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Abstract
During the nine years from October 1972 to September 1981 African horse sickness (AHS) virus was isolated from 23 suspected cases of the disease in Zimbabwe and complement fixation antibody titres indicative of recent infection were detected in a further 49 horses. The 23 isolations belonged to seven of the nine known serotypes of AHS virus. In response to a questionnaire in 1980 the owners of 20% (1,654/8,000) of the horses in Zimbabwe indicated that they had recorded 207 cases of clinically diagnosed AHS with 107 deaths from 1975 to 1980. Fifty-six cases with 50 deaths had occurred in foals and many of the other cases occurred in horses which had been vaccinated. It was concluded that the immunity induced by vaccine and maternal immunity warranted further investigation.
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Shepherd AJ, Swanepoel R, Gill DE. Evaluation of enzyme-linked immunosorbent assay and reversed passive hemagglutination for detection of Crimean-Congo hemorrhagic fever virus antigen. J Clin Microbiol 1988; 26:347-53. [PMID: 3125221 PMCID: PMC266280 DOI: 10.1128/jcm.26.2.347-353.1988] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Enzyme-linked immunosorbent assay (ELISA) and a reversed passive hemagglutination (RPHA) test were evaluated for rapid detection of Crimean-Congo hemorrhagic fever (CCHF) virus antigens. Both RPHA and ELISA detected CCHF antigen in the brains of infant mice 2 to 3 days after infection, several days before the animals sickened and died. Antigen was also detected after 1 to 2 days in infected cell culture extracts and after 2 to 4 days in culture supernatant fluids. Both tests detected CCHF antigen at threshold values of approximately 2.5 log10 tissue culture infective doses per ml and were more sensitive than complement fixation, immunodiffusion, or immunofluorescence. In a comparative study on specimens from CCHF patients, virus was isolated from 38 of 49 sera and 23 of 28 patients. Antigen was detected in 20 of 49 sera (15 of 28 patients) by RPHA and in 29 of 49 sera (18 of 28 patients) by ELISA. Antigenemia was detected more frequently in fatal cases (9 of 11) than in nonfatal cases (9 of 17). Although the antigen detection assays offered a more rapid approach than infectivity assays for diagnosing CCHF, the latter test was more sensitive. The results suggest that RPHA and ELISA may be of use in rapid diagnosis of CCHF infection, particularly in severe cases, in which the danger of nosocomial spread is greatest.
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Shepherd AJ, Swanepoel R, Leman PA, Shepherd SP. Field and laboratory investigation of Crimean-Congo haemorrhagic fever virus (Nairovirus, family Bunyaviridae) infection in birds. Trans R Soc Trop Med Hyg 1987; 81:1004-7. [PMID: 3140434 DOI: 10.1016/0035-9203(87)90379-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
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.
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Blackburn NK, Besselaar TG, Shepherd AJ, Swanepoel R. Preparation and use of monoclonal antibodies for identifying Crimean-Congo hemorrhagic fever virus. Am J Trop Med Hyg 1987; 37:392-7. [PMID: 3116871 DOI: 10.4269/ajtmh.1987.37.392] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Seven monoclonal antibodies were prepared against a South African strain of Crimean-Congo hemorrhagic fever (CCHF) virus and were found to be directed against viral nucleocapsid protein. Five of the monoclonal antibodies reacted to high titer in indirect immunofluorescence (IF) tests and enzyme-linked immunosorbent assays (ELISA) with 22 strains of CCHF virus and failed to cross-react with the closest antigenic relative of CCHF, Hazara virus, or with 4 other nairoviruses which need to be distinguished from CCHF virus in Africa. These antibodies, used in the IF technique, readily detected antigens induced by all strains of CCHF virus included in the study in cell culture monolayers and mouse brain tissue, which represent the systems commonly used for isolation of CCHF virus. The IF technique with monoclonal antibodies constitutes a rapid and specific means of identifying newly isolated strains of CCHF virus.
