Mark Bronsvoort

Health-seeking behaviour of human brucellosis cases in rural Tanzania

BackgroundBrucellosis is known to cause debilitating conditions if not promptly treated. In some rural areas of Tanzania however, practitioners give evidence of seeing brucellosis cases with symptoms of long duration. The purpose of this study was to establish health-seeking behaviour of human brucellosis cases in rural Tanzania and explore the most feasible ways to improve it.MethodsThis was designed as a longitudinal study. Socio-demographic, clinical and laboratory data were collected from patients who reported to selected hospitals in rural northern Tanzania between June 2002 and April 2003. All patients with conditions suspicious of brucellosis on the basis of preliminary clinical examination and history were enrolled into the study as brucellosis suspects. Blood samples were taken and tested for brucellosis using the Rose-Bengal Plate Test (RBPT) and other agglutination tests available at the health facilities and the competitive ELISA (c-ELISA) test at the Veterinary Laboratory Agencies (VLA) in the UK. All suspects who tested positive with the c-ELISA test were regarded as brucellosis cases. A follow-up of 49 cases was made to collect data on health-seeking behaviour of human brucellosis cases.ResultsThe majority of cases 87.7% gave a history of going to hospital as the first point of care, 10.2% purchased drugs from a nearby drug shop before going to hospital and 2% went to a local traditional healer first. Brucellosis cases delayed going to hospital with a median delay time of 90 days, and with 20% of the cases presenting to hospitals more than a year after the onset of symptoms. Distance to the hospital, keeping animals and knowledge of brucellosis were significantly associated with patient delay to present to hospital.ConclusionMore efforts need to be put on improving the accessibility of health facilities to the rural poor people who succumb to most of the diseases including zoonoses. Health education on brucellosis in Tanzania should also stress the importance of early presentation to hospitals for prompt treatment.

Mortality in East African shorthorn zebu cattle under one year: predictors of infectious-disease mortality

BackgroundInfectious livestock diseases remain a major threat to attaining food security and are a source of economic and livelihood losses for people dependent on livestock for their livelihood. Knowledge of the vital infectious diseases that account for the majority of deaths is crucial in determining disease control strategies and in the allocation of limited funds available for disease control. Here we have estimated the mortality rates in zebu cattle raised in a smallholder mixed farming system during their first year of life, identified the periods of increased risk of death and the risk factors for calf mortality, and through analysis of post-mortem data, determined the aetiologies of calf mortality in this population. A longitudinal cohort study of 548 zebu cattle was conducted between 2007 and 2010. Each calf was followed during its first year of life or until lost from the study. Calves were randomly selected from 20 sub-locations and recruited within a week of birth from different farms over a 45 km radius area centered on Busia in the Western part of Kenya. The data comprised of 481.1 calf years of observation. Clinical examinations, sample collection and analysis were carried out at 5 week intervals, from birth until one year old. Cox proportional hazard models with frailty terms were used for the statistical analysis of risk factors. A standardized post-mortem examination was conducted on all animals that died during the study and appropriate samples collected.ResultsThe all-cause mortality rate was estimated at 16.1 (13.0-19.2; 95% CI) per 100 calf years at risk. The Cox models identified high infection intensity with Theileria spp., the most lethal of which causes East Coast Fever disease, infection with Trypanosome spp., and helminth infections as measured by Strongyle spp. eggs per gram of faeces as the three important infections statistically associated with infectious disease mortality in these calves. Analysis of post-mortem data identified East Coast Fever as the main cause of death accounting for 40% of all deaths, haemonchosis 12% and heartwater disease 7%.ConclusionThe findings demonstrate the impact of endemic parasitic diseases in indigenous animals expected to be well adapted against disease pressures. Additionally, agreement between results of Cox models using data from simple diagnostic procedures and results from post-mortem analysis underline the potential use such diagnostic data to reduce calf mortality. The control strategies for the identified infectious diseases have been discussed.

Sero-Prevalence and Incidence of A/H1N1 2009 Influenza Infection in Scotland in Winter 2009–2010

Background Sero-prevalence is a valuable indicator of prevalence and incidence of A/H1N1 2009 infection. However, raw sero-prevalence data must be corrected for background levels of cross-reactivity (i.e. imperfect test specificity) and the effects of immunisation programmes. Methods and Findings We obtained serum samples from a representative sample of 1563 adults resident in Scotland between late October 2009 and April 2010. Based on a microneutralisation assay, we estimate that 44% (95% confidence intervals (CIs): 40–47%) of the adult population of Scotland were sero-positive for A/H1N1 2009 influenza by 1 March 2010. Correcting for background cross-reactivity and for recorded vaccination rates by time and age group, we estimated that 34% (27–42%) were naturally infected with A/H1N1 2009 by 1 March 2010. The central estimate increases to >40% if we allow for imperfect test sensitivity. Over half of these infections are estimated to have occurred during the study period and the incidence of infection in late October 2009 was estimated at 4.3 new infections per 1000 people per day (1.2 to 7.2), falling close to zero by April 2010. The central estimate increases to over 5.0 per 1000 if we allow for imperfect test specificity. The rate of infection was higher for younger adults than older adults. Raw sero-prevalences were significantly higher in more deprived areas (likelihood ratio trend statistic = 4.92,1 df, P = 0.03) but there was no evidence of any difference in vaccination rates. Conclusions We estimate that almost half the adult population of Scotland were sero-positive for A/H1N1 2009 influenza by early 2010 and that the majority of these individuals (except in the oldest age classes) sero-converted as a result of natural infection with A/H1N1 2009. Public health planning should consider the possibility of higher rates of infection with A/H1N1 2009 influenza in more deprived areas.

