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Ebola virus outbreaks in Africa: Past and present 全文
2012
J.J. Muyembe-Tamfum | S. Mulangu | Justin Masumu | J.M. Kayembe | A. Kemp | Janusz T. Paweska
Ebola virus outbreaks in Africa: Past and present 全文
2012
J.J. Muyembe-Tamfum | S. Mulangu | Justin Masumu | J.M. Kayembe | A. Kemp | Janusz T. Paweska
Ebola haemorrhagic fever (EHF) is a zoonosis affecting both human and non-human primates (NHP). Outbreaks in Africa occur mainly in the Congo and Nile basins. The first outbreaks of EHF occurred nearly simultaneously in 1976 in the Democratic Republic of the Congo (DRC, former Zaire) and Sudan with very high case fatality rates of 88% and 53%, respectively. The two outbreaks were caused by two distinct species of Ebola virus named Zaire ebolavirus (ZEBOV) and Sudan ebolavirus (SEBOV). The source of transmission remains unknown. After a long period of silence (1980–1993), EHF outbreaks in Africa caused by the two species erupted with increased frequency and new species were discovered, namely Côte d’Ivoire ebolavirus (CIEBOV) in 1994 in the Ivory Coast and Bundibugyo ebolavirus (BEBOV) in 2007 in Uganda. The re-emergence of EHF outbreaks in Gabon and Republic of the Congo were concomitant with an increase in mortality amongst gorillas and chimpanzees infected with ZEBOV. The human outbreaks were related to multiple, unrelated index cases who had contact with dead gorillas or chimpanzees. However, in areas where NHP were rare or absent, as in Kikwit (DRC) in 1995, Mweka (DRC) in 2007, Gulu (Uganda) in 2000 and Yambio (Sudan) in 2004, the hunting and eating of fruit bats may have resulted in the primary transmission of Ebola virus to humans. Human-to-human transmission is associated with direct contact with body fluids or tissues from an infected subject or contaminated objects. Despite several, often heroic field studies, the epidemiology and ecology of Ebola virus, including identification of its natural reservoir hosts, remains a formidable challenge for public health and scientific communities.
显示更多 [+] 显示较少 [-]Ebola virus outbreaks in Africa: Past and present 全文
2012
Muyembe-Tamfum, J.J.(Institut national de Recherche Biomédicale) | Mulangu, S.(Southern African Centre for Infectious Disease Surveillance) | Masumu, Justin(Institut national de Recherche Biomédicale) | Kayembe, J.M.(Université de Kinshasa) | Kemp, A.(National Institute for Communicable Diseases of the National Health Laboratory Service) | Paweska, Janusz T(National Institute for Communicable Diseases of the National Health Laboratory Service)
Ebola haemorrhagic fever (EHF) is a zoonosis affecting both human and non-human primates (NHP). Outbreaks in Africa occur mainly in the Congo and Nile basins. The first outbreaks of EHF occurred nearly simultaneously in 1976 in the Democratic Republic of the Congo (DRC, former Zaire) and Sudan with very high case fatality rates of 88% and 53%, respectively. The two outbreaks were caused by two distinct species of Ebola virus named Zaire ebolavirus (ZEBOV) and Sudan ebolavirus (SEBOV). The source of transmission remains unknown. After a long period of silence (1980-1993), EHF outbreaks in Africa caused by the two species erupted with increased frequency and new species were discovered, namely Cote d'lvoire ebolavirus (CIEBOV) in 1994 in the Ivory Coast and Bundibugyo ebolavirus (BEBOV) in 2007 in Uganda. The re-emergence of EHF outbreaks in Gabon and Republic of the Congo were concomitant with an increase in mortality amongst gorillas and chimpanzees infected with ZEBOV. The human outbreaks were related to multiple, unrelated index cases who had contact with dead gorillas or chimpanzees. However, in areas where NHP were rare or absent, as in Kikwit (DRC) in 1995, Mweka (DRC) in 2007, Gulu (Uganda) in 2000 and Yambio (Sudan) in 2004, the hunting and eating of fruit bats may have resulted in the primary transmission of Ebola virus to humans. Human-to-human transmission is associated with direct contact with body fluids or tissues from an infected subject or contaminated objects. Despite several, often heroic field studies, the epidemiology and ecology of Ebola virus, including identification of its natural reservoir hosts, remains a formidable challenge for public health and scientific communities.
