Transcriptome analysis reveals immune pathways underlying resistance in the common carp Cyprinus carpio against the oomycete Aphanomyces invadans.

Infection with Aphanomyces invadans is a serious fish disease with major global impacts. Despite affecting over 160 fish species, some of the species like the common carp Cyprinus carpio are resistant to A. invadans infection. In the present study, we investigated the transcriptomes of head kidney of common carp experimentally infected with A. invadans. In time course analysis, 5288 genes were found to be differentially expressed (DEGs), of which 731 were involved in 21 immune pathways. The analysis of immune-related DEGs suggested that efficient processing and presentation of A. invadans antigens, enhanced phagocytosis, recognition of pathogen-associated molecular patterns, and increased recruitment of leukocytes to the sites of infection contribute to resistance of common carp against A. invadans. Herein, we provide a systematic understanding of the disease resistance mechanisms in common carp at molecular level as a valuable resource for developing disease management strategies for this devastating fish-pathogenic oomycete.

Cattle transhumance and agropastoral nomadic herding practices in Central Cameroon.

BACKGROUND: In sub-Saharan Africa, livestock transhumance represents a key adaptation strategy to environmental variability. In this context, seasonal livestock transhumance also plays an important role in driving the dynamics of multiple livestock infectious diseases. In Cameroon, cattle transhumance is a common practice during the dry season across all the main livestock production zones. Currently, the little recorded information of the migratory routes, grazing locations and nomadic herding practices adopted by pastoralists, limits our understanding of pastoral cattle movements in the country. GPS-tracking technology in combination with a questionnaire based-survey were used to study a limited pool of 10 cattle herds from the Adamawa Region of Cameroon during their seasonal migration, between October 2014 and May 2015. The data were used to analyse the trajectories and movement patterns, and to characterize the key animal health aspects related to this seasonal migration in Cameroon. RESULTS: Several administrative Regions of the country were visited by the transhumant herds over more than 6 months. Herds travelled between 53 and 170 km to their transhumance grazing areas adopting different strategies, some travelling directly to their destination areas while others having multiple resting periods and grazing areas. Despite their limitations, these are among the first detailed data available on transhumance in Cameroon. These reports highlight key livestock health issues and the potential for multiple types of interactions between transhumant herds and other domestic and wild animals, as well as with the formal livestock trading system. CONCLUSION: Overall, these findings provide useful insights into transhumance patterns and into the related animal health implications recorded in Cameroon. This knowledge could better inform evidence-based approaches for designing infectious diseases surveillance and control measures and help driving further studies to improve the understanding of risks associated with livestock movements in the region.

Accuracy of herdsmen reporting versus serologic testing for estimating foot-and-mouth disease prevalence.

Herdsman-reported disease prevalence is widely used in veterinary epidemiologic studies, especially for diseases with visible external lesions; however, the accuracy of such reports is rarely validated. Thus, we used latent class analysis in a Bayesian framework to compare sensitivity and specificity of herdsman reporting with virus neutralization testing and use of 3 nonstructural protein ELISAs for estimates of foot-and-mouth disease (FMD) prevalence on the Adamawa plateau of Cameroon in 2000. Herdsman-reported estimates in this FMD-endemic area were comparable to those obtained from serologic testing. To harness to this cost-effective resource of monitoring emerging infectious diseases, we suggest that estimates of the sensitivity and specificity of herdsmen reporting should be done in parallel with serologic surveys of other animal diseases.

Dogslife: a web-based longitudinal study of Labrador Retriever health in the UK.

BACKGROUND: Dogslife is the first large-scale internet-based longitudinal study of canine health. The study has been designed to examine how environmental and genetic factors influence the health and development of a birth cohort of UK-based pedigree Labrador Retrievers. RESULTS: In the first 12 months of the study 1,407 Kennel Club (KC) registered eligible dogs were recruited, at a mean age of 119 days of age (SD 69 days, range 3 days - 504 days). Recruitment rates varied depending upon the study team's ability to contact owners. Where owners authorised the provision of contact details 8.4% of dogs were recruited compared to 1.3% where no direct contact was possible. The proportion of dogs recruited was higher for owners who transferred the registration of their puppy from the breeder to themselves with the KC, and for owners who were sent an e-mail or postcard requesting participation in the project. Compliance with monthly updates was highly variable. For the 280 dogs that were aged 400 days or more on the 30th June 2011, we estimated between 39% and 45% of owners were still actively involved in the project. Initial evaluation suggests that the cohort is representative of the general population of the KC registered Labrador Retrievers eligible to enrol with the project. Clinical signs of illnesses were reported in 44.3% of Labrador Retrievers registered with Dogslife (median age of first illness 138 days), although only 44.1% of these resulted in a veterinary presentation (median age 316 days). CONCLUSIONS: The web-based platform has enabled the recruitment of a representative population of KC registered Labrador Retrievers, providing the first large-scale longitudinal population-based study of dog health. The use of multiple different methods (e-mail, post and telephone) of contact with dog owners was essential to maximise recruitment and retention of the cohort.

