Official Control Program Research Articles

Cost-benefit analysis of foot and mouth disease control in Ethiopia

Foot and mouth disease (FMD) occurs endemically in Ethiopia. Quantitative insights on its national economic impact and on the costs and benefits of control options are, however, lacking to support decision making in its control. The objectives of this study were, therefore, to estimate the annual costs of FMD in cattle production systems of Ethiopia, and to conduct an ex ante cost-benefit analysis of potential control alternatives.The annual costs of FMD were assessed based on production losses, export losses and control costs. The total annual costs of FMD under the current status quo of no official control program were estimated at 1354 (90% CR: 864–2042) million birr. The major cost (94%) was due to production losses. The costs and benefits of three potential control strategies: 1) ring vaccination (reactive vaccination around outbreak area supported by animal movement restrictions, 2) targeted vaccination (annual preventive vaccination in high risk areas plus ring vaccination in the rest of the country), and 3) preventive mass vaccination (annual preventive vaccination of the whole national cattle population) were compared with the baseline scenario of no official control program. Experts were elicited to estimate the influence of each of the control strategies on outbreak incidence and number of cases per outbreak. Based on these estimates, the incidence of the disease was simulated stochastically for 10 years. Preventive mass vaccination was epidemiologically the most efficient control strategy by reducing the national outbreak incidence below 5% with a median time interval of 3 years, followed by targeted vaccination strategy with a corresponding median time interval of 5 years. On average, all evaluated control strategies resulted in positive net present values. The ranges in the net present values were, however, very wide, including negative values. The targeted vaccination strategy was the most economic strategy with a median benefit cost ratio of 4.29 (90%CR: 0.29–9.63). It was also the least risky strategy with 11% chance of a benefit cost ratio of less than one.The study indicates that FMD has a high economic impact in Ethiopia. Its control is predicted to be economically profitable even without a full consideration of gains from export. The targeted vaccination strategy is shown to provide the largest economic return with a relatively low risk of loss. More studies to generate data, especially on production impact of the disease and effectiveness of control measures are needed to improve the rigor of future analysis.

Critical analysis of molluscicide application in schistosomiasis control programs in Brazil.

In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are naturally infected by the trematode Schistosoma mansoni, the causative agent of schistosomiasis. Despite decades of governmental efforts through official control programs, schistosomiasis remains an important public health problem in the country: thousands of people are infected with the trematode each year and millions live in endemic areas. The World Health Organization recommends using a combination of molluscicide (niclosamide) and mass chemotherapy to control the transmission of schistosomiasis, with this treatment successfully reducing the morbidity of the disease. In the past, niclosamide has been used in official schistosomiasis control programs in Brazil. However, as B. glabrata recolonizes even after molluscicide application, the use of molluscicides has gradually decreased in the country until they were discontinued in 2002, mainly due to the rising global pressure to preserve the environment and the difficulties of obtaining licenses from the Brazilian Ministry of Environment to use toxic substances in aquatic ecosystems. Therefore, the discovery of new molluscicides, which could be more selective to Biomphalaria species and less harmful to the aquatic ecosystem, is necessary. In addition, political efforts to sensitize funders to provide grants for this field of research are required. In this context, this article aims to make a critical analysis of molluscicide application in schistosomiasis control programs in Brazil.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-016-0153-6) contains supplementary material, which is available to authorized users.

Systemic Foot-and-Mouth Disease Vaccination in Cattle Promotes Specific Antibody-Secreting Cells at the Respiratory Tract and Triggers Local Anamnestic Responses upon Aerosol Infection.

