[Discovery of Culex inatomii (Diptera : Culicidae) in Chongming, Shanghai].

Objective: To record the discovery of Culex inatomii in Chongming, Shanghai. Methods: Larvae and adult mosquitos of Cx. inatomii were collected in Dongtan of Chongming Island from May to November in 2015 and 2016, and their morphological characteristics were observed. The genomic DNA was extracted from adult mosquitos, PCR was performed to amplify the cytochrome c oxidaseⅠ(COⅠ) gene. Multiple alignment of COⅠ sequence was conducted with ClustalW2. Pairwise distances within and between species were calculated using MEGA v5.10 based on COⅠ sequences of Cx. inatomii, Cx. modestus, Cx. pipiens pallens, and Cx. tritaeniorhynchus. The phylogenetic tree of the above four species was constructed using neighbor joining, maximum likelihood, and Bayesian methods. Results: One hundred and fifty-six adult female mosquitos and 36 larvae of Cx. inatomii were collected. Larvae were reared to adult stage in the laboratory (17 female, 19 male). Morphologically, the subapical lobe of the sidepiece in male genitalia was divided into two parts, the anterior part having 2 bladed setae, and the posterior part having 1 bladed setae and 1 lanceolar strong setae. This strucutre can be used to distinguish Cx. inatomii from Cx. modestus. PCR of COⅠ resulted in products of approximately 650 bp. They were sequenced and the sequencing result was submitted to GenBank (accession number, KX555565-KX555570). Multiple sequence alignment revealed a 96% sequence similarity of COⅠ between Cx. inatomii and Cx. modestus. The genetic distance between Cx. inatomii and Cx. modestus was 0.047, and that within them each was 0.003 and 0.011, respectively. The phylogenetic tree showed that the four species clustered as a monophyletic clade, and each formed an individual lineage. Cx. inatomii had a closer relationship with Cx. modestus, while distant from the other two species. Conclusion: We recorded the discovery of Cx. inatomii in Chongming, Shanghai.

[Identification of three common sandfies in southern Xinjiang with multiplex PCR].

Based on the variable part of mtDNA CO I gene sequence, a multiplex PCR method was developed for the identification of the three common sandflies (Phlebotomus longiductus, Ph. wui, and Ph. alexandri) in southern Xinjiang. The results demonstrated that this multiplex PCR method was reliable, and could be used to identify the three Phlebotomus species. The PCR product of CO I gene from Ph. longiductus, Ph. wui and Ph. alexandri was 248, 632, and 395 bp, respectively.

China's application of the One Health approach in addressing public health threats at the human-animal-environment interface: Advances and challenges.

Background: Due to emerging issues such as global climate change and zoonotic disease pandemics, the One Health approach has gained more attention since the turn of the 21st century. Although One Health thinking has deep roots and early applications in Chinese history, significant gaps exist in China's real-world implementation at the complex interface of the human-animal-environment. Methods: We abstracted the data from the global One Health index study and analysed China's performance in selected fields based on Structure-Process-Outcome model. By comparing China to the Belt & Road and G20 countries, the advances and gaps in China's One Health performance were determined and analysed. Findings: For the selected scientific fields, China generally performs better in ensuring food security and controlling antimicrobial resistance and worse in addressing climate change. Based on the SPO model, the "structure" indicators have the highest proportion (80.00%) of high ranking and the "outcome" indicators have the highest proportion (20.00%) of low ranking. When compared with Belt and Road countries, China scores above the median in almost all indicators (16 out of 18) under the selected scientific fields. When compared with G20 countries, China ranks highest in food security (scores 72.56 and ranks 6th), and lowest in climate change (48.74, 11th). Conclusion: Our results indicate that while China has made significant efforts to enhance the application of the One Health approach in national policies, it still faces challenges in translating policies into practical measures. It is recommended that a holistic One Health action framework be established for China in accordance with diverse social and cultural contexts, with a particular emphasis on overcoming data barriers and mobilizing stakeholders both domestically and globally. Implementation mechanisms, with clarified stakeholder responsibilities and incentives, should be improved along with top-level design.