Risk factor analysis for antibodies to Brucella, Leptospira and C. burnetii among cattle in the Adamawa Region of Cameroon: a cross-sectional study.

Brucellosis, leptospirosis and Q fever are important livestock diseases, commonly responsible for significant production losses, yet their epidemiology in sub-Saharan Africa is largely unknown. Animal reservoirs pose the main risk of transmission to humans, where serious disease can occur. In the developing world setting, the flu-like symptoms of the acute stages of these diseases can be misdiagnosed as malaria, which can result in the administration of the wrong treatment, prolonged disease and increase in antibiotic resistance. Multivariable mixed-effects logistic regression models in this study revealed potential risk factors associated with the aforementioned pathogens in cattle in the Adamawa Region of Cameroon, with wildlife, namely, buffaloes, playing a major role in both Brucella and Coxiella burnetii seropositivity. Cattle mixing with other herds at night and cattle grazing in an area on a route taken by herds on transhumance appear to be positively associated with Leptospira seropositivity, while female cows and whether buffaloes are seen during grazing or transhumance are positively associated with C. burnetii seropositivity. On the other hand, animals that have been on transhumance in the past year and animals belonging to herdsmen of the Fulbe ethnic group appear to be protected against Leptospira and C. burnetii, respectively. Cattle of more than 2 years old appear to have increased odds of being seropositive to either pathogen. Further research is needed to confirm these findings and improve the knowledge of the epidemiology of these three pathogens in Africa, taking particular consideration of the wildlife involvement in the disease transmission.

Bovine Tuberculosis Antemortem Diagnostic Test Agreement and Disagreement in a Naturally Infected African Cattle Population.

The interferon-gamma (IFN-γ) assay and single comparative cervical skin test (SCITT) are used to estimate bovine tuberculosis (bTB) prevalence globally. Prevalence estimates of bTB, caused by Mycobacterium bovis, are poorly quantified in many Sub-Saharan African (SSA) cattle populations. Furthermore, antemortem diagnostic performance can vary at different stages of bTB pathogenesis and in different cattle populations. In this study, we aim to explore the level of agreement and disagreement between the IFN-γ assay and SCITT test, along with the drivers for disagreement, in a naturally infected African cattle population. In, 2013, a pastoral cattle population was sampled using a stratified clustered cross-sectional study in Cameroon. A total of 100 pastoral cattle herds in the North West Region (NWR) and the Vina Division (VIN) were sampled totalling 1,448 cattle. Individual animal data and herd-level data were collected, and animals were screened using both the IFN-γ assay and SCITT. Serological ELISAs were used to detect exposure to immunosuppressing co-infections. Agreement analyses were used to compare the performance between the two bTB diagnostic tests, and multivariable mixed-effects logistic regression models (MLR) were developed to investigate the two forms of IFN-γ assay and SCITT binary disagreement. Best agreement using the Cohen's κ statistic, between the SCITT (>2 mm) and the IFN-γ assay implied a 'fair-moderate' agreement for the NWR [κ = 0.42 (95%CI: 0.31-0.53)] and 'poor-moderate' for the VIN [κ = 0.33 (95% CI: 0.18-0.47)]. The main test disagreement was the animals testing positive on the IFN-γ assay and negative by the SCITT. From MLR modeling, adults (adults OR: 7.57; older adults OR = 7.21), females (OR = 0.50), bovine leucosis (OR = 2.30), and paratuberculosis positivity (OR = 6.54) were associated with IFN-γ-positive/SCITT-negative disagreement. Subsets to investigate diagnostic test disagreement for being SCITT-positive and IFN-γ-negative also identified that adults (adults OR = 15.74; older adults OR = 9.18) were associated with IFN-γ-negative/SCITT-positive disagreement. We demonstrate that individual or combined use of the IFN-γ assay and SCITT can lead to a large variation in bTB prevalence estimates. Considering that animal level factors were associated with disagreement between the IFN-γ assay and SCITT in this study, future work should further investigate their impact on diagnostic test performance to develop the approaches to improve SSA prevalence estimates.

