Prevalence of Soil-Transmitted Helminth Infections and Associated Risk Factors Among School Children in Dembecha Town, Ethiopia

Soil-transmitted helminth (STH) infections are among the most common infections that affect the poorest and most deprived communities. In most developing countries, children aged 5 to 15 years are at risk for chronic helminth infection and associated morbidity. This study aimed to determine the prevalence of STH infections and associated risk factors among three government elementary schools in Dembecha town, Ethiopia. We conducted a school-based cross-sectional study involving 316 participants between November 2019 and March 2020. A systematic random sampling method was used to select study participants from the study schools. Data related to the sociodemographic characteristics of the study participants and risk factors for STH infections were collected using a pretested questionnaire survey. Parasitological examinations of stool samples were performed using the formal-ether concentration method. Study participants aged 5 to 15 years were enrolled in this study. The overall prevalence of STH infection was 21.5% (68/316). Ascaris lumbricoides ranked highest, with a prevalence of 11.4%, followed by hookworms 7.3%, Trichuris trichiura 1.9%, and Strongloides stercoralis 0.9%. Age groups of 10-15 years (AOR =3.109; 95% CI: 1.033, 9.350), residence in Kebele 2 (AOR =2.990; 95% CI: 1.082, 8.264), illiterate mothers (AOR =4.689; 95% CI: 1.410, 15.59), and a family size of 4-6 (AOR =3.286; 95% CI: 1.299, 8.313) were significantly associated with STH infections. The prevalence of STH infections remains an important health issue for study participants. Therefore, school deworming programs twice a year are crucially needed until the prevalence falls below the level of public health importance.

Prevalence and risk factors for epizootic lymphangitis among equids in ethiopia during 2002-2023: A systematic review and meta-analysis

In Sub-Saharan Africa (SSA), particularly in Ethiopia, Epizootic Lymphangitis (EL) is the most prevalent fungal disease of equids, which causes significant economic losses as well as a decrease in equid populations. Therefore, this systematic review and meta-analysis were designed to pool the results of individual studies and estimate the prevalence of EL among equids in Ethiopia. A systematic search of research articles on the prevalence and risk factors of EL among equids in Ethiopia was conducted in registers, databases, and other sources. Cochrane's Q, inverse variance (I2), sensitivity analysis, funnel plot, Begg's, and Egger's regression tests were used to check heterogeneity and publication bias. A random-effects model was used to calculate the pooled burden of EL among equids. For this meta-analysis, a total of 7217 equids were included in the 14 eligible studies. The overall pooled prevalence of EL among equids in Ethiopia was 20.24% (95% CI: 16.27, 24.21). According to the subgroup analysis, the highest prevalence was observed in cart horses (20.98%), the Amhara region (21.46%), and studies conducted using sample sizes of 384 equids or greater (24.67%) and from 2002 to 2018 (25.52%) study periods. Harness-inflicted wounds, sharing stables or yards with harnesses, and the presence of preexisting wounds were identified as factors significantly associated with EL magnitude. Early diagnosis and proper medication, as well as implementing appropriate prevention and control measures, are necessary for the management of EL in equids.

Magnitude, associated risk factors, and trend comparisons of identified tuberculosis types among prisons in Ethiopia: A systematic review and meta-analysis

Background and Aims

Tuberculosis (TB) remained a major public health threat, particularly in developing countries with vulnerable groups, particularly prison inmates. A systematic review and meta-analysis of individual studies with varying prevalence rates were performed to identify risk factors associated with the recent magnitude of TB among prisoners.

Methods

A systematic search of research articles on the magnitude and risk factors of TB among prisoners in Ethiopia was conducted in registers, databases, and other sources. Cochran's Q, inverse variance (I 2), sensitivity analysis, funnel plot, Begg's, and Egger's regression tests were used to check heterogeneity and publication bias. A random-effects model was used to calculate the pooled burden of TB among prisoners.

