Residues of medroxyprogesterone acetate detected in sows at a slaughterhouse, Madagascar

Access to Veterinary Drugs in Sub-Saharan Africa: Roadblocks and Current Solutions

Background

Access to veterinary drugs for livestock has become a major issue over the last decade. Analysis has tended to focus on the demand for these products, while studies looking at the drivers behind their use generally focus on farmer behavior and interactions between veterinarians and farmers. However, the use of drugs also depends on structural factors that determine the functioning of the drug supply chain and farmers' access to the drugs. This article presents an overview of the factors that limit access to veterinary drugs in sub-Saharan Africa (SSA) as well as the international policy tools and arrangements that claim to improve it.

Methods

We have conducted a scoping review of the scientific and grey literature as well as the publicly-available data from both the animal health industry and international organizations. We aimed to gather information on the veterinary drugs market in SSA as well as on the international norms, recommendations, guidelines, and initiatives that impact SSA farmers' access to these drugs.

Findings

We highlight numerous barriers to veterinary drug access in SSA. The SSA market is highly dependent on imports, yet the region attracts little attention from the international companies capable of exporting to it. It suffers from a high level of fragmentation and weak distribution infrastructures and services, and is driven by the multiplication of private non-professional actors playing a growing role in the veterinary drug supply chain. The distribution system is increasingly dualized, with on the one hand the public sector (supported by development organizations) supplying small scale farmers in rural areas, but with limited and irregular means; and on the other side a private sector largely unregulated which supplies commercial and industrial farming systems. Different innovations have been developed at the international and regional levels to try to reduce barriers, such as homogenizing national legislations, donations, and vaccine banks. Alongside decades-old inter-state cooperation, many new forms of public-private partnerships and other hybrid forums continue to emerge, signaling the private sector's increasing influence in global governance.

Conclusions

Policies on animal health would be bolstered by a better understanding of the drivers behind and the components of access to veterinary drugs in different regional and national contexts. Inequalities in drug access need to be addressed and a market-driven approach adopted in order to strengthen our understanding of what determines veterinary drug use at the farm level. Policies should balance the interests of the various stakeholders, being careful not to reinforce bias toward certain diseases deemed "interesting" and neglect others that could prove to be highly important for veterinary public health.

Trace analysis of progesterone and 21 progestins in milk by ultra-performance liquid chromatography coupled with high-field quadrupole-orbitrap high-resolution mass spectrometry

A method for rapid screening and quantification of progesterone and progestins in milks by ultrahigh-performance liquid chromatography coupled with quadrupole-high field Orbitrap high-resolution mass spectrometry (UHPLC QE HF HRMS) was established. Milks samples were extracted by acetonitrile + hexane (80 + 20), purified by prime HLB SPE and analyzed by UHPLC QE HF HRMS. The detection limit of progesterone and 21 progestins in milk is between 0.05 µg/kg -0.3 μg /kg, the correlation coefficient of progesterone and progestins in the corresponding concentration range is more than 0.99, recoveries for milk samples are between 80.7% and 108.3% with the relative deviation is less than 15%.The method fulfils the requirements of veterinary drug residue detection validation of EU and China, and successfully applied to detecting the μg/kg level of progesterone and monitoring residual of progestins in real milk.

Determination of acetylgestagens in animal-derived matrix samples using enhanced matrix removal lipid clean-up in combination with ultra performance liquid chromatography-tandem mass spectrometry

A robust and confirmative method was established for the determination of six acetylgestagen residues, namely, flurogestone acetate (FGA), megestrol (MA), melengestrol acetate (MGA), chlormadinone acetate (CMA), medroxyprogesterone (MPA), and hydroxyprogesterone acetate (HPA) in animal-derived matrix samples by utilizing enhanced matrix removal lipid (EMR-lipid) clean-up in combination with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The analytes were extracted with acetonitrile, purified with a EMR-lipid cartridge, and separated with a reversed-phase C18 column. The limit of quantification (S/N ≥ 10) for CMA, FGA, HPA, MA, and MGA in all matrices was 0.5 ng/g, and for MPA, it was 1.0 ng/g; the limit of detection (S/N ≥ 3) for CMA, FGA, HPA, MA, and MGA in all matrices was 0.1 ng/g, and for MPA, it was 0.2 ng/g. The recoveries were between 61.0% and 114.8%, and the relative standard deviations (RSDs) were below 12%. The method was calibrated in a matrix-assisted standard solution in various linear ranges for the analytes and matrices, and the correlation coefficients (R²) exceeded 0.99 for all the matrices.

Hormones and Hormonal Anabolics: Residues in Animal Source Food, Potential Public Health Impacts, and Methods of Analysis

The demand for nutritious food, especially food of animal origin, is globally increasing due to escalating population growth and a dietary shift to animal source food. In order to fulfill the requirements, producers are using veterinary drugs such as hormones and hormone-like anabolic agents. Hormones such as steroidal (estrogens, gestagens, and androgens), nonsteroidal, semisynthetic, and synthetic or designer drugs are all growth-promoting and body-partitioning agents. Hence, in food animal production practice, farm owners use these chemicals to improve body weight gain, increase feed conversion efficiency, and productivity. However, the use of these hormones and hormonal growth-promoting agents eventually ends up with the occurrence of residues in the animal-originated food. The incidence of hormone residues in such types of food and food products beyond the tolerance acts as a risk factor for the occurrence of potential public health problems. Currently, different international and national regulatory bodies have placed requirements and legislative frameworks, which enable them to implement residue monitoring test endeavors that safeguard the public and facilitate the trading activity. To make the tests on the animal-origin food matrix, there are different sample extraction techniques such as accelerated solvent extraction, supercritical fluid extraction, solid phase extraction, solid-phase microextraction, and hollow-fiber liquid-phase microextraction. After sample preparation steps, the analytes of interest can be assayed by screening and confirmatory methods of analysis. For screening, immunological tests such as ELISA and radioimmunoassay are used. Detection and determination of the specific residues will be done by chromatographic or instrumental analysis. Mainly, among high-performance liquid chromatography, liquid chromatography with mass spectrometry (LC-MS, LC-MS/MS), and gas chromatography with mass spectrometry (GC-MS and GC-MS/MS) methods, LC-MS/MS is being preferred because of easier sample preparation without a derivatization step and high detection and quantification capacity.

Sorption, transport, and transformation of natural and synthetic progestins in soil-water systems

Natural and synthetic progestins are emerging endocrine disruptors that can be transported from livestock farms and agricultural fields to receiving waters via surface runoff. The transformation of progestins during transport is expected to affect the efficiencies of runoff management systems. Therefore, this study explored the sorption, transport, and transformation of progesterone, norethisterone acetate, medroxyprogesterone acetate, cyproterone acetate, dydrogesterone, and norethisterone in agricultural soil-water systems. The sorption coefficients and retardation factors (R) were positively correlated with the progestin hydrophobicities, indicating that hydrophobic interactions dominated the sorption and transport processes. During transport, dydrogesterone and progesterone were transformed into 9-10 products. The breakthrough curves of the parents and products exhibited periodical patterns over extended times. Specifically, the R values of the parents and products were positively correlated with chromatographic retention times (hydrophobicities) when the products were generated before transport. In contrast, a negative correlation (R² = 0.75-0.88) was observed when products were successively generated during transport, indicating that the transformation kinetics changed the retardation of these solutes in the columns. These observations also demonstrated that the transport potential estimates based on traditional metrics of steroid hydrophobicity are not always accurate and that runoff management measures are less effective for metastable progestins.

Spatio-temporal prevalence of porcine cysticercosis in Madagascar based on meat inspection

Background

Taenia solium cysticercosis is a parasitic meat-borne disease that is highly prevalent in pigs and humans in Africa, but the burden is vastly underestimated due to the lack of official control along the pork commodity chain, which hampers long-term control policies.

Methods

The apparent and corrected prevalences of T. solium cysticercosis were investigated in pork carcasses slaughtered and retailed in Antananarivo (Madagascar), thanks to a 12-month monitoring plan in two urban abattoirs.

Results

Overall apparent prevalence was estimated at 4.6 % [4.2 – 5.0 %]. The corrected overall prevalence defined as the estimated prevalence after accounting for the sensitivity of meat inspection was 21.03 % [19.18- 22.87 %]. Significant differences among geoclimatic regions were observed only for indigenous pigs, with an apparent prevalence estimated at 7.9 % [6.0 – 9.9 %] in the northern and western regions, 7.3 % [6.0 – 8.6 %] in the central region, and 6.2 % [4.7 – 7.8 %] in the southern region. In the central region, where both exotic and indigenous pigs were surveyed, indigenous pigs were 8.5 times [6.7 – 10.7] more likely to be infected than exotic improved pigs. Urban consumers were more likely to encounter cysticercosis in pork in the rainy season, which is a major at risk period, in particular in December. Differences between abattoirs were also identified.

Conclusion

Our results underline the need for improved surveillance and control programmes to limit T. solium cysticercosis in carcasses by introducing a risk-based meat inspection procedure that accounts for the origin and breed of the pigs, and the season.