Epidemiology and public health significance of bovine tuberculosis in cattle in the highlands of Cameroon

Bovine tuberculosis (TB) is a contagious neglected zoonosis of cattle that is prevalent but under-investigated in Cameroon, hence this study was designed to assess the epidemiology of bovine TB in cattle, risks for M. bovis infection in cattle and humans; and public health implications of zoonotic bovine TB in the highlands of Cameroon. A retrospective study of meat inspection records (1994 – 2010) was done to estimate the prevalence of TB lesions in slaughtered cattle in the North West region. The prevalence of bovine TB and anti-bovine TB antibodies in live cattle based on tuberculin skin tests (2 surveys) and immune-chromatographic assays respectively were carried out in the Western and Adamawa highlands of Cameroon. The performance of the tuberculin tests for bovine TB diagnosis in cattle using various tuberculin skin test cut-off points against the detection of anti-bovine TB antibodies (hypothesised risks of exposure) was compared. Suspected TB lesions from slaughtered cattle and infected human sputa were cultured on Lowentein – Jesen and Middlebrook 7H9 media to isolate mycobacteria agents for molecular genotyping using genomic deletion analysis and spoligotyping. Risk factors for exposure and transmission of zoonotic bovine TB infection of cattle and cattle professionals, and its public health significance were determined using structured questionnaires. Seventeen years of meat inspection record revealed that suspect TB lesions were identified in 599 of 129,165 slaughtered cattle at the Bamenda abattoir. The lungs and associated lymph nodes (over 60%) were the most affected tissues. Other results showed that the prevalence of anti-bovine TB antibodies in cattle in the study regions was 37.17%. Chi square statistics revealed that irrespective of the tuberculin test cut-off value (P48), strong associations existed between the detection of anti-bovine TB antibodies and disease status. A 95% confidence interval analysis of the comparative cervical tuberculin tests revealed that the prevalence rates were 4.67% – 7.15%, 12.02% – 15.67% and 20.56% – 24.98% at the ≥ 4mm, ≥ 3mm and ≥ 2mm cut-off points, respectively. Overall, the best test performance was realised at ≥ 3-mm, though the ≥ 2-mm cut-off point predicted more positive reactors. Age, sex, breed and husbandry practices served as significant (P<0.05) risks to the prevalence and exposure of bovine TB in cattle. The feedbacks from cattle professionals suggested that there was high possibility of cattle to cattle and cattle to human transmission of bovine TB such as intimate and repeated animal / animal and animal / human interactions, consuming unpasteurised milk and eating raw meat. Genomic deletion analysis of cultured isolates showed evidence of M. tuberculosis from cattle and M. bovis from human while spoligotyping identified five cattle M. bovis strains; and four spoligotype patterns that had not been previously described anywhere. The study has important epidemiological and public health implications requiring prompt and decisive actions from the Cameroonian authority towards controlling zoonotic bovine TB in both humans and animals. A multidisciplinary approach is needed for further collaborative research and effective control strategies such as enhancing the awareness of people to this deadly disease through continuous education, proper food handling and personal hygiene, healthy husbandry practices and maintenance of the environment.Commonwealth Scholarship Commission in the U

Prevalence and zoonotic risk factors of Mycobacterium bovis tuberculosis in cattle at the cattle-wildlife-human interface in South and East Cameroon