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Swanepoel R, Shepherd AJ, Leman PA, Shepherd SP, McGillivray GM, Erasmus MJ, Searle LA, Gill DE. Epidemiologic and clinical features of Crimean-Congo hemorrhagic fever in southern Africa. Am J Trop Med Hyg 1987; 36:120-32. [PMID: 3101525 DOI: 10.4269/ajtmh.1987.36.120] [Citation(s) in RCA: 188] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Following the diagnosis in 1981 of the first case of Crimean-Congo hemorrhagic fever (CCHF) in South Africa, an antibody survey was undertaken on cattle sera to determine the distribution of the virus and specific diagnostic tests were routinely applied to specimens from suspected cases of hemorrhagic fever to establish the medical significance of its presence. Antibody to CCHF virus was demonstrated by reversed passive hemagglutination-inhibition technique in 2,460/8,667 (28%) cattle sera and in 140/180 herds tested in South Africa, as well as in 347/763 (45%) cattle sera and in 32/34 (94%) herds tested in Zimbabwe. The antibody was found in all major cattle farming areas, but was of low prevalence along the southern coast where 2 of the 3 species of Hyalomma tick which occur in South Africa are absent. From February 1981 to January 1986, inclusive, 29 indigenous cases of CCHF were diagnosed in 16 outbreaks which arose in various locations throughout South Africa. A further 2 imported cases of CCHF arose in Zaire and Tanzania. The clinical features of infection conformed to the classical descriptions of CCHF in the Soviet Union. The fatal outcome in 11/31 cases indicates that the African disease is no less severe than that which occurs in Eurasia. It is inferred that the virus is widespread in all countries in Africa and Eurasia which lie within the limits of world distribution of ticks of the genus Hyalomma.
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Shepherd AJ, Swanepoel R, Shepherd SP, McGillivray GM, Searle LA. Antibody to Crimean-Congo hemorrhagic fever virus in wild mammals from southern Africa. Am J Trop Med Hyg 1987; 36:133-42. [PMID: 3101526 DOI: 10.4269/ajtmh.1987.36.133] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Crimean-Congo hemorrhagic fever (CCHF) virus is becoming increasingly recognized as an important human pathogen in southern Africa. In order to determine the role of wild mammals in the natural ecology of the virus, sera from 3,772 wild mammals of 87 species and from 1,978 domestic dogs collected in South Africa and Zimbabwe between 1964 and 1985 were tested for antibody to CCHF virus by reversed passive hemagglutination inhibition (RPHI) and by indirect immunofluorescence (IF). Antibody was found to be highly prevalent in large mammals in the Orders Artiodactyla and Perissodactyla such as giraffe, Giraffa camelopardalis (3/3 positive), rhinoceros, Ceratotherium simium and Diceros bicornis (7/13), eland, Taurotragus oryx (59/127), buffalo, Syncerus caffer (56/287), kudu, Tragelaphus strepsiceros (17/78), and zebra, Equus burchelli (16/93). In small mammals antibody was found in the sera of 40/293 hares, 22/1,305 rodents, and 1/74 wild carnivores, but not in 522 primates, 176 insectivores, or 19 hyrax. Antibody was also found in the sera of 118/1,978 domestic dogs. The species of wild mammal in which antibody was distributed (with highest antibody prevalence in hares and large herbivores) reflects the feeding preference of immature and adult ticks of the genus Hyalomma, suggesting that Hyalomma sp. are the principal CCHF vectors in the wild.
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Shepherd AJ, Hummitzsch DE, Leman PA, Swanepoel R, Searle LA. Comparative tests for detection of plague antigen and antibody in experimentally infected wild rodents. J Clin Microbiol 1986; 24:1075-8. [PMID: 3097065 PMCID: PMC269101 DOI: 10.1128/jcm.24.6.1075-1078.1986] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The enzyme-linked immunosorbent assay (ELISA) was compared with other standard tests for detection of plague (Yersinia pestis) antibody and antigen in multimammate mice (Mastomys coucha and M. natalensis) which were experimentally infected and then killed at daily intervals postinoculation. For detection of antibody in sera from M. natalensis, the immunoglobulin G (IgG) ELISA was equivalent in sensitivity to passive hemagglutination and more sensitive than the IgM ELISA and complement fixation. Antibody was first detected on postinfection day 6 by all four tests, but IgM ELISA titers had declined to undetectable levels after 8 weeks. For detection of fraction 1 Y. pestis antigen in rodent organs, the ELISA was less sensitive than fluorescent antibody but more sensitive than complement fixation or immunodiffusion. Plague fraction 1 antigen was detected in 16 of 34 bacteremic sera from M. coucha and M. natalensis. The threshold sensitivity of the ELISA was approximately 10(5) Y. pestis per ml.
