Pitfalls in Tick and Tick-Borne Pathogens Research, Some Recommendations and a Call for Data Sharing

Abstract

An understanding of the relationships of ticks and tick-borne pathogens can only be achieved by integrating data from multiple studies. The publication of raw material is a necessary step for wide-area meta-analyses and study design, data collection and reporting require harmonization. This is an opinion paper, not a consensus position, and is open to debate. This work reflects our view about how data should be communicated in mainstream journals. We indicate rules that should be observed in recording weather data, to avoid serendipitous correlations between the density of ticks and climate variables and recommend the inclusion of raw data in reports. We stress the need for standardized methods to collect ticks that cannot be obtained by standard flagging. The reporting of infection rates of pathogens in ticks should avoid conclusions based on pure molecular findings in feeding ticks. Studies demonstrating the vectorial capacity of ticks should not be supported only by molecular surveys of feeding ticks. Vacuous conclusions about vectorial or reservoir status based solely on the finding of genomic material of a pathogen should be discouraged. We stress that phylogenetic studies based on random selection of sequences from GenBank are unsuitable. We firmly support the development of a dedicated server of curated sequences of ticks and pathogens as a standard for future studies.

The bacterial biome of ticks and their wildlife hosts at the urban–wildland interface

“…Where ticks have been pooled, prevalence is reported based on minimum infection rates (i.e. assuming only one positive tick in each pool) [ 55 ].…”

Haemoprotozoan surveillance in peri-urban native and introduced wildlife from Australia

“…Confidence intervals for haemoprotozoan prevalence were calculated based on positive identification from blood samples only. This is due to the inherent difficulties in calculating prevalence based on blood-fed ticks ( Estrada-Peña et al., 2021 ). Additionally, the focus of the present study was the identification of haemoprotozoans from a wildlife host perspective.…”

The specificity of Babesia-tick vector interactions: recent advances and pitfalls in molecular and field studies

“…deer or foxes), birds or small mammals [ 23 , 25 , 26 , 29 , 31 , 158 ]. As mentioned at the beginning of this review, and also in many other reviews [ 19 ], the results of such studies can be inconclusive or misleading if no control of host infection is performed at the time of tick collection. When ticks are collected from species of rodents in which Babesia infections are common [ 114 , 159 , 160 ], these ticks, regardless of the species, may contain pathogen DNA (‘meal contamination’ [ 23 ]).…”

“…In recent years, the use of novel laboratory/molecular biology techniques allowing for the identification of genetic material of pathogens/endosymbionts in ticks collected from humans, domestic animals, wildlife, or the environment, has resulted in an enormous increase in new data on tick-microorganism interactions. This rapidly growing amount of new information for various tick-borne pathogens, including Babesia , presents challenges, including how the detection of the genetic material of pathogens in ticks should best be interpreted [ 19 ]. A review focused on the vector competence of hard ticks and Borrelia burgdorferi sensu lato spirochetes [ 20 ] underlined the pitfalls of concluding vector competence based only on the detection of pathogen DNA in ticks, i.e.…”