Background and Aim: Bovine tuberculosis (bTB) is a contagious and notifiable disease, which is prevalent in cattle populations of many countries and in several wildlife species worldwide. However, the role of wildlife in the transmission and/or maintenance of bTB at the human-wild animal-animal interface and the epidemiology of zoonotic disease are poorly understood in Cameroon, where many wildlife species exist. This study aimed to estimate the prevalence and zoonotic risk factors of bTB at the cattle-wildlife-human interface in the South and East regions of Cameroon. Materials and Methods: We conducted a descriptive cross-sectional study from May to October 2022 in the southern region (Vallée du Ntem and Dja et Lobo) and eastern region (Haut Nyong and Lom et Djérem) of Cameroon to determine risk factors for bTB in Zebu Bororo, Goudali, Ndama, and Simmental cattle breeds. A comparative intradermal tuberculin testing (CIDT) was performed on 160 cattle randomly selected from herds using the threshold recommended by the World Organization for Animal Health. An interviewee-administered questionnaire was used to gather epidemiological data on sociodemographics, interaction between cattle and wildlife, and awareness of zoonotic tuberculosis (TB) from 90 cattle professionals. The prevalence of bTB at the herd level and associated risk factors were estimated using multiple logistic regression models. Results: Based on the comparative intradermal tuberculin test (CIDT), the estimated prevalence of bTB in 160 cattle (Zebu Bororo, Goudali, Ndama, and Simmental) in South and East Cameroon was 6.8% (4.35%-9.41%) and 1.8% (0%-3.6%) for threshold values 3 mm and 4 mm, respectively. The prevalence obtained by simple intradermal tuberculin test (IDT) was 0.6% (0%-1.2%) for a threshold value 4 mm. Univariate analysis revealed three risk factors associated with bTB with significant odds ratios (OR; p = 0.05): herd size (OR = 4.88; 95% confidence interval [CI]: 1.24-32.56); cattle aged>10 years (OR = 0.17; 95% CI: 0.05-0.53); and victims of bTB organ seizure (OR = 0.015; 95% CI: 0.002-0.067). Multivariate analysis showed that being a cattle herder and contact between wildlife and livestock due to forage was significantly associated with bTB exposure (adjusted OR = 0.02; p = 0.001). Conclusion: Bovine TB is prevalent in cattle of the South and East Cameroon. Comparative IDT of cattle reared in the epidemiological and environmental context of the study areas yielded better results at a threshold of 3 mm than at a threshold of 4 mm recommended by the World Health Organization. Factors associated with exposure to/appearance of bTB were high herd size, cattle aged >10 years old, seizures of tuberculous organs, shepherding as a profession, and contact between cattle and wildlife can be due to lack of forage

Prevalence of bovine tuberculosis at the SODEPA Douala abattoir, Cameroon (1995 – 2003)

This paper reviews tuberculosis and other pathological cases of slaughtered cattle recorded in “SODEPA” (Société de Développement et d'Exploitations des Productions Animales) Douala abattoir from April 1995 – May 2003 to determine the status of Bovine tuberculosis and other pathological conditions in Zebu cattle. Out of a total of 385,784 (3782.20 ± 425.02) zebu cattle slaughtered during this period, 3,893 (20.17 ± 25.35) pathological lesions were recorded with 81.53 % (3174; 32.72 ± 30.30) of them being due to tuberculosis. Prevalence rates of 1.01% for all the cases put together, 0.82% for tuberculosis alone and 0.19% for the non-tuberculosis cases were obtained for the 8-year study period. The other 18.47% (719; 7.90 ± 5.80) of non-tuberculosis cases were made up of liver (76.77%), non-tuberculosis lung (10.29%), cysticercosis (5.98%), enlarged kidney (2.50%), traumatic (2.22%) and pericardiac (2.22%) lesions. Bovine tuberculosis lesions were generally 3 – 5 times more prevalent (P< 0.05) than the other lesions combined. Although the rates of occurrence of the pathological cases were highest in April and September of 1997 and 1998, there was no significant association between cases and season. The paper therefore confirms that bovine tuberculosis is endemic in Cameroon and suggests that systematic knowledge on the biodiversity of the causative agents, epidemiology and control of the disease as well as the interrelationship between animal and human tuberculosis should be updated. Keywords: Zebu cattle, pathological lesions, tuberculosis, prevalence, abattoir, Douala- Cameroon Cameroon Journal of Experimental Biology Vol. 1(2) 2005: 116-12