Results

The total national prevalence of TB among prisoners was 9.84% (95% confidence interval [CI]: 7.16-12.52). According to the subgroup analysis, the highest prevalence was observed in patients infected by latent TB (51.20%), the Southern nations, nationalities and people's region (SNNPR) (29.63%), studies conducted in ≤200 (17.50%) sample sizes, and from 2017 to 2022 (11.49%) study periods. TB infection among prisoners was significantly associated with a history of contact with TB patients (adjusted odds ratio [AOR] = 2.75; 95% CI: 0.98-4.52), coughing for ≥2 weeks (AOR = 0.08; 95% CI: -0.16-0.33), being incarcerated in overcrowded cells with poor ventilation (AOR = 0.39; 95% CI: -0.01-0.78), and increasing with the duration of imprisonment (AOR = 1.29; 95% CI: -0.39-2.97].

Conclusion

Expectably high TB magnitude is found among prison inmates in Ethiopia. Duration of incarceration, coughing, ventilation of the cell, and contact with TB patients were all predictors of TB among prisoners. The management of TB requires early diagnosis, adequate medication, and the implementation of preventative and control measures suitable for prison inmates.

Magnitude and Determinants of Intestinal Parasites among Children under Five in Ethiopia During 2010-2023: A Systematic Review and Meta-Analysis

Background: Intestinal parasitic infection (IPI) poses a serious public health threat across the globe, particularly in children in low- and middle-income countries like Ethiopia. This study was to provide pooled estimates for the individually available data on IPI and its predictors among children under five in Ethiopia. Methods: Cochrane's Q, I2, sensitivity analysis, funnel plot, Begg's, and Egger's regression tests were used to check heterogeneity and publication bias. A random-effects model was used to calculate the pooled burden of IPI among children under five. Results: The pooled prevalence of IPI among children under five was 28.27% (95% CI = 20.52-36.03%). Of these, single and mixed infections contribute to 28.02% and 0.25%. Intestinal parasites were significantly associated with eating raw fruits and vegetables [AO = 3.21, 95% CI = 1.11, 5.31]. Conclusion: Under the present scenario, the IPI ranges from 17.78 to 40.05%, and the IPI is higher in community-based studies of children under five.

Alternative mechanisms of action of metallic nanoparticles to mitigate the global spread of antibiotic-resistant bacteria

One of the biggest issues for medical professionals and a serious global concern is the emergence of multi-drug-resistant bacteria, which is the result of the overuse or misuse of antimicrobial agents. To combat this urgent problem, new drugs with alternative mechanisms of action are continuously replacing conventional antimicrobials. Nanotechnology-fueled innovations provide patients and medical professionals with hope for overcoming drug resistance. The aim of the present work was to document the antimicrobial potential and mechanisms of action of metallic nanoparticles against bacterial pathogens. Cell wall interaction and membrane penetration, reactive oxygen species (ROS) production, DNA damage, and protein synthesis inhibition were some of the generalised mechanisms recognised in the current study. In vitro and in vivo studies demonstrated that toxicity concerns and the development of bacterial resistance against nanoparticles (NPs) harden the use of metallic NP products for the treatment of drug-resistant bacterial pathogens. Therefore, researchers across the globe should actively engage in solving the above-mentioned issues.

The Many Mutations of the COVID-19 Variant: Current Perspectives on EG.5/Eris

Viral diseases pose a significant threat to public health around the world. SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) was originally identified in Wuhan, China, in 2019. Throughout the epidemic, SARS-CoV-2 has continually changed genetically, giving rise to variants that are distinct from the original virus. SARS-CoV-2 has a high-frequency mutation rate, resulting in more genetic diversity. EG.5/Eris is a subvariant and descendant of Omicron, which remains the world's most prevalent coronavirus strain of current concern. The percentage of EG.5 recorded has steadily increased across the board. Epidemiological week 29 (17-23 July 2023) saw a 17.4% global prevalence of EG.5. Mutations in the virus's genome can cause false-negative results in molecular detection and cause increased transmissibility, morbidity, and mortality due to a reduction in vaccine efficiency. Furthermore, these changes in S-protein structure alter the neutralising ability of neutralising antibodies (Nabs), resulting in a reduction in vaccine efficiency. Therefore, all countries should take efficient infection prevention and control measures as per the guidelines of the world, continental, and their country's health organisations, along with vaccine and treatment investigations.

