A study of the host range and distribution of antibody to Akabane virus (genus bunyavirus, family Bunyaviridae) in Kenya.

Serum neutralizing antibody to Akabane virus (genus bunyavirus, family Bunyaviridae) was found in a high proportion (50-95%) of cattle sampled in Kenya, while sheep and goats had fewer positive (13-33%). Camel and horse sera also contained antibody to the virus (70% and 50% respectively). The antibody was found in animals from the high altitude temperature type of grasslands, drier bushed and wooded grasslands and the semi-desert. No arthrogryposis nor hydranencephaly has been encountered in Kenya which might be related to this widespread virus infection. A wide range of Kenyan wild ruminants had antibody to Akabane virus in their sera, as also did zebra.     

Rift Valley fever virus (family Bunyaviridae, genus Phlebovirus). Isolations from Diptera collected during an inter-epizootic period in Kenya

A total of 134 876 Diptera collected in Kenya during a 3-year period were tested in 3383 pools for Rift Valley fever (RVF) virus. Nineteen pools of unengorged mosquitoes were found positive for RVF. All isolations were made from specimens collected at or near the naturally or artificially flooded grassland depressions that serve as the developmental sites for the immature stages of many mosquito species. The isolation of virus from adult male and female A. lineatopennis which had been reared from field-collected larvae and pupae suggests that transovarial transmission of the virus occurs in this species.     

Rift Valley fever virus (family Bunyaviridae, genus Phlebovirus). Isolations from Diptera collected during an inter-epizootic period in Kenya.

A total of 134 876 Diptera collected in Kenya during a 3-year period were tested in 3383 pools for Rift Valley fever (RVF) virus. Nineteen pools of unengorged mosquitoes were found positive for RVF. All isolations were made from specimens collected at or near the naturally or artificially flooded grassland depressions that serve as the developmental sites for the immature stages of many mosquito species. The isolation of virus from adult male and female A. lineatopennis which had been reared from field-collected larvae and pupae suggests that transovarial transmission of the virus occurs in this species.     

Field and laboratory investigation of Crimean-Congo haemorrhagic fever virus (Nairovirus, family Bunyaviridae) infection in birds

In November 1984 a case of Crimean-Congo haemorrhagic fever (CCHF) occurred in a worker who became ill after slaughtering ostriches (Struthio camelus) on a farm near Oudtshoorn in the Cape province of South Africa. The diagnosis was confirmed by isolation of CCHF virus from the patient's serum and by demonstration of a specific antibody response. It was suspected that infection was acquired either by contact with ostrich blood or by inadvertently crushing infected Hyalomma ticks while skinning ostriches. Reversed passive haemagglutination-inhibition antibody to CCHF virus was detected in the sera of 22/92 ostriches from farms in Oudtshoorn district, including 6/9 from the farm where the patient worked, but not in the sera of 460 birds of 37 other species. In pathogenicity studies domestic chickens proved refractory to CCHF infection, but viraemia of low intensity (maximum titre 2.5 log10 mouse ic LD50/ml) followed by a transient antibody response occurred in blue-helmeted guinea fowl (Numidia meleagris). These results offer the first direct evidence that some bird species are susceptible to CCHF virus infection.     

Prevalence,distribution, and host range of Peste des petits ruminants virus,Turkey

Peste des petits ruminants virus (PPRV, genus Morbillivirus), which causes a severe disease in sheep and goats, has only recently been officially declared to be present in Turkey. We carried out a study to determine the prevalence, distribution, and host range of PPRV in Turkey. A total of 1,607 animals, reared in 18 different locations, were monitored for the presence of antibodies to PPRV and the related virus of large ruminants, Rinderpest virus (RPV). Only two farms had animals that were free of antibody responses to either disease. Prevalence for PPRV infection varied (range 0.87%-82.6%) and was higher in sheep (29.2%) than in goats (20%). The overall antibody responses to PPRV and RPV were 22.4% and 6.28%, respectively. Two PPRVs of lineage 4, which comprises many other PPRVs whose origins are in the Middle East, the Arabian Peninsula, and southern Asia, were isolated from Turkish sheep.     

The distribution of Akabane virus in the Middle East.

