Ticks and tick-borne pathogens pose a great threat to human and animal health. The present study aimed to determine the prevalence of ticks that infest camels and investigate the presence of tick-borne pathogens in the blood of camels, associated ticks, and surrounding rodents as reservoirs. From 100 inspected camels, from different localities in the Giza governorate, 1000 ixodid ticks were collected; these ticks belonged to three genera: Hyalomma, Amblyomma, and Rhipicephalus. The genus Hyalomma was represented by four species, Hyalomma dromedarii was the most prevalent species (55.4%), followed by Hyalomma excavatum (22%), Hyalomma impeltatum (11.6%) and Hyalomma rufipes (2.8%). The genus Amblyomma was represented by two species, Amblyomma gemma (2.8%) and Amblyomma marmoreum (2.7%), while the genus Rhipicephalus was represented by only one species, Rhipicephalus pulchellus (2.7%). Ticks, camel blood, and rodents (total number 100 brown rats) are screened for tick-borne pathogens (Borrelia burgdorferi, Borrelia miyamotoi, Babesia sp., and Coxiella burnetii) using PCR. Camel blood was found to be infected with Borrelia burgdorferi (66.6%), Borrelia miyamotoi (55%), and Babesia sp. (11.6%). Coxiella burnetii DNA was detected in all the collected ticks but was not detected in the blood of camels or rodents. Borrelia miyamotoi was detected in 12.5% of H. impeltatum, 55% of Camels, and 6% of the rodents, which may indicate a proposed risk of dispersal of B. miyamotoi, the agent of tick-borne relapsing fever.

The avian tick Argas (Persicargas) arboreus is a vector of pathogens infecting the nestlings of the agriculturally beneficial bird, the buff-backed heron in Egypt. The topical treatment of the fed-mated (engorged) female A. (P.) arboreus with a sublethal dose of abamectin (10 µl 10 ppm/female) on the 3rd day after feeding (daf), reduced the concentration of total protein in the haemolymph (HL) by 13–66%, in the ovary by 30–54%, and in freshly deposited eggs by 11–16%, compared to untreated females during vitellogenesis and oviposition. However, the treatment did not prevent vitellogenesis and oviposition but reduced the number of mature oocytes (stages III–V) and deposited eggs. Additionally, it delayed the onset and slowed the progress of each process in the treated females. The application of abamectin at the onset of vitellogenesis (on the 3rd daf) in normal female and the prominent decrease inHL total protein concentration in treated female on the 4th daf pointed to a probable interference of abamectin with the release of the vitellogenesis-inducing factor (VIF) and/or other subsequent hormone(s) known to regulate vitellogenesis in this argasid tick species. Graphical abstract

Ticks are vectors of several disease agents affecting human and animal health. The ability of ticks to acquire, maintain, and transmit disease agents are factor determining the competence of ticks as vectors of etiologic agents. The present study investigates the ability of five ixodid tick species, Hyalomma dromedarii, H. excavatum, H. impeltatum, H. analoticum and Rhipicephalus annulatus to acquire, transstadially and transovarially maintain and transmit Borrelia sp. isolated from their population in nature to a laboratory animal. Although the five ixodids successfully acquired the borrelial infection by feeding on infected New Zealand rabbits, only four of the ixodids showed the ability to transstadially transfer Borrelia from the Larval-nymphal stage to the adult male, and female. Also, only R. annulatus, H. dromedarii, H. impeltatum succeed in transovarially transferring Borrelia from adult females to their progeny. Rhipicephalus annulatus was the most efficient species in acquiring borrelial infection in the laboratory (69.17%) and in transstadially transferring their natural Borrelia sp. from the infected nymphs to the emerged adult males and females with infection rates of 60 and 80%, respectively All infected females R. annulatus transovarially transmitted their natural Borrelia species to the highest percentage of the unfed larval progeny in each of F1 and F2. This was followed by H. dromedarii and H. impeltatum with 54.58% and 39.17% acquisition infection rates, and transstadially transfer Borrelia to males and females (50, 70%, and 30, 50%), respectively. Infected females of both species transmit Borrelia to the F1 and F2 (100,90%), respectively. No transovarial transmission was observed in H. impeltatum and H. analoticum. In each tick species, the transmission of Borrelia to uninfected rabbits increased by increasing the number of feeding infected stages per rabbit. Generally, female ticks were more efficient than males and adults than immatures in transmitting borrelial infection.