Microbial and Physicochemical Dynamics of Kocho, Fermented Food from Enset

Over 20 million Ethiopians depend on enset (Ensete ventricosum) as a staple or costaple food. "Kocho," "Bulla," and "Amicho" are the three main food types obtained from enset. This review aimed to summarize the physicochemical and microbial dynamics of kocho. It is the most common food obtained from the scraped pseudostem and decorticated corm of enset after a long period of fermentation. The quality of kocho depends on the maturity of the enset plant, the enset processing method, the fermentation period, and the dynamics of microorganisms during the fermentation process. Microorganisms play a significant role in kocho fermentation to enhance its nutritional quality, improve sensory properties, and reduce spoilage and disease-causing agents. The populations of microbes available in kocho fermentation include lactic acid bacteria (LAB), Enterobacteriaceae, acetic acid bacteria (AAB), yeasts and molds, and Clostridium spp., which have both positive and negative impacts on kocho quality. There is a visible variation in microbial dynamics during kocho fermentation caused by the fermentation period. As the fermentation day increases, species of LAB also increase, whereas counts of Enterobacteriaceae decrease. This is due to a decrease in pH, which leads to an increase in titratable acidity. Moisture content also slightly decreases as fermentation progresses. Dynamics in the microbial population and physicochemical parameters ensure the development of desirable qualities in kocho and enhance the acceptability of the final product. Organic acids (such as lactic acid, acetic acid, and propionic acid), bacteriocins, phenolic compounds, flavonoids, and tannins are bioactive compounds produced by microorganisms during Kocho fermentation. Further research is needed on the molecular identification of microorganisms during Kocho fermentation.

Magnitude, Associated Risk Factors, and Trend Comparisons of Urinary Tract Infection among Pregnant Women and Diabetic Patients: A Systematic Review and Meta-Analysis

Urinary tract infection (UTI) remains the most common bacterial infection that affects millions of people around the world, especially pregnant women (PW) and people with diabetes mellitus (DM). This systematic review and meta-analysis was aimed at finding the pooled prevalence of UTI and its associated risk factors among PW and DM patients. Scientific articles written in English were recovered from PubMed, ScienceDirect, Web of Science, Google Scholar, Cochrane Library, Google Engine, and University Library Databases. "Prevalence," "urinary tract infection," "associated factors," "pregnant women," "diabetic patients," and "Ethiopia" were search terms used for this study. For critical appraisal, PRISMA-2009 was applied. Heterogeneity and publication bias were evaluated using Cochran's Q, inverse variance (I2), and funnel plot asymmetry tests. A random effect model was used to calculate the pooled prevalence of UTI and its associated factors among both patients, along with the parallel odds ratio (OR) and 95% confidence interval (CI). For this meta-analysis, a total of 7271 participants were included in the 25 eligible studies. The pooled prevalence of UTI in Ethiopia among both patients was 14.50% (95% CI: 13.02, 15.97), of which 14.21% (95% CI: 12.18, 16.25) and 14.75% (95% CI: 12.58, 16.92) were cases of DM and PW, respectively. According to the subgroup analysis, the highest prevalence was observed in the Oromia region (19.84%) and in studies conducted from 2018 to 2022 (14.68%). Being female (AOR: 0.88, and 95% CI: 0.11, 1.65, P = 0.01) and having an income level ≤ 500ETB (AOR: 4.46, and 95% CI: -1.19, 10.12, P = 0.03) were risk factors significantly associated with UTI among patients with DM and PW, respectively. Furthermore, a history of catheterization (AOR = 5.58 and 95% CI: 1.35, 9.81, P < 0.01), urinary tract infection (AOR: 3.52, and 95% CI: 1.96, 5.08, P < 0.01), and symptomatic patients (AOR: 2.32, and 95% CI: 0.57, 4.06, P < 0.01) were significantly associated with UTI in both patients. Early diagnosis and appropriate medication are necessary for the treatment of UTI in patients with DM and PW.

