Living with the longhorned: A perspective on invasive Haemaphysalis longicornis ticks in the United States

Data release: targeted systematic literature search for tick and tick-borne pathogen distributions in six countries in sub-Saharan Africa from 1901 to 2020

BACKGROUND

Surveillance data documenting tick and tick-borne disease (TBD) prevalence is needed to develop risk assessments and implement control strategies. Despite extensive research in Africa, there is no standardized, comprehensive review.

METHODS

Here we tackle this knowledge gap, by producing a comprehensive review of research articles on ticks and TBD between 1901 and 2020 in Chad, Djibouti, Ethiopia, Kenya, Tanzania, and Uganda. Over 8356 English language articles were recovered. Our search strategy included 19 related MeSH terms. Articles were reviewed, and 331 met inclusion criteria. Articles containing mappable data were compiled into a standardized data schema, georeferenced, and uploaded to VectorMap.

RESULTS

Tick and pathogen matrixes were created, providing information on vector distributions and tick-pathogen associations within the six selected African countries.

CONCLUSIONS

These results provide a digital, mappable database of current and historical tick and TBD distributions across six countries in Africa, which can inform specific risk modeling, determine surveillance gaps, and guide future surveillance priorities.

Sustained efficacy of collars containing 10% w/w imidacloprid and 4.5% w/w flumethrin (Seresto®) in dogs against laboratory challenge with Haemaphysalis longicornis (Neumann, 1901) ticks

Background

Haemaphysalis longicornis ticks are reported on dogs from an increasing geographic range. This study aimed to determine the sustained efficacy of Seresto^® collars (imidacloprid/flumethrin) against experimental infestations of H. longicornis in dogs.

Methods

Twenty-four Beagle dogs previously assessed for their suitability to harbor ticks were included in the study and randomized into three groups of eight dogs each. Two of the groups were treated with collars at different time points: at the first tick infestation, dogs in group 1 had already worn collars for 92 days, while dogs in group 2 had received collars only on the previous day, thus allowing evaluation of two different treatment durations at the same point in time. Infestation of the treated groups was conducted at 1, 7, 28, and 56 days (group 2) and 92, 119, 147, 168, 196, 227, and 238 days (group 1) after collar placement. Group 3 served as untreated control and was infested whenever the dogs of the other two groups were infested. Infestations were conducted using 50 viable, adult, unfed female ticks of a US isolate of H. longicornis per dog. Ticks were removed and counted 48 h after each infestation. Health and body weight of the dogs were monitored throughout the study. The efficacy against ticks was calculated for groups 1 and 2 based on arithmetic mean values at each assessment day according to Abbott’s formula. The mean post-treatment H. longicornis tick counts were compared statistically between treatments, using an analysis of variance with a treatment effect untransformed tick count.

Results

Dogs in the control group were adequately infested at all tick counts. Efficacy was 88.2% on day 3, however well above 90% (i.e., 98.3 to 100%) at all other time points up to day 240. Statistical analysis confirmed significantly different live tick counts (P < 0.001) between the treated groups and the control group at all time points.

Conclusions

The 8-month sustained acaricidal efficacy demonstrated by the Seresto^® collar (imidacloprid/flumethrin) provides a reliable strategy against H. longicornis infestations in dogs.

Graphical Abstract