Prevalencia de Fasciola hepatica y Paramphistomidae en bovinos de doble propósito en una hacienda del trópico bajo andino colombiano / Prevalence of Fasciola hepatica and Paramphistomidae in dual purpose cattle in a farm in the Colombian low Andean tropic

RESUMEN En muchos países la fasciolosis y la paramfistomosis representan un grave problema para la salud del sector pecuario. En Colombia hay registros de ambas distomatosis en bovinos, la mayoría en el trópico alto andino, las cuales generan pérdidas econômicas anuales cercanas a 40 000 000 000 COP. El objetivo de esta investigación fue determinar la prevalencia de fasciolosis y paramfistomosis en vacunos de la hacienda La Candelaria, Caucasia (Colombia), y la presencia de caracoles hospederos intermediarios. Para cumplirlo, se realizó un estudio descriptivo de corte transversal con muestreo no probabilístico por conveniencia. Se recolectaron heces de los animales y se hizo el diagnóstico mediante la técnica modificada de Dennis. Se establecieron las prevalencias de los digeneos de acuerdo con el sexo, peso, edad y raza. Se recolectaron caracoles dulciacuícolas en la zona estudiada y se identificaron por morfologia. Se analizaron 466 muestras fecales de 178 bovinos, de las razas Cebú (Bos indicus), BON (blanco orejinegro) y del cruce entre ellas. Se diagnosticaron F. hepatica y Paramphistomidae con prevalencias del 2,2% y 30,9%, respectivamente. En el 1,1% de los vacunos se diagnosticó coinfección. Ambas trematodosis prevalecieron en las hembras (p = 0,03). Se identificaron moluscos dulciacuícolas Ampullariidae, Physidae y Planorbidae sin estadios larvarios de digeneos. Se concluyó que los bovinos de doble propósito de la hacienda La Candelaria están expuestos a F. hepatica y Paramphistomidae, y, probablemente, se infectan en los predios de la hacienda. Paramphistomidae es más prevalente que F. hepatica, lo cual concuerda con lo descrito en algunos estudios realizados en hatos del trópico alto andino colombiano. Paramphistomidae se encontró en todos los grupos etarios.

ABSTRACT Fasciolosis and paramphistomosis are a major health problem for the livestock economy worldwide. In Colombia, both distomatosis are reported in cattle, particularly in high Andean tropics, with annual economic losses close to COP 40 billion. The goal of this study was to determine the prevalence of fasciolosis and paramphistomosis in cattle from La Candelaria farm, Caucasia (Colombia), and the presence of intermediate host snails. A descriptive cross-sectional study was carried out with non-probability convenience sampling. Stool samples were collected from the animals and the diagnosis was made using the modified Dennis technique. Digenea prevalence were determined according to sex, weight, age, and race. Freshwater snails were collected in the studied area and were identified by morphology. 400 and 66 fecal samples from 178 bovines of the Zebu (Bos indicus), BON (white-eared white) breeds and the cross between them were analyzed. Fasciola hepatica and Paramphistomidae were diagnosed with a prevalence of 2,2% and 30,9%, respectively. Coinfection was diagnosed in 1,1% of the cattle. Both trematodosis were most frequent in females (p = 0,03). Freshwater molluscs Ampullariidae, Physidae and Planorbidae without digenea larval stages were identified. It was concluded that dual-purpose cattle from La Candelaria farm are exposed to F. hepatica and Paramphistomidae and are probably infected on the farm grounds. Paramphistomidae was more prevalent than F. hepatica, which agrees with other studies in herds from the Colombian high Andean tropics. Paramphistomidae was found in all age groups.

Genetic analysis of ID1-DBL2X predicts its validity as a vaccine candidate in Colombia and supports at least two independently introduced Plasmodium falciparum populations in the region.

Pregnancy-associated malaria (PAM) poses a threat to both the mother and fetus, increasing the risk of severe maternal anemia, fetal growth restriction and low birth weight infants. Two vaccines are currently in development to protect women from Plasmodium falciparum in pregnancy. Both vaccine constructs target the ID1-DBL2X domain of VAR2CSA, a protein expressed on the surface of infected erythrocytes (IEs) that mediates parasite sequestration in the placenta. Although development of an effective vaccine may be hampered by ID1-DBL2X polymorphisms expressed by field isolates, a recent study showed that genetic variation of this domain in South American parasite populations is much lower than in other geographical locations. This suggests that a recombinant vaccine designed to be efficacious in Africa and Asia is likely to be efficacious in South America. However, these studies did not include Colombian parasite populations in their analyses, which are known to be genetically distinct from other South American parasite populations due to their independent introduction from Africa. Therefore, we sought to determine the genetic variation of the ID1-DBL2X domain in Colombian parasites to assess the potential efficacy of the vaccine against PAM in this region. Through sequence analysis and population genetics, we show that there is a low degree of genetic variation amongst Colombian parasite populations and that a vaccine containing conserved antigen variants for worldwide populations is likely to be protective against PAM in Colombia. Our analysis also points towards an African origin for Colombian parasite populations, and suggests that their introduction into Colombia was a recurrent process encompassing multiple introduction events.