Maternal antibody uptake, duration and influence on survival and growth rate in a cohort of indigenous calves in a smallholder farming system in western Kenya.

The passive transfer of antibodies from dams to offspring via colostrum is believed to play an important role in protecting neonatal mammals from infectious disease. The study presented here investigates the uptake of colostrum by 548 calves in western Kenya maintained under smallholder farming, an important agricultural system in eastern Africa. Serum samples collected from the calves and dams at recruitment (within the first week of life) were analysed for the presence of antibodies to four tick-borne haemoparasites: Anaplasma marginale, Babesia bigemina, Theileria mutans and Theileria parva. The analysis showed that at least 89.33% of dams were seropositive for at least one of the parasites, and that 93.08% of calves for which unequivocal results were available showed evidence of having received colostrum. The maternal antibody was detected up until 21 weeks of age in the calves. Surprisingly, there was no discernible difference in mortality or growth rate between calves that had taken colostrum and those that had not. The results are also important for interpretation of serosurveys of young calves following natural infection or vaccination.

HEMATOLOGIC AND BIOCHEMICAL REFERENCE INTERVALS FOR WILD OSPREY NESTLINGS (PANDION HALIAETUS)

A retrospective study of blood samples from 95 osprey (Pandion haliaetus) nestlings from Scotland and England, collected opportunistically over a 10-yr period, was performed to determine hematologic and plasma biochemistry reference intervals. The age of the sampled nestlings was estimated to be between 4 and 8 wk. Ninety-five percent reference intervals were determined for all hematologic and biochemical variables using parametric and nonparametric methods as appropriate. No blood parasites were detected. This is the first published study providing baseline reference data for osprey nestlings, and it is hoped the data will be of use to wildlife veterinarians and biologists in assessing the health of this species.

Estimating diagnostic accuracy of the tuberculin skin test and abbatoir meat inspection from bovine tuberculosis surveillance data

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Circulation of Foot-and-Mouth Disease Virus in Africa and identification of the underlying constraints using Phylogeographic methods

Foot and mouth disease is endemic in sub-Saharan Africa and can lead to important and continuous economic losses for the infected countries. Due the complexity of the disease epidemiology and the lack of data there is a need to use novel approaches to fill the gaps in our understanding of the circulation of FMD in this continent. Using a phylogeographical approach we reconstructed the circulation of foot and mouth disease virus serotypes A, O and SAT2 in Africa and evaluated the influence of potential environmental and anthropological predictors on the virus diffusion. Our results show that the circulation of serotypes A and O seems mainly driven by commercial exchanges while the SAT2 serotype origin can be found in wildlife populations. Both indirect transmission through persistence in the environment and anthropological activities such as cattle movements seem to have an impact on the circulation of the serotype O.Foot and mouth disease (FMD) is endemic in sub-Saharan Africa and can lead to important and continuous economic losses for affected countries. Due to the complexity of the disease epidemiology and the lack of data there is a need to use inferential computational approaches to fill the gaps in our understanding of the circulation of FMD virus on this continent. Using a phylogeographic approach we reconstructed the circulation of FMD virus serotypes A, O and SAT2 in Africa and evaluated the influence of potential environmental and anthropological predictors of virus diffusion. Our results show that over the last hundred year the continental circulation of the tree serotypes was mainly driven by livestock trade. Whilst our analyses show that the serotypes A and O were introduced in Africa trough livestock trades, the SAT2 serotype probably originates from African wildlife population. The circulation of serotype O in eastern Africa is impacted by both indirect transmission through persistence in the environment and anthropological activities such as cattle movements.

Brucellosis: veterinary and medical perspectives

BRUCELLOSIS IN HUMANS AND ANIMALS World Health Organization 98 pages, paperback, US

Assessment of the utility of using intra- and intervertebral minimum sagittal diameter ratios in the diagnosis of cervical vertebral malformation in horses.

22.50. FAO, OIE, WHO. 2006. ISBN 978 92 4 1547130 ![Figure][1] BRUCELLOSIS continues to present a major public health challenge due to under-reporting and misdiagnosis,