The pathology of co-infection with Usutu virus and Plasmodium spp. in naturally infected Eurasian blackbirds (Turdus merula)

Usutu virus (USUV) is a mosquito-borne zoonotic flavivirus causing mortality in Eurasian blackbirds ( Turdus merula) in Europe. In dead blackbirds, avian malaria co-infection due to mosquito-borne hemosporidians (e.g., Plasmodium spp.) has been reported. In humans, a similar co-infection of a flavivirus, Dengue virus, and Plasmodium spp. is causing increased severity of clinical disease. Currently, the effects of co-infection of arboviruses and hemosporidians in blackbirds remain unclear. This study investigates the rate of USUV and Plasmodium spp. co-infection in found-dead blackbirds ( n = 203) from 2016 to 2020 in the Netherlands. Presence of Plasmodium spp. was evaluated by cytology (43/203; 21,2%), histopathology (94/186; 50,5%) and qPCR (179/203; 88,1%). The severity of histological lesions in USUV and Plasmodium spp. co-infected dead blackbirds (121/203; 59,6%) were compared with those in Plasmodium spp. single-infected cases. Additionally, since no knowledge is present on the infection rate on live birds and mosquitoes in the Netherlands, a small group of live blackbirds ( n = 12) and selected in the field-collected mosquito pools ( n = 96) in 2020 were tested for the presence of Plasmodium spp. The latter was detected in the tested live blackbirds by qPCR (8/10; 80%), and cytology (3/11; 27,3%) and in the mosquito pools by qPCR (18/96; 18,7%). For this study, co-infection between USUV and Plasmodium spp. was observed only in the dead blackbirds. The high Plasmodium spp. presence, associated with lower lesions score, in single infected found dead birds suggest a predominantly smaller pathogenic role as single agent. On the other hand, the higher histological lesion scores observed in USUV and Plasmodium spp. co-infected birds suggests a major pathogenic role for the virus or an increased severity of the lesions due to a possible interplay of the two agents

Muggen en klimaataanpassingen

Vorig zomer waren er voor het eerst mensen in Nederland besmet met het Westnijlvirus, waarschijnlijk door de gewone huissteekmug. Vaak denken mensen dat wadi's een ideale broedplaats zijn voor muggen, maar dat is niet het geval. Wetenschappers brengen nu met behulp van publiek in kaar waar muggenoverlast en klimaataanpassingen samen vallen - of juist niet

Muggen en klimaataanpassingen

Vorig zomer waren er voor het eerst mensen in Nederland besmet met het Westnijlvirus, waarschijnlijk door de gewone huissteekmug. Vaak denken mensen dat wadi's een ideale broedplaats zijn voor muggen, maar dat is niet het geval. Wetenschappers brengen nu met behulp van publiek in kaar waar muggenoverlast en klimaataanpassingen samen vallen - of juist niet

Blood-feeding patterns of Culex pipiens biotype pipiens and pipiens/molestus hybrids in relation to avian community composition in urban habitats

Abstract Background Culex pipiens sensu stricto (s.s.) is considered the primary vector of Usutu virus and West Nile virus, and consists of two morphologically identical but behaviourally distinct biotypes (Cx. pipiens biotype pipiens and Cx. pipiens biotype molestus) and their hybrids. Both biotypes are expected to differ in their feeding behaviour, and pipiens/molestus hybrids are presumed to display intermediate feeding behaviour. However, the evidence for distinct feeding patterns is scarce, and to date no studies have related differences in feeding patterns to differences in host abundance. Methods Mosquitoes were collected using CO2-baited traps. We collected blood-engorged Cx. pipiens/torrentium specimens from 12 contrasting urban sites, namely six city parks and six residential areas. Blood engorged Cx. pipiens/torrentium mosquitoes were identified to the species and biotype/hybrid level via real-time polymerase chain reaction (PCR). We performed blood meal analysis via PCR and Sanger sequencing. Additionally, avian host communities were surveyed via vocal sounds and/or visual observation. Results We selected 64 blood-engorged Cx. pipiens/torrentium mosquitoes of which we successfully determined the host origin of 55 specimens. Of these, 38 belonged to biotype pipiens, 14 were pipiens/molestus hybrids and the identity of three specimens could not be determined. No blood-engorged biotype molestus or Cx. torrentium specimens were collected. We observed no differences in feeding patterns between biotype pipiens and pipiens/molestus hybrids across different habitats. Avian community composition differed between city parks and residential areas, whereas overall avian abundance did not differ between the two habitat types. Conclusions Our results show the following: (1) Cx. pipiens s.s. feeding patterns did not differ between city parks and residential areas, regardless of whether individuals were identified as biotype pipiens or pipiens/molestus hybrids. (2) We detected differences in host availability between city parks and residential areas. (3) We show that in both urban habitat types, biotype pipiens and pipiens/molestus hybrids fed on both mammalian and avian hosts. This underscores the potential role in arbovirus transmission of biotype pipiens and pipiens/molestus hybrids. Graphical Abstrac