Effects of body conformation and udder morphology on milk yield of zebu cows in North region of Cameroon

Aim: The aim of the study was to assess the effect of udder morphological characteristics on milk yield in zebu cows of Cameroon. Materials and Methods: The diameter and height of the udder, length and diameter of the teat, and the milk yield were measured in 29 Djafun (Red Mbororo) and 19 Aku (White Fulani) cows in Lougguere zootechnical station in the North region of Cameroon. Results: Overall, strong positive correlation (rp=0.60) between the diameter (240.21±28.58 mm) and height (131.12±23.64 mm) of udders (p<0.001) and between length (39.51±6.44 mm) and diameter (19.85±3.08 mm) of teats (rp=0.78) were found in the zebu cows. Udder morphologic characteristics varied significantly (p<0.005) according to breed, lactation stage and parity, and height at whiters. There was significant (p<0.001) correlations between udder diameter (rp=0.541) and height (rp=0.549) with milk yield. Conclusion: This study ascertained udder morphological characteristics values in local zebu cows, and showed that udder size is strong and positively correlated to milk yield. The findings are useful in genetic improvement programs of zebu cows

Rabies incidence and burden in three cities of Cameroon (2004–2013)

Rabies is a fatal disease occurring worldwide and especially in almost all the countries in Asia and Africa including Cameroon. Though animal and human rabies is prevalent in Cameroon, the epidemiology and socio-economic burden of the disease in the country is not known. Therefore, a 10-year (October 2004–April 2013) retrospective study on the incidence of animal and human rabies and its burden in Garoua, Ngaoundéré and Yaoundé in Cameroon was carried out. Records of human cases were extracted from the database of the regional hospitals, and animal cases from the databases of Centre Pasteur and National Veterinary Laboratory. The burden of the disease was assessed through the estimation of costs linked to preventive measures (vaccination), corrective procedures (Post Exposure Treatment), Disability-Adjusted Life Year (DALY) and overall societal cost of the disease. Overall, 56 rabies-suspected human deaths, corresponding to an incidence of 0.02 ± 0.00 ‱ and Animal Rabies Incidence (ARI) of 0.37 ± 0.00 % among 1844 suspected animal cases were recorded. The economic loss due to preventive measures of 326,046 ± 28,130.85 USD, related to corrective procedures of 806,741.25 ± 2,466.08 USD, and DALY of 1690.28 ± 4.76 years were estimated. This is the first study that highlights the enormous socio-economic burden associated with animal and human rabies in endemic parts of Cameroon and emphasizes on enhancing rabies eradication strategy focusing on the One Health approach

Bacterial Pathogens Involved in Bovine Mastitis and Their Antibiotic Resistance Patterns in the Adamawa Region of Cameroon

Data on the sensitivity pattern of bacteria are scarce in sub-Saharan Africa, especially in Cameroon. This paper reports the prevalence of bovine mastitis and major bacterial pathogens associated with the disease and their antimicrobial profiles in the Adamawa Region of Cameroon. It was conducted to investigate the sensitivity pattern of bacteria isolated from mastitis cases that could be helpful in the application of appropriate therapeutic measures. For this study, 224 lactating cows were examined. A high average prevalence (59.8%) in subclinical mastitis was recorded as compared to clinical mastitis (3.6%; χ2=163.7, P=10-4). Out of the 135 clinical and subclinical mastitis cases recorded, bacteria were cultured from 115 milk samples (85.2%, n=135). In all, 14 different bacterial pathogens were isolated including: coagulase negative Staphylococci (27.5%), Staphylococcus aureus (23.3%), Escherichia coli (11.3%), Streptococcus agalactiae (7.1%), Streptococcus dysagalactiae (4.2%), Enterococcus faecalis (2.8%), Klebsiella pneumoniae (2.8%), Enterobacter aerogenes (2.1%), Pseudomonas aeruginosa (2.1%), Corynebacterium spp. (1.4%), Proteus spp. (1.4%), Brucella spp. (1.4%), Mycoplasma spp. (0.7%), and Mycobacterium spp. (0.7%). A major variationin the sensitivity of isolated bacteria against 14 different antibiotics was noticed. Overall the sensitivity test revealed that Enrofloxacin, Gentamicin, and to a lesser extent Oxacillin and Amoxicillin/Clavulanic acid, were most efficacious. The study gives a significant contribution to the epidemiology and contributes to reducing the lack of knowledge about the antibiotic resistance patterns of major bacterial mastitis in Cameroon. The application of these antibiotics could be beneficial in resolving the cases of bovine mastitis in dairy herds. Keywords: Antibiotic resistance; Cameroon: Cattle; Mastitis; Pathogenic bacteria

