Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ARBOVIRUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1993

[Surveillance of the circulation of arbovirus of medical interest in the region of eastern Senegal].

A study about the circulation of arboviruses of medical interest in southeastern Senegal was conducted from 1988 to 1991, during and around the periods of transmission. Specific IgM antibodies were detected by ELISA test in human sera, as a sign of a recent infection within 2 to 5 months. The comparison of the serological IgM results from human surveys in different villages, and the isolations of arboviruses from mosquitoes during the same period of time permitted a rapid and global evaluation of the circulation of these viruses. A low level of yellow fever virus activity was detected both in humans and mosquitoes in 1988 to 1990. A dengue 2 epizootic occurred in 1989-1990. Dengue 2 virus was isolated from humans and mosquitoes in 1990. Some dengue 2 outbreak may occur in the upcoming years. A Zika virus epizootic outbreak was observed each year. A human strain was isolated in 1990. The other flaviviruses (West-Nile, Kedougou, Wesselsbron), Chikungunya virus, Rift Valley Fever virus and Crimean-Congo Hemorrhagic Fever virus did not seem to present a major public health concern in southeastern Senegal.

Animals↗
PubMedDate not supplied

[Arbovirus circulation in the Republic of Guinea].

In 1978-1991 the USSR-Guinea Virological and Microbiological Laboratory functioned in Kindia, the Republic of Guinea. Arbovirus activity in this country was studied by a number of virologists and other specialists. Their personal contribution and achievements in this collaboration are reflected in the present paper. About 74,000 mosquitoes, 100,000 Ixodidae ticks, 1,500 wild birds, 2,700 bats, 106 monkeys, and 308 other mammals, 927 blood samples collected from febrile patients were examined in 1978-1989, using inoculation of new-born white mice. As a result of this work 127 strains of the following arboviruses were isolated: Chikungunia (1 strain), Dengue 2 (4), Saboya (7), Wesselsbron (1), Bunyamwera (4), M'Poko (5), Rift Valley Fever (6), CHF-Congo (9), Dugbe (22), Bhanja (6), Forecariah (2), Jos (26), Abadina (15), Kindia (2), Ark 6956 (1), Fomede (2), Bluetongue (9), Mossuril (2), AnK 6009 (1), and Kolente (2). Dengue 2, Wesselsbron, Bunyamwera, M'Poko, Kindia, Mossuril viruses were isolated from mosquitoes. Ixodidae ticks were sources for isolation of Chikungunia, Saboya, CCHF, Dugbe, Bhanja, Forecaciah, Jos, Abadina, Kindia, Ark 6956, Fomede, Bluetongue, and Kolente viruses. Saboya, RVF, Fomede, Kolente, AnK 6909 were isolated from bats (Chiroptera); Saboya, Abadina, and Bluetongue viruses from birds. One strain of Dugbe virus was originated from the brain of Cercopithecus patas. Bunyamwera and Abadina viruses were isolated from the blood of two febrile patients. Serological identification of many strains was kindly conducted at the Pasteur Institute, Dakar (J. P.Digoutte) and some at the YARU, USA (R. Shope). Kindia and Ark 6956 (Reovirus, gr. Palyam), Fomede (gr. Chobar Gorge), Forecariah (Bunyavirus, gr. Bhanja), Kolente (Rhabdovirus) were identified as an original type of Lagos bat virus. The results of seroepidemiological surveys are also presented.

Animals↗
PubMed1977

Epidemiological investigations on arbovirus infections at Igbo-Ora, Nigeria.

A study of arbovirus infections occurring in Igbo-Ora community was carried out between May and October 1975. Haemagglutination inhibition test performed on seventy-eight human sera showed a high prevalence of antibodies against all the six arboviruses used. Percentage of positive sera were as follows: Chikungunya, (28%); Yellow fever (36%); Dengue type 1 (67%); Dengue type 2 (45%). Prevalence of HI antibodies to West Nile and Wesselsbron viruses were 44% and 59% respectively. Virus isolation studies carried out on 148 blood samples yielded three viruses: Yellow fever, Dengue type 1 and Zika. Antibody conversions to these three viruses were demonstrated in seven persons within the period of study.