Evaluation of Soil Streptomyces Isolates from North-Western Ethiopia as Potential Inhibitors against Spoilage and Foodborne Bacterial Pathogens

The outbreak and spread of foodborne diseases is a serious concern for global healthcare and security. Finding novel antimicrobial agents with diverse mechanisms of action against the current spoilage and foodborne bacterial pathogens is a central strategy to overcome the problems of antibiotic resistance. Soil actinomycetes are the major antimicrobial producers with great biopreservative and medical value. This study was aimed at isolating Streptomyces from soil samples of northwestern Ethiopia against spoilage and foodborne bacterial pathogens. Thirty-six soil samples were collected at a depth of 5–10 cm in the rhizosphere and agricultural soils of soybean. A total of 118 actinomycete strains were isolated and screened primarily using the perpendicular streak plate method against 3 Gram-positive and 3 Gram-negative bacterial strains. Out of 118 isolates, 36/118 (30.50%) were active against at least two of the tested bacteria, of which 8 isolates were selected for their wide-spectrum antibacterial activities. During the disc diffusion assay, the eight in vitro ethyl acetate extract antibacterial activities range from 7 to 24 mm. The minimum inhibitory concentration and minimum bactericidal concentration values range from 0.10 to 0.25 μg/mL and 0.15 to 0.40 μg/mL, respectively. Following the morphological, physiological, biochemical, and molecular characteristics, eight potent isolates were identified as follows: Streptomyces fasciculus, Streptomyces roseochromogenes, Streptomyces ruber, Streptomyces glaucus, Streptomyces griseus, Streptomyces cellulosae, Streptomyces griseoflavus, and Streptomyces xanthophaeus. After the treatment of potent Streptomyces cell-free culture supernatant with proteinase K, papain, α-amylase, and lysozyme enzymes, their antagonistic effects were also observed. Most Streptomyces cell-free culture supernatant antibacterial activity was highly resistant to heat, acidity, organic solvents, and additives. Thus, the results of this investigation revealed that soil actinomycetes could be a valuable source for novel antibacterial agents applicable in food biopreservation and the treatment of spoilage and foodborne bacterial pathogens.

The Bacterial Profile and Antimicrobial Susceptibility Patterns of Urinary Tract Infection Patients at Pawe General Hospital, Northwest Ethiopia

Urinary tract infection remains the most common infection widespread worldwide in both community and hospital settings. Rapidly increasing antibiotic resistance of uropathogens is resulting in limited treatment options. Thus, understanding the current uropathogens and their antimicrobial susceptibilities is essential for effective urinary tract infection treatment. The purpose of this study was to isolate, characterize, and determine the antimicrobial susceptibility patterns of bacterial pathogens associated with urinary tract infection at Pawe General Hospital in Northwest Ethiopia. A hospital-based cross-sectional study design was conducted from January to April, 2020, at Pawe General Hospital. Midstream urine specimens were collected from 141 individuals with suspected urinary tract infection for bacteriological identification and antimicrobial susceptibility testing. Among the 141 study participants, twenty-nine (20.6%) showed significant bacteriuria. Escherichia coli (42.6%) had the highest proportion of isolated uropathogen followed by Klebsiella spp. and Pseudomonas spp. each (10.7%); Proteus spp. (9.3%); coagulase negative staphylococci, Staphylococcus aureus, and Enterobacter spp. each (6.7%); Citrobacter spp. (4%); and Enterococcus faecalis and Streptococcus spp. each (1.3%). Outpatient isolates showed a resistance of 64% and 78.6% to amoxicillin-clavulanic acid and tetracycline, respectively. Inpatients showed 63.9% and 87.2% of resistance to cephalexin and tetracycline. It was also observed that all the isolates have a multiple antimicrobial resistance index greater than 0.20 except Citrobacter spp. (0.142) in inpatients. Even though in this locality, most isolates were sensitive to ceftriaxone, gentamicin, ciprofloxacin, nitrofurantoin, and norfloxacin, they are considered appropriate antimicrobials for empirical treatment of urinary tract bacterial infections. Periodic monitoring of etiology and drug susceptibility is highly recommended, along with health education on the transmission and causes of urinary tract infection.

High prevalence of Antibiotic Resistance Bacteria isolated from Municipal Solid Waste Dumpsite, Bahir Dar, Ethiopia.. [DOI: 10.21203/rs.3.rs-1182902/v1]