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Swanepoel R, Struthers JK, Erasmus MJ, Shepherd SP, McGillivray GM, Shepherd AJ, Hummitzsch DE, Erasmus BJ, Barnard BJ. Comparative pathogenicity and antigenic cross-reactivity of Rift Valley fever and other African phleboviruses in sheep. J Hyg (Lond) 1986; 97:331-46. [PMID: 3537119 PMCID: PMC2083542 DOI: 10.1017/s0022172400065426] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Homologous and heterologous haemagglutination-inhibition (HAI), complement-fixation (CF), immunodiffusion (ID) and mouse neutralization tests were performed with the Lunyo (LUN) and a Zimbabwean strain of Rift Valley fever (RVF) virus, the prototype and a South African strain of Arumowot (AMT) virus and prototype strains of Gordil (GOR), Saint-Floris (SAF) and Gabek Forest (GF) viruses, using immune mouse ascitic fluids prepared against these viruses. Reactions of identity occurred in all tests between LUN and the Zimbabwean strains of RVF and between the two strains of AMT virus. Otherwise, cross-reactions occurred between all the phleboviruses in HAI tests, while reactions in CF, ID and neutralization tests were monospecific for virus serotypes, except that weak cross-reaction occurred between GOR and SAF viruses in CF and ID tests. Four sheep infected subcutaneously with the Zimbabwean strain of RVF virus developed transient fever, viraemia, leucopaenia, relative thrombocytopaenia, haemoconcentration and raised serum enzyme levels, which indicated that the sheep had developed necrotic hepatitis. Disseminated focal necrotic hepatitis was confirmed in a sheep killed for examination on day 4 post-infection. The other three sheep recovered uneventfully after only mild depression and anorexia. Groups of three sheep infected with SAF, GOR, AMT and GF viruses had no demonstrable viraemia or other sign of infection or illness, except that the sheep infected with AMT developed mild fever lasting less than 24 h. Antibody responses were monitored at intervals over a period of 24 weeks in all sheep by homologous and heterologous HAI, CF and cell culture neutralization (CPENT) tests. Homologous antibody responses were marked in the RVF-infected sheep and their sera cross-reacted strongly in HAI tests with antigens of the other viruses. The sera of the RVF-infected sheep cross-reacted less markedly in CF and CPENT tests. Homologous antibody responses were poor in all the sheep infected with phleboviruses other than RVF, and the cross-reactivity of their sera for RVF antigen or virus was negligible. All sheep were challenged with RVF virus 48 weeks after their initial infection. The sheep which had originally been infected with RVF virus were immune and developed neither fever nor viraemia. All other sheep developed fever, viraemia and antibodies to RVF virus. It was concluded that the African phleboviruses, other than RVF, are unlikely to cause disease in livestock or to induce antibodies which could cause confusion in the diagnosis of RVF.
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Shepherd AJ, Swanepoel R, Leman PA, Shepherd SP. Comparison of methods for isolation and titration of Crimean-Congo hemorrhagic fever virus. J Clin Microbiol 1986; 24:654-6. [PMID: 3095367 PMCID: PMC268994 DOI: 10.1128/jcm.24.4.654-656.1986] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The fluorescence focus assay and the plaque assay in CER cells were compared with mouse inoculation for the isolation and titration of Crimean-Congo hemorrhagic fever virus. The fluorescence focus assay and the plaque assay were of similar sensitivity, but both produced 10- to 100-fold lower titers than did mouse inoculation. For specimens from 26 Crimean-Congo hemorrhagic fever patients in South Africa, virus was isolated from 20 by mouse inoculation and from only 11 by cell culturing. Although cell cultures were less sensitive for the isolation of virus from clinical specimens, they produced diagnostic results much more rapidly.
