Ticks are obligate hematophagous ectoparasites that transmit a wide variety of pathogens to humans and animals. The incidence of tick-borne diseases has increased worldwide in both humans and domestic animals over the past years. In recent years, studies have shown that targeting tick proteins by vaccination can not only reduce blood feeding and reproduction of tick, but also the infection and transmission of pathogens from the tick to the vertebrate host. In this article, I review physiological features of tick blood feeding and the tick-protective antigens that have been identified for the formulation of anti-tick vaccines.

Japan experienced an autochthonous dengue fever epidemic in 2014. It was the first episode of local transmission of dengue fever in about 70 years. The number of inbound tourists to Japan is increasing year by year; in 2018, the number exceeded 30 million, which was more than twice the number in 2014. Accordingly, the risk of arboviral pathogens, such as dengue, chikungunya, and zika, invading Japan is increasing. As Tokyo will host the 2020 Olympic and Paralympic games, we need to prepare for the increased potential for local transmission of mosquito-borne diseases. To this end, we demonstrated a drill for controlling the mosquito vector of dengue fever at Shinjuku Gyoen National Garden in September 2019. In this article series, the emergency drill is outlined.

In preparation for the 2020 Olympic and Paralympic Games in Tokyo, a training drill for controlling dengue mosquito vector was held at Shinjuku Gyoen National Garden in September 2019. The training drill aimed to confirm the network and cooperation among related organizations when pathogenic arboviruses are detected in mosquito vectors. This training was also expected to be applied in case that local transmission of dengue was confirmed. These organizations included garden management office; municipal health centers; pest control organization; insecticide suppliers; Ministry of Health, Labor and Welfare; Ministry of the Environment; and National Institute of Infectious Diseases. On the training day, >160 participants gathered for confirmation of the evacuation process and demonstration of dengue mosquito vector control with insecticides. This article outlines the training procedure that can be used as a reference point for future training drills conducted at related organizations as well as in case that we face to actual epidemics.

Mosquito density was investigated at Shinjuku Gyoen National Garden as part of an emergency drill for controlling the mosquito vector of dengue fever in preparation for the 2020 Olympic and Paralympic games in Tokyo. The average mosquito density at 57 collection sites was 6.9 individuals/site. Aedes albopictus was predominant and accounted for 76.6% of the total number of mosquitoes collected. In insecticide-treated sites, 18 sites were selectively investigated for mosquito density, and 74 mosquitoes were collected before insecticide treatment. After insecticide treatment, no mosquitoes were found at any collection site. Basic data, such as mosquito species, distribution, and density, collected by monitoring mosquitoes from 2015 to 2019 at the garden were very useful in designing this investigation.

To prepare for an epidemic of mosquito-borne diseases including dengue, chikungunya and Zika, we demonstrated a training of insecticide spray to eliminate Aedes albopictus at Shinjuku Gyoen National Garden. Three insecticide-spraying methods were used and treatment efficacy of each method was evaluated; 302.5 m²/min (carbon dioxide formulation), 69.4 m²/min (ultra low volume, ULV), and 71.2 m²/min (power spray). It was shown that it is important to select the most appropriate insecticide application method and formulation depending on the size of the field, available number of workers, and the weather conditions.

In 2014, an outbreak of dengue fever occurred in the Tokyo metropolis for the first time in approximately 70 years. Since then, more than 200 imported dengue cases have been reported each year, in parallel with an upsurge in the number of overseas visitors into Japan. Therefore, the risk of an outbreak of dengue fever remains unchanged. On September 2, 2019, a drill for an Aedes-borne virus outbreak was conducted in the Shinjuku Gyoen National Garden. In the drill, mosquitoes were collected in the Garden and examined for the presence of Aedes-borne viruses. However, no viruses including dengue virus were detected in the mosquitoes. This review presents the results of the virus detection drill and discusses the possibility of establishment of persistent DENV transmission cycles in Japan from the aspect of the viral ecology.

A new species of black fly, Simulium dadagaunense, is described based on a female reared from a pupa from Nepal. This species is assigned to the Simulium (Simulium) striatum species-group, and is characterized in the female by the relatively narrow frons, weakly developed fronto-ocular area, and cibarium with four tiny processes. In addition, S. grisescens Brunetti originally described from India is newly recorded from Nepal.

From 2013 to 2014, ixodid ticks (Acari: Ixodidae) were collected by flagging at seven sites of two areas, Noto and Kaga, in Ishikawa Prefecture, Honshu, Japan. As a result of the survey, the following four ixodid species were collected: Haemaphysalis flava, Haemaphysalis longicornis, Ixodes ovatus, and Ixodes turdus. This is the first record of I. turdus from Ishikawa Prefecture. Haemaphysalis flava was the dominant species in Noto area. On the other hand, Haemaphysalis longicornis was predominant in Kaga area.

We detected a zoonotic parasite, the rat lungworm Angiostrongylus spp. in Norway rats Rattus norvegicus that were collected in February each year from 2015 to 2020 outside buildings in a 21-hectare business district in Yokohama. The infection rate of the parasite in rats that were two months old or older jumped from 4.9% in 2015 to 28.6% in 2017 when flowerpots were set along the roadside, but it decreased to nearly 7% in 2018 and 2019 and to 0% in 2020 when those flowerpots were removed. It is likely that the rate increased because the flowerpots supplied intermediate hosts of the lungworm, i.e., slugs and snails with habitats.