Adolescent↗
PubMed1976

Infection rate of arboviruses in Dutch recruits returning from Surinam.

Paired serum samples from approximately 650 Dutch recruits residing temporarily in Surinam, the first sample being collected on arrival, the second when leaving the country, were examined for haemagglutination-inhibiting antibodies to two types of arbovirus (Mucambo and Restan) isolated from local mosquitoes, and to two types of arbovirus (Oriboca and Caraparu) isolated from human blood. In a group of inidviduals in whom mild febrile illness had been reported, antibodies had developed in 3.9 to 6.7%, and in a group without reported history of febrile illness in 3.0 to 47% for each of the viruses.

Animals↗
PubMed1979

Evaluation of Aedes albopictus tissue culture for use in association with arbovirus isolation.

The susceptibility and sensitivity of Aedes albopictus cell cultures to five different primary and four different low-passage arboviruses were tested. Yellow fever, West Nile, Ilesha, eastern equine encephalitis, and Flanders viruses replicated in A albopictus tissue cultures. Replication was determined by the ability of selected tissue culture fluids to infect suckling mice, and by recovery from tissue culture fluid of progressively increasing amounts of complement-fixing (CF) antigen with time. Virus persistence was demonstrated with Nodamura, western equine encephalitis, and Mayaro viruses, but multiplication was not proven; neither persistence nor multiplication was demonstrated with a Kemerovo group virus. When yellow fever and Ilesha viruses were simultaneously inoculated into A albopictus culture, CF antigen for each was consistently detected. In a more detailed comparative study of field specimens, 12 unpassaged strains of yellow fever virus were tested for infectivity in A albopictus tissue culture, Vero cells, and baby mice. Higher titers of virus were detected (0.8--2.3 log ID50 per ml) in Vero cell culture than in A albopictus tissue culture or baby mouse systems. These results suggest the feasibility of using A albopictus cells in association with the primary isolation of arboviruses.

Aedes↗
PubMed1976

Arbovirus infections in Sarawak: the role of the domestic pig.

The possible role of pigs as arbovirus maintenance hosts and their importance as amplifier hosts was studied. Blood samples from 464 pigs of all ages collected in 1962 and 1964 were tested against 10 arboviruses. Antibodies to Japanese encephalitis and Getah viruses were particularly prevalent and their calculated monthly infection rates were 19-5% and 13-3% respectively. In 1969, 447 pigs were bled monthly throughout the year and the infection rates for Japanese encephalitis virus were calculated in pigs during the first year of life. Infection rates were not uniform throughout the year; the rate increases as the pig grew older and there was a marked seasonal increase in the infection rate in the period from November to January. This coincided with the seasonal major population peak of Culex tritaeniorhynchus following intense breeding of this mosquito prior to rice planting. It is suggested that, in Sarawak, the pig acts as a maintenance host of Japanese encephalitis in a cycle involving C. gelidus mosquitoes and also acts as an important amplifier host towards the end of the year in a cycle involving C. tritaeniorhynchus. It is further suggested that Getah virus is maintained in a similar cycle between C. tritaeniorhynchus and pigs.

Age Factors↗
PubMed1984

A simplified new method for the identification of arboviruses: virus detection using enzyme immunoassay on cultured cells.

A simple new method is reported for the identification of arbovirus isolates and the titration of arboviruses. Horseradish peroxidase conjugated Staphylococcus aureus protein A was used for the indirect staining of virus antigens grown in an Aedes albopictus cell line, C6/36 cells. Thirty-five isolates from Culex tritaeniorhynchus mosquitoes were examined by this method and 20 of these were identified as Japanese encephalitis virus (JEV). These results were confirmed by immunofluorescent assay and plaque neutralization test. Comparative titration of JEV, Murray Valley encephalitis (MVE) and Kunjin viruses showed that this method was as sensitive as the chick embryo plaque assay. Specific enzymatic reactions on these virus-infected cells began to appear before day 3 and reached the end-point on day 5 post-infection of C6/36 cells, whereas the cytopathic effect (CPE) appeared about 2 days later than the positive enzymatic reactions. Fixation with 10% formalin for 0.5-8 h did not damage the positive reaction in infected cells and did not increase the background colour of uninfected cells.

