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B.M. McIntosh

Bio: B.M. McIntosh is an academic researcher. The author has contributed to research in topics: Population. The author has an hindex of 1, co-authored 1 publications receiving 32 citations.
Topics: Population

Papers
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Journal ArticleDOI
TL;DR: The present survey offers no conclusive evidence that this virus has been active among the population sampled, but neutralization test results gave further evidence of activity of a wide spectrum of viruses, but showed that immunity levels were highest with Sindbis, West Nile, Wesselsbron, Bunyamwera and Germiston viruses.
Abstract: Sera collected in 1959 from 602 residents of 19 localities in the Caprivi Strip and Bechuanaland Protectorate were tested for HI antibodies against 15 viruses—4 from Group A, 7 from Group B, 1 from Group C, 2 from the Bunyamwera Group, and Rift Valley fever virus. Results of these tests were largely negative for the 5 localities in the Kalahari Desert, but indicated a great deal of virus activity in the Caprivi Strip and the Okavango Basin. Sera positive in the HI test were further tested with the respective viruses by the mouse neutralization test. Selected sera were also tested for neutralizing antibodies against 4 other ungrouped viruses. Neutralization test results gave further evidence of activity of a wide spectrum of viruses, but showed that immunity levels were highest with Sindbis, West Nile, Wesselsbron, Bunyamwera and Germiston viruses. The results of yellow fever neutralization tests with sera collected in the Okavango Basin during 2 previous surveys are reviewed. The present survey offers no conclusive evidence that this virus has been active among the population sampled.

35 citations


Cited by
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Journal ArticleDOI
TL;DR: The conclusion reached is that increased human population growth in decades ahead coupled with increased international travel and trade is likely to sustain and increase the threat of further geographical spread of current and new arboviral disease.
Abstract: Key aspects of 36 mosquito-borne arboviruses indigenous to Africa are summarized, including lesser or poorly-known viruses which, like Zika, may have the potential to escape current sylvatic cycling to achieve greater geographical distribution and medical importance. Major vectors are indicated as well as reservoir hosts, where known. A series of current and future risk factors is addressed. It is apparent that Africa has been the source of most of the major mosquito-borne viruses of medical importance that currently constitute serious global public health threats, but that there are several other viruses with potential for international challenge. The conclusion reached is that increased human population growth in decades ahead coupled with increased international travel and trade is likely to sustain and increase the threat of further geographical spread of current and new arboviral disease.

192 citations

Journal ArticleDOI
08 Jul 2010-PLOS ONE
TL;DR: It is found that CHIKV infection of HEK293T mammalian cells is independent of clathrin heavy chain and- dependent of functional Eps15, and requires integrity of Rab5-, but not Rab7-positive endosomal compartment.
Abstract: Background The replicative cycle of chikungunya virus (CHIKV), an alphavirus that recently re-emerged in India and in Indian Ocean area, remains mostly unknown The aim of the present study was to investigate the intracellular trafficking pathway(s) hijacked by CHIKV to enter mammalian cells Methodology/Principal Findings Entry pathways were investigated using a variety of pharmacological inhibitors or overexpression of dominant negative forms of proteins perturbating cellular endocytosis We found that CHIKV infection of HEK293T mammalian cells is independent of clathrin heavy chain and- dependent of functional Eps15, and requires integrity of Rab5-, but not Rab7-positive endosomal compartment Cytoskeleton integrity is crucial as cytochalasin D and nocodazole significantly reduced infection of the cells Finally, both methyl β-cyclodextrin and lysomotropic agents impaired CHIKV infection, supporting that a cholesterol-, pH-dependent step is required to achieve productive infection Interestingly, differential sensitivity to lysomotropic agents was observed between the prototypal 37997 African strain of CHIKV and the LR-OPY1 virus isolated from the recent outbreak in Reunion Island Conclusions Together our data indicate that CHIKV entry in its target cells is essentially mediated by clathrin-independent, Eps15-dependent endocytosis Despite that this property is shared by the prototypal 37997 African strain of CHIKV and the LR-OPY1 virus isolated from the recent outbreak in La Reunion Island, differential sensitivity to lysomotropic agents may support that the LR-OPY1 strain has acquired specific entry mechanisms