显示更多 [+] 显示较少 [-]Comparative study on three locally developed live orf virus vaccines for sheep in Saudi Arabia 全文
2012
Fahdel M. Housawi | Eltayb M. Abuelzein | Ahmed A. Gamee | Adel I. Alafaleq
The epidemiology of orf virus infection in Saudi Arabia (SA) has been researched since 1990. The results obtained during this period indicate that the disease is widespread, has great economic impact and that no vaccine has been used against it. The present study compares the immunogenicity and protective efficacy of three locally developed live orf virus vaccines. Two of them differ in their passage history in Vero cell culture and the third was used as a virulent virus in glycerine buffer. To the best of the authors’ knowledge, no similar comparative study has been conducted in the Middle East utilising three types of vaccines prepared from the same virus strain. Selection of the candidate seed orf virus and performance of the quality control tests were as laid out by the OIE for veterinary vaccine production. The vaccine seed virus was a field orf virus isolated from a previous orf outbreak in Saudi Arabia. A simple novel formula was developed to calculate the rate of reduction in the healing time (RHT %) in the challenged sheep. This allowed direct comparison of the efficacy of the three types of vaccines employed in the present study. The efficacy of each vaccine was tested on a cohort of local Noemi sheep.
显示更多 [+] 显示较少 [-]Resource mapping and emergency preparedness to infectious diseases in human and animal populations in Kibaha and Ngorongoro districts, Tanzania 全文
2012
E.D. Karimuribo | B. Jones | M.I. Matee | D.M. Kambarage | S. Mounier-Jack | M.M. Rweyemamu
A rapid situation analysis was conducted in Kibaha and Ngorongoro districts in Tanzania to map resources as well as analysing emergency preparedness to infectious diseases in animal (domestic and wild) and human populations. Kibaha was chosen as a district close to a commercial city (Dar es Salaam) while Ngorongoro represented a remote, border district with high interactions between humans, domestic and wild animals. In this study, data on resources and personnel as well as emergency preparedness were collected from all wards (n = 22), human health facilities (n = 40) and livestock facilities in the two districts using interview checklists and questionnaires. Descriptive statistics for resources were calculated and mapped by district. Kibaha district had a higher human population density, more health workers, better equipped health facilities and better communication and transport systems. On the other hand, Ngorongoro had a higher population of livestock and more animal health facilities but a poorer ratio of animal health workers to livestock. The average ratio of health personnel to population in catchment areas of the health facilities was 1:147 (range of 1:17−1:1200). The ratio of personnel to human population was significantly higher in Kibaha (1:95) than in Ngorongoro (1:203) district (p = 0 < 0.001). Considering the limited resources available to both human and animal health sectors and their different strengths and weaknesses there are opportunities for greater collaboration and resource-sharing between human and animal health for improved surveillance and emergency-preparedness.
显示更多 [+] 显示较少 [-]<i>Bartonella</i> spp. in human and animal populations in Gauteng, South Africa, from 2007 to 2009 全文
2012
Anastasia N. Trataris | Jennifer Rossouw | Lorraine Arntzen | Allan Karstaedt | John Frean
Bartonellae are highly adaptive organisms that have the ability to evade the host immune system and cause persistent bacteraemia by occupying the host’s erythrocytes. Bartonella spp. is under-studied and health care professionals often misdiagnose Bartonella-related infections. The aim of this study was to investigate the carriage of Bartonella spp. circulating in human and animal populations in Gauteng using culturing and polymerase chain reaction (PCR) detection. A total of 424 human, 98 cat, 179 dog, and 124 wild rodent blood samples were plated onto specialised media and incubated for 7–21 days at 37 ºC in CO2. Culture isolates morphologically similar to Bartonella control strains were confirmed by PCR and sequenced to determine species. Deoxyribonucleic acid (DNA) was extracted from all blood samples and tested by nested PCR. Bartonella could only be cultured from the cat and rodent specimens. Cat isolates were > 99% similar to Bartonella henselae URBHLIE 9, previously isolated from an endocarditis patient, and rat isolates were > 98% similar to either RN24BJ (candidus ‘Bartonella thailandensis’) or RN28BJ, previously isolated from rodents in China. The PCR prevalences were 22.5% in HIV-positive patients, 9.5% in clinically healthy volunteers, 23.5% in cats, 9% in dogs and 25% in rodents. Findings of this study have important implications for HIV-positive patients.
