St. Louis Encephalitis
Sunit K. Singh, Daniel Růžek in Neuroviral Infections, 2013
In the eastern and western regions of the US, SLEV transmission networks are separated by epidemiological differences based on the virus transmission’s ecological determinants (Reisen 2003). In the eastern states, main vectors belong to the Culex pipiens complex (Culex pipiens pipiens and Culex pipiens quinquefasciatus) and its main hosts are house sparrows (Passer domesticus). These peridomestic mosquitoes vectors develop frequently in rich organic material water such as sewers and peridomestic water reservoirs. These mosquitoes are spread in urban and suburban ambient densely populated, especially where sanitary conditions are deficient. In the western regions of the USA, the main vector mosquito is Culex tarsalis. This specie reproduces in flooded and irrigated soils, and in industrial or urban residual water (Mitchell 1980). Humans are frequently exposed in rural areas, often determined by recreational and working activities. Periurban and wild birds act as hosts, mainly those abundant in agricultural areas close to water sources such as house sparrows (Passer domesticus) and house finches (Carpodacus mexicanus) (McLean and Bowen 1980).
Engineering control of insect-borne diseases
Sandy Cairncross, Richard Feachem in Environmental Health Engineering in the Tropics, 2018
There are two main kinds of mosquito-borne filariasis. The first, Bancroftian filariasis due to Wuchereria bancrofti causes 90% of all cases of infection and occurs widely in the tropics (Figure 15.5). In certain areas, particularly in the towns and cities of Asia, Egypt and coastal Brazil, it is transmitted by the night-feeding Culex pipiens mosquitoes. Culex pipiens is a group or ‘complex’ of closely related mosquitoes (Curtis and Feachem 1981), which vary in such physiological characteristics as ability to hibernate or lay their first batch of eggs without taking a blood meal. The member of the Culex pipiens complex most widespread as a vector of Bancroftian filariasis is Culex quinquefasciatus which is the principal vector in the coastal cities of Brazil and of East Africa, and through much of urban Asia. However, in China and Japan the vector is C. pipiens pallens, while in Egypt it is C. pipiens molestus. Bancroftian filariasis is also transmitted by other mosquitoes (Figure 15.5). In much of Africa it is transmitted by the same Anopheles species that transmit malaria. In Polynesia, it is transmitted by day-feeding Aedes species and is one of the major disease problems of the area.
Water-related insect vectors of disease *
Jamie Bartram, Rachel Baum, Peter A. Coclanis, David M. Gute, David Kay, Stéphanie McFadyen, Katherine Pond, William Robertson, Michael J. Rouse in Routledge Handbook of Water and Health, 2015
RVF outbreaks have occurred in several sub-Saharan African countries as well as in the Arabian Peninsula, and many other countries in Africa that have been spared a significant outbreak have reported isolated cases or serological evidence of presence of the virus. RVF remains endemic in southern and eastern Africa, largely because the vectors are capable of transovarial (parent-to-offspring) transmission of the virus. Virus is passed into the eggs of Aedes mosquitoes, as shown by the detection of virus in adult male and female Aedes lineatopennis reared in the lab from field-collected specimens in Kenya (Linthicum et al., 1985). Other Aedes mosquitoes have this capability as well; therefore where Aedes is the dominant vector, epidemics occur following rainfall-induced increases in mosquito abundance. However, some vectors of the virus, such as Culex mosquitoes that act as primary vectors in Egypt and Arabia, are not capable of transovarial transmission. Hence, the occurrence of an epidemic in those areas requires reintroduction of the virus through transport of infected animals or wind-borne transport of mosquitoes (Gerdes, 2004).
Impact of gamma irradiation on the development and reproduction of Culex pipiens (Diptera; Culicidae)
Published in International Journal of Radiation Biology, 2018
Mosquitoes play a serious role as vectors of numerous vertebrate blood pathogens. Culex pipiens Linnaeus (L) is a very common mosquito species in Egypt (Hassan et al. 2003; El-Kholy et al. 2018) studied its possible role in Hepatitis C virus transmission. It is the overwhelming vector of Wuchereria bancrofti that causes filariasis in humans (Abdel-Hamid et al. 2013), Rift Valley fever virus (El-Bahnasawy et al. 2013a) and West Nile virus (El-Bahnasawy et al. 2013b). Contemporary control methods, which largely rely on chemical insecticides, are not always effective due to the prevalent resistance of the mosquitoes to these insecticides. In addition, chemical insecticides have adverse effects on the environment, health and food chain through biomagnification of chemicals to the levels that exceed normal (Kumar et al. 2013).
Entomological factors in relation to the occurrence of Japanese encephalitis in Malkangiri district, Odisha State, India
Published in Pathogens and Global Health, 2019
Sonia Thankachy, Smrutidhara Dash, Sudhansu Sekhar Sahu
A total of 3,085 adult mosquitoes were collected, belonging to 24 species of two genera; Culex (8 species) and Anopheles (16 species), out of which 2132 (69.1%) were Culex mosquitoes and 953 (30.9%) were Anopheles mosquitoes. Among Culex species, Cx. vishnui (42.1%) was predominant followed by Cx. whitmorei (19.0%), Cx. fuscocephalus (15.0%), Cx. tritaeniorhynchus (12.2%), Cx. bitaeniorhynchus (6.7%), Cx. quinquefasciatus (2.5%) and Cx. gelidus (2.4%). There was only one Cx. fuscitarsis collected during the study period. Out of the 16 Anopheles species, An. nigerrimus (48.3%) was predominant followed by An. vagus (13.3%), An. subpictus (11.8%), An. barbirostris (10.9%), An. pallidus (5.5%), An. culicifacies (3.6%), An. splendidus (2.2%), An. annularis (1.9%), An. jeyporiensis (0.8%), An. jamesii (0.6%), An. maculatus (0.4%), An. ramsayi (0.2%), An. varuna (0.2%), An. tessellatus (0.1%), An. theobaldi (0.1%) and An. aconitus (0.1%).
Current development of Zika virus vaccines with special emphasis on virus-like particle technology
Published in Expert Review of Vaccines, 2021
Velasco Cimica, Jose M Galarza, Sujatha Rashid, Timothy T. Stedman
An indirect immunization approach against ZIKV and other arboviruses such as DENV, YFV, and CHIKV is represented by the AGS-v (NIAID) (Table 1), a subunit peptide vaccine (NIAID) that targets the mosquito salivary proteins [126]. This novel approach resulted from the observation that co-deposition of mosquito saliva with an arbovirus allows the pathogen to enter the host and replicate more efficiently. Mouse studies revealed that intradermal inoculation of West Nile virus (WNV) with Culex tarsalis saliva resulted in higher viral loads and faster onset of neuro-invasive disease compared to mice who were inoculated intradermally with the virus alone [127]. AGS-v was administered by prime-boost immunization in healthy adults with and without an adjuvant during a phase I clinical trial. The results of the trial demonstrated that the vaccine was relatively safe in all immunization groups, and it was immunogenic only when formulated with an adjuvant (Montanide ISA 51) [128]. The AGS-v immunization strategy, however, has some caveats. There is a lack of evidence that mosquito salivary proteins are involved in arbovirus infection in humans, and the approach lacks protection for non-mosquito routes of Zika transmission such as sexual, intrauterine, or blood transfusion.
Related Knowledge Centers
- Arbovirus
- Avian Malaria
- Metamorphosis
- West Nile Virus
- Mosquito
- Disease Vector
- Japanese Encephalitis
- Saint Louis Encephalitis
- Filariasis
- Zika Virus