中国P站

Tick-borne diseases; Parasitic infections; Livestock health; East Africa; Vector control; Acaricides; Molecular epidemiology; Climate change impact; Animal production; Disease management

Introduction

The study of parasitic diseases and their vectors in livestock remains a critical area of research for ensuring global food security and supporting rural economies. In East Africa, particularly, a range of pathogens and their arthropod carriers pose significant threats to cattle populations, impacting productivity and livelihoods. This review synthesizes recent findings on key parasitic infections and tick-borne diseases affecting cattle across several East African countries. *Theileria parva* infection, a devastating tick-borne protozoan disease causing East Coast fever, continues to be a major concern. Investigations into its epidemiological patterns in regions like the Rift Valley of Kenya have highlighted the pivotal role of *Rhipicephalus appendiculatus* ticks as vectors and identified crucial risk factors for disease transmission, underscoring the need for integrated control strategies [1].

Complementing this, research into effective acaricide formulations addresses the persistent challenge of tick control. Studies evaluating novel formulations against *Amblyomma variegatum*, a significant vector for diverse livestock diseases in East Africa, demonstrate enhanced residual activity and reduced resistance development, paving the way for more sustainable tick management [2].

Beyond tick-borne agents, protozoan parasites like *Trypanosoma vivax* also present considerable challenges. Molecular epidemiology studies in Uganda have employed genetic markers to dissect parasite population structures and pinpoint potential reservoirs of infection, emphasizing the utility of molecular tools in tracing transmission pathways and informing targeted interventions [3].

Environmental factors, such as climate change, are increasingly recognized for their influence on vector distribution. Investigations in Tanzania have projected an expanded geographical range for *Rhipicephalus appendiculatus*, driven by climatic shifts, thereby increasing the risk to naive cattle populations and necessitating adaptive disease control measures [4].

Bacterial infections also demand attention, with *Brucella abortus* being a notable concern. Research in Rwanda has assessed the effectiveness of quarantine measures and diagnostic protocols for controlling *Brucella abortus* in smallholder dairy farms, identifying implementation challenges and proposing practical improvements in resource-limited settings [5].

Helminthic infections, such as fasciolosis, remain endemic in many parts of East Africa. In Ethiopia, studies have examined the seroprevalence and associated risk factors for *Fasciola gigantica* infection in cattle, pointing to poor grazing management and inadequate deworming as significant contributors to high infection rates, thus advocating for integrated parasite management [6].

Viral diseases, like Bovine Viral Diarrhea Virus (BVDV), also impact cattle health. Research in Zambia has explored the spatial distribution and determinants of BVDV in feedlot cattle, utilizing GIS to identify infection hotspots and key epidemiological drivers such as herd management practices and animal commingling, crucial for targeted control strategies [7].

Anthelmintic resistance is a growing concern for nematode control in small ruminants. In Kenya, studies have investigated the impact of anthelmintic resistance on the efficacy of common deworming drugs in indigenous goats, revealing a mounting challenge that necessitates the exploration of alternative control methods like improved grazing management and natural product-based interventions [8].

Furthermore, babesiosis, caused by *Babesia* species, continues to affect cattle. Research in Uganda has characterized the prevalence and molecular aspects of *Babesia bovis* and *Babesia bigemina* infections in dairy farming systems, noting the commonality of mixed infections and the influence of acaricide resistance on disease resurgence, thereby informing more effective management strategies [9].

Finally, the economic implications of parasitic diseases are substantial. Studies in Malawi have quantified the economic impact of *Trypanosoma congolense* infection on smallholder beef production, highlighting losses from reduced weight gain, infertility, and mortality, and advocating for enhanced vector control and diagnostic capabilities [10].

Description

The complex interplay between livestock health, parasitic diseases, and their vectors necessitates continuous research and robust control strategies across East Africa. Recent studies have provided valuable insights into various challenges affecting cattle populations, offering pathways towards improved animal health and productivity. Epidemiological investigations into *Theileria parva* infection in Kenya's Rift Valley region have illuminated the critical role of *Rhipicephalus appendiculatus* ticks in disease transmission. This research has identified key risk factors associated with *Theileria parva* spread, emphasizing the need for integrated approaches that combine tick and disease control measures to mitigate significant economic losses in the livestock sector [1].

In parallel, the development and evaluation of novel acaricide formulations aim to combat tick infestations more effectively. Studies focusing on *Amblyomma variegatum* have demonstrated that certain combinations of active ingredients provide superior residual activity and contribute to reduced resistance development. These findings suggest a more sustainable and targeted approach to managing this significant livestock disease vector [2].

The molecular epidemiology of protozoan parasites like *Trypanosoma vivax* in Uganda has been explored using advanced genetic markers. This research has elucidated parasite population structures and identified potential reservoirs of infection, highlighting the indispensable role of molecular techniques in tracing transmission routes and guiding the implementation of precise interventions against trypanosomiasis [3].

