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Epidemiology of Paratuberculosis in the Middle East Region

Nyamweya is a Kenyan scholar who has done many years of research on a diversity of topics

A cow suffering from paratuberculosis

A cow suffering from paratuberculosis

Introduction

Paratuberculosis is a chronic disease which affects both animals and human beings. The condition is said to be caused by a bacteria known as Mycobacterium avium subsp. paratuberculosis (MAP). Apart from this disease affecting public health concerns, it poses direct and indirect economic implications as well as the general animal welfare. The ailment has a capability of infecting a broad range of animal species which include ruminants and especially in countries which are agriculturally developed. As far as the Middle East is concerned, paratuberculosis, is more prevalent in domestic livestock and to some small extent humans. This paper explores the potential human exposure of this health problem, future control in human, diagnosis, prevention and future control in animals. The last part of the paper summarizes the discussion.

Diagnosis in Animals

According to Wright et al (2020), paratuberculosis which is categorized among the “iceberg diseases” could take several years before being manifested. Moreover, some of these cases may simply remain undetected. However, the author gives out some tidbits and biomarkers that could help out in detecting diseased and infected animals. Among these signs include expression of particular genes, peptides and cytokines.

Other manifestations according to Almujalli, and Al-Ghamdi (2012) include significant reduction in milk production, leanness, infertility, and diarrhea. However, these marks may not necessarily imply the prevalence of the condition. Dated methods that are still being relied upon include use of serology, skin tests and pathogen shedding. These skin tests are able to detect advanced phases of infections, serology and faecal culture. The Johnin skin test is considered to be positive when the thickness of the skin is found to be more than ≥4 mm. This method is commonly used in paratuberculosis diagnosis due to the fact that it is less costly and a specific test for early diagnosis for the disease for majority of the animals.

Nonetheless, the use of fecal culture is the common standard used in MAP identification. The process entails observing colonies of animal’s feces and milk samples in tubes that contain mycobactin. Using ISMav2, which is a genetic element, the fecal and milk samples are cloned, sequenced and compared with extant sequences in Genban. The level of homology present is an indication of Map presence or lack of it in the samples presented (McAloon et al, 2019).

Prevention and Future Control in Animals

There are a number of measures used to prevent transmission among animals. Among these is to reduce and minimize calf exposure to adult faeces, use of cull-and test, as well as minimizing interactions with affected animals. The two common preventive and control measures, which include test-and cull and calf management, have been taunted as being effective in preventing the transmission and spread of this diseases as well as in stabilizing the heard status. Essentially, a reduced calf-exposure to adult faeces and infected animals has been found to be the most influential, followed by detection and culling of infected animals (Whittington, et al, 2019). Aziz-ur-Rehman et al (2017) also adds that the current and future risk based control programs and strategies which have been used by various countries including the United States, Canada, Denmark, and Norway works by combining risk indicators and factors( based on clinical and production data) to conduct a risk assessment for every herd. The outcome from this program is then used inreducing the prevalence of paratuberculosis in animals. Vaccination regimens also look promising for future prevention and control of paratuberculosis.

Potential Human Exposure of Paratuberculosis

Garvey (2018) found a connection between paratuberculosis in domestic animals and Crohn’s disease in humans. Particularly, the author notes the possibility of Mycobacterium avium spreading from animals to human hosts through food-born transmission routes, and water. Eslami, et al (2019) explains that the food-borne transmission route poses significant risks to vulnerable populations especially those whose immune systems are low, young children and aged persons. However, milk and its related products stand out to be the most common transmission route of MAP from animals to humans. The presence of MAP in raw milk and its associated products is reinforced by the ability of this organism to survive even a midst the processes of mil pasteurization. Once the parasitic organismim enters the host’s system, it uses a molecular mimicry to evade the immune system of the host, display peptide sequences that appear as those of the host cells eventually disrupting the non-self and self recognition systems.

