Schistosome Vaccines for Domestic Animals.

Hong You,Yuesheng Li,Pengfei Cai,Donald Mcmanus,Biniam Tebeje

doi:10.3390/tropicalmed3020068

Hong You, Yuesheng Li + Show 3 more

Open Access

https://doi.org/10.3390/tropicalmed3020068

Copy DOI

Abstract

Schistosomiasis is recognized as a tropical disease of considerable public health importance, but domestic livestock infections due to Schistosoma japonicum, S. bovis, S. mattheei and S. curassoni are often overlooked causes of significant animal morbidity and mortality in Asia and Africa. In addition, whereas schistosomiasis japonica is recognized as an important zoonosis in China and the Philippines, reports of viable schistosome hybrids between animal livestock species and S. haematobium point to an underappreciated zoonotic component of transmission in Africa as well. Anti-schistosome vaccines for animal use have long been advocated as part of the solution to schistosomiasis control, benefitting humans and animals and improving the local economy, features aligning with the One Health concept synergizing human and animal health. We review the history of animal vaccines for schistosomiasis from the early days of irradiated larvae and then consider the recombinant DNA technology revolution and its impact in developing schistosome vaccines that followed. We evaluate the major candidates tested in livestock, including the glutathione S-transferases, paramyosin and triose-phosphate isomerase, and summarize some of the future challenges that need to be overcome to design and deliver effective anti-schistosome vaccines that will complement current control options to achieve and sustain future elimination goals.

Highlights

As well as being a disease of great public health importance, schistosomiasis can be a chronic debilitating infection of animals and a problem of considerable economic significance in Asia and many parts of Africa
S. bovis has recently come into the spotlight as an emerging clinical health threat as well following the isolation of S. haematobium-S. bovis hybrids from children in Senegal [3] and after a recent schistosomiasis outbreak in France [4]
The immunological control of animal schistosomiasis was first advanced as an option in the 1970s as in many endemic areas, in Africa, the use of molluscicides or chemotherapy as interventions was either too expensive or impractical [13]

Summary

Introduction

As well as being a disease of great public health importance, schistosomiasis can be a chronic debilitating infection of animals and a problem of considerable economic significance in Asia and many parts of Africa. Animal schistosomiasis is likely to be a significant cost to affected communities due to its direct and indirect impacts on livelihoods These findings underscore the need for improved disease control in animals, to reduce the zoonotic transmission of S. japonicum and S. mekongi, and to prevent the spread of hybrid schistosomes to humans from animal reservoirs. Domesticated animals represent significant reservoirs of S. japonicum, and their vaccination offers an approach to control schistosomiasis by interrupting its zoonotic transmission Pertinent to this are studies undertaken in China [11] and the Philippines [12], which showed that bovines, in particular, are major animal reservoir hosts for S. japonicum, responsible for up to 90% of environmental egg contamination

The Early Days—Irradiated Larval Vaccines

The Glutathione S-Transferases

Method of Immunization Regimen

Paramyosin

Findings

Challenges and Opportunities for the Future