Foot-and-mouth disease (FMD) is a highly contagious viral disease affecting biungulate species. Commercial vaccines, formulated with inactivated FMD virus (FMDV), are regularly used worldwide to control the disease. Here, we studied the generation of antibody responses in local lymphoid tissues along the respiratory system in vaccinated and further aerosol-infected cattle. Animals immunized with a high-payload monovalent FMD vaccine developed high titers of neutralizing antibodies at 7 days postvaccination (dpv), reaching a plateau at 29 dpv. FMDV-specific antibody-secreting cells (ASC), predominantly IgM, were evident at 7 dpv in the prescapular lymph node (LN) draining the vaccination site and in distal LN draining the respiratory mucosa, although in lower numbers. At 29 dpv, a significant switch to IgG1 was clear in prescapular LN, while FMDV-specific ASC were detected in all lymphoid tissues draining the respiratory tract, mostly as IgM-secreting cells. None of the animals (n = 10) exhibited FMD symptoms after oronasal challenge at 30 dpv. Three days postinfection, a large increase in ASC numbers and rapid isotype switches to IgG1 were observed, particularly in LN-draining virus replication sites already described. These results indicate for the first time that systemic FMD vaccination in cattle effectively promotes the presence of anti-FMDV ASC in lymphoid tissues associated with the respiratory system. Oronasal infection triggered an immune reaction compatible with a local anamnestic response upon contact with the replicating FMDV, suggesting that FMD vaccination induces the circulation of virus-specific B lymphocytes, including memory B cells that differentiate into ASC soon after contact with the infective virus. Over recent decades, world animal health organizations as well as national sanitary authorities have supported the use of vaccination as an essential component of the official FMD control programs in both endemic and disease-free settings. Very few works studied the local immunity induced by FMD vaccines at the respiratory mucosa, and local responses induced in vaccinated animals after aerosol infection have not been described yet. In this work, we demonstrate for the first time that systemic FMD vaccination (i) induced the early presence of active antigen-specific ASC along the respiratory tract and (ii) prompted a rapid local antibody response in the respiratory mucosa, triggered upon oronasal challenge and congruent with a memory B-cell response. This information may help to understand novel aspects of protective responses induced by current FMD vaccines as well as to provide alternative parameters to establish protection efficiency for new vaccine developments.

Effects of Caligus rogercresseyi (Boxshall and Bravo, 2000) infestation on physiological response of host Salmo salar (Linnaeus 1758): Establishing physiological thresholds

Abstract After the sanitary crisis suffered by the Chilean salmon industry (infectious salmon anemia virus and Caligus rogercresseyi), the Chilean National Fisheries Service implemented an official surveillance and control program, including a threshold at which control measures of lice must be taken. However, this threshold was set as a way to prevent outbreaks of the parasite population and did not consider salmon welfare. This study evaluated how different abundances of attached and mobile stages of C. rogercresseyi affected the physiological response of Salmo salar and identified the threshold at which parasite populations caused negligible physiological effects on the host. Three groups of S. salar juveniles, with two replicates each, were randomly assigned to six tanks. Two experimental groups were subjected to infestation pressures of 50 and 100 copepodids per fish, and the control group was not exposed to any copepodids. Sampling was done at 1 day pre-infestation and 1, 8, 16, and 22 days postinfestation. During sampling, C. rogercresseyi specimens were classified as either copepodid, chalimus I–II, chalimus III–IV and adults (female and male). The physiological variables measured in the sampled fish were cortisol (as the primary stress response) and plasma proteins, amino acids, triglycerides, lactate, osmolality, and number and diameter of skin mucous cells (as secondary stress responses). All variables were analyzed using a piecewise linear approach. Significant effects were observed for all variables and along the development of the parasite. The lowest threshold of which negligible impact was observed was six adult C. rogercresseyi per fish: above this level, the fish physiology was altered. Advanced stages of the parasite were the most detrimental to fish physiology, as suggested by both high cortisol levels and chronic energy demand. This is the first study to evaluate the effects of C. rogercresseyi on S. salar physiology, information that constitutes a valuable, objectively derived tool to aid in the development of effective, integrated pest management programs.