A Cross-Sectional, Population-Based, Seroepidemiological Study of Rift Valley Fever in Cameroonian Cattle Populations.

Rift Valley fever (RVF) is an important emerging zoonoses causing abortion and neonatal deaths in livestock and hemorrhagic fever in humans. It is typically characterized by acute epidemics with abortion storms often preceding human disease and these events have been associated with the El Niño weather cycles. Outside of areas that experience epidemics, little is known about its epidemiology. Here, we present results from a serological study using biobank samples from a study of cattle conducted in 2013 at two sites in Cameroon. A total of 1,458 cattle from 100 herds were bled and sera screened using a commercially available RVF ELISA. The overall design-adjusted animal-level apparent seroprevalence of RVF exposure for the Northwest Region (NWR) of Cameroon was 6.5% (95% CI: 3.9-11.0) and for the Vina Division (VIN) of the Adamawa Region was 8.2% (95% CI: 6.2-11.0). The age-stratified serological results were also used to estimate the force of infection, and the age-independent estimates were 0.029 for the VIN and 0.024 for the NWR. The effective reproductive number was ~1.08. Increasing age and contact with wild antelope species were associated with an increased risk of seropositivity, while high altitudes and contact with buffalo were associated with a reduced risk of seropositivity. The serological patterns are more consistent with an endemical stability rather than the more typical epidemic patterns seen in East Africa. However, there is little surveillance in livestock for abortion storms or in humans with fevers in Cameroon, and it is, therefore, difficult to interpret these observations. There is an urgent need for an integrated One Health approach to understand the levels of human- and livestock-related clinical and asymptomatic disease and whether there is a need to implement interventions such as vaccination.

Seroepidemiology of Crimean-Congo Haemorrhagic Fever among cattle in Cameroon: Implications from a One Health perspective.

BACKGROUND: Crimean-Congo Haemorrhagic Fever (CCHF) is a tick-borne viral zoonotic disease distributed across several continents and recognized as an ongoing health threat. In humans, the infection can progress to a severe disease with high fatality, raising public health concerns due to the limited prophylactic and therapeutic options available. Animal species, clinically unaffected by the virus, serve as viral reservoirs and amplifier hosts, and can be a valuable tool for surveillance. Little is known about the occurrence and prevalence of Crimean-Congo Haemorrhagic Fever Virus (CCHFV) in Cameroon. Knowledge on CCHFV exposure and the factors associated with its presence in sentinel species are a valuable resource to better understand transmission dynamics and assess local risks for zoonotic disease emergence. METHODS AND FINDINGS: We conducted a CCHFV serological survey and risk factor analysis for animal level seropositivity in pastoral and dairy cattle in the North West Region (NWR) and the Vina Division (VD) of the Adamawa Region in Cameroon. Seroprevalence estimates were adjusted for sampling design-effects and test performance. In addition, explanatory multivariable logistic regression mixed-effects models were fit to estimate the effect of animal characteristics, husbandry practices, risk contacts and ecological features on the serological status of pastoral cattle. The overall seroprevalence was 56.0% (95% CI 53.5-58.6) and 6.7% (95% CI 2.6-16.1) among pastoral and dairy cattle, respectively. Animals going on transhumance had twice the odds of being seropositive (OR 2.0, 95% CI 1.1-3.8), indicating that animal movements could be implicated in disease expansion. From an ecological perspective, absolute humidity (OR 0.6, 95% CI 0.4-0.9) and shrub density (OR 2.1, 95% CI 1.4-3.2) were associated with seropositivity, which suggests an underlying viral dynamic connecting vertebrate host and ticks in a complex transmission network. CONCLUSIONS: This study demonstrated high seroprevalence levels of CCHFV antibodies in cattle in Cameroon indicating a potential risk to human populations. However, current understanding of the underlying dynamics of CCHFV locally and the real risk for human populations is incomplete. Further studies designed using a One Health approach are required to improve local knowledge of the disease, host interactions and environmental risk factors. This information is crucial to better project the risks for human populations located in CCHFV-suitable ecological niches.

Bovine Tuberculosis Epidemiology in Cameroon, Central Africa, Based on the Interferon-Gamma Assay.

