|Year : 2016 | Volume
| Issue : 4 | Page : 205-209
Primary tuberculosis in a nomadic Fulani population and their cattle herds in Kano, Nigeria: a one health approach
Hamza Muhammad1, Mahmood M Dalhat2, Zaiyad G Habib3, Musa M Bello4, Abubakar U Bello5, Ahmad M Yakasai6, Aisha H Sadauki7, Bashir Hussaini2, Baffa A Gwaram1, Faruk Sarkin-Fada8, Kamilu Karaye1, Idris Abdulkadir5, Abdulrazaq G Habib1
1 Department of Medicine, Aminu Kano Teaching Hospital, Kano; Department of Medicine, Bayero University, Kano, Nigeria
2 Department of Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria
3 Department of Medicine, University of Abuja Teaching Hospital, Gwagwalada, Abuja, Nigeria
4 Department of Community Medicine, Aminu Kano Teaching Hospital, Kano, Nigeria
5 Department of Veterinary Medicine, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria
6 College of Medical Sciences, Northwest University, Kano, Nigeria
7 Department of Paediatrics, Aminu Kano Teaching Hospital, Kano, Nigeria
8 Department Medical Microbiology, Bayero University, Kano, Nigeria
|Date of Web Publication||11-Jul-2017|
Department of Medicine, Aminu Kano Teaching Hospital, Kano
Background: Nigeria has a large population of Fulani pastoralists. Zoonotic infections like bovine tuberculosis (TB) are common among nomadic Fulani and their livestock. Close interaction between the nomads and their animals provide a critical human–animal interface with potential for transmission of zoonoses. We conducted a survey to determine the prevalence of primary TB infection among nomads and their cattle in Kano, north-western Nigeria.
Materials and Methods: We performed tuberculin skin test (TST) to all inhabitants of the nomadic setting and a randomly selected population of their cattle. We obtained sociodemographic information and symptoms of pulmonary TB in both respondents and their cattle. We explore knowledge of respondents regarding risk of disease transmission between them and their livestock. We compare rates of TST among the respondents and the cattle. Participants with features of active TB were referred for further evaluation and treatment.
Results: Out of 244 individuals evaluated, 103 (42.2%) were females with a median age (range) of 35 years (1–80 years). Among 167 participants who consented for and returned for TST reading, 45 (26.9%) were positive; 33 (73.3%) of which were between 20 and 50 years of age. A total of 29 (11.9%) respondents reported having cough for at least 3 weeks at the time of the study. Of the 244 participants interviewed, 51 (20.9%) reported having animals with chronic cough. A total of 26 (12.7%) of the 204 cattle tested had positive TST. Majority of the respondent (71%) were aware of potential risk of transmission of infectious diseases between them and their herds.
Conclusion: High TST positivity among the nomads of economically viable age and their herds suggests that TB is prevalent in their communities with potential for animal–human transmission. TB and other infectious diseases control programs should capture nomads in their planning and implementation.
Keywords: Cattle herd, fulani, prevalence, tuberculosis
|How to cite this article:|
Muhammad H, Dalhat MM, Habib ZG, Bello MM, Bello AU, Yakasai AM, Sadauki AH, Hussaini B, Gwaram BA, Sarkin-Fada F, Karaye K, Abdulkadir I, Habib AG. Primary tuberculosis in a nomadic Fulani population and their cattle herds in Kano, Nigeria: a one health approach. Sub-Saharan Afr J Med 2016;3:205-9
|How to cite this URL:|
Muhammad H, Dalhat MM, Habib ZG, Bello MM, Bello AU, Yakasai AM, Sadauki AH, Hussaini B, Gwaram BA, Sarkin-Fada F, Karaye K, Abdulkadir I, Habib AG. Primary tuberculosis in a nomadic Fulani population and their cattle herds in Kano, Nigeria: a one health approach. Sub-Saharan Afr J Med [serial online] 2016 [cited 2019 Oct 17];3:205-9. Available from: http://www.ssajm.org/text.asp?2016/3/4/205/210206
| Introduction|| |
The Fulani or Fula is one of the largest ethnolinguistic groups in Africa. They are widely dispersed and culturally diverse ethnic group distributed mainly in west and central Africa and the Sudan. A significant proportion of Fulani is nomadic, making them the largest pastoral nomadic group in the world.