Contributions of the National Institute of Parasitic Diseases to the control of visceral leishmaniasis in China.

Visceral leishmaniasis (VL) caused by Leishmania spp. is an important vector-borne disease prevalent in China. VL was rampant in the vast area of China north of the Yangtze River before the founding of the People's Republic of China in 1949. As a result of strenuous interventions, the disease was basically eliminated in most of the former epidemic areas in 1958-60. At present, only sporadic cases occur in the western regions of China. In the process, National Institute of Parasitic Diseases at China CDC and the Chinese Center for Tropical Diseases Research (NIPD-CTDR) have achieved great impact in controlling the diseases as well as in research on Leishmania spp. This review summarized the contribution of experts from NIPD-CTDR to the control and elimination of VL in various aspects, such as understanding the epidemiological features of VL, confirmation of VL vectors and their distribution, development of control tools including diagnostics and insecticides, monitoring and evaluation supported by information management, technical supports to the control programmes, as well as analysis of the challenges faced. At the same time, it puts forward constructive suggestions for the ultimate interruption of VL transmission in China.

New strains of Japanese encephalitis virus circulating in Shanghai, China after a ten-year hiatus in local mosquito surveillance.

BACKGROUND: Continuous vector pathogen surveillance is essential for preventing outbreaks of mosquito-borne diseases. Several mosquito species acting as vectors of Japanese encephalitis virus (JEV), dengue virus, Zika virus, malaria parasites and other pathogens are primary mosquito species in Shanghai, China. However, few surveys of human pathogenic arboviruses in mosquitoes in Shanghai have been reported in the last ten years. Therefore, in this study, we evaluated mosquito activity in Shanghai, China during 2016 and tested for the presence of alphaviruses, flaviviruses, orthobunyaviruses and several parasitic pathogens. RESULTS: Five pooled samples were JEV-positive [4/255 pools of Culex tritaeniorhynchus and 1/256 pools of Cx. pipiens (s.l.)] based on analysis of the NS5 gene. Alphaviruses, orthobunyaviruses, Plasmodium and filariasis were not found in this study. Phylogenetic and molecular analyses revealed that the JEV strains belonged to genotype I. Moreover, newly detected Shanghai JEV strains were genetically close to previously isolated Shandong strains responsible for transmission during the 2013 Japanese encephalitis (JE) outbreak in Shandong Province, China but were more distantly related to other Shanghai strains detected in the early 2000s. The E proteins of the newly detected Shanghai JEV strains differed from that in the live attenuated vaccine SA14-14-2-derived strain at six amino residues: E130 (Ile→Val), E222 (Ala→Ser), E327 (Ser→Thr), E366 (Arg→Ser/Pro), E393 (Asn→Ser) and E433 (Val→Ile). However, no differences were observed in key amino acid sites related to antigenicity. Minimum JEV infection rates were 1.01 and 0.65 per 1000 Cx. tritaeniorhynchus and Cx. pipiens (s.l.), respectively. CONCLUSIONS: Five new Shanghai JEV genotype I strains, detected after a ten-year hiatus in local mosquito surveillance, were genetically close to strains involved in the 2013 Shandong JE outbreak. Because JEV is still circulating, vaccination in children should be extensively and continuously promoted. Moreover, JEV mosquito surveillance programmes should document the genotype variation, intensity and distribution of circulating viruses for use in the development and implementation of disease prevention and control strategies.

Application of community-based and integrated strategy to reduce malaria disease burden in southern Tanzania: the study protocol of China-UK-Tanzania pilot project on malaria control.