显示更多 [+] 显示较少 [-]Detection of <i>Brucella abortus</i> in Chiredzi district in Zimbabwe 全文
2012
Calvin Gomo | Shuvai Musari | Michel de Garine-Wichatitsky | Alexandre Caron | Davies M. Pfukenyi | Henriette van Heerden
Brucellosis is an endemic disease in Zimbabwe caused by the genus <em>Brucella</em>. <em>Brucella</em> seroprevalence was recently reported to be high in the wildlife-livestock interface in the Chiredzi district and the neighbouring Gonarezhou National Park (GNP) in Zimbabwe, and higher amongst communal cattle with an abortion history and access to grazing in GNP than amongst communal cattle with no abortion history or access to grazing in GNP. The aim of this study was to investigate <em>Brucella</em> species in brucellosis seropositive cattle in the Chiredzi district with access to GNP using isolation and identification. Isolation of<em> Brucella </em>species from whole blood (<em>n</em> = 18) and milk samples (<em>n</em> = 10) from seropositive animals with an abortion history was based on the rose Bengal test (RBT) and enzyme-linked immunoassays (enzyme- linked immunosorbent assay [ELISA]; indirect ELISA and complement ELISA), using microbiology and polymerase chain reaction (PCR) methods. <em>Brucella abortus</em> was cultured and identified from blood and milk collected from seropositive cows in both communal areas. The<em> Brucella</em>-specific 16-23S intergenic spacer (ITS) PCR and multiplex AMOS-PCR assays verified the identification of the cultures. Our results confirmed that <em>B. abortus</em> is present in cattle on communal farms in the Chiredzi district in Zimbabwe and might cause cattle abortions. The need for implementing control measures and raising public awareness on zoonotic transmission of brucellosis are recommended.
显示更多 [+] 显示较少 [-]Molecular identification of <i>Cordylobia anthropophaga</i > Blanchard (Diptera: Calliphoridae) larvae collected from dogs (<i>Canis familiaris</i>) in Jos South, Plateau State, Nigeria 全文
2012
Ndudim I. Ogo | Emmanuel Onovoh | Oluyinka O. Okubanjo | Ruth C. Galindo | Jose-Manuel P. de la Lastra | Jose de la Fuente
Myiasis-causing larvae were extracted from dogs attending veterinary clinics in Plateau State, Nigeria and subjected to molecular analysis involving polymerase chain reaction amplification of the 28S rRNA gene of blowflies, cloning and sequencing techniques. All larvae were confirmed as Cordylobia anthropophaga Blanchard (Diptera: Calliphoridae) after the initial morphological identification. This is the first molecular identification of any myiasis-causing fly species in Nigeria and may serve as a reliable alternative to morphological identification where samples are not well preserved or difficult to identify to species level.