Nigeria has a sizable population of Fulani pastoralists mostly in the northern part of the country. They have a nomadic lifestyle, rearing cattle, and continuously moving toward appropriate pasturage, water sources, and livestock markets, whereas avoiding harsh weather, tsetse flies, and livestock bandits. The Fulani population is economically productive and contributes to the food needs of Nigerians in that they produce dairy and meat from cattle herds; dung and bulls used for farming, and cattle tax. It is estimated that up to 80% of the Nigerian population depends on this group for beef and dairy products.,
Nigeria also has one of the world’s highest burden of tuberculosis (TB) affecting both settled and nomadic populations. There is paucity of data on the burden of both communicable and noncommunicable diseases among the nomadic Fulani (NF), a vulnerable group in Nigeria. Literacy level and access to health care among them is relatively low compared to average Nigerians. They are also commonly afflicted by other diseases of neglect as a consequence of inequities in healthcare access and lifestyle.
The Fulani live with their cattle and are also at increased risk of developing bovine TB (a cattle-related disease) that can complicate human immunodeficiency virus (HIV); moreover, TB is the commonest cause of death in HIV infection. The actual burden of TB amongst NF is not known. The young men in the Fulani clan are sent far afield with the cattle herd, a practice that is disruptive of family values and that can be associated with behaviors that may increase risk of acquiring HIV infection, which serve as the commonest predisposing factor for acquiring TB in sub-Saharan Africa.,
We conducted a descriptive cross-sectional study to determine the prevalence of primary TB among a seminomadic population.
| Materials and Methods|| |
The study was conducted in Tofa village, Rano Local Government Area of Kano State, Nigeria a settlement with a large population of the NF.
We administered structured questionnaires to consenting individuals or caregivers to obtain information on age, gender, income, weight, height, and body mass index (BMI). Further information was obtained on knowledge, attitude, practices, and potential risks (behavior) and prevention against TB. Data were collected by staff of the Department of Medicine, Aminu Kano Teaching Hospital, Kano. They comprise residents in subspecialty training and laboratory staff. They were trained for a period of 2 days to ensure uniformity and consistency of the collected data.
Focussed Group Discussions (FGDs) were conducted with selected members of the community to determine knowledge, attitude, practices, potential risks, and prevention of TB. Four FGDs were conducted: young men (15–39 years), middle aged (40–64 years), elderly men (65 years and above), and women of reproductive age (15–45 years). The FGD guide was developed using key thematic areas aimed at determining awareness of and preventive measures against development of common communicable and noncommunicable diseases. Each session was conducted by two interviewers with experience in conducting qualitative research. One of the interviewers moderated the interview, whereas the other documented the proceedings. The data collected were grouped into various thematic areas to enable identification of the most recurrent themes.
Tuberculin Skin Test
We conducted tuberculin skin test (TST) for TB by intradermal injection of 0.1 ml of purified protein derivative (PPD), containing 5TU manufactured by Span Diagnostic Limited, Surat, Gujarat, India. The presence or absence of an induration and the largest transverse diameter was determined by inspection, palpation, and outlining using a ball-point pen. An induration of 10 mm or more, 72-h postinjection was considered positive. False-positive can occur following exposure to environmental or atypical mycobacteria. The test has limitation in immunocompromised individuals due to anergy, for example, patients with HIV, malignancy, steroid therapy, anticancer chemotherapy, and posttransplant patients.