Animals↗
PubMed1970

The platelet aggregation test in group B arbovirus infections.

A new serological method, the platelet aggregation (PA) test, was used to study Group B arbovirus infections, which are often associated with thrombocytopenia. The method is based on the interaction of antigen-antibody complexes with platelets. The PA test was nearly as good as the haemagglutination-inhibition (HI) test for epidemiological studies of tick-borne encephalitis (16 out of 18 HI positive sera) and was superior to the complement-fixation test which was positive in 10 out of 18 HI positive sera. The PA test could be used in the serological diagnosis of Group B arbovirus infection. The titres with the PA test were of the same magnitude as the HI titres, and about ten times higher than the CF titres. Two pairs of dengue haemorrhagic fever sera showed high initial PA titres. The role of immune complexes in the pathogenesis of haemorrhagic fevers is discussed.

Antigen-Antibody Reactions↗
PubMed1981

A preliminary investigation of the ecology of arboviruses in the Derby area of the Kimberley region, Western Australia.

A survey of mosquito populations in the Derby area of the Kimberley region, Western Australia, in March/April of 1977 yielded a total of 3,318 adult female mosquitoes. Fifteen taxa were represented, seven being new locality records for this area. Culex annulirostris was the dominant species, comprising 85.41% of the total catch. All mosquitoes collected were processed for virus isolation and thirteen strains of four (and possibly five) distinct arboviruses were obtained, all from pools of Culex annulirostris. These viruses include Murray Valley encephalitis, Ross River, Wongal, an untyped non-haemagglutinating member of the Koongol group and a virus which reacts to polyvalent antisera against the Anopheles A and B groups. With the exception of Ross River, all these viruses had been previously isolated from the Ord River Valley, some 500 km to the north-east. Comparison of virus isolations in the Ord Valley and Derby supports the suggestion that both sites share a common viral flora. Both also display an exceedingly high overall isolation rate (approximately 20% for Cx. annulirostris pools). Such comparisons suggest that a number of arboviruses transmitted by Cx. annulirostris are active throughout the Kimberley region and have peak isolation rates at the end of the wet season. Further studies are needed to fully define these viral cycles.

Animals↗
PubMed1975

Sensitivities of neurotropic arboviruses to human interferon.

The sensitivities of selected neurotropic arboviruses (St. Louis encephalitis, Western equine encephaltis, and La Crosse viruses) to human interferon and polyriboinosinic-polyribocytidylic acid (poly I-poly C) were determined in primary human fetal glial cell cultures. The sensitivities were measured by an end point (inhibition of virus yield). All of the viruses were sensitive to human interferon and poly I-poly C; St. Louis encephalitis and Western equine encephalitis viruses were inhibited at concentrations of interferon actually measured in the brains of persons who died from these infections. For St. Louis encephalitis and Western equine encephalitis viruses, viral replication and induction of interferon varied among cell cultures derived from individual fetuses. The present experiments may provide an approach toward understanding the problem of different host susceptibilities to neurotropic arbovirus infections.

Arboviruses↗
PubMed1990

Isolation of arboviruses from Culicoides midges (Diptera: Ceratopogonidae) in Colorado during an epizootic of vesicular stomatitis New Jersey.

An arbovirus survey was conducted in Colorado and Utah during an epizootic of vesicular stomatitis New Jersey (VSNJ) that occurred in the western United States in 1982-1983. From 120,422 insect specimens assayed, 106 viruses were isolated. Four were rhabdoviruses (VSNJ), three were orbiviruses (bluetongue serotype-11), 92 were Bunyamwera group (65 Main Drain and 27 Lokern), and seven were Simbu group (Buttonwillow) bunyaviruses. Culicoides spp. accounted for 105 viral isolates (C. (Selfia) spp., C. variipennis (Coquillett), C. stellifer (Coquillett), and C. cockerellii (Coquillett], and one was from Simulium bivittatum Malloch. C. (Selfia) spp. accounted for 59% of all pooled specimens and was the source of 89.6% (95) of the isolates. Insects from two sites accounted for 44% (52,802) of all pooled specimens and 67% (71) of the viral isolates. The isolations of VSNJ, Main Drain, Lokern, and Buttonwillow viruses from C. (Selfia) spp. are the first arbovirus isolations reported for this subgenus; this is the first time these viruses have been isolated from Culicoides species other than C. variipennis.