Background The emergence of antibiotic resistance (ABR) among environmental microbes has been challenging global health. ABR can be transferred to human-associated bacteria aggravating the spread of antimicrobial resistance. Due to poor solid waste disposal practices, municipal solid waste dumpsite (MSWDS) can be a reservoir for antimicrobial resistant microorganisms, such as bacteria. This study aimed to assess the prevalence of antibiotic resistance (ABR) bacteria at Bahir Dar city MSWDS. Methods Soil samples were collected from three randomly selected sites within the dumpsite from November 2020 to May 2021. Bacteria were isolated, identified and tested for ABR using standard procedures. Results In this study, 71 distinct colonies were isolated and identified to ten bacterial genera based on cultural characteristics and biochemical tests. The pooled antibiotic résistance rate was 85.9%. Resistance to the tested antibiotics ranged between 0% for erythromycin and 100% for amoxicillin among the bacterial isolates. High proportions of the isolates were found to be resistant to amoxicillin (100%), vancomycin (87%) and nalidixic acid (73.3%). Substantial proportions of the isolates were also resistant to Streptomycin (54.5%), sulfonamide (50%) and tetracycline (48.5%). On the other hand, high sensitivity rates to erythromycin (90.91%), ciprofloxacin (83.10%), chloramphenicol (77.46%) and gentamicin (63.49%) were recorded. All isolates related to Staphylococcus spp., and most isolates related to Pseudomonas, Escherichia, Klebsiella, Salmonella, Enterococcus, Citrobacter, Shigella and Proteus species were resistant at least to one antibiotic drug. The overall multidrug resistance (MDR) rate was 49.3%, and a high rate of MDR was demonstrated among isolates related to Escherichia spp. (75%), Staphylococcus spp. (68.8%), Pseudomonas spp. (62.5%) and Klebsiella spp. (60%), where each isolate resisted at least 5 antibiotic drugs. Conclusion From the present study, it can be concluded that a high incidence of ABR exists in Bahir Dar city MSWDS. The occurrence of the high level of ABR to commonly used antibiotics in this study demands a proper waste management system, as well as surveillance programs to monitor for antimicrobial resistance determinants in municipal solid wastes. Moreover, detailed studies on the isolates and ABR genes will give a better insight into the prevalence of ABR in the waste dumpsite.

Antibacterial Activity of Lactic Acid Bacteria Isolated from Fermented Ethiopian Traditional Dairy Products against Food Spoilage and Pathogenic Bacterial Strains

Fermented Ethiopian traditional dairy products containing LAB that show antibacterial activities against various food spoilage and pathogenic bacteria have been used for the preservation of fermented dairy products for a long time. However, there are no comprehensive scientific reports on the antibacterial activity of LAB isolated from various fermented dairy products in Pawe Woreda. The objective of the study was to evaluate the antibacterial activity of LAB isolated from traditionally fermented Ethiopian dairy products against spoilage and pathogenic bacteria. Thirty-five samples of fermented dairy products were collected from three cattle-farming areas of Pawe Woreda. A total of 97 LAB were isolated and screened primarily using the perpendicular streak plate method against 3 Gram-positive and 3 Gram-negative bacterial strains. Out of the 97 strains, 10 were active against at least two of the tested bacteria, of which 7 strains were selected for secondary screening by their broad-spectrum antibacterial activities. The seven in vitro antibacterial activities of the extract ranged from 5 to 16 mm in diameter during the secondary screening. In this study, Z2, Z4, and N2 strains exhibited the highest inhibition zone with broad-spectrum activity against all tested bacteria. The MIC and MBC values range from 0.10 to 0.30 µg/µL and 0.20 to 0.50 µg/µL, respectively. Following morphological, physiological, biochemical, and molecular characteristics, seven potent strains were identified as Lactobacillus acidophilus, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, Leuconostoc mesenteroides, Streptococcus thermophilus, and Lactococcus lactis. According to the findings of this study, Ethiopian fermented dairy products were the most potent source of bioactive compounds with potential effects against food spoilage and pathogenic bacterial strains.

Spatial analysis of the impact of climate change factors and adaptation strategies on productivity of wheat in Ethiopia