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Swanepoel R, Struthers JK, Erasmus MJ, Shepherd SP, McGillivray GM, Erasmus BJ, Barnard BJ. Comparison of techniques for demonstrating antibodies to Rift Valley fever virus. J Hyg (Lond) 1986; 97:317-29. [PMID: 3537118 PMCID: PMC2083537 DOI: 10.1017/s0022172400065414] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Nine serological techniques were compared by monitoring the response to infection with Rift Valley fever (RVF) virus in three sheep. Antibodies were monitored daily for the first 14 days after infection, then weekly and later fortnightly up to week 24. The earliest antibody response was detected in one sheep on day 3 by a plaque reduction neutralization test, and by day 6 antibodies were demonstrable in all three sheep by haemagglutination-inhibition, reversed passive haemagglutination-inhibition, immunodiffusion, indirect immunofluorescence (IF), enzyme-linked immunosorbent assay and neutralization of cytopathic effect in cell cultures. Antibodies were demonstrable by complement fixation on day 8 at the earliest. IF and the two neutralization techniques produced the highest titres, but all tests could be used satisfactorily for the serological diagnosis of RVF. Inactivated antigen could be used for all except the neutralization tests. A radioimmunoassay technique using 125I-labelled staphylococcal protein A detected antibodies on day 8 at the earliest and produced lower mean titres than some of the other techniques. This was probably because sheep immunoglobulins bind protein A poorly.
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61
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Kiley MP, Swanepoel R, Mitchell SW, Lange JV, Gonzalez JP, McCormick JB. Serological and biological evidence that Lassa-complex arenaviruses are widely distributed in Africa. Med Microbiol Immunol 1986; 175:161-3. [PMID: 3724663 DOI: 10.1007/bf02122440] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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62
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Shepherd AJ, Swanepoel R, Shepherd SP, Leman PA, Blackburn NK, Hallett AF. A nosocomial outbreak of Crimean-Congo haemorrhagic fever at Tygerberg Hospital. Part V. Virological and serological observations. S Afr Med J 1985; 68:733-6. [PMID: 3933129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A nosocomial outbreak of Crimean-Congo haemorrhagic fever occurred in Tygerberg Hospital near Cape Town in September 1984 when 7 medical personnel became ill after admission of an index patient. The disease was fatal in the index and 1 secondary case, and was confirmed in the index and 6 secondary cases by isolation of the virus. An antibody response was demonstrated in the remaining patient, thought to be a tertiary case, but the fact that the patient received immune plasma therapy raises doubts about the validity of the diagnosis. The index case had contact with ticks and horses but his infection could not be related to a specific incident.
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63
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Swanepoel R, Shepherd AJ, Leman PA, Shepherd SP, Miller GB. A common-source outbreak of Crimean-Congo haemorrhagic fever on a dairy farm. S Afr Med J 1985; 68:635-7. [PMID: 3933131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
An outbreak of Crimean-Congo haemorrhagic fever (CCHF) on a dairy farm in the Orange Free State in 1984 is described. Forty-six cows were purchased from the western Cape Province in January 1984; 2 died from the tick-borne disease anaplasmosis in March and a labourer who helped butcher the carcasses became ill a few days later. Another cow died at the end of April and within 9 days 4 people who had come into contact with its blood became ill. Antibodies to CCHF virus were found in the sera of the 5 patients but not in other residents of the farm. Three patients recovered from a severe influenza-like illness without seeking medical attention; 1 patient, who was admitted to hospital, recovered from illness marked by haematemesis, epistaxis and amnesia and the 5th patient died of complications of surgery for brain haemorrhage. Antibody studies indicated that many of the cows became infected with CCHF after their arrival on the farm. It can be deduced that animals reared in tick-free, or relatively tick-free, circumstances, which are then moved to where they are subject to heavy parasitization by ticks, can acquire common tick-borne diseases of livestock plus CCHF infection simultaneously. In such circumstances there is a definite risk of human exposure to CCHF-infected blood or other tissues.
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64
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Swanepoel R, Shepherd AJ, Leman PA, Shepherd SP. Investigations following initial recognition of Crimean-Congo haemorrhagic fever in South Africa and the diagnosis of 2 further cases. S Afr Med J 1985; 68:638-41. [PMID: 3933132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Sera from 124 cattle herds were tested, and antibodies to Crimean-Congo haemorrhagic fever (CCHF) were found in 93 herds. The prevalence of antibodies was high in the interior of the country, in excess of 90% in some herds, but was less than 4% in cattle along the coast from Cape Town to East London. Only 17 out of 1109 (1,5%) human residents of 55 farms had antibodies to CCHF, while none of 164 veterinary research workers or 98 veterinarians engaged in farm animal practice had them. Specimens from 130 suspected cases of viral haemorrhagic fever were examined and CCHF was diagnosed only in the patient previously reported as the first case of the disease to be recognized in this country. A further 2 cases of CCHF were diagnosed by examining 318 specimens from patients with nonfatal febrile illness. Both patients had contact with livestock. Increasing awareness of the disease will probably lead to an increase in the number of cases diagnosed, but there are no grounds for concluding that the disease is on the increase.
