Fatimaezzahra Amarir1,2,3, Abdelkbir Rhalem1, Abderrahim Sadak3, Marianne Raes2, Mohamed Oukessou4, Aouatif Saadi1,5, Mohammed Bouslikhane1, Charles G Gauci6, Marshall W Lightowlers6, Nathalie Kirschvink2, Tanguy Marcotty2. 1. Laboratory of Parasitology, Department of Pathology and Veterinary Public Health, Hassan II Agronomy and Veterinary Institute (IAV), Rabat, Morocco. 2. Integrated Veterinary Research Unit, Department of Veterinary Medicine, Namur Research Institute for Life Sciences (NARILIS), University of Namur, Belgium. 3. Laboratory of Zoology and General Biology, Parasitological and Ecological Unit, Faculty of Sciences, Mohammed V University, Rabat, Morocco. 4. Unit of Physiology and Therapeutics, Department of Veterinary Biological and Pharmaceutical Sciences, Hassan II Agronomic and Veterinary Institute, Rabat, Morocco. 5. Fundamental and Applied Research for Animals and Health (FARAH), University of Liège, Liège, Belgium. 6. Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Australia.
Abstract
BACKGROUND: Cystic echinococcosis (CE) is an important cause of human morbidity and mortality worldwide, particularly in Morocco and other North African countries. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the potential of three strategies to reduce Echinococcus granulosus transmission: (1) 4-monthly treatment of dogs with praziquantel, (2) vaccination of sheep with the EG95 vaccine and (3) a combination of both measures. These measures were implemented during four consecutive years in different areas of the Middle Atlas Mountains in Morocco. The outcome of the interventions was assessed through hydatid cyst (viable and non-viable) counts in liver and lungs using necropsy or in vivo ultrasound examination of the liver. A total of 402 lambs were recruited for annual vaccination with the EG95 anti-E. granulosus vaccine and 395 similar lambs were selected as non-vaccinated controls. At approximately four years of age the relative risk (estimated as odds ratio) for vaccinated sheep to have viable hydatid cysts compared with non-vaccinated controls was 3% (9.37% of the vaccinated sheep were found infected while 72.82% of the controls were infected; p = 0.002). The number of viable cysts in vaccinated animals was reduced by approximately 97% (mean counts were 0.28 and 9.18 respectively; p<0.001). An average of 595 owned dogs received 4-monthly treatment during the 44 months trial, corresponding to 91% of the owned dog population. Approximately, 5% of them were examined for E. granulosus adult worms by arecoline purge or eggs in feces (confirmed by PCR). The proportion of infected dogs significantly decreased after treatment (12% versus 35%; p<0.001). Post-treatment incidence of re-infestation corresponded to a monthly risk of 4% (95% CI: 3-6%). Treatment of owned dogs on a 4-monthly basis did not reduce the level of transmission of E. granulosus to sheep, nor did it enhance the level of control generated by vaccination of sheep with EG95, possibly because of unowned dogs and wild canids were not treated. CONCLUSIONS/SIGNIFICANCE: These data suggest that vaccination of sheep with EG95 has the potential to reduce the level of CE in Morocco and in other parts of the world with similar transmission dynamics. Under the epidemiological circumstances existing in the trial area, 4-monthly treatment of owned dogs with praziquantel was insufficient to have a major impact of E. granulosus transmission to sheep.
BACKGROUND:Cystic echinococcosis (CE) is an important cause of human morbidity and mortality worldwide, particularly in Morocco and other North African countries. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the potential of three strategies to reduce Echinococcus granulosus transmission: (1) 4-monthly treatment of dogs with praziquantel, (2) vaccination of sheep with the EG95 vaccine and (3) a combination of both measures. These measures were implemented during four consecutive years in different areas of the Middle Atlas Mountains in Morocco. The outcome of the interventions was assessed through hydatid cyst (viable and non-viable) counts in liver and lungs using necropsy or in vivo ultrasound examination of the liver. A total of 402 lambs were recruited for annual vaccination with the EG95 anti-E. granulosus vaccine and 395 similar lambs were selected as non-vaccinated controls. At approximately four years of age the relative risk (estimated as odds ratio) for vaccinated sheep to have viable hydatid cysts compared with non-vaccinated controls was 3% (9.37% of the vaccinated sheep were found infected while 72.82% of the controls were infected; p = 0.002). The number of viable cysts in vaccinated animals was reduced by approximately 97% (mean counts were 0.28 and 9.18 respectively; p<0.001). An average of 595 owned dogs received 4-monthly treatment during the 44 months trial, corresponding to 91% of the owned dog population. Approximately, 5% of them were examined for E. granulosus adult worms by arecoline purge or eggs in feces (confirmed by PCR). The proportion of infecteddogs significantly decreased after treatment (12% versus 35%; p<0.001). Post-treatment incidence of re-infestation corresponded to a monthly risk of 4% (95% CI: 3-6%). Treatment of owned dogs on a 4-monthly basis did not reduce the level of transmission of E. granulosus to sheep, nor did it enhance the level of control generated by vaccination of sheep with EG95, possibly because of unowned dogs and wild canids were not treated. CONCLUSIONS/SIGNIFICANCE: These data suggest that vaccination of sheep with EG95 has the potential to reduce the level of CE in Morocco and in other parts of the world with similar transmission dynamics. Under the epidemiological circumstances existing in the trial area, 4-monthly treatment of owned dogs with praziquantel was insufficient to have a major impact of E. granulosus transmission to sheep.
Authors: Kevin Louis Bardosh; Ikhlass El Berbri; Marie Ducrotoy; Mohammed Bouslikhane; Fassi Fihri Ouafaa; Susan C Welburn Journal: J Biosoc Sci Date: 2016-09
Authors: Pasi K Korhonen; Liina Kinkar; Neil D Young; Huimin Cai; Marshall W Lightowlers; Charles Gauci; Abdul Jabbar; Bill C H Chang; Tao Wang; Andreas Hofmann; Anson V Koehler; Junhua Li; Jiandong Li; Daxi Wang; Jiefang Yin; Huanming Yang; David J Jenkins; Urmas Saarma; Teivi Laurimäe; Mohammad Rostami-Nejad; Malik Irshadullah; Hossein Mirhendi; Mitra Sharbatkhori; Francisco Ponce-Gordo; Sami Simsek; Adriano Casulli; Houria Zait; Hripsime Atoyan; Mario Luiz de la Rue; Thomas Romig; Marion Wassermann; Sargis A Aghayan; Hasmik Gevorgyan; Bicheng Yang; Robin B Gasser Journal: Commun Biol Date: 2022-03-03