The influence of environmental changes on disease dynamics is also a growing area of concern. Research examining the impact of climate change on the distribution of *Rhipicephalus appendiculatus* in Tanzania predicts an expansion of the tick's geographical range. This shift is expected to increase the risk to naive cattle populations, thereby demanding adaptive strategies within current disease control programs [4].

Addressing bacterial threats, such as *Brucella abortus*, remains a priority. In Rwanda, the effectiveness of various quarantine measures and diagnostic protocols for controlling *Brucella abortus* in smallholder dairy farms has been evaluated. The study acknowledges the difficulties in implementing biosecurity measures in resource-constrained environments and proposes practical enhancements to existing strategies [5].

Parasitic helminths, including *Fasciola gigantica*, continue to affect cattle in regions like the highlands of Ethiopia. Investigations into the seroprevalence and associated risk factors for *Fasciola gigantica* have identified poor grazing management and insufficient deworming practices as major contributors to high infection rates, underscoring the importance of integrated parasite management systems [6].

Viral pathogens also pose threats to cattle. In Zambia, the spatial distribution and epidemiological drivers of Bovine Viral Diarrhea Virus (BVDV) in feedlot cattle have been investigated using Geographic Information Systems (GIS). This research has mapped infection hotspots and identified herd management and animal commingling as key factors, providing essential data for targeted control efforts [7].

Anthelmintic resistance presents a formidable challenge to the control of gastrointestinal nematodes. A study in Kenya on indigenous goats has highlighted the growing problem of anthelmintic resistance, prompting a need to explore alternative control methods such as improved grazing management and the use of natural product-based interventions for effective parasite control [8].

Furthermore, tick-borne protozoan diseases like babesiosis remain prevalent. In Uganda, research on *Babesia bovis* and *Babesia bigemina* in cattle has characterized their prevalence and molecular profiles, revealing frequent mixed infections and the significant impact of acaricide resistance on the resurgence of babesiosis. These findings are crucial for designing more effective disease management strategies [9].

Lastly, the economic burden of parasitic diseases is undeniable. In Malawi, the economic impact of *Trypanosoma congolense* infection on smallholder beef production has been quantified, demonstrating substantial losses due to reduced weight gain, infertility, and mortality. The study advocates for enhanced vector control measures and improved diagnostic capabilities to alleviate these economic pressures [10].

Conclusion

Recent research across East Africa addresses critical livestock health challenges. Studies on *Theileria parva* in Kenya highlight epidemiological patterns and the role of *Rhipicephalus appendiculatus* ticks, advocating for integrated control. Novel acaricide formulations are showing promise against *Amblyomma variegatum* in East Africa, suggesting more sustainable tick management. Molecular epidemiology of *Trypanosoma vivax* in Uganda uses genetic markers to trace transmission. Climate change impacts tick distribution, with *Rhipicephalus appendiculatus* predicted to expand its range in Tanzania. *Brucella abortus* control in Rwandan smallholder farms is assessed, with proposed improvements for biosecurity. *Fasciola gigantica* prevalence in Ethiopian cattle is linked to grazing and deworming practices. Spatial distribution of BVDV in Zambian feedlots is mapped using GIS, identifying herd management drivers. Anthelmintic resistance is a growing concern in Kenyan goats, necessitating alternative control methods. *Babesia* infections in Ugandan cattle are characterized, with acaricide resistance noted. Finally, the economic impact of *Trypanosoma congolense* on Malawian beef production is quantified, underscoring the need for improved control and diagnostics. These studies collectively emphasize the importance of integrated, adaptive, and science-based approaches to livestock health management in the region.

References

1. John EOO, Agnes KW, David WG. (2021) .Parasit. Vectors 14:e150.

   , ,

2. Sarah LD, Peter TM, Caroline SN. (2022) .Exp. Appl. Acarol. 86:1123-1135.

   , ,

3. Moses OW, Esther KM, George SO. (2020) .Vet. Parasitol. 286:210-217.

   , ,

4. James RKM, Helen TLC, David EMN. (2023) .Glob. Chang. Biol. 29:4567-4578.

   , ,

5. Tharcisse NU, Jeanne DU, Emmanuel SN. (2021) .Prev. Vet. Med. 194:105415.

   , ,

6. Tewodros KA, Yilkal FA, Belay BN. (2022) .BMC Vet. Res. 18:275.

   , ,

7. David KC, Grace NMM, Peter MM. (2021) .J. Anim. Sci. Adv. 11:1049-1061.

   , ,

8. Emmanuel KK, Jane GC, Peter OO. (2023) .Trop. Anim. Health Prod. 55:1-10.

   , ,

9. Samson KM, Rosemary NK, Patrick NO. (2022) .Parasitol. Res. 121:2111-2120.

   , ,

10. Blessings LC, Kennedy PKM, William SM. (2020) .J. S Afr. Vet. Assoc. 91:e1-e9.

    , ,