Mapping Nairobi's dairy food system: An essential analysis for policy, industry and research

Demand for dairy products in sub-Saharan Africa, is expected to triple by 2050, while limited increase in supply is predicted. This poses significant food security risk to low income households. Understanding how the dairy food system operates is essential to identify mitigation measures to food insecurity impact. This study aims to determine the structure and functionality of Nairobi's dairy system using a value chain mapping approach

Use of the nested polymerase chain reaction for detection of Toxoplasma gondii in slaughterhouse workers in Thika District, Kenya

Background. The widely used methods of diagnosis of Toxoplasma gondii are serological. Current reports indicate a high seroprevalence of T. gondii in humans in Kenya. There is a need for more sensitive diagnostic tests, especially when the specific antibody titres are below detectable threshold levels. Use of the polymerase chain reaction (PCR) targeting the repetitive 529 base pair loci has been reported to be sensitive and specific.Objective. To detect T. gondii in a high-risk group of public health workers in Thika District, Kenya.Methods. In total, 87 human blood samples were collected from male slaughterhouse workers between 1 March 2013 and 25 June 2013. The DNA extracted was amplified by the nested PCR.Results. T. gondii was detected in 39.1% (34/87) of the workers. In the cow-sheep-goat slaughterhouses the prevalence ranged between 20% and 60%, while all the chicken slaughterhouse workers (6/6, 100%) tested positive. The difference in T. gondii positivity between the workers in the chicken slaughterhouse and those in the cattle-sheep-goat slaughterhouses was statistically significant (p=0.003).Conclusion. This study shows the presence of T. gondii in an asymptomatic high-risk group in Thika District, indicating the need for enhancement of public health awareness

Use of the nested polymerase chain reaction for detection of Toxoplasma gondii in slaughterhouse workers in Thika District, Kenya

Background. The widely used methods of diagnosis of Toxoplasma gondii are serological. Current reports indicate a high seroprevalence of T. gondii in humans in Kenya. There is a need for more sensitive diagnostic tests, especially when the specific antibody titres are below detectable threshold levels. Use of the polymerase chain reaction (PCR) targeting the repetitive 529 base pair loci has been reported to be sensitive and specific.Objective. To detect T. gondii in a high-risk group of public health workers in Thika District, Kenya.Methods. In total, 87 human blood samples were collected from male slaughterhouse workers between  1 March 2013 and  25 June 2013. The DNA extracted was amplified by the nested PCR.Results. T. gondii was detected in 39.1% (34/87) of the workers. In the cow-sheep-goat slaughterhouses the prevalence ranged between 20% and 60%, while all the chicken slaughterhouse workers (6/6, 100%) tested positive. The difference in T. gondii positivity between the workers in the chicken slaughterhouse and those in the cattle-sheep-goat slaughterhouses was statistically significant (p=0.003).Conclusion. This study shows the presence of T. gondiiin an asymptomatic high-risk group in Thika District, indicating the need for enhancement of public health awareness.

Piloting a livestock identification and traceability system in the northern Tanzania–Narok–Nairobi trade route

We designed and piloted a livestock identification and traceability system (LITS) along the Northern Tanzania–Narok–Nairobi beef value chain. Animals were randomly selected and identified at the primary markets using uniquely coded ear tags. Data on identification, ownership, source (village), and the site of recruitment (primary market) were collected and posted to an online database. Similar data were collected in all the markets where tagged animals passed through until they got to defined slaughterhouses. Meat samples were collected during slaughter and later analyzed for tetracycline and diminazene residues using high-performance liquid chromatography (HPLC). Follow up surveys were done to assess the pilot system. The database captured a total of 4260 records from 741 cattle. Cattle recruited in the primary markets in Narok (n = 1698) either came from farms (43.8%), local markets (37.7%), or from markets in Tanzania (18.5%). Soit Sambu market was the main source of animals entering the market from Tanzania (54%; n = 370). Most tagged cattle (72%, n = 197) were slaughtered at the Ewaso Ng’iro slaughterhouse in Narok. Lesions observed (5%; n = 192) were related to either hydatidosis or fascioliasis. The mean diminazene aceturate residue level was 320.78 ± 193.48 ppb. We used the traceability system to identify sources of animals with observable high drug residue levels in tissues. Based on the findings from this study, we discuss opportunities for LITS—as a tool for surveillance for both animal health and food safety, and outline challenges of its deployment in a local beef value chain—such as limited incentives for uptake

