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<i>Bartonella henselae</i> and <i>Bartonella quintana</i> seroprevalence in HIV-positive, HIV-negative and clinically healthy volunteers in Gauteng, South Africa
2012
Anastasia N. Trataris | Lorraine Arntzen | Jennifer Rossouw | John Frean | Allan Karstaedt
Bartonella is a genus of opportunistic, Gram-negative bacilli transmitted from animals to human hosts. Bartonellae are newly emerging pathogens that can cause a variety of clinical manifestations in both immunocompromised and healthy persons. The aims were to determine the IgG and IgM seroprevalences of Bartonella henselae and Bartonella quintana in immunocompromised and immunocompetent individuals using an immunofluorescence assay (IFA). A total of 382 HIV-positive outpatients of the Chris Hani Baragwanth HIV-clinic, 382 retrospective residual samples from HIV-negative antenatal patients, and 42 clinically healthy volunteers were tested using a commercially available IFA kit to determine the prevalence of IgG and IgM antibodies to B. henselae and B. quintana. The IgM and IgG seroprevalences for the HIV-positive patients were 14% (53/382) and 32% (121/382), respectively, compared to 18% for both IgM (62/342) and IgG (63/342) in the HIV- negative antenatal patients. Similarly, the prevalence for IgM was 17% (7/42) and IgG was 19% (8/42) for the clinically healthy volunteers. HIV-positivity appears to be a significant risk factor for Bartonella infection, compared with healthy subjects. Although IFAs have a high sensitivity for Bartonella antibody detection, they have various limitations including cross-reactivity with other closely-related human pathogens.
Show more [+] Less [-]The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa
2012
Anita L. Michel | Roy G. Bengis
The African buffalo (Syncerus caffer) is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after ‘Big Five’ in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD), Corridor disease (theileriosis), bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population’s survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.
Show more [+] Less [-]One Health: Towards safeguarding the health, food security and economic welfare of communities
2012
David Nabarro
Modulatory effect of ascorbic acid on physiological responses of transported ostrich chicks
2012
Minka N. Salka | Ayo J. Olusegun
The aims of this study were to determine the modulating role of ascorbic acid (AA) on rectal temperature (RT), heterophil to lymphocyte (H to L) ratio and aberrant behaviours of ostrich chicks transported by road for 4 h during hot-dry conditions. Twenty ostrich chicks aged 2.5 months, of both sexes and belonging to the Red Neck breed, served as subjects of the study. The chicks were assigned randomly to AA-treated and control groups, consisting of 10 chicks each. The AA-treated group was administered orally with 100 mg/kg body weight of AA dissolved in 5 mL of sterile water 30 min before transportation, whilst the control group was given the equivalent of sterile water only. The thermal load (TL) experienced in the vehicle during transportation fluctuated between 31 °C and 89 °C, as calculated from the ambient temperature and relative humidity. Transportation induced hyperthermia, lymphopenia, heterophilia and aberrant behaviours of pecking, wing fluffing and panting, which were ameliorated by AA administration. The relationships between the TL, journey duration and physiological variables of RT, H to L ratio and aberrant behaviours recorded during transportation were significantly and positively correlated in the control group. In AA-treated group the relationships were not significantly correlated. In conclusion, the results showed for the first time that AA ameliorated the adverse effects of stress caused by road transportation on the aberrant behaviours, RT and H to L ratio of ostrich chicks during the hot-dry season.
Show more [+] Less [-]Wildlife-associated zoonotic diseases in some southern African countries in relation to game meat safety: A review
2012
Johan L. Bekker | Louw C. Hoffman | Piet J. Jooste
With on-going changes in land use practices from conventional livestock farming to commercial, wildlife-based activities, the interface or interaction between livestock and wildlife is increasing. As part of the wildlife-based activities of ecotourism, breeding and hunting, game farmers are also exploring the utilisation of meat from hunted or harvested game. The expanding interface or increased interaction between livestock and wildlife increases the risk of disease incidence and the emergence of new diseases or the re-emergence of previously diagnosed diseases. The risk is not only related to domestic and wild animal health, but also to the occupational hazards that it poses to animal handlers and the consumers of game meat. This review endeavours to highlight the role that game plays in the spreading of zoonotic diseases to other animals and humans. Examples of zoonotic diseases that have occurred in wild animals in the past, their relevance and risk have been summarised and should function as a quick reference guide for wildlife veterinarians, ecologists, farmers, hunters, slaughter staff, processors and public health professionals.