159 citations

Journal Article
TL;DR: Twenty-four species of South African wild animals were tested for the presence of antibodies against the viruses of 16 common diseases of domestic animals, finding that most viruses were more prevalent in the high-rainfall zone in KwaZulu-Natal.
Abstract: Twenty-four species of South African wild animals were tested for the presence of antibodies against the viruses of 16 common diseases of domestic animals. Positive results were obtained for African horsesickness, equine encephalosis, equid herpes virus-1, infectious bovine rhinotracheitis, Allerton disease (Herpes mammillitis), lumpy skin disease, parainfluenza, encephalomyocarditis, bluetongue, Wesselsbron disease, bovine ephemeral fever, and Akabane disease complex. No antibodies could be demonstrated against the viruses of equine influenza, equine infectious anaemia, equine viral arteritis and Rift Valley fever. The negative results substantiate observations that the latter diseases, with the exception of equine viral arteritis, are absent in South Africa. The number of animal species found positive for a specific virus, ranged from 0-16. No antibodies were found in crocodiles and warthogs, whereas antibodies against Wesselsbron and bovid herpes virus-1 were present in 16 species. Antibodies against viruses of horses were found almost exclusively in zebras and, although elephants reacted to African horsesickness, no neutralizing antibodies against it could be demonstrated in their sera. Zebras were also found to be positive for Wesselsbron and Akabane, which are usually regarded as viruses of ruminants. Antibodies against most viruses were encountered in all vegetation zones in South Africa but, as a rule, most viruses were more prevalent in the high-rainfall zone in KwaZulu-Natal.

86 citations

Journal ArticleDOI
TL;DR: RVF is endemic in this region, people are at considerable risk of infection, and that a heretofore unrecognized mode of human infection under nonepizootic conditions may be transmission via contact with infected animals or humans.
Abstract: To investigate past infection in and transmission of Rift Valley fever (RVF) virus to humans within an endemic focus, we undertook a retrospective cohort study of the seminomadic Peul people living in sub-Saharan northcentral Senegal. Residents of the rural settlement of Yonofere five years of age or older were studied during February-May 1989. Anti-RVF virus IgG was found in blood samples of 22.3% of 273 persons who responded to a standard questionnaire; none had IgM antibodies. Seropositivity was similar for males (25.4%) and females (21.1%), increased markedly with age for both sexes, and varied considerably among compounds (groups of huts) (0-37.5%). Risk factors for past RVF virus infection were nursing sick people, assisting animals during abortions/births, and treating sick animals. In all age groups, odds ratios (ORs) for RVF viral antibody among females who reported treating sick animals were three to six times greater than for those who did not. The ORs for males who reported assisting with animal births/abortions and nursing sick people were approximately five times those for males who did not. Serologic prevalence of RVF viral antibody among sheep averaged 30.1% overall (0.8% IgM), but varied among compounds (0-66.7%) in a manner different from that of humans. The seasonal abundance and relative density of potential mosquito vectors were estimated by monthly samples captured in Centers for Disease Control and Prevention-type traps. Mosquito abundance varied seasonally with rainfall (> 90% captures during four months). Species diversity was large (28 spp.), dominated by Aedes and Culex. Rift Valley fever virus was not isolated from 142 pools of 2,956 unengorged mosquitoes tested, although three other arboviruses were found. Results indicate that RVF is endemic in this region, people are at considerable risk of infection, and that a heretofore unrecognized mode of human infection under nonepizootic conditions may be transmission via contact with infected animals or humans.

86 citations

Journal ArticleDOI
TL;DR: The study confirms the epidemiological data, specifically with regard to the re-emergence of CHikV and throws light on the evolutionary dynamics of CHIK viruses.

68 citations