Antimicrobial Usage, Susceptibility Profiles, and Resistance Genes in Campylobacter Isolated from Cattle, Chicken, and Water Samples in Kajiado County, Kenya

Campylobacter organisms are the major cause of bacterial gastroenteritis and diarrhoeal illness in man and livestock. Campylobacter is growingly becoming resistant to critically crucial antibiotics; thereby presenting public health challenge. This study aimed at establishing antimicrobial use, susceptibility profiles, and resistance genes in Campylobacter isolates recovered from chicken, cattle, and cattle-trough water samples. The study was conducted between October 2020 and May 2022 and involved the revival of cryopreserved Campylobacter isolates confirmed by PCR from a previous prevalence study in Kajiado County, Kenya. Data on antimicrobial use and animal health-seeking behaviour among livestock owners (from the same farms where sampling was done for the prevalence study) were collected through interview using a pretested semistructured questionnaire. One hundred and three isolates (29 C. coli (16 cattle isolates, 9 chicken isolates, and 4 water isolates) and 74 C. jejuni (38 cattle isolates, 30 chicken isolates, and 6 water isolates)) were assayed for phenotypic antibiotic susceptibility profile using the Kirby–Bauer disk diffusion method for ampicillin (AX), tetracycline (TE), gentamicin (GEN), erythromycin (E), ciprofloxacin (CIP), and nalidixic acid (NA). Furthermore, detection of genes conferring resistance to tetracyclines (tet (O), β-lactams (blaOXA-61), aminoglycosides (aph-3-1), (fluoro)quinolones (gyrA), and multidrug efflux pump (cmeB) encoding resistance to multiple antibiotics was detected by mPCR and confirmed by DNA sequencing. The correlation between antibiotic use and resistance phenotypes was determined using the Pearson’s correlation coefficient (r) method. Tetracyclines, aminoglycosides, and β-lactam-based antibiotics were the most commonly used antimicrobials; with most farms generally reported using antimicrobials in chicken production systems than in cattle. The highest resistance amongst isolates was recorded in ampicillin (100%), followed by tetracycline (97.1%), erythromycin (75.7%), and ciprofloxacin (63.1%). Multidrug resistance (MDR) profile was observed in 99 of 103 (96.1%) isolates; with all the Campylobacter coli isolates displaying MDR. All chicken isolates (39/39, 100%) exhibited multidrug resistance. The AX-TE-E-CIP was the most common MDR pattern at 29.1%. The antibiotic resistance genes were detected as follows: tet (O), gyrA, cmeB, blaOXA-61, and aph-3-1 genes were detected at 93.2%, 61.2%, 54.4%, 36.9%, and 22.3% of all Campylobacter isolates, respectively. The highest correlations were found between tet (O) and tetracycline-resistant phenotypes for C. coli (96.4%) and C. jejuni (95.8%). A moderate level of concordance was observed between the Kirby–Bauer disk diffusion method (phenotypic assay) and PCR (genotypic assay) for tetracycline in both C. coli (kappa coefficient = 0.65) and C. jejuni (kappa coefficient = 0.55). The study discloses relatively high resistance profiles and multidrug resistance to antibiotics of critical importance in humans. The evolution of the multidrug-resistantCampylobacter isolates has been linked to the use and misuse of antimicrobials. This poses a potential hazard to public and animal health, necessitating need to reduce the use of antibiotics in livestock husbandry practice coupled with stringent biosecurity measures to mitigate antimicrobial resistance

Antimicrobial resistant Escherichia coli isolates detected in raw milk of livestock in pastoral areas of northern Kenya