The rob(1;29) chromosome translocation in endangered Andalusian cattle breeds

In this study, we analysed the distribution of the t(1;29) Robertsonian translocation to determine whether this polymorphism contributes to the low reproduction efficiency observed in five endangered Andalusian (Spain) cattle breeds: Berrenda en Negro (BN), Berrenda en Colorado (BC), Cardena Andaluza (CA), Pajuna (PA) and Negra Andaluza (NA). All these breeds were reared exclusively in reproductive isolation under grazing conditions with natural mating. In total, we analysed the distribution of the rob(1;29) translocation in 714 animals: 192 BN, 235 BC, 156 CA, 56 PA and 75 NA. We also examined the translocation frequencies, F statistics and deviations from Hardy–Weinberg equilibrium among different herds and breeds and characterised the influence of geographical location and sex. The FST values (P<0.05) revealed differences among the breeds and herds in BC, BN and CA. There were no significant geographical differences, except in the Cardena breed (P<0.001). In addition to reproductive isolation, the differences observed among the herds might reflect the sporadic movement of bulls belonging to flocks with a high frequency of translocation, genetic drift and anthropic selection. The rob(1;29) frequency was reduced in some breeds, potentially reflecting the effects of human selection and breeding strategies implemented through official control programmes for this anomaly. In other breeds, the translocation remains present at high frequencies, reflecting crossbreeding with the Retinta breed, which has a high frequency of rob(1;29). No significant deviation in the expected percentage of heterozygotes was detected in any breed. The differences observed in the rob(1;29) frequencies in the endangered Andalusian cattle might be more attributable to internal factors than to differences between the breeds. Further studies regarding the mobility of sires among herds are warranted to determine the origin of the variations in the rob(1;29) frequencies observed in endangered Andalusian breeds.

In-house quality control material of nicarbazin and narasin in eggs: preparation and inter-laboratory evaluation

Coccidiostats are a group of pharmacologically active substances widely used in veterinary practice. Their residues are detected relatively often in poultry tissues and egg samples analyzed as part of official residue control programs in the European Union. Therefore, accuracy of quantitative results needs to be monitored through internal and external quality control studies. In addition, the use of materials containing incurred residues would be welcome to for ongoing monitoring of the method accuracy. Unfortunately, in the field of veterinary drug residues, certified reference materials are often unavailable. Therefore, in-house quality control material of incurred lyophilized eggs containing narasin and nicarbazin has been produced and characterized. The eggs originated from hens receiving feed with coccidiostat premix Maxiban were mixed to obtain presumed concentrations of residues and freeze-dried. Homogeneity of the material was verified by the duplicate analysis of ten random samples, and the results proved that the between samples variation was negligible in comparison with the method repeatability. No measurable loss of analytes was observed within 1 year; the slope of the regression line of the results of stability measurements was not significantly different from zero. The assigned values were expressed as medians of the results of inter-laboratory comparison performed in four different European laboratories; the uncertainty of the material was estimated, taken into consideration all above tests, resulting in (14.4 ± 2.53) µg/kg for nicarbazin and (7.91 ± 1.52) µg/kg for narasin.

Evaluation of the use of CALUX results for dioxins and dioxin-like PCBs analysis for quantitative human exposure assessments

The objective of this study was to evaluate if the analysis results of dioxins and dioxin-like PCBs in food matrices obtained using the screening CALUX (Chemically Activated LUciferase gene eXpression) method, could be used for quantitative risk assessment.Contamination data of dioxins and dioxin-like PCBs in food matrices (dairy product, eggs, fish, animal fat and vegetable oil) obtained by the CALUX screening method and by the reference method (GC-HRMS) have been compared. Significant differences between the two methods were observed. Median concentrations of dioxins with the CALUX methods for the food matrices are about twice the median concentration of dioxins with the GC-HRMS. These discrepancies indicate that the data obtained using the CALUX method within the framework of the Belgian official control program cannot be used in risk assessment, specifically for an accurate estimation of the dietary intake of dioxins and dioxin-like PCBs. This can be explained, on one hand, by the promiscuous nature of the Aryl hydrocarbon Receptor (AhR) (whose ligand activation is responsible of the response measured in the CALUX assay) as it effectively binds to a large number of diversely shaped compounds not belonging to the 17 dioxins/furans and the 12 dioxin-like PCBs congeners. On the other hand, the assay is implemented as a screening tool for compliance monitoring where emphasis on method performance is required around the maximum levels, leading to a lack of accuracy for lower or higher concentrations.

