CI: 10.94-26.10), and K. pneumoniae (8.33%, 95% CI: 3.88-15.23). The study detected 31.58% (6/19, 95% CI: 12.58-56.55) of the flea pools, and one (1/1) mite pool was positive with Rickettsia spp. S. enterica showed the highest antimicrobial resistance (100% resistant to 8 antimicrobials). The top resistant antimicrobials were from cephalosporin, followed by penicillin and tetracycline groups. E. coli (26.92%, 95% CI:11.57-47.97) and K. pneumonia (50%, 95% CI: 6.76- 93.24) were ESBL (extended-spectrum beta-lactamases) producers. The studied rodents are indicators of the presence and dispersal of zoonotic pathogens in Qatar. Urgent action is needed to prevent future spillover of these pathogens at the human-animal-environment interface. It is essential to understand the biology, epidemiology, and transmission dynamics of these pathogens. Farm biosecurity and integrated pest management approach should be implemented in the farm premises. Implementing the One Health approach to combat rodent-borne zoonoses in order to reduce the risk of the future epidemic in Qatar is strongly recommended.