BACKGROUND: During the past six decades, remarkable success on malaria control has been made in China. The major experience could be shared with other malaria endemic countries including Tanzania with high malaria burden. Especially, China's 1-3-7 model for malaria elimination is one of the most important refined experiences from many years' efforts and key innovation measures for malaria elimination in China. METHODS: The China-UK-Tanzania pilot project on malaria control was implemented from April, 2015 to June, 2018, which was an operational research with two communities receiving the proposed interventions and two comparable communities serving as control sites. The World Health Organization "Test, Treat, Track" (WHO-T3) Initiative, which calls for every suspected case to receive a diagnostic test, every confirmed case to be treated, and for the disease to be tracked, was integrated with Chinese experiences on malaria control and elimination for exploration of a proper model tailored to the local settings. Application of China's 1-3-7 model integrating with WHO-T3 initiative and local resources aiming at reducing the burden of malaria in terms of morbidity and mortality by 30% in the intervention communities in comparison with that at the baseline survey. DISCUSSION: The China-UK-Tanzania pilot project on malaria control was that at China's first pilot project on malaria control in Africa, exploring the feasibility of Chinese experiences by China-Africa collaboration, which is expected that the strategies and approaches used in this project could be potential for scaling up in Tanzania and African countries, and contribute to the acceleration of malaria control and elimination in Africa.

Co-circulation of Aedes flavivirus, Culex flavivirus, and Quang Binh virus in Shanghai, China.

BACKGROUND: With increases in global travel and trade, the spread of arboviruses is undoubtedly alarming. Pathogen detection in field-caught mosquitoes can provide the earliest possible warning of transmission. Insect-specific flavivirus (ISFV) has been first detected in 1991 and documented worldwide in the latest ten years. Although infection with ISFVs is apparently limited to insects, an increase in the infection rate of mosquito-borne flaviviruses may be able to induce cytopathic effects in vertebrate cells during co-infection with other human pathogens. However, little is known whether ISFVs persist in most regions of China. METHODS: During the mosquito activity season in 2016, a surveillance program was carried out to detect ISFVs in mosquitoes in metropolitan Shanghai, China. The presence of ISFVs was randomly tested in different species of mosquitoes using RT-PCR-based and hemi-nested PCR assays, following by the sequencing of PCR products. Sequences from positive pooled samples were compared with those deposited in GenBank. Thereafter, sequences of representative insect flaviviruses were used for further phylogenetic and molecular evolutionary analyses. RESULTS: Our investigations showed: (1) the presence of Aedes flavivirus (AEFV) in 11/161 pooled samples (nine pools in Songjiang District, one pool in Huangpu District, and one pool in Qingpu District) of Aedes albopictus, (2) the presence of Quang Binh virus (QBV) in 10/195 pooled samples (all in Chongming District) of Culex tritaeniorhynchus; and (3) the presence of Culex flavivirus (CxFV) in 9/228 pooled samples (six pools in Pudong New Area, two pools in Huangpu District, and one pool in Chongming District) of Cx. pipiens. Furthermore, phylogenetic analyses of the gene sequences of envelope proteins indicated that Shanghai CxFV strains belonged to the Asia/USA genotype. The overall maximum likelihood estimation values (and 95% confidence interval) for CxFV, QBV, and AEFV in mosquitoes collected in Shanghai in 2016 were 1.34 (0.66-2.45), 1.65 (0.87-2.85), and 1.51 (0.77-2.70) per 1000, respectively. CONCLUSIONS: This study reveals the presence and the geographical distribution of ISFVs, and determines the genetic variation and the infection rate of ISFVs in Shanghai, China. At least, three insect flaviviruses including ISFVs, AEFV, CxFV, and QBV, co-circulate in this area. To our knowledge, this is the first report of AEFV in China.

Monitoring of malaria vectors at the China-Myanmar border while approaching malaria elimination.