Ruminant brucellosis in Upper Egypt (2005–2008)

Brucellosis is endemic among humans and ruminant in Egypt and recent reports suggest that its incidence may be increasing. In this study we describe the frequency of brucellosis among different ruminant species in Upper Egypt and its spatial distribution using the data generated by a large-scale control campaign undertaken between 2005 and 2008. A total of 120,090 individual animals of different ruminant species were tested during the campaign. The true proportions of brucellosis were estimated as 0.79% (CI: 0.71%–0.87%), 0.13% (CI: 0.08%–0.18%), 1.16% (1.05%–1.27%) and 0.44% (0.34%–0.54%) among cattle, buffaloes, sheep and goats respectively. We estimated that 0.2% (CI: 0.16%–0.23%) of households in the study area keep at least one seropositive animal. Spatial autocorrelation of the proportions of seropositive households and seropositive animals was assessed using Global Univariate Moran's I and Local Univariate LISA. These analyses showed that the distribution of seropositive animals has considerable spatial heterogeneity with clustering in the northern governorates of the study area. Our results show that brucellosis is widespread and heterogeneously distributed in Upper Egypt. At the current level of available resources it is very unlikely that test and slaughter could be implemented with the intensity needed to be effective and other control measures that could replace or complement the test and slaughter policy in place should be considered. Also, this study illustrates some of the challenges faced by bilateral projects that have to accommodate an externally funded intervention with an ongoing national official disease control program.

Assessment and simulation of the implementation of brucellosis control programme in an endemic area of the Middle East

Brucellosis is an important zoonosis in Middle Eastern countries. In this study we assessed the extent of the application of planned official brucellosis control programmes in Kafr El Sheikh governorate, Egypt and we used a stochastic simulation model to assess the probable impact of changes to the official control strategy on the dynamics of small-ruminant brucellosis. Our results show that <7% of female livestock were tested in any given year in the study area and that quarantine was not consistently applied to infected herds. Simulation results revealed the inability of the applied control measures to reduce the prevalence of small-ruminant brucellosis. Given our assumptions, the intensity with which infected animals are removed under the actual levels of implementation of test-and-slaughter programmes would permit brucellosis to remain endemic at a level >8% of the sheep and goat population.

Comparison of culture, ELISA and PCR Techniques for salmonella detection in faecal samples for cattle, pig and poultry

BackgroundPerformances of different salmonella detection methods were evaluated by applying them to of artificially contaminated faecal specimens from cattle, pigs and poultry. The NMKL71 method, being the standard reference method for detection of salmonella in the official Swedish control program, was compared with the proposed ISO method using MSRV-selective enrichment for culturing, and also with three commercial ELISA- based systems, Bioline Selecta, Bioline Optima and Vidas, a commercial PCR-based method, BAX® system, and three different strategies using PCR detection using a non-commercial PCR system.ResultsAltogether, 391 samples were tested, and the overall results clearly indicate that, when faeces from all animal species and all serotypes were included, the MSRV performed best, with a calculated accuracy of 99% and a calculated sensitivity of 98%. The second most sensitive and specific method was the BAX® system, using the modified enrichment protocol as recommended by the manufacturer for faecal samples. However, this protocol includes one additional day of work, as compared with the standard procedure for food sample analysis by the same method. The different strategies for salmonella detection using non-commercial PCR showed a sensitivity and specificity in the same range as the BAX® method; furthermore, results were obtained more quickly. The various commercial ELISA methods and the NMKL method showed the poorest performance of the methods included in the study, and were closely dependent on the origin of the faeces used and on which salmonella strain was to be detected.ConclusionThe study showed that the sensitivity of the different methods depended to a great extent on the origin of the faecal matrices and the salmonella strains used to "spike" the samples.