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Krimmel EF, Lutsch AGK, Swanepoel R, Brink J. Contribution to time-resolved enhanced chemical etching and simultaneous annealing of ion implantation amorphized silicon under intense laser irradiation. ACTA ACUST UNITED AC 1985. [DOI: 10.1007/bf00620461] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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66
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Swanepoel R, Leman PA, Shepherd AJ, Shepherd SP, Kiley MP, McCormick JB. Identification of Ippy as a Lassa-fever-related virus. Lancet 1985; 1:639. [PMID: 2857974 DOI: 10.1016/s0140-6736(85)92175-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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67
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Abstract
Rift Valley fever virus-induced protein synthesis was examined by polyacrylamide gel electrophoresis and fluorography. Five virus-induced polypeptides were detected, the nucleocapsid protein N, the nucleus-associated nonstructural protein NS1, the glycoproteins G1 and G2, and a protein of molecular weight 80K. The N, G1, G2, and 80K proteins were present in virion preparations. Sequential studies showed that NS1 accumulated in the nucleus as soon as it was formed and readily associated with nuclei partitioned from noninfected cells. The G1 and G2 proteins labelled with [3H]glucosamine and [3H]mannose. NS1 was shown to be the only virus-induced protein which was phosphorylated.
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Shepherd AJ, Leman PA, Hummitzsch DE, Swanepoel R. A comparison of serological techniques for plague surveillance. Trans R Soc Trop Med Hyg 1984; 78:771-3. [PMID: 6533848 DOI: 10.1016/0035-9203(84)90014-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Sera collected from 691 dogs and 231 rodents in South Africa were tested in parallel by the passive haemagglutination (PHA) and enzyme-linked immunosorbent assay (ELISA) for antibodies to the Fraction 1 antigen of the plague bacillus (Yersinia pseudotuberculosis subsp. pestis). There was a high degree of correlation between the tests, both in over-all numbers positive and in serum titres. 42 dog sera were positive by PHA and 41 by ELISA, 40 sera being positive by both tests. However, using ELISA the numbers of non-specific reactors in dog sera were cut by almost two thirds compared to PHA. The results of tests on rodent sera were identical: only one rodent was positive in both tests. The findings suggest that the ELISA test may have advantages over PHA for large scale serological surveillance.
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69
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Swanepoel R, Struthers JK, Shepherd AJ, McGillivray GM, Nel MJ, Jupp PG. Crimean-congo hemorrhagic fever in South Africa. Am J Trop Med Hyg 1983; 32:1407-15. [PMID: 6418019 DOI: 10.4269/ajtmh.1983.32.1407] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Crimean-Congo hemorrhagic fever virus was isolated for the first time in South Africa in February 1981, from the blood of a 13-year-old boy who died in Johannesburg after attending a camp in a nature reserve in the western Transvaal. Virus was isolated from 21/120 pools of questing ticks from the nature reserve, the infected species being Hyalomma marginatum rufipes and H. truncatum. Virus was also isolated from 4/38 pools of partially engorged ticks and other ectoparasites collected off hosts, the infected species being H.m. rufipes, H. truncatum and Rhipicephalus evertsi. Antibodies were found in the sera of 5/74 humans, 8/26 wild vertebrates, 74/270 sheep, and 109/170 cattle from the reserve and surrounding farms. Antibodies were also found in 28/200 hares from various locations in the country. It was concluded that the virus is widely prevalent in South Africa, but the full medical and veterinary significance of its presence has yet to be determined.