显示更多 [+] 显示较少 [-]Effect of packing on changes in erythrocyte osmotic fragility and malondialdehyde concentration in donkeys administered with ascorbic acid 全文
2012
Folashade Olaifa | Joseph O. Ayo | Suleiman F. Ambali | Peter I. Rekwot
Experiments were performed with the aim of investigating the effect of packing on erythrocyte osmotic fragility (EOF) and malondialdehyde (MDA) concentration in donkeys, and the effect of ascorbic acid (AA). Twelve apparently healthy donkeys raised under the traditional extensive system served as experimental subjects. Six donkeys administered orally with AA (200 mg/kg) and subjected to packing were used as experimental animals, whilst six others not administered with AA served as controls. Blood samples were collected pre- and post-packing from all the donkeys for the determination of MDA and EOF. At 0.3% Sodium Chloride (NaCl) concentration, the percentage haemolysis was 93.69% ± 2.21% in the control donkeys and the value was significantly (<em>P</em> < 0.05) higher than the value of 71.31% ± 8.33%, recorded in the experimental donkeys. The post-packing MDA concentration obtained in the control donkeys was 39.62 µmol ± 4.16 µmol, and was not significantly different (<em>P</em> > 0.05) from the value of 35.97 µmol ± 2.88 µmol recorded in the experimental donkeys. In conclusion, the increase in haemolysis obtained in the donkeys suggested that packing induced oxidative stress, which was ameliorated by AA administration.
显示更多 [+] 显示较少 [-]Epidemiological investigation into the introduction and factors for spread of Peste des Petits Ruminants, southern Tanzania 全文
2012
Epaphras A. Muse | Esron D. Karimuribo | George C. Gitao | Gerald Misinzo | Lesakit S.B. Mellau | Peter L.M. Msoffe | Emmanuel S. Swai | Mbyuzi O. Albano
Epidemiological investigation into the introduction and factors for spread of Peste des Petits Ruminants, southern Tanzania 全文
2012
Epaphras A. Muse | Esron D. Karimuribo | George C. Gitao | Gerald Misinzo | Lesakit S.B. Mellau | Peter L.M. Msoffe | Emmanuel S. Swai | Mbyuzi O. Albano
A study was carried out to confirm and identify sources and elucidate factors associated with the introduction of Peste des Petits Ruminants (PPR) in southern Tanzania. This study was conducted in Tandahimba and Newala districts of Mtwara region following suspected outbreak of PPR in the area. Qualitative data were collected using semi-structured questionnaires and in-depth interviews of key informants who included goat and sheep owners with suspected cases of PPR and animal health service providers as well as local administrative authority. Additionally, 216 serum samples and 28 swabs were collected for serological and virological laboratory disease confirmation. The results show that PPR was first introduced in Likuna village of Newala district in February 2009 through newly purchased goats from the Pugu livestock market located about 700 km in the outskirts of Dar es Salaam city. Factors which contributed to spread of PPR included communal grazing and the cheap prices of sick animals bought by livestock keepers for slaughtering in other villages. Laboratory findings confirmed presence of PPR in the area by RT-PCR and serological analysis revealed that seroprevalence was 31%. These findings have confirmed, for the first time, introduction of PPR in southern Tanzania. The presence of PPR poses high risk of southward spread of the disease to other southern African countries in the SADC region thus calling for concerted and collaborative efforts in prevention and control of the disease to avoid losses. Further elaborate studies on the spread, prevalence and risk factors associated with the disease should urgently be investigated.