Arbovirus persistence in North-Western Europe: Are mosquitoes the only overwintering pathway?

In some areas in temperate Europe, genomic analyses of mosquito-borne virus outbreaks have revealed the presence of similar virus strains over several years, indicating local overwintering of these viruses. However, it remains unclear how mosquito-borne viruses can persist in winter, when conditions are generally unfavourable for virus circulation. One of the presumed routes of virus persistence is via diapausing mosquitoes. Here, we set out to study whether arbovirus persistence of West Nile virus (WNV), Usutu virus (USUV) and Sindbis virus (SINV) occurs in diapausing mosquitoes in the Netherlands. To this end, mosquito collections were carried out in the winter of 2020 and 2021, in hibernacula located in two areas with previously observed WNV and/or USUV activity. In total, we collected 4200 mosquitoes belonging to four species (Culex pipiens, Culiseta annulata, Anopheles maculipennis s.l., and Culex territans), which were pooled in 490 monospecific pools. These pools were subjected to WNV-, USUV- and SINV-screening using a multiplex real-time RT-PCR assay. All mosquito pools tested negative for the presence of WNV, USUV and SINV RNA. Consequently, we did not find evidence of arbovirus persistence in diapausing mosquitoes in the Netherlands, even though USUV and WNV have re-appeared in birds and/or mosquitoes during the summer seasons of 2020–2022. Concluding, given the persistence of USUV and WNV in the Netherlands and SINV in other temperate regions, this study highlights the importance of further research on (alternative) arbovirus overwintering routes

Anopheles maculipennis complex in The Netherlands : first record of Anopheles daciae (Diptera: Culicidae)

Despite their past importance as vectors of indigenous malaria, the species composition and spatial distribution of the members of the Anopheles maculipennis complex have been studied to a limited extent in the Netherlands. Therefore, this investigation focuses on the distribution of the members of this complex in the Netherlands, including Anopheles daciae, which has recently been found in countries bordering the Netherlands. In the framework of a national mosquito surveillance between 2010 and 2021, a total of 541 specimens of An. maculipennis s.l. were analyzed from 161 locations covering the entire territory. In addition, 89 specimens were analyzed from overwintering sites during the winter of 2020/2021. All individual mosquitoes were identified to species-level using Sanger sequencing of the ribosomal internal transcribed spacer 2. To characterize the habitat of An. maculipennis s.l. in the Netherlands, land cover use data was extracted in a 1 km buffer area around each finding location. For populations collected in summers between 2010 and 2021, the most frequent species was An. messeae, present in 88.19% of the locations, followed by An. maculipennis s.s. (11.80%), An. atroparvus (3.72%) and An. daciae (3.72%). Anopheles daciae was found in the southern inland areas of the country. Furthermore, An. messeae and An. daciae occurred in sympatry at overwintering sites. This study provides relevant information on the occurrence of species of the Anopheles maculipennis complex in the Netherlands, contributing to a better estimation of the risk of mosquito-borne disease in the country

The pathology of co-infection with Usutu virus and Plasmodium spp. in naturally infected Eurasian blackbirds (Turdus merula)