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70
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Gear JH, Miller GB, Martins H, Swanepoel R, Wolstenholme B, Coppin A. Tick-bite fever in South Africa. The occurrence of severe cases on the Witwatersrand. S Afr Med J 1983; 63:807-10. [PMID: 6687765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Tick-bite fever, the variety of tick typhus occurring in southern Africa, is caused by Rickettsia conori var. pijperi and is transmitted by hard or ixodid ticks. It is usually a mild disease, especially in children and young adults, but in middle-aged and elderly patients (and sometimes in young adults) it may assume a severe form. This is characterized by high fever, severe headache, delirium, stupor and occasionally coma, and a profuse maculopapular rash which becomes haemorrhagic and is associated with petechiae in the skin and later, but rarely, by the development of gangrene of the fingers and toes. During these severe attacks the central nervous system may be involved and marked disorders of liver and kidney function sometimes lead to kidney failure and the need for treatment and dialysis in an intensive care unit. Three illustrative cases are described in which diagnosis was delayed. One patient died; 2 patients responded to administration of tetracycline. The danger of allowing tick-infested dogs onto one's bed is stressed. Infections transmitted by dog ticks tend to be more severe than those acquired via ticks from the bushveld, possibly because they so often occur in middle-aged and elderly patients. Serological tests have recently indicated that there are antigenic differences between 'suburban' and 'bushveld' strains; these clearly require further study.
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71
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Swanepoel R, Struthers JK, McGillivray GM. Reversed passive hemagglutination and inhibition with Rift Valley fever and Crimean-Congo hemorrhagic fever viruses. Am J Trop Med Hyg 1983; 32:610-7. [PMID: 6407347 DOI: 10.4269/ajtmh.1983.32.610] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Reversed passive hemagglutination (RPHA) tests were performed by coating glutaraldehyde-fixed and tannic acid-treated sheep erthrocytes with antibodies to Rift Valley fever (RVF) and Crimean-Congo hemorrhagic fever (CCHF) viruses. Cells coated with crude antibody, in the form of mouse immune ascitic fluid, reacted with high specificity and sensitivity in RPHA tests with live or inactivated virus antigens. In inhibition (RPHI) tests, RVF antibody titers in human and sheep sera were similar to those determined by hemagglutination inhibition test. RVF virus antigen could be detected in viremic sheep sera by the RPHA technique. RPHI antibody titers to CCHF virus in human and hare sera were similar to indirect immunofluorescence (IF) titers, but sheep and cattle sera with RPHI titers of 1:32 or less were negative in IF tests.
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72
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Johnson BK, Ocheng D, Gitau LG, Gichogo A, Tukei PM, Ngindu A, Langatt A, Smith DH, Johnson KM, Kiley MP, Swanepoel R, Isaacson M. Viral haemorrhagic fever surveillance in Kenya, 1980-1981. TROPICAL AND GEOGRAPHICAL MEDICINE 1983; 35:43-47. [PMID: 6684336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Following two cases of Marburg virus disease in Kenya in 1980, viral haemorrhagic fever surveillance was undertaken in western Kenya. Over a 21-month period investigations, including virus isolation attempts, patient and contact serology, visits to areas where suspected cases occurred, interviewing family members and neighbours of suspected cases and following up any additional illnesses in these areas, were carried out. During the study two cases were found that were likely to have been Ebola haemorrhagic fever based on rising antibody titres or positive serology in contacts. Diagnoses of hepatitis A, hepatitis B, malaria, bacterial septicaemia or other causes were arrived at in 24 cases. No diagnosis could be made in 26 instances. 741 human sera were tested for antibodies against Marburg, Ebola, Congo haemorrhagic fever, Rift Valley fever or Lassa fever viruses by indirect fluorescence. Eight sera were positive for Ebola virus antibodies, all of which were from suspected cases or contacts of suspected cases. Two sera were antibody positive to Congo virus and one had antibodies against Rift Valley fever virus. No Marburg or Lassa virus antibodies were detected.
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73
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Struthers JK, Swanepoel R. Identification of a major non-structural protein in the nuclei of Rift Valley fever virus-infected cells. J Gen Virol 1982; 60:381-4. [PMID: 7108491 DOI: 10.1099/0022-1317-60-2-381] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
A non-structural protein of mol. wt. 34 X 10(3) was demonstrated in the nuclei of Rift Valley fever virus-infected Vero cells by SDS-polyacrylamide gel electro-phoresis. The protein appears to correspond to the virus-induced antigen demonstrated by indirect immunofluorescence in intranuclear inclusions.