Risk, knowledge and preventive measures of smallholder dairy farmers in northern Malawi with regard to zoonotic brucellosis and bovine tuberculosis

Milk production using local cattle breed-types is an age-old practice in Malawi. Although dairy farming is becoming more common as a result of the increasing population and demand for milk and milk products, there is limited knowledge of the farmers’ awareness of zoonotic disease risks, their preventative practices and the disease burden in animals. This study determined dairy farmers’ general knowledge of zoonoses, assessed their risks for infection with zoonotic bovine tuberculosis (bTB) and brucellosis, and evaluated farm practices to prevent disease transmission. A questionnaire was drawn up and administered by the authors. It was used to collect information about the knowledge and preventive practices of 140 out of 684 registered dairy farmers at Mzuzu Agricultural Development Division, northern Malawi. During a second visit to 60 out of the 140 farms, a total of 156 and 95 cattle were tested for brucellosis and tuberculosis, respectively. Most farmers (77.1%) knew or had heard of zoonotic diseases, whilst 75.0% correctly named at least one zoonotic disease. More survey participants named tuberculosis as a zoonotic disease compared to brucellosis (74.3% versus 2.9%). The most commonly named means of transmission were milk (67.0%) and meat (56.0%). Almost all survey participants (96.4%) practised at least one farm activity that could lead to potential transmission of brucellosis or bTB, including sale (67.0%) and consumption (34.0%) of unpasteurised milk. Antibodies against brucellosis were found in 12 cattle (7.7%), whilst one animal (1.1%) reacted to the tuberculin skin test. General knowledge about possible transmission of diseases between humans and animals was high, although most farmers practised risk behaviours that could potentially expose the public to milk-borne zoonotic diseases such as brucellosis and bTB. Furthermore, some animals had positive results for brucellosis and tuberculosis tests. Therefore, improvement of zoonotic disease prevention programmes, as well as further investigation into the prevalence and risk factors for zoonoses, is recommended

Determining Factors and Zootechnical Output of Biosecurity Practices in Fish Farms in the Wouri Division, Cameroon

Biosecurity practice limits the occurrence of diseases and economic losses in fish farms. The objective of this study was to characterize fish farming in the Administrative Division of Wouri, Cameroon (3°97′04″–3°58′13″N; 9°76′78″–9°46′4.3″E) and assess the biosecurity practices. A cross-sectional biosecurity audit was then conducted in 33 fish farms from March to May 2022. The “snow ball” technique, on-farm observations, and face-to-face interviews of farm managers using a semistructured questionnaire were used for data collection. The results showed that most of the fish farmers were between 18 and 40 years of age (63.64%) and not trained in fish farming (60.61%). The lack of finance (57.57%) was the main constraint to the biosecurity practice. The high fish mortality rate (>15%) was recorded in 66% of the farms. Overall, the compliance rate (CR = 40.52 ± 14.70%) and adoption rate (AR = 40.40 ± 30.10%) of biosecurity measures were intermediate. No type C farm or at the minor risk level of contamination was recorded. Farmers of 18 to 40 years of age (45.24 ± 14.75%) who attended higher school (43.83 ± 14.44%) and received training in fish farming (47.44 ± 14.39%) recorded a significant higher CR. The CR and AR were significantly higher for the isolation component (CR = 60.17 ± 19.81%; AR = 60.17 ± 25.68%) followed by traffic control (CR = 53.53 ± 25.87%; AR = 53.53% ± 34.86) and sanitation (CR = 27.70 ± 19.70%; AR = 29.84 ± 26.00%). A strong (R2 = 0.725), positive, and significant (p=0.019) linear relationship was found between the level of education of fish farmers and the biosecurity compliance rate while the health status of fish was weakly (R2 = 0.207), positively, and significantly (p=0.017) influenced by the compliance rate. Fish farming is an income-generating activity that still requires socioeconomic, technical, and institutional efforts for optimal productivity. The Cameroonian government should emphasize on the education, training, and capacity building of farmers on biosecurity practices to minimise the introduction, establishment, and spread of diseases