Serological evidence was used to confirm an outbreak of Akabane disease in cattle in the Turkish Province of Aydin in 1980. Thereafter, serum collections from the Middle East were screened for the presence of neutralizing antibodies to Akabane virus. The results indicate that the virus was present in a number of provinces on the south Turkish coast in 1979 and 1980 but that it probably did not persist into 1981; the virus had also been present on Cyprus in 1980 and on at least one previous occasion. There was also evidence of limited virus transmission in the Orontes river valley in Syria in 1979 and less precise evidence to show that occasional infection occurred in the lower Jordan river valley. The failure of Akabane virus to persist in southern Turkey for more than two years indicates that this area is open to epidemic rather than endemic infection. The presence of neutralizing antibodies in the eastern Turkish Provinces of Gaziantep and Diyarbakir suggests that this might be the route whereby Akabane virus occasionally invades the Middle East region.     

Partial genetic characterization of Sedlec virus (Orthobunyavirus,Bunyaviridae)

Sedlec virus (SEDV) was isolated from the blood of a reed warbler (Acrocephalus scirpaceus) in July 1984 in South Moravia, Czech Republic. In this study first genetic data of SEDV are presented which allow an estimate on its phylogenetic and taxonomic positioning within the genus Orthobunyavirus. The phylogenetic analysis of a 369 nt long stretch within the S segment (nucleocapsid protein gene and non-structural S protein gene) indicates genetic relatedness of SEDV to Leanyer virus and Simbu group viruses, while the phylogenetic tree based on 1796 nt long sequences of the L segment (RNA-dependent RNA polymerase gene) demonstrates genetic relationship of SEDV to two yet unclassified orthobunyaviruses: I612045 virus (isolated in India in 1961) and Oyo virus (isolated in Nigeria in 1964). Considering the genetic distances and the phylogenetic analyses, SEDV might represent a novel serogroup of the Orthobunyavirus genus.     

Rift Valley fever in Kenya: the presence of antibody to the virus in camels (Camelus dromedarius)

Five hundred and seventy-one camel sera collected after an epizootic of Rift Valley Fever were examined for antibody to the virus. Clinical disease had not been observed in cattle and sheep in the ecosystems shared with the camels. Positive sera with high titres of serum neutralizing antibody were found in 22% of camels at one of the seven sampling sites.     

Temporal,geographic, and host distribution of avian paramyxovirus 1 (Newcastle disease virus)

Newcastle disease is caused by virulent forms of avian paramyxovirus of serotype 1 (APMV-1) and has global economic importance. The disease reached panzootic proportions within two decades after first being identified in 1926 in the United Kingdom and Indonesia and still remains endemic in many countries across the world. Here we review information on the host, temporal, and geographic distribution of APMV-1 genetic diversity based on the evolutionary systematics of the complete coding region of the fusion gene. Strains of APMV-1 are phylogenetically separated into two classes (class I and class II) and further classified into genotypes based on genetic differences. Class I viruses are genetically less diverse, generally present in wild waterfowl, and are of low virulence. Class II viruses are genetically and phenotypically more diverse, frequently isolated from poultry with occasional spillovers into wild birds, and exhibit a wider range of virulence. Waterfowl, cormorants, and pigeons are natural reservoirs of all APMV-1 pathotypes, except viscerotropic velogenic viruses for which natural reservoirs have not been identified. Genotypes I and II within class II include isolates of high and low virulence, the latter often being used as vaccines. Viruses of genotypes III and IX that emerged decades ago are now isolated rarely, but may be found in domestic and wild birds in China. Containing only virulent viruses and responsible for the majority of recent outbreaks in poultry and wild birds, viruses from genotypes V, VI, and VII, are highly mobile and have been isolated on different continents. Conversely, virulent viruses of genotypes XI (Madagascar), XIII (mainly Southwest Asia), XVI (North America) and XIV, XVII and XVIII (Africa) appear to have a more limited geographic distribution and have been isolated predominantly from poultry.     