Food safety surveillance through a risk based control programme: Approach employed by the Belgian Federal Agency for the safety of the food chain

Summary The principal responsibility of the Belgian Federal Agency for the Safety of the Food Chain (FASFC) is to guarantee the safety along the food chain. In order to accomplish this responsibility, the FASFC has developed an integrated official control program to check compliance with various regulations. The original methodology developed and applied by FASFC is presented. This methodology is based on risk evaluation, statistical tools and current scientific knowledge.

Cross-contamination of ruminant feed stuffs in Bavaria after the comprehensive feed ban

The results of the official feed control program in Bavaria between 1997 and 2002 document that the proportion of ruminant feedstuffs that was cross-contaminated with animal material was distinctively reduced after the comprehensive feed ban since 2001, and decreased close to zero in 2002. The results underline the high efficiency of the comprehensive feed ban. They also indicate risks of a potential re-admittance of animal protein for nonruminant domestics under the momentary production procedures.

Confirmatory analysis of 17β-boldenone, 17α-boldenone and androsta-1,4-diene-3,17-dione in bovine urine by liquid chromatography–tandem mass spectrometry

A sensitive and selective liquid chromatography–tandem mass spectrometry (LC–MS–MS) method for confirmatory analysis of 17β-boldenone (17β-BOL), 17α-boldenone (17α-BOL) and androsta-1,4-diene-3,17-dione (ADD) in bovine urine was developed. [ 2H 2]17β-Testosterone (17β-T-d 2) was used as the internal standard. Sample preparation involved enzymatic hydrolysis and purification on a C 18 solid-phase extraction column. Chromatographic separation of the analytes was obtained using an RP-C 18 HPLC column. LC–MS–MS detection was carried out with an atmospheric pressure chemical ionisation (APCI) source equipped with a heated nebulizer (HN) interface operating in the positive ion mode. For unambiguous hormone confirmation, three analyte precursor–product ion combinations were monitored during multiple-reaction monitoring (MRM) LC–MS–MS analysis. Overall recovery (%), repeatability (relative standard deviations, RSD, %) and within-laboratory reproducibility (RSD, %) ranged from 92.2 to 97.7%, from 6.50 to 2.94% and from 13.50 to 5.04%, respectively, for all analytes. The limit of quantification in bovine urine was 0.20 ng ml −1 for 17β-BOL and ADD and 0.50 ng ml −1 for 17α-BOL. The validated method was successfully applied for determination of 17β-BOL, 17α-BOL and ADD in a large number of bovine urine samples collected within the national Official Residue Control Program.

Planning an Indian Modernity: The Gendered Politics of Fertility Control

With a population estimated at over 971 million India is expected to overtake China as the worlds most populous country in the twenty-first century. Notwithstanding the growing debate among social scientists activists and policy makers about linkages between population development and the environment in the public mind India continues to be associated with images of teeming and exploding masses mired in human degradation ecological devastation and civil strife. In this context it bears pointing out that the Indian state was the first in the world to initiate an official population control program in 1952. Nearly fifty years later assessments of the Indian family planning programs performance are mixed but the Indian fertility rate is declining despite overall population growth. Our interest in this article is not to argue for or against population control or to evaluate Indias success or failure in this regard but to address Indias state-sponsored population control program-its history ideology and strategies-and to examine the contours of a nationalist modernist project that is by definition gendered and classed and an ongoing product of struggles between multiple actors both beyond and within the state. We argue that Indian family planning intervention which is part of a broad postcolonial developmental agenda represents both an appropriation of and resistance to a hegemonic Western conception of the modern. We analyze the national fertility control programs domestication of modernity through a selective indigenization of modernitys core values noting that at another level this process-the linking of individual and family reproductive behavior to national welfare and the promotion of modernity as embodied practice-is itself an inherently modern project as is the phenomenon of government planning. Furthermore we draw attention to the overtly paternalistic and elitist character of the Indian fertility control program that targets women of all classes and the poor in general. (excerpt)

Serological and Molecular Diagnosis of Bovine Viral Diarrhoea Virus and Evidence of other Viral Infections in Dairy Calves with Respiratory Disease in Venezuela