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74
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Blackburn NK, Swanepoel R. An investigation of flavivirus infections of cattle in Zimbabwe Rhodesia with particular reference to Wesselsbron virus. J Hyg (Lond) 1980; 85:1-33. [PMID: 6300226 PMCID: PMC2134009 DOI: 10.1017/s0022172400027066] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A three-part epidemiological investigation was made on flaviviruses:1. As a preliminary to tests on cattle sera from the field, the antigenic cross-reactivity of Wesselsbron, Spondweni, Usutu, Banzi, West Nile and yellow fever flaviviruses was studied in antisera prepared in guinea pigs. As described earlier for flaviviruses, sera were found to be highly cross-reactive in haemagglutination-inhibition (HAI) tests, less cross-reactive in complement-fixation (CF) tests and were virtually monospecific in microneutralization (NT) tests in Vero cell cultures.2. Infection with Wesselsbron (WSL) virus produced mild febrile illness and viraemia in 5 out of 6 newborn calves, 3 out of 4 pregnant heifers and 3 out of 4 ewes. One heifer produced a weak calf which died soon after birth with WSL antibodies in its serum, indicating that infection had occurred in utero. The 3 other heifers produced healthy calves which lacked antibody in pre-colostral serum. Pathological changes occurred in the foetus in 2 out of 3 pregnant ewes and the ewe produced a healthy lamb which had antibodies to WSL virus in pre-colostral serum.Unlike the situation in guinea pigs, cattle sera were monospecific for WSL virus in CF tests, but sheep sera cross-reacted with Banzi and yellow fever viruses. Re-infection of the cattle with Banzi, West Nile, Spondweni and Usutu viruses failed to induce marked antibody responses. The results suggest that antibodies to WSL virus in cattle sera from the field can be distinguished from those induced by other flaviviruses by quantitative serological tests.3. HAI antibodies to WSL virus were detected in 2648/14395 cattle sera tested over 11 years from 1967 to 1978 in the course of investigation of abortion, infertility and other diseases. Results of quantitative HAI, CF and NT tests with six flaviviruses on 409 selected sera confirmed that infection was due to WSL virus. Serological evidence failed to implicate WSL virus as a cause of abortion in cattle. In a prospective study, abortion occurred in only one out of 21 heifers observed to gain WSL infection during pregnancy in the field, but abortion also occurred in five out of 207 heifers which did not become infected with WSL. No histopathological lesions diagnostic of WSL disease were observed in 1998 specimens from cattle, sheep and goats examined over 44 months prior to October 1972, and WSL virus was isolated once, from the organs of a cow, out of 2106 specimens from cattle sheep and goats tested virologically over six years from October 1972 to September 1978. HAI antibodies to WSL virus were detected in one out of 374 sera from aborted cattle foetuses. It was concluded that WSL virus is not an important cause of disease in cattle, despite widespread occurrence of infection.
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75
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Chambers PG, Swanepoel R. Rift valley fever in abattoir workers. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1980; 26:122-6. [PMID: 7190877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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76
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Foggin CM, Swanepoel R. Rabies in Rhodesia: the current situation. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1979; 25:98-103. [PMID: 455425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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77
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Maar SA, Swanepoel R, Gelfand M. Rift Valley fever encephalitis. A description of a case. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1979; 25:8-11. [PMID: 421266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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78
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Swanepoel R, Manning B, Watt JA. Fatal Rift Valley fever of man in Rhodesia. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1979; 25:1-8. [PMID: 421262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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79
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Fivaz BH, Swanepoel R, McKenzie RL, Wilson A. Passive transmission of Campylobacter fetus by immunised bulls. Aust Vet J 1978; 54:531-3. [PMID: 582385 DOI: 10.1111/j.1751-0813.1978.tb00325.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Two groups of 24 heifers were mated with 3 immunised and 3 susceptible bulls respectively. Six heifers in each group were infected artificially with Campylobacter fetus sub-sp. fetus biotype venerealis. Among susceptible heifers mated with immunised bulls, 13/18 became pregnant and 5/18 yielded evidence of infection with C. fetus. Among susceptible heifers mated with susceptible bulls, 7/18 became pregnant and 10/18 yielded evidence of infection. C. fetus was isolated on one occasion from an immunised bull, but the immunised bulls failed to develop carrier status and one was shown to be refractory to artificial challenge. Susceptible bulls developed carrier status during the breeding period. It is suggested that passive transmission of C. fetus by immunised bulls can occur under conditions of intensive sexual activity.