Animals↗
PubMed1990

Effects of house sparrow age and arbovirus infection on attraction of mosquitoes.

To test the hypothesis that arbovirus infection or advancing age increases the attractiveness of avian hosts to vector mosquitoes, we used an olfactometer that measures the response of mosquitoes to the passive, vertical diffusion of host-related cues. St. Louis encephalitis or western equine encephalomyelitis virus infection in house sparrows (Passer domesticus (L.], regardless of age, had no detectable effect on Culex quinquefasciatus Say or Cx. tarsalis Coquillett attraction, respectively, at close range. Sparrow age, however, was associated positively with increased Cx. quinquefasciatus attraction; i.e., nestlings were significantly less attractive than adults, and there was a trend for increased mosquito attraction as nestling age increased. When birds were examined in groups, attraction was not equal to the sum of the individual birds in the group. Nestlings, either alone or in a group, were less attractive than a single adult. One adult plus three older nestlings were more attractive than one adult with three young nestlings, but no more attractive than one adult alone. We speculate on the epidemiological significance of these laboratory results to arbovirus epizootic transmission.

Age Factors↗
PubMed2001

Arbovirus infection increases with group size.

Buggy Creek (BCR) virus is an arthropod-borne alphavirus that is naturally transmitted to its vertebrate host the cliff swallow (Petrochelidon pyrrhonota) by an invertebrate vector, namely the cimicid swallow bug (Oeciacus vicarius). We examined how the prevalence of the virus varied with the group size of both its vector and host. The study was conducted in southwestern Nebraska where cliff swallows breed in colonies ranging from one to 3700 nests and the bug populations at a site vary directly with the cliff swallow colony size. The percentage of cliff swallow nests containing bugs infected with BCR virus increased significantly with colony size at a site in the current year and at the site in the previous year. This result could not be explained by differences in the bug sampling methods, date of sampling, sample size of the bugs, age structure of the bugs or the presence of an alternate host, the house sparrow (Passer domesticus). Colony sites that were reused by cliff swallows showed a positive autocorrelation in the percentage of nests with infected bugs between year t and year t+1, but the spatial autocorrelation broke down for year t+2. The increased prevalence of BCR virus at larger cliff swallow colonies probably reflects the larger bug populations there, which are less likely to decline in size and lead to virus extinction. To the authors' knowledge this is the first demonstration of arbovirus infection increasing with group size and one of the few known predictive ecological relationships between an arbovirus and its vectors/hosts. The results have implications for both understanding the fitness consequences of coloniality for cliff swallows and understanding the temporal and spatial variation in arboviral epidemics.

Age Factors↗
PubMed1976

Comparative studies of some African arboviruses in cell culture and in mice.

Twenty African arboviruses, five alphaviruses, nine flaviviruses, three Bunyamwera Group viruses, two Bwamba Group viruses and one ungrouped virus were titrated in parallel in 11 cell systems in suckling mice and adult mice. The relative sensitivities of the in vitro and in vivo systems have been compared. The highest infectivities were obtained in suckling mice. Vero and LLC-MK2 cells produced plaques with the greatest number of viruses and Semliki Forest virus grew most readily. Ntaya virus and Dengue 1 virus were difficult to culture in vitro and Zika virus yielded better in cell culture than in adult or suckling mice. In vitro and in vivo neutralization tests were made on human sera in groups of 50. Each group of sera was tested against one of five viruses, representative of three of the arbovirus groups titrated. Good agreement was obtained between the two test systems with West Nile, O'nyong-nyong and Wesselsbron viruses but there were significant differences in results obtained with Germiston and Pongola viruses.

Africa↗
PubMed2005

Mosquito vectors of the 1998-1999 outbreak of Rift Valley Fever and other arboviruses (Bagaza, Sanar, Wesselsbron and West Nile) in Mauritania and Senegal.