BACKGROUND: Tengchong County was one of the counties located at the China-Myanmar border with high malaria incidence in the previous decades. As the pilot county for malaria elimination at the border area, Tengchong County is aiming to be the first county to achieve malaria elimination goal. A cross-sectional entomological survey was carried out to evaluate the feasibility of elimination approach and assess the receptivity of malaria reintroduction. METHODS: Light traps associated with live baits were used to investigate the abundance of adult mosquitoes in nine villages in Tengchong County. Light traps were set to collect adult mosquitoes in both human houses and cowsheds from dusk till dawn in each site. RESULTS: A total of 4948 adult Anopheles mosquitoes were collected from May to December in two villages. Of the mosquitoes were captured, 24.2% were in human houses and 75.8% in cowsheds. The peak of abundance occurred in July for An. sinensis and in September-October for An. minimus (s.l.) Ten Anopheles species were collected, the most prevalent being An. sinensis (50.3%), An. peditaeniatus (31.6%) and An. minimus (s.l.) (15.8%), contributing to 97.6% of the sample. Potential breeding sites were also investigated and a total of 407 larvae were collected, with An. sinensis (50.1%) and An. minimus (s.l.) (46.2%) as predominant species. Ponds and rice fields were the two preferred breeding sites for Anopheles mosquitoes; however, the difference between the number of adults and larvae captured suggest other breeding sites might exist. Both An. sinensis and An. minimus (s.l.) were found zoophilic with human blood index as 0.21 and 0.26, respectively. No Plasmodium positive Anopheles specimens were found by PCR among 4,000 trapped mosquitoes. CONCLUSIONS: Although no indigenous malaria cases have been reported in Tengchong County since 2013, there is still a risk from the presence of vectors in the context of human population movements from neighboring malaria endemic areas. The presence of An. sinensis, associated to rice fields, is particularly worrying. Sustained entomological surveillance is strongly suggested even after malaria elimination certification.

First records of Triatoma rubrofasciata (De Geer, 1773) (Hemiptera, Reduviidae) in Foshan, Guangdong Province, Southern China.

BACKGROUND: Triatomines, also known as kissing bugs, which are found throughout the world and especially in Latin America, are well known natural vectors that transmit American trypanosomiasis, also called Chagas disease. In China, the presence of two species of Triatoma (Triatoma rubrofasciata and T. sinica) was recorded in the past. Due to the growing population and the increasing risk of the global spread of Chagas disease, triatomines became a potential public health nuisance, and in 2016, we started monitoring triatomine activities in southern China. METHODS: Triatomine specimens were collected by the National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, and identified by their morphological characteristics under a dissecting microscope. In addition to morphological analysis, the genomic DNA of the specimens was extracted, and the mitochondrial 16S rRNA, the cytochrome b (CytB) gene and the nuclear ribosomal 28S rRNA gene were PCR-amplified to analyze and confirm the species genetically. RESULTS: One female adult insect and one male adult insect were collected in a dwelling in the rural area of Shunde County, Foshan City, Guangdong Province, China (22°42'44.63″N, 113°08'45.34″E). The results from the morphological and genetic analyses indicated that these triatomines were T. rubrofasciata. CONCLUSIONS: This is the first time that the occurrence of T. rubrofasciata has been confirmed in Foshan City, Guangdong Province in southern China. Further studies are needed to reach a clearer understanding of the ecology of this species of triatomine, since it has been found to be naturally infected by Trypanosoma cruzi and T. conorhini and there is evidence of its domiciliation capabilities.

Phlebotomine sand flies (Diptera: Psychodidae) transmitting visceral leishmaniasis and their geographical distribution in China: a review.

After the existence of phlebotomine sand flies was first reported in China in 1910, the distribution of different species and their role in the transmission of visceral leishmaniasis (VL) have been extensively studied. Up until 2008, four species have been verified as vectors of VL, namely, Phlebotomus chinensis (Ph. sichuanensis), Ph. longiductus (Ph. chinensis longiductus), Ph. wui (Ph. major wui), and Ph. alexandri. The sand fly species vary greatly depending on the natural environments in the different geographic areas where they are endemic. Ph. chinensis is euryecious and adaptable to different ecologies, and is thus distributed widely in the plain, mountainous, and Loess Plateau regions north of the Yangtze River. Ph. longiductus is mainly distributed in ancient oasis areas south of Mt. Tianshan in the Xinjiang Uygur autonomous region. Ph. wui is the predominant species in deserts with Populus diversifolia and Tamarix vegetation in Xinjiang and the western part of the Inner Mongolia autonomous region. Finally, Ph. alexandri is steroecious and found only in stony desert areas, such as at the foot of the mountains in Xinjiang and the western Hexi Corridor, in Gansu province. This review summarized the relationship between the geographic distribution pattern of the four sand fly species and their geographical landscape in order to foster research on disease distribution and sand fly control planning. Furthermore, some problems that remained to be solved about vectors of VL in China were discussed.