Despite sub-Saharan Africa (SSA) accounting for ~20% of the global cattle population, prevalence estimates and related risk factors of bovine tuberculosis (bTB) are still poorly described. The increased sensitivity of the IFN-γ assay and its practical benefits suggest the test could be useful to investigate bTB epidemiology in SSA. This study used a population-based sample to estimate bTB prevalence, identify risk factors and estimate the effective reproductive rate in Cameroonian cattle populations. A cross-sectional study was conducted in the North West Region (NWR) and the Vina Division (VIN) of Cameroon in 2013. A regional stratified sampling frame of pastoral cattle herds produced a sample of 1,448 cattle from 100 herds. In addition, a smaller cross-sectional study sampled 60 dairy cattle from 46 small-holder co-operative dairy farmers in the NWR. Collected blood samples were stimulated with bovine and avian purified protein derivatives, with extracted plasma screened using the IFN-γ enzyme-linked immunosorbent assay (Prionics Bovigam®). Design-adjusted population prevalences were estimated, and multivariable mixed-effects logistic regression models using Bayesian inference techniques identified the risk factors for IFN-γ positivity. Using the IFN-γ assay, the prevalence of bTB in the dairy cattle was 21.7% (95% CI: 11.2-32.2). The design-adjusted prevalence of bTB in cattle kept by pastoralists was 11.4% (95% CI: 7.6-17.0) in the NWR and 8.0% (95% CI: 4.7-13.0) in the VIN. A within-herd prevalence estimate for pastoralist cattle also supported that the NWR had higher prevalence herds than the VIN. Additionally, the estimates of the effective reproductive rate R t were 1.12 for the NWR and 1.06 for the VIN, suggesting different transmission rates within regional cattle populations in Cameroon. For pastoral cattle, an increased risk of IFN-γ assay positivity was associated with being male (OR = 1.89; 95% CI:1.15-3.09), increasing herd size (OR = 1.02; 95% CI:1.01-1.03), exposure to the bovine leucosis virus (OR = 2.45; 95% CI: 1.19-4.84) and paratuberculosis (OR = 9.01; 95% CI: 4.17-20.08). Decreased odds were associated with contacts at grazing, buffalo (OR = 0.20; 95% CI: 0.03-0.97) and increased contact with other herds [1-5 herds: OR = 0.16 (95% CI: 0.04-0.55); 6+ herds: OR = 0.18 (95% CI: 0.05-0.64)]. Few studies have used the IFN-γ assay to describe bTB epidemiology in SSA. This study highlights the endemic situation of bTB in Cameroon and potential public health risks from dairy herds. Further work is needed to understand the IFN-γ assay performance, particularly in the presence of co-infections, and how this information can be used to develop control strategies in the SSA contexts.

The epidemiology of bacterial zoonoses in pastoral and dairy cattle in Cameroon, Central Africa.

Previous work identified that bacterial zoonoses (Brucella species, Coxiella burnetii and Leptospira hardjo) were present in Cameroonian pastoral cattle. To assess the characteristics of this zoonotic risk, we analyse seroprevalence of each pathogen and the associated management, herd and environmental factors in Cameroonian pastoral and dairy cattle. Cross-sectional samples included pastoralist herds in the Northwest Region (NWR n = 750) and Vina Division (VD n = 748) and small holder dairy herds in the NWR (n = 60). Exposure to Brucella spp., C. burnetii and L. hardjo were screened for using commercial ELISAs and population adjusted estimates made. In addition, individual, herd and ecological metadata were collected and used to identify risk factors associated with animal-level seropositivity. In the pastoral cattle, seroprevalence to Brucella spp. was relatively low but was higher in the NWR (4.2%, CI: 2.5%-7.0%) than the VD (1.1%: CI 0.5%-2.4%), while L. hardjo seroprevalence was much higher though similar in the NWR (30.7%, CI 26.3%-35.5%) and VD (35.9%, CI 31.3%-40.7%). No differences were noted in C. burnetii seroprevalence between the two study sites (NWR: 14.6%, CI 11.8%-18.0%. VD: 12.4%, 9.6%-15.9%). Compared to pastoral, dairy cattle had lower seroprevalences for L. hardjo (1.7%, CI: 0.0%-4.9%), C. burnetii (0.0%, CI 0.0%-6.0%) but similar for Brucella spp. (5.0%, CI 0.0%-10.6%). Increased odds of Brucella spp. seropositivity were associated with owning sheep or rearing sheep and fencing cattle in at night. Adult cattle had increased odds of being seropositive for both C. burnetii and L. hardjo. Additionally, exposure to C. burnetii was associated with local ecological conditions and L. hardjo was negatively associated with cattle undertaking transhumance. This work highlights that exposure to these 3 important production diseases and occupational zoonoses are widespread in Cameroonian cattle. Further work is required to understand transmission dynamics between humans and livestock to inform implementation of effective control measures.