Antimicrobial agents are used widely in veterinary and human medicine worldwide. However, their use has suffered a major setback globally due to the emergence of antimicrobial resistance (AMR) in a wide range of microorganisms. This study aimed to investigate the prevalence of AMR in household milk for human consumption in Isiolo County, Kenya. The study identified 42 Escherichia coli (E.coli) isolates from 304 milk samples that were collected in randomly selected households in northern Kenya. E. coli was isolated using Eosin Methylene Blue Agar and identified using biochemical tests. The isolates were confirmed using Polymerase Chain Reaction (PCR) and sequencing. The antimicrobial resistance profiles of the isolates to 11 antimicrobial agents were evaluated by disc diffusion method on Mueller Hinton Agar. Additionally, the isolates were evaluated for antimicrobial genetic determinants conferring the resistance phenotypes to beta-lactams and tetracycline. Overall, 95% of the isolates were resistant to at least one of the tested antimicrobials. Large proportions (81%) of the isolates were resistant to beta-lactams followed by tetracycline (55%) and streptomycin (29%). All the isolates were, however, susceptible to ciprofloxacin and nalidixic acid. Multidrug resistance (MDR) was observed in 14.28% of the isolates and beta-lactam resistant isolates were confirmed to be harbouring blaSHV, blaTEM and blaCTX-M genes. The demonstration of AMR determinants and especially Extended Spectrum Beta Lactamase (ESBL) carriers in milk reveals the risk posed to food safety, particularly to communities that consume raw milk. This study found that raw milk consumed in Isiolo County was contaminated with resistant strains of E. coli. There is, therefore, a need to determine the sources of this resistance and implement interventions to reduce the emergence and spread of AMR bacteria. We recommend implementation of measures that could reduce the presence of antimicrobial resistant E. coli strains in raw milk food chain

Antimicrobial usage and detection of multidrug-resistant Staphylococcus aureus, including methicillin-resistant strains in raw milk of livestock from northern Kenya

The association of antimicrobial usage (AMU) with prevalence of antimicrobial-resistant (AMR) Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) in livestock raw milk consumed by pastoralists in Kenya remains unclear. We investigated the relationship between AMU and emergence of multidrug-resistant (MDR) S. aureus, including MRSA in raw milk of livestock. AMU data were obtained using sales records from veterinary pharmacies. S. aureus was isolated from 603 milk samples from various livestock species, including sheep, goat, cow, and camel reared in Isiolo and Marsabit counties in Kenya. Resistant phenotypes and genotypes were determined by disc diffusion and molecular methods, respectively. Correlation between AMU and occurrence of resistance was determined by Pearson's correlation coefficient (r) method. The consumption of various antimicrobial classes were as follows; 4,168 kg of oxytetracycline, 70 kg of sulfonamides, 49.7 kg of aminoglycosides, 46 kg of beta-lactams, 39.4 kg of macrolides, and 0.52 kg for trimethoprim. The S. aureus isolates were mainly resistant to tetracycline (79%), ampicillin (58%), and oxacillin (33%), respectively. A few isolates (5–18%) were resistant to clindamycin, cephalexin, erythromycin, kanamycin, and ciprofloxacin. Most of the MDR-S. aureus isolates were MRSA (94%). The genetic determinants found in the AMR isolates included tetK/tetM (96.5%/19%) for tetracycline, blaZ (79%) for penicillin, aac (6′)/aph (2′′)/aph (3′)-IIIa (53%) for aminoglycosides, mecA (41%) for oxacillin, and msrA/ermA (24%/7%) for macrolides. Oxytetracycline usage was correlated to tetK/tetM (r = 0.62/1) detection, penicillins to mecA/blaZ (r = 0.86/0.98), aminoglycoside to aac (6′)/aph (2′′)/aph (3′)-IIIa (r = 0.76/−13), and macrolide usages for detection of ermA/msrA (r = 0.94/0.77). AMU appeared to be associated with occurrence of MDR-SA and the tetM detection. Consumption of raw milk contaminated with MRSA could pose a serious public health risk in pastoral communities in northern Kenya