Diversity and prevalence of gastrointestinal parasites in farmed pigs in Southeast Gabon, Central Africa

Background and Aim: Gastrointestinal infestations caused by intestinal parasites are the most important diseases and the most common in pigs in the tropics. These parasites are often associated with a huge economic loss. This study aimed to assess the diversity and prevalence of gastrointestinal parasites in farmed pigs from Haut-Ogooue Province, in South East Gabon. Materials and Methods: From March 2018 to July 2018, 156 samples of pig feces collected from nine different farms were analyzed under light microscopy. The identification of eggs, cysts, and oocysts in fecal samples was done using two qualitative techniques: Flotation and sedimentation. Results: After examination, the results obtained revealed an overall infestation level of 98.7% (154/156). We found ten parasite types with infestation levels that varied from species: Balantidium coli (120/156), Oesophagostomum spp. (100/156), Isospora suis (102/156), Ancylostoma spp. (17/156), Trichostrongylus spp. (28/156), Hyostrongylus spp. (13/156), Strongyloides spp. (7/156), Ascaris suum (8/156), Globocephalus spp. (1/156), and spirurida (1/156). The study of risk factors revealed that factors such as sex, age, and physiological condition may influence the diversity and level of infestation of animals by gastrointestinal parasites. Conclusion: For better prevention of parasitism in these farms, it would be interesting to implement health monitoring and to ensure good hygiene. Finally, further studies would be needed to better evaluate the distribution of these parasites in Gabon and the involvement of these animals in the transmission cycle of parasitic zoonoses

Poultry Litter Contamination by Escherichia coli Resistant to Critically Important Antimicrobials for Human and Animal Use and Risk for Public Health in Cameroon

Residues of antimicrobials used in farm can exert selective pressure and accelerate the occurrence of multidrug resistant bacteria in litter. This study aimed to investigate the resistance profile of Escherichia coli isolated from poultry litter. A total of 101 E. coli strains was isolated from 229 litter samples collected and stored for two months in the laboratory at room temperature. Antimicrobial susceptibility testing was performed using the disk diffusion method. An overall resistance prevalence of 58.4% (95% CI: 48.8–68.0) was obtained with 59 E. coli strains resistant to various antimicrobial agents. High levels of resistance were observed with ciprofloxacin (21/59: 36%), imipenem (27/59: 45%), norfloxacin (44/59: 74%), ceftriaxone (44/59: 74%), and levofloxacin (44/59: 75%). These antimicrobials classified under the Watch group by WHO are indicators of the high AMR risk to public health in Cameroon. Multivariable logistic regression analysis revealed that a greater probability of high level of E. coli multidrug resistance was associated with lack of training in poultry farming (OR = 0.13, p = 0.01), less experience in poultry farming (OR = 11.66 p = 0.04), and the high frequency of digestive tract disease (OR = 0.10; p = 0.001). This study revealed that poultry litter constitutes a potential source of dissemination of resistant germs from farm animals to the environment and humans