Early warning indicators for hock burn in broiler flocks.

Hock burn is a common disease of broiler chickens affecting flock welfare and farmer income. Here we use hierarchical logistic regression (HLR) models to identify risk factors for hock burn using data from 5895 flocks, collected over 3.5 years by a large UK broiler company. The results suggest that at 2 weeks of age, weight and weight density may be useful predictors of flocks at risk of a high incidence of hock burn. In contrast, stocking density at placement is not. The use of these and other variables in disease prevention add value to routinely collected management data and can assist in improving broiler welfare and farm income.

Molecular insights into the mechanisms of susceptibility of Labeo rohita against oomycete Aphanomyces invadans.

Aphanomyces invadans, the causative agent of epizootic ulcerative syndrome, is one of the most destructive pathogens of freshwater fishes. To date, the disease has been reported from over 160 fish species in 20 countries and notably, this is the first non-salmonid disease that has resulted in major impacts globally. In particular, Indian major carps (IMCs) are highly susceptible to this disease. To increase our knowledge particularly with regards to host immune response against A. invadans infection in a susceptible host, the gene expression profile in head kidney of A. invadans-infected and control rohu, Labeo rohita was investigated using RNA sequencing. Time course analysis of RNA-Seq data revealed 5608 differentially expressed genes, involved among others in Antigen processing and presentation, Leukocyte transendothelial migration, IL-17 signaling, Chemokine signaling, C-type lectin receptor signaling and Toll-like receptor signaling pathways. In the affected pathways, a number of immune genes were found to be downregulated, suggesting an immune evasion strategy of A. invadans in establishing the infection. The information generated in this study offers first systematic mechanistic understanding of the host-pathogen interaction that might underpin the development of new management strategies for this economically devastating fish-pathogenic oomycete A. invadans.

Comparison of Two Rift Valley Fever Serological Tests in Cameroonian Cattle Populations Using a Bayesian Latent Class Approach.

Rift Valley Fever is an important zoonotic viral disease of livestock occurring across much of Africa causing acute febrile illness, abortion, and neonatal death in livestock particularly sheep and cattle and a range of disease in humans from mild flu-like symptoms to more severe haemorrhagic fever and death. Understanding the epidemiology requires well-evaluated tools including antibody detection ELISAs. It is well-recognized that tests developed in one population do not necessarily perform as well when used in different populations and it is therefore important to assess tests in the populations in which they are to be used. Here we describe the performance of a commercial RVF ELISA (ID.Vet) and an in-house plaque reduction neutralization test (PRNT80). A Bayesian no gold standard latent class model for two tests and ≥2 populations based on the Hui-Walter model was used to estimate the test parameters using a range of populations based on geographical separation and age to assess consistency of performance across different sub-populations. The ID.Vet ELISA had an estimated diagnostic sensitivity (Se) of 0.854 (0.655-0.991 95%BCI) and specificity (Sp) of 0.986 (0.971-0.998 95%BCI) using all the data and splitting the population by geographical region compared to 0.844 (0.660-0.973 95%BCI) and 0.981 (0.965-0.996 95%BCI) for the PRNT80. There was slight variation in the mean Se and Sp in different sub-populations mainly in Se estimates due to small numbers of positives in the sub-populations but the 95% BCI generally overlapped suggesting a very consistent performance across the different geographical areas and ages of animals. This is one of few reports of serological evidence of RVF in Central Africa and strongly suggests the virus is actively circulating in this cattle population. This has important public health implications and RVF should be considered as a differential in both livestock disease cases as well as human febrile cases in West and Central Africa not just East Africa. We also demonstrate that the performance of the commercial ELISA is comparable to the PRNT80 but has the advantages of speed, lower cost and no containment needs making it a much more useful test for low and middle income settings (LMICs).

Characterizing Livestock Markets, Primary Diseases, and Key Management Practices Along the Livestock Supply Chain in Cameroon.