Ethical approval was obtained from the Research Ethics Committee of Kano State Hospitals Services Management Board, Kano. Written informed consent was obtained from each adult participant and assent was obtained in case of minors before recruitment into the study. We adhered to all the ethical principles outlined in the Declaration of Helsinki.
The source of cattle used in this study was NF cattle herd.
The participants had cattle herds, which they rear in the open field with no animal handling facilities. All cattle were paired before testing started, and one pair was handled at a time. Three to four men were required per pair. One man applies a head restraint, whereas the rest restrained the animal using a rope on the head and a milker’s hobble on the rear legs. All restraint procedures were performed by the herders themselves because the cattle were more familiar with them.
The majority of cattle tested had no permanent identification. An oil-based paint was used to serially number the cattle in each herd. The paint was applied on the back after the animals were restrained. The numbers were large enough that they were easily read for at least 1 week after application.
Tuberculin test procedure
An experience veterinarian conducted, read, and interpreted the tuberculin test, using PPD obtained from Prionics Lelystad, Netherlands to screen cattle for Mycobacterium bovis. The technique used was the single intradermal caudal fold test. A 2-ml automatic syringe with 26G needle was used. A distance of 5 to 7 cm away from the base of the tail on the left site was cleaned with dry cotton and 0.1 ml of bovine PPD tuberculin was carefully deposited intradermally.
Reading and interpretation of the test
The test was read 72-h postinjection, the restraint procedures for the reading was as described for injecting the PPD. The technique of reading the test has been described. In summary, the injection site of each animal was examined both visually and by palpation. All responses to the tuberculin test were recorded on tuberculin test form. D-symbols were used for diffuse response, whereas N-symbols were used for circumscribed or nodular responses.
For the purpose of our study, in which most of the herds tested had no previous tuberculin test recorded, all reactions, nodular or diffuse were interpreted as positive. All responses that were inconclusive and not prominent enough were interpreted as suspect. All animals with no reaction to the tuberculin test were interpreted as negative.
Frequencies, ranges, and means with standard deviations were used to describe patients’ characteristics. Median and range were used for skewed data. Chi-squared, Fisher’s exact, and Student’s t tests were used to compare categorical and continuous variables as appropriate. Estimates were computed as odds ratios with 95% confidence intervals limits. A P value of <0.05 was considered statistically significant. The statistical analysis was carried out using SPSS version 16.0 software (SPSS Inc, Chicago, III, USA).
| Result|| |
A total of 244 individuals were evaluated; of whom, 103 (42.2%) were females [see [Table 1]. The median age (range) was 35 years (1–80 years). One hundred and sixty-seven of the 244 participants who had TST returned for further evaluation, giving a drop-out rate of 31.6%. Moreover, among the 167 participants who consented for and returned for TST reading, 45 (26.9%) were positive; 38 (84.4%) of whom were within the economically active age group of 15 to 64 years.
A history of cough for at least 3 weeks duration and wasting were found among 33 (13.7%) and 16 (6.6%) of the respondents, respectively. Moreover, nine (27.3%) of the respondents with chronic cough and five (31.3%) of the respondents with history of wasting had positive TST. History of diabetes mellitus was reported by nine (3.7%) of the respondents, whereas only one participant had previous history of TB.
Of the 244 participants interviewed, 65 (34.0%) reported having sick animal within the past 6 months, and 51 (78.5%) of the sick animals had chronic cough. Majority of the respondents (71%) were aware of the potential risk of transmission of infectious diseases between them and their herds.
The bivariate regression analysis revealed no significant association between positive TST and chronic cough, history of wasting, or gender [Table 1] and [Table 2].
The FGD revealed that respondents considered TB as an important and common disease with potential for animal to human transmission, but lacked knowledge of appropriate preventive measures against it. The respondents failed to link seeking treatment and care for their sick animals as a preventive measure against zoonoses. According to a 35-year old: “The diseases that affect the animals can also affect the owner.” A 53-year old opined: “Sometimes we get lucky to have a veterinary doctor with us to treat the animals.” Majority of the participants identified potable water supply, access roads, and a healthcare facility in that order as their priority needs.
