| an epidemiologic and serologic study of arboviruses in lake rudolf basin. | an epidemiologic and serologic study of arboviruses was done in 1972 in the basin of lake rudolf. the main object of this study was to demarcate the southern limit of the yellow fever epidemic which occurred from 1959 to 1962 in southern sudan and ethiopia. other purposes were to contribute to the inventory of arboviruses and their distribution in this region. the ethnic groups were studied: the nyangatom and the dassanetch in ethiopia and the turkana in northern kenya. the results of tests on s ... | 1975 | 242102 |
| sindbis and west nile virus infections in the witwatersrand-pretoria region. | from mid-december 1983 until mid-april 1984, there was an epidemic of sindbis (sin) virus infection in the witwatersrand-pretoria region in which hundreds of human cases were diagnosed clinically. twenty-eight of these diagnoses were confirmed in the laboratory by seroconversion as being infections with sin virus, and 5 cases of infection with west nile (wn) virus were also found. attempts to isolate virus from 66 patients, mainly from serum specimens, were unsuccessful. infection rates for the ... | 1986 | 3016922 |
| first field evidence for natural vertical transmission of west nile virus in culex univittatus complex mosquitoes from rift valley province, kenya. | west nile virus is a mosquito borne flavivirus endemic over a large geographic area including africa, asia, and the middle east. although the virus generally causes a mild, self-limiting febrile illness in humans, it has sporadically caused central nervous system infections during epidemics. an isolate of west nile virus was obtained from a pool of four male culex univittatus complex mosquitoes while we were conducting an investigation of rift valley fever along the kenya-uganda border in februa ... | 2000 | 10813479 |
| the ecology of west nile virus in south africa and the occurrence of outbreaks in humans. | this paper reviews studies done on west nile virus (wnv) in south africa, mainly between 1962 and 1980 on the temperate inland plateau (highveld and karoo). the virus is maintained in an enzootic transmission cycle between feral birds and the ornithophilic mosquito culex univittatus. about 30 avian species have been shown to be involved without mortality. humans, and other mammals, although they may have antibodies, are considered blind-alleys in the transmission cycle except perhaps some dogs. ... | 2001 | 11797772 |
| west nile virus in southern portugal, 2004. | west nile virus (wnv) genomic rna was detected by reverse transcription-polymerase chain reaction (rt-pcr) in six out of 57 mosquito pools collected in southern portugal, during the summer of 2004, yielding an infection rate (ir) of 2.8/1,000 mosquitoes. phylogenetic analysis of a 217-nucleotide fragment of the ns5 coding region, amplified from culex pipiens s.l. and culex univittatus unfed females, demonstrated a close relationship with wnv strains circulating in the mediterranean basin (italy, ... | 2005 | 16417437 |
| mosquito surveys and west nile virus screening in two different areas of southern portugal, 2004-2007. | longitudinal mosquito surveys were carried out in southern portugal from 2004 to 2007, in a wetland area (comporta, district of setúbal) and around the perimeter of a dam irrigation plant that created the largest artificial lake in europe, 250 km(2) (alqueva, districts of evora and beja). our aim was to study the diversity, abundance, and seasonal dynamics of mosquitoes, comparing these two different areas, to screen mosquitoes for west nile virus (wnv), an arboviral agent already detected in po ... | 2010 | 20854020 |
| environmental temperature on the vector competence of culex univittatus (diptera: culicidae) for west nile virus. | the effects of the extrinsic incubation temperature on the vector competence of culex univittatus theobald for west nile (wn) virus were studied. a mean titer of 7.0 log10 cpd50/ml of mosquito suspension was reached in orally infected mosquitoes after 11, 15, and 16 d of incubation at 26 and 30 degrees c and at fluctuating temperatures in an outside cage (mean temperature, 23.5 degrees c), respectively. in contrast, 22 and 58 d were required to reach the same titers at 18 and 14 degrees c, respe ... | 1993 | 8459423 |
| ability of selected kenyan mosquito (diptera: culicidae) species to transmit west nile virus under laboratory conditions. | west nile virus (wnv) is currently active in kenya as evidenced by the detection of antibodies in birds bled as part of an avian influenza surveillance program in 2009. although wnv has been isolated from several mosquito species in kenya, no studies have ever been conducted to determine which of these species are competent vectors of this virus. therefore, we allowed kenyan mosquitoes to feed on 2- or 3-d-old chickens that had been infected with a lineage one strain of wnv 24-48 h earlier. thes ... | 2011 | 22238879 |
| species composition and wnv screening of mosquitoes from lagoons in a wetland area of the algarve, portugal. | the aim of this study was to evaluate mosquito abundance, species diversity, larval and adult population dynamics in seven lagoons integrated in the wetland coastal system of the algarve, portugal, in the summer of 2007, as well as the screening of these for west nile virus (wnv). wnv has been isolated from mosquitoes in this region, in the summer of 2004, next to the putative area of infection of two linked human wn cases. adult mosquitoes were collected with cdc traps baited with co(2), and po ... | 2011 | 22347862 |
| [updated inventory of mosquitoes (diptera: culicidae) of the island of la réunion, indian ocean]. | a literature analysis coupled with new entomological surveys conducted between 2009 and 2012 led to changes in the list of mosquito species present on the island of la réunion. using morphological criteria, orthopodomyia arboricollis is replaced by or. reunionensis. on the basis of morphometrical and genetic criteria, culex univittatus is replaced by cx. neavei. cx. poicilipes, which was already reported missing 40 years ago, has not been found again. anopheles arabiensis is confirmed as the onl ... | 2013 | 23681758 |
| laboratory studies on the transmission of west nile virus by culex (culex) univittatus theobald; factors influencing the transmission rate. | | 1974 | 4423657 |
| climatic controls on west nile virus and sindbis virus transmission and outbreaks in south africa. | abstract the processes influencing the magnitude of west nile virus (wnv) transmission from 1 year to the next require thorough investigation. the intensity of wnv transmission is related to the dynamics and interactions between the pathogen, vector, vertebrate hosts, and environment. climatic variability is one process that can influence interannual disease transmission. south africa has a long wnv and sindbis virus (sinv) record where consistent climate and disease relationships can be ident ... | 2011 | 21995260 |
| comparative morphological and molecular analysis confirms the presence of the west nile virus mosquito vector, culex univittatus, in the iberian peninsula. | culex univittatus and culex perexiguus mosquitoes (diptera: culicidae) are competent arbovirus vectors, but with unclear morphological differentiation. in europe, and in the iberian peninsula in particular, the presence of either or both species is controversial. however, in order to conduct adequate surveillance for arboviruses in this region, it is crucial to clarify whether cx. univittatus is present or not, as well as to critically assess existing differentiation tools. this study aimed to c ... | 2016 | 27884174 |