Live animal markets are common hotspots for the dispersal of multiple infectious diseases in various production systems globally. In Cameroon livestock trade occurs predominantly via a system of livestock markets. Improving the understanding of the risks associated with livestock trade systems and markets is, therefore, key to design targeted and evidence-based interventions. In the current study, official transaction records for a 12-month period were collected from 62 livestock markets across Central and Southern Cameroon, in combination with a questionnaire-based survey with the livestock markets stakeholders. The available information collected at these markets was used to characterize their structural and functional organization. Based on trade volume, cattle price and the intensity of stakeholder attendance, four main classes of livestock markets were identified. Despite an evident hierarchical structure of the system, a relatively limited pool of infectious diseases was consistently reported as predominant across market classes, highlighting homogeneous disease risks along the livestock supply chain. Conversely, the variable livestock management practices reported (e.g., traded species, husbandry practices, and transhumance habits) highlighted diverse potential risks for disease dissemination among market classes. Making use of readily available commercial information at livestock markets, this study describes a rapid approach for market characterization and classification. Simultaneously, this study identifies primary diseases and management practices at risk and provides the opportunity to inform evidence-based and strategic communication, surveillance and control approaches aiming at mitigating these risks for diseases dissemination through the livestock supply chain in Cameroon.

Risk factors for the use of prescription antibiotics on UK broiler farms.

OBJECTIVES: Despite growing concerns about the emergence of antibiotic-resistant strains of bacteria, little work has been carried out to investigate reasons for prescription antibiotic use in UK farming systems. We carried out a nationwide survey of broiler farms to determine risk factors for the use of prescription antibiotics. METHODS: A cross-sectional questionnaire-based survey of UK broiler farms was undertaken covering flock placement dates from July 2002 until July 2003 and was based on information concerning 54% of the national broiler population reared on 497 farms. Data were collected on all aspects of broiler production and multivariable logistic regression analyses were performed to determine risk factors for two dependent variables; therapeutic and preventive use of antibiotics. RESULTS: The major indications for the use of antibiotics for therapeutic purposes were enteric and respiratory disease, the strongest association being with the occurrence of necrotic enteritis. No direct association was found between the use of antibiotics for preventive purposes and disease. Multivariable logistic regression analysis indicated that the main drivers for the use of antibiotics for disease prevention may be poultry company disease prevention policies and farm management practices. CONCLUSIONS: With increasing restrictions on the use of antibiotics in food-producing animals, research efforts need to be focused on the epidemiology of enteric and respiratory disease in poultry. The cost of disease to the broiler industry is great, resulting in the use of antibiotics for preventive purposes to safeguard against large financial losses. More research into alternative disease control measures is required.

Epidemiological consequences of an incursion of highly pathogenic H5N1 avian influenza into the British poultry flock.

Highly pathogenic avian influenza and in particular the H5N1 strain has resulted in the culling of millions of birds and continues to pose a threat to poultry industries worldwide. The recent outbreak of H5N1 in the UK highlights the need for detailed assessment of the consequences of an incursion and of the efficacy of control strategies. Here, we present results from a model of H5N1 propagation within the British poultry industry. We find that although the majority of randomly seeded incursions do not spread beyond the initial infected premises, there is significant potential for widespread infection. The efficacy of the European Union strategy for disease control is evaluated and our simulations emphasize the pivotal role of duck farms in spreading H5N1.

Tuberculosis in people newly diagnosed with HIV at a large HIV care and treatment center in Northwest Cameroon: Burden, comparative screening and diagnostic yields, and patient outcomes.