An investigation based on 2 studies was carried out to assess the involvement of bovine virus diarrhoea virus (BVDV), bovine herpesvirus type 1 (BHV-1), and bovine respiratory syncytial virus (BRSV) in calf respiratory disease in dairy farms in Venezuela. In the first study, 8 farms were selected and paired serum samples from 42 calves with respiratory disease were tested by ELISA for antibodies to the 3 viruses. Seroconversion to BVDV, BHV-1, and BRSV was found to 5, 2, and 6 farms out of the 8, respectively. The proportion of calves that showed seroconversion to BVDV, BHV-1, and BRSV were 19%, 14%, and 26%, respectively. In the second study, another farm having previous serological evidence of BVDV infection was selected. The decline of maternal antibodies against BVDV was monitored in 20 calves and the half-life of maternal antibodies was 34 +/- 12 days presumably indicating an early natural infection with BVDV. Furthermore, sera free of BVDV antibodies that were collected in studies 1 and 2 and were assayed for the presence of BVDV by nested RT-PCR. Two BVDV strains were detected and compared to those of ruminant and porcine pestiviruses. Both strains were assigned to subgroup Ib of type I BVDV. This investigation provides information on BVDV genotypes circulating in Venezuela and may contribute to the establishment of official control programmes against the viruses studied.

Control comunitario de las infecciones endémicas: pensando los haceres sanitarios colectivos de los campesinos de los Andes peruanos

Discussing four rural experiences with leishmaniasis and malaria control in the Peruvian Andes, this paper analyzes concepts of peripheral health cultures and underlying logic in practical action. Peripheral health cultures in this case refer to the planning, organizing, and intervention abilities used to cope with relevant local health problems. The logic of practical action refers to the constant creation of specific action modes, different from those of other groups. In conclusion, this paper suggests the transformation of official disease control programs by incorporating such forms of logic, characterized by solidarity, inclusion, and cultural appropriateness.

Sociomedical aspects of malaria control in Colombia

A household interview survey combined with a serological survey on the incidence of malaria attacks and prevalence of antibodies has been carried out in rural and urban areas of the pacific coast of Colombia. Additional information on people's knowledge, attitudes and behaviour towards malaria was collected by means of participant observation and informal interviews. The results show that people incorporate modern and traditional elements into their concepts of the disease and treatment strategies. The deficiencies of the official control programmes are shown from the people's point of view. Some human factors which influence malaria transmission are discussed and an estimate of the accuracy of self-diagnosis presented.

The Post-War Tuberculosis Program in the Philippines

1) During a recent five year period, 1,000,000 persons in the Philippines were examined and approximately 9 per cent were found to be suffering from tuberculosis. While this is probably a higher percentage than exists throughout the Islands, it is a reasonably good criterion of the magnitude of our problem. 2) When these cases were found, facilities were not available for isolation or adequate treatment so they remained free to continue spreading infection. It was not even possible to provide medicine and supplementary food for them. 3) BCG had previously been used in the Philippines on a small scale but without impressive results. However, it was suggested and strongly encouraged by the World Health Organization as the method of solving the problem. 4) BCG has become the official tuberculosis control program and has absorbed a great share of the financial resources available to combat tuberculosis. 5) Nowhere has the effectiveness of BCG been placed beyond dispute. Authorities on tuberculosis remain unconvinced of its value. Opponents of BCG are asked for the time being to stop being men of science but to accept this vaccine without the rigorous demonstration of its harmlessness and effectiveness that are demanded of other medical preparations. 6) BCG has not proved itself elsewhere and there is no reason to anticipate that it will do so in the Philippines. It can only waste money that might otherwise be used to combat the disease at its roots and it can only encourage laymen in the false conviction that a short-cut can be found. 7) The only program that offers any promise of controlling tuberculosis in the Philippines consists of nation-wide education, sanitation, hospital construction for isolation simultaneous with case finding and a vigorous government program directed to improvement of the standards of living. Until these measures are undertaken, tuberculosis will remain with us as a serious public health problem, BCG or no. It is our duty to insist upon the fundamental program so successfully employed elsewhere and to avoid unproved short-cuts.