显示更多 [+] 显示较少 [-]Epidemiological investigation into the introduction and factors for spread of Peste des Petits Ruminants, southern Tanzania 全文
2012
Muse, Epaphras A.(Sokoine University of Agriculture Department of Veterinary Microbiology and Parasitology) | Karimuribo, Esron D(Sokoine University of Agriculture Department of Veterinary Medicine and Public Health) | Gitao, George C(University of Nairobi Department of Veterinary pathology, Microbiology and Pathology) | Misinzo, Gerald(Sokoine University of Agriculture Department of Veterinary Microbiology and Parasitology) | Mellau, Lesakit S.B.(Sokoine University of Agriculture Department of Veterinary Medicine and Public Health) | Msoffe, Peter L.M.(Sokoine University of Agriculture Department of Veterinary Medicine and Public Health) | Swai, Emmanuel S.(Veterinary Investigation Centre Arusha) | Albano, Mbyuzi O.(Veterinary Investigation Centre Arusha)
A study was carried out to confirm and identify sources and elucidate factors associated with the introduction of Peste des Petits Ruminants (PPR) in southern Tanzania. This study was conducted in Tandahimba and Newala districts of Mtwara region following suspected outbreak of PPR in the area. Qualitative data were collected using semi-structured questionnaires and in-depth interviews of key informants who included goat and sheep owners with suspected cases of PPR and animal health service providers as well as local administrative authority. Additionally, 216 serum samples and 28 swabs were collected for serological and virological laboratory disease confirmation. The results show that PPR was first introduced in Likuna village of Newala district in February 2009 through newly purchased goats from the Pugu livestock market located about 700 km in the outskirts of Dar es Salaam city. Factors which contributed to spread of PPR included communal grazing and the cheap prices of sick animals bought by livestock keepers for slaughtering in other villages. Laboratory findings confirmed presence of PPR in the area by RT-PCR and serological analysis revealed that seroprevalence was 31%. These findings have confirmed, for the first time, introduction of PPR in southern Tanzania. The presence of PPR poses high risk of southward spread of the disease to other southern African countries in the SADC region thus calling for concerted and collaborative efforts in prevention and control of the disease to avoid losses. Further elaborate studies on the spread, prevalence and risk factors associated with the disease should urgently be investigated.
显示更多 [+] 显示较少 [-]The epidemiology and socio-economic impact of Rift Valley fever epidemics in Tanzania: A review 全文
2012
Calvin Sindato | Esron Karimuribo | E.G. Mboera
A review was conducted to provide comprehensive update on Rift Valley fever (RVF) in Tanzania, with particular attention devoted to trend of occurrence, epidemiological factors, socio-economic impact and measures which were applied to its control. Information presented in this paper was obtained through extensive literature review. Rift Valley fever was documented for the first time in Tanzania in 1977. This was followed by epidemics in 1997 and 2007. Contrary to the latest epidemic in 2007 sporadic cases of RVF during the previous epidemics were confined to mainly livestock and mostly affecting northern parts of Tanzania. The latest disease epidemic expanded to cover wider areas (mostly northern and central zones) of the country involving both human and domestic ruminants. During the latest disease outbreak 52.4% (n = 21) of regions in Tanzania mainland were affected and majority (72.7, n = 11) of the regions had concurrent infections in human and animals. Phylogenetic comparison of nucleotide and amimo acid sequences revealed different virus strains between Kenya and Tanzania. Epidemiological factors that were considered responsible for the previous RVF epidemics in Tanzania included farming systems, climatic factors, vector activities and presence of large population of ruminant species, animal movements and food consumption habits. Majority of the RVF positive cases in the latest epidemic were livestock under pastoral and agro-pastoral farming systems. The disease caused serious effects on rural people’s food security and household nutrition and on direct and indirect losses to livestock producers in the country. Psycho-social distress that communities went through was enormous, which involved the thinking about the loss of their family members and/or relatives, their livestock and crop production. Socially, the status of most livestock producers was eroded in their communities. Cessation of lucrative trade in ruminants resulted in serious economic losses to the populations who were totally dependent upon this income. Livestock internal market flows drastically dropped by 37% during latest epidemic. Rift Valley fever epidemics had dramatic impact of RVF outbreak on the international animal trade in which there was a 54% decline in exports equivalent to loss of $352 750.00. The estimate of loss as a result of deaths for cattle was $4 243 250.00 whereas that of goats and sheep was $2 202 467.00. Steps taken to combat epidemics included restriction of animal movements, ban of the slaughter of cattle and vaccination of livestock and health education. From past epidemics we have learnt that each subsequent outbreak had expanded to cover wider areas of the country. The disease had dramatic socio-economic impacts both at community and nation at large. The main challenges related to the control of RVF outbreaks included lack of preparedness plan for RVF, poor coordination and information transmission, limited facilities and manpower for RVF outbreak intervention. Control of the 2007 RVF epidemic was largely the result of animal and human health agencies working in an integrated manner.
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