Isolation and characterization of Oya virus a member of Simbu serogroup,family Bunyaviridae,isolated from Karnataka,India

During a study on Japanese encephalitis (JE) from Kolar district of Karnataka state, India in 1986; two virus isolates were obtained in infant Swiss albino mouse from a pig and a human serum sample. For characterization of these virus isolates, they were propagated in Vero CCL-81 cells. These virus isolates were screened for flaviviruses (Japanese encephalitis, West Nile, Dengue, Kyasanur forest disease) and Alphavirus (Chikungunya) by RT-PCR and found to be negative. Further these they were screened for bunyaviruses using genus-specific primers. A virus isolate from a human sample was sequenced using next generation sequencing; which identified it as Oya virus, Simbu group of the genus Orthobunyavirus of the family Bunyaviridae. Phylogenetic analysis of L, M, S (N and NSs) revealed its close association with Chinese strain of Oya virus in Simbu serogroup with the distance of 6.5 > 4.2 > 3.2% for nucleotides and 2.4 > 0.8 > 0.0% for the amino acid of L > M > S segments respectively. Based on the PCR results; an isolate from pig sample was also confirmed as Oya virus. This study was strengthened by findings of IgG antibody positivity against Oya virus in retrospective serum samples of suspected febrile illness cases from this area by an indigenously developed ELISA. Oya virus positivity was also recorded in human samples collected from Karnataka using nested RT-PCR. This is the first report of the presence of Oya virus in human samples. Further studies are needed to determine disease-causing potential in humans.     

Rift Valley fever in Kenya: the presence of antibody to the virus in camels (Camelus dromedarius).

Five hundred and seventy-one camel sera collected after an epizootic of Rift Valley Fever were examined for antibody to the virus. Clinical disease had not been observed in cattle and sheep in the ecosystems shared with the camels. Positive sera with high titres of serum neutralizing antibody were found in 22% of camels at one of the seven sampling sites.     

Possible windborne spread to western Turkey of bluetongue virus in 1977 and of Akabane virus in 1979

An outbreak of bluetongue in sheep started in the Menderes valley, Aydin Province, Western Turkey, in October 1977. The severity of the disease indicated that it had not been there before but had been introduced into the area. Analysis showed that, while it was possible for the virus to have been brought into the area by movement of infected animals, there was also a period of south-easterly winds which could have carried infected midges from Cyprus, where bluetongue was present. During the night of 14-15 October 1977, south-easterly winds could have brought midges infected with bluetongue virus for the 15 h flight at a height possibly of 500 m and at temperatures of about 20 degrees C. A depression moving north-eastwards accompanied by rain may have affected the landing of midges in the Menderes valley on the morning of 15 October. An outbreak of arthrogryposis-hydranencephaly in newly born calves occurred in March-May 1980, also in the Menderes valley, Aydin Province. The severity of the outbreak indicated that Akabane virus had not been in the area before but had been introduced in September-November the previous year. While infected animals could have brought the virus into the area, analysis based on the probable time of infection of pregnant dams showed that easterly winds at the end of September or beginning of October 1979 could have brought insects infected with Akabane virus into the Menderes valley from eastern Turkey or northern Syria. These analyses illustrate the use of meteorological data to backtrack to possible sources and to identify the time of infection.     

A study of the distribution and abundance of the adult malaria vector in western Kenya highlands

Background  

A sharp rise in the malaria mortality rate has been observed recently in western Kenya. Malaria is transmitted by mosquito vectors. Malaria control strategies can be more successful if the distribution and abundance of mosquito vectors is predicted. However, how mosquito vectors are distributed in space remain poor understood, and this question is rarely studied using spatial methods. This study aims to provide a better understanding of the distribution and abundance of mosquito vectors. To achieve this objective, spatial and non-spatial methods were employed. The data on the distribution of adult mosquitoes, and mosquito breeding habitats in a study area in western Kenya, and environmental variables were analyzed.     

A study of Cytomegalovirus, Epstein-Barr virus and Herpesvirus hominis (types 1 and 2) antibody in institutionalized and non-institutionalized children.