[Comparative analysis of mitochondrial genomes of Angiostrongylus cantonensis].

OBJECTIVE: To compare the diversity of mitochondrial genomes of Angiostrongylus cantonensis in the mainland of China. METHODS: According to the population genetic of A. cantonensis, seven female worms were selected to characterize the mitochondrial (MT) genomes. Twelve primer pairs based on known MT genome (GQ398121) were used for PCR. The target fragments were sequenced and aligned. The gene localization, genome structure, composition of nucleotide, distribution of variable sites, and phylogeny were analyzed by employing multiple softwares. RESULTS: Five distinct types were identified from seven complete MT genomes. They were similar in size and structure, i.e., ranging 13,491-13,502 bp, including 12 protein-coding genes, 2 ribosomal genes, 22 tRNA genes, and 2 major non-coding regions. All the genes were localized at the same strand and had the same transcription direction. A total of 745 variable sites were identified, accounting for 5.5%. Among the variable sites, 59 were deletion/insert mutations, 105 transversions, and 581 transitions. The variable sites distributed evenly at the complete genome. CONCLUSION: The study reveals the mutation profile in the whole MT genome of A. cantonensis and thus will facilitate the development of intraspecific differential diagnosis.

[Relationship between proximal-tip location and partial necrosis in distally based sural neuro fasciocutaneous flap: an analysis of 157 flaps].

OBJECTIVE: To explore the influence of proximal-tip location on partial necrosis in distally based sural neuro fasciocutaneous flap. METHODS: From April 2001 to May 2009,157 distally based sural neuro fasciocutaneous flaps were conducted to repair the soft tissue defect in distal region of lower leg, ankle and feet in 153 patients. Date of the flaps and the patients were retrospectively analyzed. From the tip of lateral malleolus to the popliteal crease, posterior aspect of the lower leg was equally divided into 9 regions that were 1st to 9th region from inferiorly to superiorly, respectively. The flaps were divided into 2 groups: survival group (including uneventfully survived flaps, flaps with distally epidermal necrosis and with wound dehiscence) and partial necrosis group. Based on the location of the proximal tip of flaps, the flaps were stratified into 4 groups: flaps with the proximal tip locating in the 6th or lower region (group A), the 7th region (group B), the 8th region (group C) and the 9th region (group D). Harvesting the flaps started from exploring the perforator of peroneal vessel in the adipofascial pedicle, then the flaps were elevated retrogradely. RESULTS: Of the 157 flaps, 125 survived uneventfully,8 showed distal epidermal necrosis,wound dehiscence occurred in 6 flaps, 18 flaps (11.5%) showed distal partial necrosis. Partial necrosis occurred in zero of 19 flaps in group A (0), 1 of 44 flaps in group B (2.3% ), 7 of 62 flaps in group C (11.3% ) and 10 of 32 flaps in group D (31.3% ). The differences in partial necrosis rate between group A and group B , group B and group C, were not statistically significant (P > 0.05). Partial necrosis rate was higher in group D than in group C (P = 0.012), it was lower in group A + group B (1.6%) than in group C + group D (18. 1% ) (P = 0. 001). CONCLUSIONS: Distally based sural neuro fasciocutaneous flap can survive reliably when the proximal tip of flap is not beyond the junction between lower 7/9 and upper 2/9 of the lower leg, whereas probability of partial necrosis occurring in the flap increase significantly when the proximal tip of flap locates in upper 1/9 of the lower leg.