Improved management of drugs, hormones and pesticides in Africa : policy and trade issues

Drugs, hormones and pesticides are chemical compounds used for alleviation of various diseases in animals. There are many classes of drugs which have been used and in the case of natural steroid hormones these have been used to increase mass gain by stimulating protein anabolism. Pesticides have been used for many years in the control of ectoparasites which transmit important human and livestock diseases. The purpose of the present article is to review procedures for management of veterinary products to facilitate national and international trade

Efficacy of doxycycline in a goat model of Pasteurella pneumonia : research communication

The clinical efficacy of doxycycline (Doxycen(R), Cenavisa, Spain), a long-acting preparation, was evaluated for treatment of Pasteurella haemolytica infection in 6 goats. One goat was not infected and served as a control. The disease was induced by intratracheal inoculation of 107 to 109 cfu of P. haemolytica. Confirmation of respiratory disease was based on evidence of appropriate clinical signs. Before and after initiation of doxycycline treatment on day 10, each goat was examined daily. Three clinical responses to doxycycline treatment were noted. Mean rectal temperatures decreased from 40.1 oC to normal, while mean respiratory rate decreased from the pre-treatment value of 32 to 27/min after 4 days. Other clinical signs associated with pneumonia resolved within 3-5 days post treatment. In addition the minimum inhibitory concentration of DOTC for the P. haemolytica isolate was found to be <0.5 mg/mℓ. The present study indicates that DOTC may be a useful antimicrobial agent in the treatment of caprine pasteurellosis

ANTIMICROBIAL RESISTANCE IN SALMONELLA SEROTYPES ISOLATED FROM SLAUGHTER ANIMALS IN KENYA

Objectives: To isolate Salmonella from food animals and characterise the antimicrobial resistanceof the isolates.Design: A random sampling of slaughter animals was carried out.Setting: Department of Public Health, Pharmacology and Toxicology, University of Nairobi, Kenyaand Institute for Animal Breeding, Neustadt-Mariensee, Germany.Subjects: Two hundred and eighty five samples, including faecal samples and carcass, cloacal andpharyngeal swab samples were analysed.Results: Sixteen (5.6%) of 285 samples were positive for Salmonella. The prevalence of Salmonellaon pig carcasses (19%) was higher than in faeces (8.6%). Three Salmonella enterica sub-speciesenterica serovars, namely Saintpaul (S. Saintpaul), Braenderup (S. Braenderup), and Heidelberg(S. Heidelberg), were identified, with S. Saintpaul being the predominant serovar. Antimicrobialresistance was found in 35.7% of all the isolates. The S. Heidelberg isolates were susceptible to allthe antimicrobial agents tested. Multidrug resistance was found in 7.1% of the resistant Salmonellaisolates. Plasmids were only detected in S. Heidelberg. Ampicillin resistance was based on expressionof a blaTEM gene, while chloramphenicol, streptomycin, and tetracycline resistances were encodedby the genes catAl, strA, and tet(A), respectively.Conclusion: Pigs may serve as reservoirs of antimicrobial resistant Salmonella and slaughterhousecross-contamination of pork may be a food safety risk. We recommended that slaughterhousehygiene be improved to minimise contamination of pig carcasses

Drug sensitivity of trypanosome populations from cattle in a peri-urban dairy production system in Uganda

Cattle from 50 farms in Mukono County, Uganda, were monitored for trypanosomes every second month over an 18-month period (1995–1996) by mini-anion exchange chromatography and haematocrit centrifugation techniques. Eighteen trypanosome isolates collected from cattle during this period were characterised in cattle, goats and mice for their sensitivity to homidium, isometamidium and diminazene; 10 of the isolates were selected randomly, 8 were from animals that had the highest serum isometamidium concentrations at the time the isolates were collected. All the isolates contained only Trypanosoma brucei and/or T. vivax. In naı̈ve Boran (Bos indicus) cattle the isolates exhibited low pathogenicity and were sensitive to diminazene aceturate at 3.5 mg/kg body weight (bw) and isometamidium chloride at 0.5 mg/kg bw. In goats, 5 of 8 isolates were highly pathogenic, producing clinical signs indicative of central nervous system involvement within 60 days of infection; all such isolates contained T. brucei. However, all 8 populations were sensitive in goats to diminazene aceturate at 3.5 mg/kg bw. In contrast, 4 populations were refractory to treatment with isometamidium chloride at 0.5 mg/kg bw in at least 1 out of 3 goats each. Furthermore, 5 populations were refractory to treatment with homidium chloride at 1.0 mg/kg bw in a minimum of 2 out of 3 goats each. In mice, the 50% curative dose values for 11 Mukono isolates that contained T. brucei ranged from 0.30 to 1.89 mg/kg bw for diminazene aceturate, from 0.02 to 0.17 mg/kg bw for isometamidium chloride and from 0.90 to 4.57 mg/kg bw for homidium chloride. Thus, by comparison to reference drug-sensitive populations, all the stabilates were highly sensitive to diminazene and isometamidium, while some expressed low levels of resistance to homidium