The result of intradermal tuberculin test for M. bovis is presented in [Table 3]. A total of 204 cattle were tested; 82 (40.2%) were males. Twenty-six (12.7%) had positive TST; of whom, 10 (12.2%) were males and 16 (13.1%) were females [Table 3].
| Discussion|| |
In this population-based study involving all age groups from an African seminomadic setting, 26% of the population were infected with Mycobacterium tuberculosis. The major occupation of the participants was livestock rearing. The high prevalence of primary TB among the cattle herd in this study has significant epidemiological and public health implications.
High TST positivity among the nomads and their cattle herds suggests high potential for animal–human transmission. The observed closeness of the NF to their animals offers ample opportunity for zoonotic transmission of diseases. Most cases of TB are caused by M. tuberculosis complex, M. bovis, which is a member of the complex, can be acquired by consumption of raw milk, close association between cattle and man, and also inadequate meat hygiene.
There has been increased interest in drug-resistance strains of M. tuberculosis, M. bovis, and Mycobacterium avium, because several of such strains have been isolated from HIV/Acquired Immunodeficiency Syndrome (AIDS)-infected patients and other immunocompromized humans. M. bovis acquired from cattle or their products may be contributing to the increasing number of cases of TB treatment failure seen in humans as M. bovis is known to be inherently resistant to pyrazinamide. Infection with M. bovis can cause pulmonary, disseminated, or extrapulmonary disease. Contact with infected animals is a source of M. bovis infection for humans and is a recognized occupational health hazard for abattoir workers, veterinarians, and livestock handlers.
The prevalence of primary TB in this study is lower than reported from an adult population-based study in South African urban population with high prevalence of TB and HIV; it was also lower than what was obtained in previous community-based studies conducted in some other African settings that found the prevalence of primary TB to be ranging from 31% in Ethiopia to 40% in Zimbabwe., In this study, gender, older age, weight loss, low BMI, and presence of chronic cough were not significantly associated with positive TST.
The results obtained from this study within the livestock is slightly higher than the 11.8% recorded in a similar study conducted by Shehu in Zaria, north-western Nigeria. A prevalence of 14% positive TST was reported among lactating cattle in Kaduna and Abuja area in central Nigeria. There is an upward trend in prevalence from 4% observed in 1976 to 14% reported in 2007 in different locations within Nigeria. This indicates that bovine TB infection is prevalent in all parts of Nigeria and might suggest the existence of foci of infection in different parts of the country. The reason for these foci is unknown but might be attributed to management practices such as migration of nomads between the north and southern regions in search of greener pasture during the dry and the raining seasons and the presence and build up of mycobacterial infections in the environment.
No significant relationship was found between different genders among the cattle herd. This could probably be because M. bovis infection does not have any gender discrimination.
Economic implication of test and slaughter policy in Nigeria with an estimated cattle population of about 20 million and prevalence of M. bovis infection among cattle ranging from 2.5 to 14% as reported from several studies in Nigeria is huge.,, However, test and slaughter policy with adequate compensation to the farmers, followed by regular meat inspection at abattoir and slaughter houses is the practice in the industrialize world.
Not testing for HIV is a major limitation for the study; however, this study was conducted to serve as a baseline and to establish relationship with the community. We planned to assess for other parameter in future, including HIV status.
| Conclusion|| |
High positive TST among the nomads and their cattle herds suggest TB is endemic in their community. Public health authorities should devise innovative measures to reach this neglected, vulnerable population. There is need for integration of human and animal health, and health education on preventive measures involving human immunization against mycobacterium should be encouraged. During the conduct of the study, herders were advised on proper sanitary measures regarding milk and milk product processing. Zoonotic disease transmission between humans and animals should be further evaluated using molecular methods. Identified priority needs of the community should be addressed by the appropriate authorities.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]