Wheat production is expected to be challenged by future climate change. However, it is unclear how wheat grown in diverse agroecologies will respond to climate change and adaptation management strategies. A geospatial simulation study was conducted to understand the impacts of climate change and adaptation management strategies on wheat (Triticum aestivum L.) production in Ethiopia. Simulation results showed that the average long-term baseline (1980-2005) wheat yield ranged from 1593 to 3356 kg/ha. This wheat yield range is within the national average (2100-2700 kg/ha) for this decade. In regions with cooler temperatures (<21 °C), mid-century temperatures and elevated CO₂, along with increased N fertilizer slightly improved attainable yield levels above 3000 kg/ha. Whereas, in regions with heat and drought conditions wheat yield declined regardless the increase of N or CO₂ levels. Wheat yield increased at a diminishing rate with increase in N fertilizer rate. However, N fertilizer did not increase yields under low rainfall conditions. Two to five irrigation per season contributed to yield improvement for low rainfall locations, while yield did not substantially improve for locations receiving adequate seasonal rainfall. Therefore, based on this study, improved N fertilizer application in combination with increased CO₂ could improve wheat yield under future climate in most wheat producing regions (with adequate rainfall) of Ethiopia. Our results provide valuable information regarding impacts of climate change factors and adaptation strategies for producers, researchers, extension professionals and policy makers.

Newly identified mutations at the CSN1S1 gene in Ethiopian goats affect casein content and coagulation properties of their milk

Very high casein content and good coagulation properties previously observed in some Ethiopian goat breeds led to investigating the αs1-casein (CSN1S1) gene in these breeds. Selected regions of the CSN1S1 gene were sequenced in 115 goats from 5 breeds (2 indigenous: Arsi-Bale and Somali, 1 exotic: Boer, and 2 crossbreeds: Boer × Arsi-Bale and Boer × Somali). The DNA analysis resulted in 35 new mutations: 3 in exons, 3 in the 5' untranslated region (UTR), and 29 in the introns. The mutations in exons that resulted in an amino acid shift were then picked to evaluate their influence on individual casein content (αs1-, αs2-, β-, and κ-CN), micellar size, and coagulation properties in the milk from the 5 goat breeds. A mutation at nucleotide 10657 (exon 10) involved a transversion: CAG→CCG, resulting in an amino acid exchange Gln77→Pro77. This mutation was associated with the indigenous breeds only. Two new mutations, at nucleotide 6072 (exon 4) and 12165 (exon 12), revealed synonymous transitions: GTC→GTT in Val15 and AGA→AGG in Arg100 of the mature protein. Transitions G→A and C→T at nucleotides 1374 and 1866, respectively, occurred in the 5' UTR, whereas the third mutation involved a transversion T→G at nucleotide location 1592. The goats were grouped into homozygote new (CC), homozygote reference (AA), and heterozygote (CA) based on the nucleotide that involved the transversion. The content of αs1-CN (15.32g/kg) in milk samples of goats homozygous (CC) for this newly identified mutation, Gln77→Pro77 was significantly higher than in milks of heterozygous (CA; 9.05g/kg) and reference (AA; 7.61g/kg) genotype animals. The αs2-, β-, and κ-CN contents showed a similar pattern. Milk from goats with a homozygous new mutation had significantly lower micellar size. Milk from both homozygote and heterozygote new-mutation goats had significantly shorter coagulation rate and stronger gel than the reference genotype. Except the transversion, the sequence corresponded to allele A and presumably derived from it. Therefore, this allele is denoted by A3. All goats from the reference genotype (AA) were homozygous for the allele at nucleotide position 1374 and 1866, whereas all mutations in the 5' UTR existed in a heterozygous form in both heterozygous (CA) and the new mutation (CC) genotype. The newly identified mutation (CC) detected in some of the goat breeds is, therefore, important in selection for genetic improvement and high-quality milk for the emerging goat cheese-producing industries. The finding will also benefit farmers raising these goat breeds due to the increased selling price of goats. Further studies should investigate the effect of this amino acid exchange on the secondary and tertiary structure of the αs1-CN molecule and on the susceptibility of peptide hydrolysis by digestive enzymes.

Studies on the reproductive performance of Ethiopian sheep by means of an enzyme immunoassay technique; a review

Measurement of the concentration of hormones associated with reproductive function in female animals can aid in the evaluation of their reproductive status. In particular, from the point of view of production, determination of the concentration of circulatory progesterone can aid in the correct assessment of ewes. Many investigators have used radioimmunoassay for this purpose, but the enzyme-linked immunosorbent assay (ELISA) is equally reliable, quicker and cheaper. This report reviews the use of the ELISA in Ethiopian Menz sheep. Progesterone profiles in Ethiopian Menz sheep during pubertal development, the oestrous cycle, pregnancy and post-partum anoestrus were similar to those of temperate breeds. The practical applications of progesterone determination to sheep production and the requirement for the correct handling of samples are emphasized.