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

Drug sensitivity of trypanosome populations from cattle in a peri-urban dairy production system in Uganda

Cattle from 50 farms in Mukono County, Uganda, were monitored for trypanosomes every second month over an 18-month period (1995–1996) by mini-anion exchange chromatography and haematocrit centrifugation techniques. Eighteen trypanosome isolates collected from cattle during this period were characterised in cattle, goats and mice for their sensitivity to homidium, isometamidium and diminazene; 10 of the isolates were selected randomly, 8 were from animals that had the highest serum isometamidium concentrations at the time the isolates were collected. All the isolates contained only Trypanosoma brucei and/or T. vivax. In naïve Boran (Bos indicus) cattle the isolates exhibited low pathogenicity and were sensitive to diminazene aceturate at 3.5 mg/kg body weight (bw) and isometamidium chloride at 0.5 mg/kg bw. In goats, 5 of 8 isolates were highly pathogenic, producing clinical signs indicative of central nervous system involvement within 60 days of infection; all such isolates contained T. brucei. However, all 8 populations were sensitive in goats to diminazene aceturate at 3.5 mg/kg bw. In contrast, 4 populations were refractory to treatment with isometamidium chloride at 0.5 mg/kg bw in at least 1 out of 3 goats each. Furthermore, 5 populations were refractory to treatment with homidium chloride at 1.0 mg/kg bw in a minimum of 2 out of 3 goats each. In mice, the 50% curative dose values for 11 Mukono isolates that contained T. brucei ranged from 0.30 to 1.89 mg/kg bw for diminazene aceturate, from 0.02 to 0.17 mg/kg bw for isometamidium chloride and from 0.90 to 4.57 mg/kg bw for homidium chloride. Thus, by comparison to reference drug-sensitive populations, all the stabilates were highly sensitive to diminazene and isometamidium, while some expressed low levels of resistance to homidium

Staphylococcus aureus enterotoxin genes detected in milk from various livestock species in northern pastoral region of Kenya

Staphylococcus aureus (SA) food poisoning results from consumption of preformed S. aureus enterotoxins in food. The enterotoxins are one of the most important virulence factors of the bacterium. The risk posed by contamination of milk intended for human consumption by pathogenic S. aureus in pastoral areas in Kenya is still generally not well documented yet this information is critical for ensuring safety to consumers who sometimes may take unpasteurized milk. This study, therefore determined the prevalence of S. aureus enterotoxin genes in raw milk from cattle, goats, sheep and camels intended for human consumption in northern Kenya. A total of 603 milk samples from 57 zebu cattle, 346 galla goats, 8 red Maasai and dorper sheep, 4 one-humped camel (Camelus dromedaries) and 188 pooled from all animals were collected from Isiolo and Marsabit counties of Kenya. S. aureus isolates were cultured from milk samples using a selective media, mannitol salt agar (MSA). Suspect colonies of SA were further analyzed using biochemical tests. Polymerase chain reaction and sequencing techniques were used to confirm SA and detect sea, seb, sec, sed and see enterotoxin genes. Overall, potentially pathogenic S. aureus harboring enterotoxic genes were detected in 85 (14.09 %, 95 % CI: 11.55-17.1 %) of the total milk samples. Genes encoding enterotoxins were detected in the S. aureus bacteria isolated from the milk samples. At least one type of S. aureus enterotoxin gene (SE) was detected in 74.11% (95 % CI: 63.91-82.24 %) of the 85 isolates. The most frequently encountered gene in the two counties was see (51; 60%, 95 % CI: 49.73-69.76 %) followed by sea (22; 25.88 %, 95 % CI: 17.76 -36.09 %) and sec (19; 22.35 %, 95 % CI: 14.8-32.29 %). None of the isolates tested positive for sed. Overall, 21 of the 85 (24.7%, 95 % CI: 16.76-34.83 %) strains harbored more than one enterotoxin gene. More than half of the S. aureus isolates harbored at least one of the enterotoxin coding genes, indicating milk samples contaminated by S. aureus could have a high chance of causing staphylococcal food intoxication. Consumption of raw and sour milk in the region could increase the risk of staphylococcal food poisoning and pastoral communities in the region are therefore advised to consume pasteurized milk

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran