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Biomedical subjects

S B Halstead

Publications and source records attributed to S B Halstead.

142 records · Page 8Linked to original sources
PubMed1966

Mosquito-borne haemorrhagic fevers of South and South-East Asia.

During the past decade outbreaks of a severe haemorrhagic disease caused by dengue viruses of multiple types have been reported in the Philippines, Thailand, Malaysia, Viet-Nam and eastern India. In many of these outbreaks chikungunya virus, a group A arbovirus, was simultaneously the cause of similar but probably milder disease. Both these viruses appear to be able to be able to produce classical dengue fever in some individuals and disease with haemorrhagic manifestations in others. Because of the growing public health importance and the progressive spread of this disease a unified review of its clinical and epidemiological features has been needed. This paper presents the history and salient clinical features of mosquito-borne haemorrhagic fever and summarizes recent epidemiological studies and current diagnostic and control methods.

Aedes↗
PubMedDate not supplied

Tissue culture-based rabies vaccines: vaccine production technology transfer.

Overcoming stagnation in rabies prevention programs in the developing world requires national strategies that include plans to adopt existing facilities for production of low-cost efficacious tissue culture-based vaccine. Transfer of tissue culture technology for the production of rabies vaccine has been supported by the World Health Organization and The Rockefeller Foundation, and in the fall of 1986 the location of the optimal site for the initial technology transfer program was agreed upon. Funds were provided to assemble training staff and to purchase the supplies and equipment to furnish a production facility at the Veterinary Products Company of Colombia (VECOL) located in Bogota, Colombia.

Animals↗
PubMedDate not supplied

Antibody, macrophages, dengue virus infection, shock, and hemorrhage: a pathogenetic cascade.

Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) in children is reliably associated with the presence of dengue antibody--actively or passively acquired--before the onset of illness. Limited observations by electron microscopy and fluorescent antibody testing and the recovery of virus from tissues obtained at autopsy show that dengue viruses are consistently associated with cells of mononuclear phagocyte lineage. In particular, virus is associated with Kupffer cells, pulmonary macrophages, and mononuclear cells in skin and blood. Endothelial cells fail to demonstrate necrosis or inflammatory changes. Since acute vascular permeability, shock, and hemorrhage occur late in illness, a plausible hypothesis is that phlogistic factors, resulting from interactions with elements of the immune response, are released from virus-infected mononuclear phagocytes. Such phenomena as generalized depression of mitotic activity of bone marrow cells, destruction of mature polymorphonuclear leukocytes, complement activation, and abnormal hemostasis may serve as markers of these phlogistic factors. It will be of interest to establish whether other viral hemorrhagic fevers involve the same target cells as in DHF/DSS and are mediated by similar effector mechanisms.

Age Factors↗
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Selective primary health care: strategies for control of disease in the developing world. XI. Dengue.

Since World War II, dengue viruses have progressively extended their geographic domain and have increased as causes of human morbidity and mortality. This complex of four flaviviruses is principally transmitted to humans by the bite of Aedes aegypti, the yellow fever vector. Factors that promote the indoor storage of water are congenial to the breeding of A. aegypti. These include the dislocations of wars, overpopulation , and urbanization. By the mid-20th century, A. aegypti eradication campaigns had nearly succeeded in much of the Western Hemisphere. Since then, there has been a steady degradation in ability to cope with this species despite the fact that a newly emerged, severe immunopathologic disorder, dengue hemorrhagic fever/dengue shock syndrome, endows dengue epidemics with grave consequences. Development of a vaccine against dengue is complicated by the need to develop four different live attenuated vaccines and by a justifiable caution imposed by dengue immunopathology. A wide range of proven methods have been and are available to reduce populations of A. aegypti. This paper argues that the eradication strategy adopted earlier in this century is still viable and cost effective. Critical to a successful control program is a prioritied approach, a thorough, disciplined planning effort, a commitment to assessment, adequate compensation of staff, and, above all, the will to succeed.

Aedes↗
PubMedDate not supplied

Antibody-mediated enhancement of Wesselsbron virus in P388D1 cells.

Antibody-mediated enhancement of Wesselsbron virus was investigated in P388D1 cell cultures. Virus infection was enhanced in culture by various dilutions of homologous and heterologous flavivirus antibody. Highest enhancement ratios and enhancing antibody titres were obtained with the homologous antibody. Enhancement of Wesselsbron virus infection in P388D1 cultures was also dependent on the multiplicity of infection (MOI) used; cultures infected at the lowest MOI produced the highest enhancement ratios. Of the four heterologous flavivirus IMAF tested for ability to enhance Wesselsbron virus infection, Potiskum virus antibody produced highest fold enhancement and possessed the highest enhancing antibody titre. Zika, Uganda S and Dakar bat IMAF produced lower fold enhancement and had lower enhancing antibody titres.

Animals↗