An overview on Sardinia's soft ticks (Ixodida: Argasidae)

Soft ticks (Acari: Argasidae) in the island nations of Southeast Asia: A review on their distribution, associated hosts and potential pathogens

Soft ticks (Acari: Argasidae) are the second major family of the blood feeding metastriates and vectors of a number of viral and bacterial pathogens for both humans and animals. Despite the growing effort on tick surveillance and studies worldwide, there is still limited information on the soft tick distribution in the island nations of Southeast Asia, especially species that are medically and veterinarily important. With the aim to provide an overview of the current status of knowledge on soft tick distribution in the island nations of Southeast Asia (Malaysia, Singapore, Brunei, Indonesia, the Philippines and Timor-Leste), this article reviews the species of soft ticks (Acari: Argasidae) and their associated hosts and pathogens, with the addition of a pictorial summary and list of tick species discovered in this region. The most prevalent soft tick genus is Carios, and the host species most associated with findings of soft ticks in this region are bats, particularly of the Pteropodidae and Vespertilionidae families. Furthermore, the only known pathogen originating from soft ticks in the island nations of Southeast Asia was the Keterah virus, which was isolated from Argas pusillus tick in Malaysia.

African Swine Fever Circulation among Free-Ranging Pigs in Sardinia: Data from the Eradication Program

African swine fever virus (ASFV), the cause of a devastating disease affecting domestic and wild pigs, has been present in Sardinia since 1978. In the framework of the regional ASF eradication plan, 4484 illegal pigs were culled between December 2017 and February 2020. The highest disease prevalence was observed in the municipality with the highest free-ranging pig density, and culling actions drastically reduced ASFV circulation among these animals. ASFV-antibody were detected in 36.7% of tested animals, which were apparently healthy, thus, the circulation of low-virulence ASFV isolates was hypothesized. ASFV genome was detected in 53 out of 2726 tested animals, and virus isolation was achieved in two distinct culling actions. Two ASFV haemadsorbing strains were isolated from antibody-positive apparently healthy pigs: 55234/18 and 103917/18. Typing analysis revealed that both isolates belong to p72 genotype I, B602L subgroup X; phylogenetic analysis based on whole genome sequencing data showed that they were closely related to Sardinian ASFV strains collected since 2010, especially 22653/Ca/2014. Our data suggested the absence of immune-escaped ASFV variants circulating among free-ranging pigs, indicating that other elements contributed to virus circulation among these animals. Understanding factors behind disease persistence in endemic settings might contribute to developing effective countermeasures against this disease.

Near-fatal anaphylaxis with Kounis syndrome caused by Argas reflexus bite: a case report

Background

The pigeon tick Argas reflexus is a temporary parasite of pigeons. It bites during night hours and lies briefly on its prey, as long as it takes the blood meal. When pigeons are not accessible, ticks look for other hosts, invading nearby flats and biting humans.

Case presentation

We present the case of a woman aged 46 years who experienced severe anaphylaxis during the night which required emergency medical treatment, tracheal intubation and hospitalization in intensive care unit. Kounis syndrome was documented by transient ST depression and elevation of troponin. The allergological work up ruled out hypersensitivity to drugs, latex and foods containing alpha-gal, which is a cause of anaphylaxis. Basal serum tryptase was in normal range (8.63 ng/ml). When questioned about the presence of ticks, the patient brought into view various specimens of ticks that were recognized by an entomologist as Argas reflexus.

Conclusions

An in vitro diagnosis of allergy to Argas reflexus is currently not feasible because, though the major allergen Arg r 1 has been isolated, allergen extracts are not commercially available. Therefore, the diagnosis of anaphylaxis from Argas reflexus, when other causes of anaphylaxis are excluded, must rely only on history and clinical findings, as well as on the presence of pigeons and/or pigeon ticks in the immediate domestic environment.

Standardized Risk Analysis Approach Aimed to Evaluate the Last African Swine Fever Eradication Program Performance, in Sardinia

From more than 40 years African swine fever (ASF) is endemic in Sardinia. Historically, areas at higher risk are located throughout some inland parts of this island where domestic pigs are still illegally kept in semi-wild conditions, living in contact with the local wild boar population, thereby creating perfect conditions for disease endemicity. A new eradication plan (EP-ASF15-18) has been ongoing for the past 3 years, based on a comprehensive strategy adapted to the local situation and focused on strong actions on domestic pig farms, wild boars (WB), and the third Sardinian typical involved population [illegal free-ranging pigs (FRPs)]. A fundamental aspect of the plan is the classification of pig farms as "controlled" or "certified," based on clinical, structural, and biosecurity characteristics. The eradication plan also provides for strong action against illegal farms and pig meat marketing channels. In addition, this plan establishes specific control measures for WB hunting and ASF checks. Each control strategy is specifically based on municipality risk level, to focus actions and resources on areas at higher risk of endemic or re-emerging ASF. Thus, precise risk classification is fundamental to this goal. The aim of the present work was to establish an ASF risk index, to provide a summary measure of the risk level in the Sardinian municipalities. This synthetic measure can express the different aspects of a multidimensional phenomenon with a single numerical value, facilitating territorial and temporal comparisons. To this end, retrospective data (years 2011-2018) were used. The ASF risk index is the result of the algorithmic combination of numerical elementary indicators: disease prevalence in the suid populations, WB compliance with EP-ASF15-18, domestic pig compliance with EP-ASF15-18, and presence of FRPs. A negative binomial regression model has been applied and predictors calculated to obtain a risk index for each municipality. The result of the risk analysis was discussed and considered according to expert opinion and consensus. The results of this study, expressed as risk score and classified into five risk levels, can be used to help define actions to be carried out in each Sardinian municipality, according to the risk assessment for the territory.