BACKGROUND: Diagnosis of tuberculosis in people living with HIV is challenging due to non-specific clinical presentations and inadequately sensitive diagnostic tests. The WHO recommends screening using a clinical algorithm followed by rapid diagnosis using the Xpert MTB/RIF assay, and more information is needed to evaluate these recommendations in different settings. METHODS: From August 2012 to September 2013, consecutive adults newly diagnosed with HIV in Bamenda, Cameroon, were screened for TB regardless of symptoms by smear microscopy and culture; the Xpert MTB/RIF assay was performed retrospectively. Time to treatment and patient outcomes were obtained from routine registers. RESULTS: Among 1,149 people enrolled, 940 (82%) produced sputum for lab testing; of these, 68% were women, the median age was 35 years (IQR, 28-42 years), the median CD4 count was 291cells/µL (IQR, 116-496 cells/µL), and 86% had one or more of current cough, fever, night sweats, or weight loss. In total, 131 people (14%, 95% CI, 12-16%) had sputum culture-positive TB. The WHO symptom screening algorithm had a sensitivity of 92% (95%CI, 86-96%) and specificity of 15% (95%CI, 12-17%) in this population. Compared to TB culture, the sensitivity of direct smear microscopy was 25% (95% CI, 18-34%), and the sensitivity of Xpert was 68% (95% CI, 58-76); the sensitivity of both was higher for people reporting more symptoms. Only one of 69 people with smear-negative/culture-positive TB was started on TB treatment prior to culture positivity. Of 71 people with bacteriologically-confirmed TB and known outcome after 6 months, 13 (17%) had died, including 11 people with smear-negative TB and 6 people with both smear and Xpert-negative TB. CONCLUSIONS: Use of the most sensitive rapid diagnostic test available is critical in people newly diagnosed with HIV in this setting to maximize the detection of bacteriologically-confirmed TB. However, this intervention is not sufficient alone and should be combined with more comprehensive clinical diagnosis of TB to improve outcomes.

Association of Fasciola gigantica Co-infection With Bovine Tuberculosis Infection and Diagnosis in a Naturally Infected Cattle Population in Africa.

Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a major livestock and public health problem in both high and low-income countries. With the current absence of an effective vaccine, control in cattle populations is reliant on regular testing and removal of positive animals. However, surveillance and control are hampered by imperfect diagnostic tests that have poorly described properties in naturally infected populations. Recent research in cattle co-infected with the temperate liver fluke, Fasciola hepatica, has raised concerns about the performance of the intradermal skin test in high fluke incidence areas. Further, recent studies of parasitic co-infections have demonstrated their impact on Th1 and Th2 responses, concurrent disease pathology and susceptibility to mycobacterial infections. Here we report for the first time the association of co-infection with the tropical liver fluke, Fasciola gigantica, with the presence of bTB-like lesions and the IFN-γ response in naturally infected African cattle. After adjusting for age and sex we observed a complex interaction between fluke status and breed. Fulani cattle had a higher risk of having bTB-like lesions than the mixed breed group. The risk of bTB-like lesions increased in the mixed breed group if they had concurrent evidence of fluke pathology but was less clear in the coinfected Fulani breed. Further, we observed a slight decline in the IFN-γ levels in fluke infected animals. Finally we explored factors associated with IFN-γ false negative results compared to the presence of bTB-like lesions. Fulani cattle had a higher risk of having a false negative result compared to the mixed breed group. Further, the mixed breed cattle had an increased risk of being false negative if also co-infected with fluke. Interesting, as with the risk of bTB-like lesions, this association was less clear in the Fulani cattle with weak evidence of a slight decrease in risk of having a false negative test result when fluke pathology positive. This interesting interaction where different breeds appear to have different responses to co-infections is intriguing but further work is needed to confirm and understand more clearly the possible confounding effects of different other co-infections not measured here, breed, management or exposure risks.

Evaluation of detailed training data to identify risk factors for retirement because of tendon injuries in Thoroughbred racehorses.

OBJECTIVE: To identify the risk factors for premature retirement because of tendon injury in a Thoroughbred racehorse population. ANIMALS: 175 Thoroughbred racehorses (cases) at the Hong Kong Jockey Club that were retired from racing because of tendon injury between 1997 and 2004 and for which the last preretirement exercise was at a fast pace were each matched with 3 control horses that were randomly selected from all uninjured horses that had galloped on the same date as that last exercise episode. PROCEDURES: Training data for all horses were examined. Conditional logistic regression analyses were performed to identify risk factors for retirement from racing attributable to tendon injury. Two multivariable conditional logistic regression models were created; each contained 8 explanatory variables. RESULTS: Compared with control horses, case horses were older at the time of import, accumulated more race distance soon after import, were more likely to have had previous official veterinary or ultrasonographic examinations, raced fewer times during their career, and were in training for a longer period and had exercised at a reduced intensity during the 180-day period preceding the last fast-paced work date. CONCLUSIONS AND CLINICAL RELEVANCE: In addition to identification of risk factors for tendon injury among racing Thoroughbreds, results have suggested that resources focused on obtaining accurate training data may be misdirected in the absence of internationally agreed criteria for incident tendon injury among racehorses. Nevertheless, changes in training intensity and findings of previous clinical examinations could be used to identify horses at risk of tendon injury-associated retirement.