Future Control of Paratuberculosis in Humans

A lot of initiatives have been undertaken as a means of controlling and possibly eradicating pTB exposure among humans. Among these is to reduce the risk of transmission for the purpose of eliminating infection sources. These includes the use of isolation and quarantine for affected persons which is aimed at preventing transmission from affected people to those not yet affected. In addition, a number of vaccines have been designed while others are in the process of being designed to raise immunity of people and increase resistance to possible infections. The core objective is to reduce the environmental, food, and water contamination and exposure of susceptible individuals who include children and aged people from the infections. Biosecurity is also poised to be a good measure to control pTB among humans (Bognár, et al, 2019).

Summary

This paper has explored the epidemiology of Paratuberculosis in the Middle East Region. The focus was the diagnosis methods of this ailment in animals, prevention and control approaches in animals, potential human exposure, and future control of this infection on humans. In particular, there are several marks that are used to diagnoise pTB in animals. These include expression of particular genes, peptides and cytokines, significant reduction in milk production, leanness, infertility, and diarrhea. Furthermore, dated methods that are still being relied upon include use of serology, skin tests and pathogen shedding. These skin tests are able to detect advanced phases of infections, serology and faecal culture. Common prevention and control measures of this infection among animals include calf- management which entails reducing and minimizing calf exposure to adult faeces, as well as test-and cull method which is similar to guarantine. The potential exposure and transmission of this disease to humans have also been discussed. Accordingly, the core careers and agents identified include the environment, food and water. The identified transmission routes of pTB to humans have been particularly found to pose notable risks to vulnerable population especially those with low immunity, children and the aged persons. This therefore, calls for stringent relevant measures to control and prevent the transmission. This measure includes reducing the environmental, food, and water contamination and exposure of susceptible individuals who include children and aged people from the infections. The development and use of vaccines specifically designed for this disease is also found to be paramount in reducing exposure. What is more, biosecurity is also presumed to an effective measure to control pTB among humans.


References

Aziz-ur-Rehman; Javed, M. T.; Rizvi, F.; Khan, M. N. (2017). Prevalence of paratuberculosis in cattle and buffaloes in Faisalabad and associated risk factors. Journal of Animal and Plant Sciences, 27 (6) pp 1867-1872

Almujalli, A. M.; Al-Ghamdi, G. M. (2012). Clinicopathological findings of partuberclosis in camels possible steps for control strategy. Research Journal of Biological Sciences, 2012, 7, 3, pp 128-131

Eslami, M.; Shafiei, M.; Ghasemian, A.; Valizadeh, S.; Al-Marzoqi, A. H.; Mostafavi, S. K. S.; Nojoomi, F.; Mirforughi, S. A. (2019). Mycobacterium avium paratuberculosis and Mycobacterium avium complex and related subspecies as causative agents of zoonotic and occupational diseases. Journal of Cellular Physiology, 234, (8), pp 12415-12421

Bognár, B.; Farkas, K.; Fornyos, K.; Zrufkó, R.; Baumgartner, W.; Khol, J. L.; Jurkovich, V.

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Garvey, M. (2018). Mycobacterium avium subspecies paratuberculosis: a possible causative agent in human morbidity and risk to public health safety. Open Veterinary Journal, 8 (2), pp 172-181

McAloon, C. G.; Roche, S.; Ritter, C.; Barkema, H. W.; Whyte, P.; More, S. J.; O'Grady, L.; Green, M. J.; Doherty, M. (2019). A review of paratuberculosis in dairy herds - Part 2: On-farm control. Veterinary Journal, 246, pp 54-58

Wright, K.; Plain, K.; Purdie, A.; Saunders, B. M.; Silva, K. (2020). Biomarkers for detecting resilience against mycobacterial disease in animals. Infection and Immunity, 88 (1), pp e00401-19

Whittington, R.; Donat, K.; Weber, M. F.; Kelton, D.; Nielsen, S. S.; Eisenberg, S.; Arrigoni, N.; Juste, R.; Sáez, J. L.; Dhand, N.; Santi, A.; Michel, A.; Barkema, H.; Kralik, P.; Kostoulas, P.; Citer, L.; Griffin, F.; Barwell, R.; Moreira, M. A. S.; Slana, I.; Koehler, H.; Singh, S. V.; YooHanSang; Chávez-Gris, G.; Goodridge, A.; Ocepek, M. (2019). Control of paratuberculosis: who, why and how. A review of 48 countries. BMC Veterinary Research, 15, pp, 198.

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