Experimental Seneca Valley virus infection in sows and their offspring.

Neonatal mortality has been increasingly reported on swine breeding farms experiencing swine idiopathic vesicular disease (SIVD) outbreaks, which can be accompanied by lethargy, diarrhea, and neurologic signs in neonates. Seneca Valley Virus (SVV), or Senecavirus A, has been detected in clinical samples taken from pigs with SIVD. Experimental SVV inoculation has caused vesicular disease in pigs, particularly during the stages from weaning to finishing. However, it remains crucial to investigate whether SVV directly contributes to the increase in neonatal mortality rates. The following study was conducted to chronicle the pathogenesis of SVV infection in sows and their offspring. Ten sows were intranasally inoculated with 4.75 × 107 plaque-forming units of the virus per sow either late in gestation (n = 5) or within fourteen days of farrowing (n = 5). Each sow replicated SVV following intranasal inoculation, but only one out of ten sows developed a vesicular lesion on the snout. Evidence of transplacental infection was observed in two litters, and an additional two litters became infected following parturition out of five litters from sows inoculated in late gestation. No clinical signs were observed in the infected neonates. Likewise, no clinical signs were observed in the other five litters inoculated after farrowing, although each piglet did replicate the challenge virus. In this study, the experimental challenge of SVV did not result in neonatal mortality in contrast to observations in the field; however, it has shed light on the pathogenesis of the virus, the transmission of SVV between sows and their offspring, and host immune response that can help shape control measures in the field.

H7N6 low pathogenic avian influenza outbreak in commercial turkey farms in Chile caused by a native South American Lineage.

In December 2016, low pathogenic avian influenza (LPAI) caused by an H7N6 subtype was confirmed in a grow-out turkey farm located in Valparaiso Region, Chile. Depopulation of exposed animals, zoning, animal movement control and active surveillance were implemented to contain the outbreak. Two weeks later, a second grow-out turkey farm located 70 km north of the first site was also infected by H7N6 LPAI, which subsequently spilled over to one backyard poultry flock. The virus involved in the outbreak shared a close genetic relationship with Chilean aquatic birds' viruses collected in previous years. The A/turkey/Chile/2017(H7N6) LPAI virus belonged to a native South American lineage. Based on the H7 and most of the internal genes' phylogenies, these viruses were also closely related to the ones that caused a highly pathogenic avian influenza outbreak in Chile in 2002. Results from this study help to understand the regional dynamics of influenza outbreaks, highlighting the importance of local native viruses circulating in the natural reservoir hosts.

The immunogenetic diversity of the HLA system in Mexico correlates with underlying population genetic structure.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) allele groups and alleles by PCR-SSP based typing in a total of 15,318 mixed ancestry Mexicans from all the states of the country divided into 78 sample sets, providing information regarding allelic and haplotypic frequencies and their linkage disequilibrium, as well as admixture estimates and genetic substructure. We identified the presence of 4268 unique HLA extended haplotypes across Mexico and find that the ten most frequent (HF > 1%) HLA haplotypes with significant linkage disequilibrium (Δ'≥0.1) in Mexico (accounting for 20% of the haplotypic diversity of the country) are of primarily Native American ancestry (A*02~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*08~DQB1*04, A*68~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*14~DQB1*03:01, A*24~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*04~DQB1*03:02, A*02~B*40:02~DRB1*04~DQB1*03:02, A*68~B*35~DRB1*04~DQB1*03:02, A*02~B*15:01~DRB1*04~DQB1*03:02). Admixture estimates obtained by a maximum likelihood method using HLA-A/-B/-DRB1 as genetic estimators revealed that the main genetic components in Mexico as a whole are Native American (ranging from 37.8% in the northern part of the country to 81.5% in the southeastern region) and European (ranging from 11.5% in the southeast to 62.6% in northern Mexico). African admixture ranged from 0.0 to 12.7% not following any specific pattern. We were able to detect three major immunogenetic clusters correlating with genetic diversity and differential admixture within Mexico: North, Central and Southeast, which is in accordance with previous reports using genome-wide data. Our findings provide insights into the population immunogenetic substructure of the whole country and add to the knowledge of mixed ancestry Latin American population genetics, important for disease association studies, detection of demographic signatures on population variation and improved allocation of public health resources.