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80
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Mills RP, Swanepoel R, Hayes MM, Gelfand M. Dumb rabies: its development following vaccination in a subject with rabies. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1978; 24:115-7. [PMID: 28180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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81
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Swanepoel R, Foggin CM. The occurrence, diagnosis, treatment and control of rabies in Rhodesia. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1978; 24:107-14. [PMID: 679273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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82
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Swanepoel R, Blackburn NK, Efstratiou S, Condy JB. Studies on Rift Valley fever in some African murids (Rodentia: Muridae). J Hyg (Lond) 1978; 80:183-96. [PMID: 632561 PMCID: PMC2130003 DOI: 10.1017/s0022172400053535] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Brains, spleens and livers of 2214 murids, 27 shrews and 7 dormice, trapped at 7 sites in Rhodesia, were tested in 277 pools for the presence of Rift Valley Fever virus. There were no isolations of Rift Valley Fever, but 69 isolations of an unidentified virus were obtained. Sixteen out of 867 sera had low-titre haemagglutination-inhibition activity against Rift Valley Fever antigen, but only one out of 1260 sera had neutralizing antibody. The evidence suggests that murids fail to encounter infection in nature and are unlikely to play a role in circulation and dissemination of Rift Valley Fever virus. Four out of seven widely distributed species of muried, Rhabdomys pumilio, Saccostomys campestris, Aethomys chrysophilus and Lemniscomys griselda, were shown to be capable of circulating amounts of virus likely to be infective for mosquitoes.
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83
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Swanepoel R, Efstratiou S, Blackburn NK. Mycoplasma capricolum associated with arthritis in sheep. Vet Rec 1977; 101:446-7. [PMID: 595298 DOI: 10.1136/vr.101.22.446] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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84
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Swanepoel R, Blackburn NK. Demonstration of nuclear immunofluorescence in Rift Valley fever infected cells. J Gen Virol 1977; 34:557-61. [PMID: 323417 DOI: 10.1099/0022-1317-34-3-557] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Eosinophilic intranuclear filaments described previously in Rift Valley Fever infected cells, were shown to fluoresce specifically in an indirect technique with antiserum to the virus. Actinomycin D failed to suppress development of the filaments or replication of the virus.
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85
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86
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Swanepoel R. Studies on the epidemiology of Rift Valley Fever. J S Afr Vet Assoc 1976; 47:93-4. [PMID: 940102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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87
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Mackenzie PK, Boyt WP, Emslie VW, Lander KP, Swanepoel R. Immunosuppression in ovine trypanosomiasis. Vet Rec 1975; 97:452-3. [PMID: 1216438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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88
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Goldsmid JM, Rogers S, Gane NF, Dick J, Swanepoel R. Toxoplasmosis in the Rhodesian African. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1975; 21:196-8. [PMID: 1182796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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89
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Swanepoel R, Blackburn NK, Efstratiou S. An investigation of the relationship between infection with Toxoplasma gondii and contact with animals. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1974; 20:206-10. [PMID: 4426086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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90
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Swanepoel R, Cruickshank JG. Arthropod borne viruses of medical importance in Rhodesia 1968-1973. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1974; 20:71-9. [PMID: 4842729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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91
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Dent RI, Cruickshank JG, Gordon JA, Swanepoel R. An investigation of the effects of inoculated and intralymphatic vaccinia virus on primary and secondary deposits of malignant melanoma. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1972; 18:173-6. [PMID: 4650359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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92
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Cruickshank JG, Swanepoel R, Lowe RF, Robertson T, Moore H. Australia antigen--Rhodesia. 2. Survey of urban blood donors and rural populations. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1972; 18:113-6. [PMID: 5068863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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93
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Swanepoel R, Cruickshank JG. Smallpox in Rhodesia and the use of the electron microscope in the diagnosis of this and other diseases. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1972; 18:68-72. [PMID: 5037898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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94
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95
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Cruickshank JG, Swanepoel R. Australia antigen--Rhodesia. 1. Pilot survey. THE CENTRAL AFRICAN JOURNAL OF MEDICINE 1971; 17:205-7. [PMID: 5002838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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