Following an outbreak of Rift Valley fever (RVF) in south-eastern Mauritania during 1998, entomological investigations were conducted for 2 years in the affected parts of Senegal and Mauritania, spanning the Sénégal River basin. A total of 92 787 mosquitoes (Diptera: Culicidae), belonging to 10 genera and 41 species, were captured in light traps. In Senegal, Culex poicilipes (41%) and Mansonia uniformis (39%) were the most abundant species caught, whereas Aedes vexans (77%) and Cx. poicilipes (15%) predominated in Mauritania. RVF virus was isolated from 63 pools of Cx. poicilipes: 36 from Senegal in 1998 and 27 from Mauritania in 1999. These results are the first field evidence of Cx. poicilipes naturally infected with RVFV, and the first isolations of this virus from mosquitoes in Mauritania - the main West African epidemic and epizootic area. Additional arbovirus isolates comprised 25 strains of Bagaza (BAG) from Aedes fowleri, Culex neavei and Cx. poicilipes; 67 Sanar (ArD 66707) from Cx. poicilipes; 51 Wesselsbron (WSL) from Ae. vexans and 30 strains of West Nile (WN) from Ma. uniformis, showing differential specific virus-vector associations in the circulation activity of these five arboviruses.

Animals↗
PubMed1975

The protective role of thymus-derived lymphocytes in arbovirus-induced meningoencephalitis.

The inflammatory response in mouse brain and the elimination of virus from the brain following intracerebral inoculation of a group A arbovirus has been shown to be T-cell dependent. Virus persists in the brain of T-cell depleted mice, and inflammation is depressed. Virus persists in the brain of T-cell depleted mice, and inflammation is depressed. Inflammation is restored by transfer of immune cells but not by immune serum, and the transferred cells are effective in reducing virus titres in the absence of circulating antibody. Transferred antibody is not efficient in protecting infected mice. The cells that restore inflammation can come from mice immunized with a group A arbovirus of the same subtype but not from mice immunized with more distantly related viruses. Macrophages may be important effector cells working in collaboration with T cells.

Animals↗
PubMed1975

Cellular resistance to arbovirus infection.

When an arbovirus enters an arthropod in an infected blood meal, several mechanisms may interact to affect its life cycle and ultimate transmissibility. Intrinsic absolute failure in the establishment of infection must be contrasted with infection that is successfully established but is variably modulated in its viral yield throughout the vector's life-span. Degrees of vertebrate host resistance make this modulation a central factor in determining whether an arthropod is an important vector in nature; moreover, human intervention that affects modulating mechanisms may become a basis for disease control. In the absence of evidence of real immune resistance to arbovirus infections in arthropods, other more primitive modulating mechanisms must be considered: interferonlike substances may be formed in arthropod cells; arthropod cells may "cure" themselves by a unique endophagocytic digestion of their virus burden; homologous interference with viral replicative processes may be mediated via wild or mutant viral RNA species acting to shut down further RNA synthesis; and homologous interference may be mediated by RNA of defective-interfering virus formed earlier in infection.

Aedes↗
PubMed2001

Human arbovirus infections worldwide.

Viral diseases transmitted by blood-feeding arthropods (arboviral diseases) are among the most important of the emerging infectious disease public health problems facing the world at the beginning of the third millennium. There are over 534 viruses listed in the arbovirus catalogue, approximately 134 of which have been shown to cause disease in humans. These are transmitted principally by mosquitoes and ticks. In the last two decades of the twentieth century, a few new arboviral diseases have been recognized. More important, however, is the dramatic resurgence and geographic spread of a number of old diseases that were once effectively controlled. Global demographic and societal changes, and modern transportation have provided the mechanisms for the viruses to break out of their natural ecology and become established in new geographic locations where susceptible arthropod vectors and hosts provide permissive conditions for them to cause major epidemics. West Nile virus is just the the latest example of this type of invasion by exotic viruses. This paper will provide an overview of the medically important arboviruses and discuss several in more detail as case studies to illustrate our tenuous position as we begin the twenty-first century.

Aedes↗