Genetic diversity of HLA system in two populations from San Luis Potosí, Mexico: San Luis Potosí City and rural San Luis Potosí.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 117 Mexicans from the state of San Luis Potosí living in the city of San Luis Potosí (N = 30) and rural communities (N = 87), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state include 13 Native American, six European, two African and two Asian haplotypes. Admixture estimates revealed that the main genetic components are Native American (52.72 ±â€¯0.66% by ML; 48.29% of Native American haplotypes) and European (34.62 ±â€¯4.28% by ML; 32.48% of European haplotypes), and a relatively high African genetic component (12.66 ±â€¯4.61% by ML; 10.26% of African haplotypes).

Genetic diversity of HLA system in three populations from Coahuila, Mexico: Torreón, Saltillo and rural Coahuila.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 684 Mexicans from the state of Coahuila living in Saltillo (N = 72), Torreón (N = 396) and rural communities (N = 216), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Coahuila include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Coahuila are European (49.72 ±â€¯4.18% by ML; 37.49% of European haplotypes) and Native American (45.01 ±â€¯2.69% by ML; 42.98% of Native American haplotypes), while African genetic component is less apparent (5.27 ±â€¯1.88% by ML; 9.92% of African haplotypes).

Genetic diversity of HLA system in two populations from Tamaulipas, Mexico: Ciudad Victoria and rural Tamaulipas.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 148 Mexicans from the state of Tamaulipas living in Ciudad Victoria (N = 23) and rural communities (N = 125), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in the state of Tamaulipas include ten Native American, three European and one African haplotypes. Admixture estimates revealed that the main genetic components in the state of Tamaulipas are Native American (54.69 ±â€¯0.93% by ML; 47.65% of Native American haplotypes) and European (34.66 ±â€¯5.62% by ML; 33.56% of European haplotypes), and a relatively high African genetic component (10.65 ±â€¯5.05% by ML; 12.42% of African haplotypes).

Genetic diversity of HLA system in two populations from Nuevo León, Mexico: Monterrey and rural Nuevo León.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 665 Mexicans from the state of Nuevo León living in the city of Monterrey (N = 226) and rural communities (N = 439), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Nuevo León include 12 Native American and three European haplotypes. Admixture estimates revealed that the main genetic components in the state of Nuevo León are Native American (54.53 ±â€¯0.87% by ML; 48.88% of Native American haplotypes) and European (38.67 ±â€¯4.06% by ML; 32.59% of European haplotypes), and a less prominent African genetic component (6.80 ±â€¯4.30% by ML; 8.26% of African haplotypes).

Genetic diversity of HLA system in two populations from Durango, Mexico: Durango city and rural Durango.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 479 Mexicans from the state of Durango living in Durango city (N = 153) and rural communities (N = 326), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Durango include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in Durango are European (54.34 ±â€¯1.68%) and Native American (45.66 ±â€¯2.24%), while African genetic component was virtually absent (0.00 ±â€¯2.03%). However, African haplotypes could be estimated at a proportion of 9.13%.

Genetic diversity of HLA system in three populations from Chihuahua, Mexico: Chihuahua City, Ciudad Juárez and rural Chihuahua.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 461 Mexicans from the state of Chihuahua living in Chihuahua city (N = 119), Ciudad Juárez (N = 106) and rural communities (N = 236), to obtain information regarding allelic and haplotypic frequencies and their linkage disequilibrium. We find that the most frequent haplotypes found in the state of Chihuahua include seven Native American and three European haplotypes. Admixture estimates revealed that the main genetic components in Chihuahua are European (52.12 ±â€¯0.88% by ML; 41.53% of European haplotypes) and Native American (39.51 ±â€¯2.17% by ML; 37.45% of Native American haplotypes), while African genetic component was less apparent (8.36 ±â€¯1.47% by ML; 11.70% of African haplotypes).

Genetic diversity of HLA system in a population sample from Aguascalientes, Mexico.

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 95 Mexicans from the state of Aguascalientes to obtain information regarding allelic and haplotypic frequencies and their linkage disequilibrium. We find that the most frequent haplotypes in the state of Aguascalientes include four Native American, three European and one Asian haplotypes. Admixture estimates revealed that the main genetic components in the state of Aguascalientes are Native American (54.53 ±â€¯3.22% by ML; 44.21% of Native American haplotypes) and European (44.34 ±â€¯0.45% by ML; 40.53% of European haplotypes), and a relatively low African genetic component (1.13 ±â€¯2.33% by ML; 5.26% of African haplotypes).