Journal Article

Prevalence of pathogens in ticks collected from humans through citizen science in Belgium

Tersago, Katrien, Suin, Vanessa, Fonville, Manoj, De Regge, Nick, Lernout, Tinne, Sprong, Hein

2019

Overview

Background In order to evaluate the risk of human exposure to tick-borne pathogens in Belgium, a study on the prevalence of several pathogens was conducted on feeding ticks removed from humans in 2017. Methods Using a citizen science approach based on an existing notification tool for tick bites, a sample of ticks was collected across the country. Collected ticks were screened by PCR for the presence of the following pathogens: Anaplasma phagocytophilum , Babesia spp., Borrelia burgdorferi ( sensu lato ), Borrelia miyamotoi , Neoehrlichia mikurensis , Rickettsia helvetica and tick-borne encephalitis virus (TBEV). Results In total, 1599 ticks were included in the sample. The great majority of ticks belonged to Ixodes ricinus (99%); other tick species were identified as Ixodes hexagonus (0.7%) and Dermacentor reticulatus (0.3%). Borrelia burgdorferi ( s.l. ) was detected in 14% of nymphs and adult ticks. Adult ticks (20%) were more likely to be infected than nymphs (12%). The most common genospecies were B. afzelii (52%) and B. garinii (21%). Except for TBEV, the other tick-borne pathogens studied were all detected in the tick sample, although at a lower prevalence: 1.5% for Babesia spp.; 1.8% for A. phagocytophilum ; 2.4% for B. miyamotoi ; 2.8% for N. mikurensis ; and 6.8% for R. helvetica . Rickettsia raoultii , the causative agent of tick-borne lymphadenopathy, was identified for the first time in Belgium, in two out of five D. reticulatus ticks. Co-infections were found in 3.9% of the examined ticks. The most common co-infection was B. burgdorferi ( s.l .) +  N. mikurensis. Conclusions Although for most of the tick-borne diseases in Belgium, other than Lyme borreliosis, no or few cases of human infection are reported, the pathogens causing these diseases were all (except for TBEV) detected in the tick study sample. Their confirmed presence can help raise awareness among citizens and health professionals in Belgium on possible diseases other than Lyme borreliosis in patients presenting fever or other non-characteristic symptoms after a tick bite.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: adults / Anaplasma phagocytophilum / Animals / Arachnid Vectors - microbiology / Arachnid Vectors - virology / Arachnids / Babesia / Bacteria - classification / Bacteria - genetics / Bacteria - isolation & purification / Belgium / Biomedical and Life Sciences / Biomedicine / Bites (Injuries) / Borrelia burgdorferi / Borrelia infections / Borrelia miyamotoi / Borreliosis / Citizen Science / Deoxyribonucleic acid / Dermacentor - microbiology / Dermacentor - virology / Dermacentor reticulatus / Disease / Diseases / DNA / Encephalitis / Encephalitis Viruses, Tick-Borne - genetics / Encephalitis Viruses, Tick-Borne - isolation & purification / Entomology / etiological agents / Fever / Health aspects / human diseases / Humans / Identification / Illnesses / Infections / Infectious Diseases / Insect bites / Ixodes - microbiology / Ixodes - virology / Ixodes hexagonus / Ixodes ricinus / Lyme borreliosis / Lyme disease / Lymphadenopathy / Lymphatic diseases / Medical personnel / mixed infection / Nucleotide sequence / Nymphs / Parasitic diseases / Parasitology / Pathogenic microorganisms / Pathogens / PCR / Polymerase Chain Reaction / Prevalence / Questionnaires / Rickettsia helvetica / risk assessment / Signs and symptoms / Skin / Symptoms / Tick-borne diseases / Tick-borne encephalitis / Tick-borne encephalitis virus / Tick-borne pathogens / Ticks / Tropical Medicine / Veterinary Medicine/Veterinary Science / Virology / Viruses / Websites