Show more [+] Less [-]Ticks infesting animals in the Sudan and southern Sudan: Past and current status
2012
Ahmed A. ElGhali | Shawgi M. Hassan
In this review, we collate information about ticks identified in different parts of the Sudan and South Sudan since 1956 in order to identify gaps in tick prevalence and create a map of tick distribution. This will avail basic data for further research on ticks and policies for the control of tick-borne diseases. In this review, we discuss the situation in the Republic of South Sudan as well as Sudan. For this purpose we have divided Sudan into four regions, namely northern Sudan (Northern and River Nile states), central Sudan (Khartoum, Gazera, White Nile, Blue Nile and Sennar states), western Sudan (North and South Kordofan and North, South and West Darfour states) and eastern Sudan (Red Sea, Kassala and Gadarif states).
Show more [+] Less [-]Resource mapping and emergency preparedness to infectious diseases in human and animal populations in Kibaha and Ngorongoro districts, Tanzania
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.
Show more [+] Less [-]Prevalence of <i>Cryptosporidium</i> spp. and <i>Giardia duodenalis</i> in pigs in Lusaka, Zambia
2012
Joyce Siwila | Kabemba E. Mwape
This study was aimed at determining the prevalence of <em>Cryptosporidium</em> spp. and <em>Giardia duodenalis</em> in pigs which were being raised in intensive management systems. Faecal samples were collected from pigs of all age groups from three different piggery units. Samples were collected directly from the rectum for piglets and weaners and from the floor within 2 min – 5 min of excretion for sows and boars. At the time of collection, faecal consistency was noted as being normal, pasty or diarrhoeic. Samples were analysed further using the Merifluor® <em>Cryptosporidium</em>/<em>Giardia</em> immunofluorescence assay. All piggeries had at least one pig infected with either parasite. From a total 217 samples collected, 96 (44.2%; confidence interval [CI] = 37.6% – 50.9%) were positive for <em>Cryptosporidium</em> spp., whilst 26 (12%; CI = 7.6% – 16.3%) had <em>G. duodenalis</em> parasites. Of all the pigs, 6.9% (15/217) harboured both parasites. With regard to <em>Cryptosporidium</em> spp. infection, statistically significant differences were observed amongst the three units (<em>p</em> = 0.001), whereas no significant differences were observed for <em>G. duodenalis</em> infection (<em>p</em> = 0.13). Prevalence was higher in weaners as compared to other pig classes for both parasites, with significant differences being observed for <em>G. duodenalis</em> infection (<em>p</em> = 0.013). There was, however, no difference in infection between male and female pigs for both parasites. Furthermore, most infections were asymptomatic. From the study results it was clear that <em>Cryptosporidium</em> spp. and <em>G. duodenalis</em> infections were prevalent amongst pigs in the piggeries evaluated and, as such, may act as a source of infection for persons who come into contact with them.
Show more [+] Less [-]Investigation of water sources as reservoirs of <i>Vibrio cholerae</i> in Bepanda, Douala and determination of physico-chemical factors maintaining its endemicity
2012
Akoachere J.-F.K. Tatah | Kwedjeu M.C. Pulcherie | Ndip L. Mande | Njom H. Akum
Cholera remains a significant cause of mortality in developing countries. Outbreaks of the disease are associated with poverty, lack of potable water and poor sanitation. The survival and persistence of Vibrio cholerae in water has been shown to depend on physico-chemical factors. We studied water sources in Bepanda, an overcrowded neighbourhood in Douala, Cameroon, with limited access to portable water and very poor sanitary conditions as reservoirs of V. cholerae. We analysed 318 samples from various sources (well, tap, stream) from February to July 2009 using standard microbiological techniques and characterised isolates serologically using the polyvalent O1/O139 antisera. Susceptibility to antibiotics previously used for cholera treatment in Douala was studied using the disk diffusion method. Physico-chemical factors (temperature, pH and salinity) that could maintain the endemicity of the organism were analysed using standard methods. Eighty-seven (27.4%) samples were contaminated, with high isolation rates being obtained from streams (52.4%) and wells (29.8%). The number of isolates was significantly higher (P < 0.05) in the rainy season (35.5%). We detected 23 (24%) O1 serogroup isolates in streams and wells, whilst 64 (66.6%) were non-O1/non-O139. Temperature and salinity correlated positively with the occurrence of the organisms. All isolates were susceptible to fluoroquinolones but high resistance rates to trimethoprim or sulfamethozaxole and tetracycline were observed. Vibrio cholerae is endemic in Bepanda with O1 and non-O1/non-O139 serogroups co-existing in the streams and wells hence the possibility of future outbreaks of cholera if sanitation and drinking water quality are not improved. Temperature and salinity are amongst the factors maintaining the endemicity of the organism.
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