In an attempt to demonstrate differences in antibody prevalence between free-living and institutionalized children, antibodies to Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Herpesvirus hominis (HVH), types 1 and 2, were assayed in 123 children. The children comprised three groups consisting of 41 institutionalized patients with Down's syndrome (all non-disjunctive trisomy-G karyotype and equal numbers of age-, sex-, and race-matched non-mongoloid institutionalized subjects and non-institutionalized normal controls. CMV antibody titer values were statistically similar in the three groups. However, fewer mongoloids (21.9%) were seropositive than other institutionalized retardates (39.0%) and normal control subjects (43.9%). Antibody titer values to EBV were also similar; however, in comparison to the other groups, significantly more mongoloids were seropositive at younger ages. More mongoloids were seropositive to HVH-1 and had higher antibody titers than the other two groups. Antibody to HVH-2 was more prevalent in institutionalized subjects, 85.4% in mongoloids and 65.8% in other institutionalized retardates, than in normal non-institutionalized children (26.8%).     

河南省甲型H1N1流感病毒抗体人群分布的横断面调查

目的 调查河南省人群甲型H1N1流感抗体的分布.方法 选择河南省的不同城区和农村进行采样,共采4 651份样品,RDE处理血清后,用鸡血球测定HI,以侧倾出现泪滴判定,大于40的为阳性.结果 省会城市的抗体阳性率为27.76％,地市级城市抗体阳性率为27.13％,农村地区为18.81％,城市阳性率显著高于农村,各年龄段抗体阳性率不等,6～17岁年龄组抗体阳性率较高.结论 河南省的人群已经初步形成了甲型H1N1的免疫屏障,但是还比较薄弱,有待于科学使用甲型H1N1疫苗,提高人群抗体分布水平.     

A genome-wide association study of host genetic determinants of the antibody response to Anthrax Vaccine Adsorbed

Several lines of evidence have supported a host genetic contribution to vaccine response, but genome-wide assessments for specific determinants have been sparse. Here we describe a genome-wide association study (GWAS) of protective antigen-specific antibody (AbPA) responses among 726 European-Americans who received Anthrax Vaccine Adsorbed (AVA) as part of a clinical trial. After quality control, 736,996 SNPs were tested for association with the AbPA response to 3 or 4 AVA vaccinations given over a 6-month period. No SNP achieved the threshold of genome-wide significance (p=5 × 10(-8)), but suggestive associations (p<1 × 10(-5)) were observed for SNPs in or near the class II region of the major histocompatibility complex (MHC), in the promoter region of SPSB1, and adjacent to MEX3C. Multivariable regression modeling suggested that much of the association signal within the MHC corresponded to previously identified HLA DR-DQ haplotypes involving component HLA-DRB1 alleles of *15:01, *01:01, or *01:02. We estimated the proportion of additive genetic variance explained by common SNP variation for the AbPA response after the 6 month vaccination. This analysis indicated a significant, albeit imprecisely estimated, contribution of variation tagged by common polymorphisms (p=0.032). Future studies will be required to replicate these findings in European Americans and to further elucidate the host genetic factors underlying variable immune response to AVA.     

Possible windborne spread to western Turkey of bluetongue virus in 1977 and of Akabane virus in 1979.

An outbreak of bluetongue in sheep started in the Menderes valley, Aydin Province, Western Turkey, in October 1977. The severity of the disease indicated that it had not been there before but had been introduced into the area. Analysis showed that, while it was possible for the virus to have been brought into the area by movement of infected animals, there was also a period of south-easterly winds which could have carried infected midges from Cyprus, where bluetongue was present. During the night of 14-15 October 1977, south-easterly winds could have brought midges infected with bluetongue virus for the 15 h flight at a height possibly of 500 m and at temperatures of about 20 degrees C. A depression moving north-eastwards accompanied by rain may have affected the landing of midges in the Menderes valley on the morning of 15 October. An outbreak of arthrogryposis-hydranencephaly in newly born calves occurred in March-May 1980, also in the Menderes valley, Aydin Province. The severity of the outbreak indicated that Akabane virus had not been in the area before but had been introduced in September-November the previous year. While infected animals could have brought the virus into the area, analysis based on the probable time of infection of pregnant dams showed that easterly winds at the end of September or beginning of October 1979 could have brought insects infected with Akabane virus into the Menderes valley from eastern Turkey or northern Syria. These analyses illustrate the use of meteorological data to backtrack to possible sources and to identify the time of infection.