Usutu virus (USUV) is a mosquito-borne zoonotic flavivirus causing mortality in Eurasian blackbirds (Turdus merula) in Europe. In dead blackbirds, avian malaria co-infection due to mosquito-borne hemosporidians (e.g., Plasmodium spp.) has been reported. In humans, a similar co-infection of a flavivirus, Dengue virus, and Plasmodium spp. is causing increased severity of clinical disease. Currently, the effects of co-infection of arboviruses and hemosporidians in blackbirds remain unclear. This study investigates the rate of USUV and Plasmodium spp. co-infection in found-dead blackbirds (n = 203) from 2016 to 2020 in the Netherlands. Presence of Plasmodium spp. was evaluated by cytology (43/203; 21,2%), histopathology (94/186; 50,5%) and qPCR (179/203; 88,1%). The severity of histological lesions in USUV and Plasmodium spp. co-infected dead blackbirds (121/203; 59,6%) were compared with those in Plasmodium spp. single-infected cases. Additionally, since no knowledge is present on the infection rate on live birds and mosquitoes in the Netherlands, a small group of live blackbirds (n = 12) and selected in the field-collected mosquito pools (n = 96) in 2020 were tested for the presence of Plasmodium spp. The latter was detected in the tested live blackbirds by qPCR (8/10; 80%), and cytology (3/11; 27,3%) and in the mosquito pools by qPCR (18/96; 18,7%). For this study, co-infection between USUV and Plasmodium spp. was observed only in the dead blackbirds. The high Plasmodium spp. presence, associated with lower lesions score, in single infected found dead birds suggest a predominantly smaller pathogenic role as single agent. On the other hand, the higher histological lesion scores observed in USUV and Plasmodium spp. co-infected birds suggests a major pathogenic role for the virus or an increased severity of the lesions due to a possible interplay of the two agents

World Heart Federation Cholesterol Roadmap.

BACKGROUND: The World Heart Federation has undertaken an initiative to develop a series of Roadmaps. OBJECTIVES: The aim of these is to promote development of national policies and health systems approaches and identify potential roadblocks on the road to effective prevention, detection and management of cardiovascular disease (CVD) in low-and middle-income countries (LMIC), and strategies for overcoming these. This Roadmap focuses on elevated blood cholesterol, a leading risk factor for myocardial infarction, stroke, and peripheral arterial disease. METHODS: Through a review of published guidelines and research papers, and consultation with a committee composed of experts in clinical management of cholesterol and health systems research in LMIC, this Roadmap identifies (1) key interventions for primordial, primary and secondary prevention of CVD through detection, treatment, and management of elevated cholesterol and familial hypercholesterolemia (FH); (2) gaps in implementation of these interventions (knowledge-practice gaps); (3) health system roadblocks to treatment of elevated cholesterol in LMIC; and (4) potential strategies for overcoming these. RESULTS: Despite strong evidence of the importance of cholesterol levels in primary or secondary prevention of CVD, and the effectiveness of statin therapy for cholesterol lowering and reduction of CVD risk, gaps exist in the detection, treatment, and management of high cholesterol globally. Some potential roadblocks include poor access to laboratory facilities or trained professionals for cholesterol management, low awareness of FH among the general population and health professionals, unaffordability of statins for patient households, and low awareness of the importance of persistent adherence to lipid-lowering medication. Potential solutions include point-of-care testing, provision of free or subsidized lipid-lowering medication, and treatment adherence support using text message reminders. CONCLUSIONS: Known effective strategies for detection, treatment, and management of elevated cholesterol and FH exist, but there are barriers to their implementation in many low-resource settings. Priorities for health system intervention should be identified at the national level, and the feasibility and effectiveness of proposed solutions should be assessed in specific contexts. Many solutions proposed in this Roadmap may apply to other cardiovascular conditions and present opportunities for integration of CVD care in LMIC

Detection of west nile virus in a common whitethroat (curruca communis) and culex mosquitoes in the Netherlands, 2020

On 22 August, a common whitethroat in the Netherlands tested positive for West Nile virus lineage 2. The same bird had tested negative in spring. Subsequent testing of Culex mosquitoes collected in August and early September in the same location generated two of 44 positive mosquito pools, providing first evidence for enzootic transmission in the Netherlands. Sequences generated from the positive mosquito pools clustered with sequences that originate from Germany, Austria and the Czech Republic

Detection of West Nile virus in a common whitethroat (Curruca communis) and Culex mosquitoes in the Netherlands, 2020

On 22 August, a common whitethroat in the Netherlands tested positive for West Nile virus lineage 2. The same bird had tested negative in spring. Subsequent testing of Culex mosquitoes collected in August and early September in the same location generated two of 44 positive mosquito pools, providing first evidence for enzootic transmission in the Netherlands. Sequences generated from the positive mosquito pools clustered with sequences that originate from Germany, Austria and the Czech Republic. © 2020 European Centre for Disease Prevention and Control (ECDC). All rights reserved