Sera from patients with American cutaneous leishmaniasis and Chagas disease and from monkeys infected with either Trypanosoma cruzi or Trypanosoma rhodesiense show, in RIAs, strong binding to mouse laminin. A distinct although weaker binding activity is also detected in normal human sera. The antibodies recognize a common carbohydrate epitope present on mouse laminin, which was assigned to a terminal galactosyl(alpha 1-3)-galactose group. Distinct crossreactions were observed with some other basement membrane proteins, rabbit glycosphingolipids, defucosylated human B blood group substance and components produced by some human tumor cells. Only little activity was, however, found on laminin obtained from human placenta. The data indicate that the antibodies arising in infectious diseases are stimulated by similar carbohydrate epitopes present on the surface of parasites. Tissue-specific occurrence of such epitopes may exist and explain the involvement of distinct tissues in autoimmune disorders.

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Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant economic losses to the swine industry worldwide. While PRRSV has been endemic in North America since 1989, it was not until 1999 that the virus was first described in South America. Notably, recently an increased number of PRRSV outbreaks have been reported in South American countries. However, epidemiological information related to these outbreaks is limited and the genetic characteristics of the PRRSV strains circulating in the region are poorly understood. In this study, we describe the genetic analyses of PRRSV strains associated with severe PRRS outbreaks in Peru. Samples originating from 14 farms located in two Departments in Peru (Lima and Arequipa), were subjected to RT‐PCR amplification of the PRRSV ORF5 gene and sequencing followed by restriction fragment length polymorphism (RFLP) analysis. Results demonstrated the circulation of PRRSV‐2 in Peru. Notably ORF5 RFLP typing revealed that 15 (75%) of the PRRSV strains detected in this study belong to the RFLP 1‐7‐4 type. Phylogenetic analysis showed that the Peruvian strains are closely related to the highly virulent PRRSV 1‐7‐4 strains that emerged in the US in 2013–2014. Results here indicate the presence of highly virulent PRRSV 1‐7‐4 strains in Peru and provide important information on the geographical distribution of PRRSV, confirming the recent geographical expansion of this important swine pathogen towards South America.

Using rabbit erythrocyte-derived neutral glycosphingolipids enriched for a defined ceramide pentasaccharide as antigens, we have detected elevated anti-galactosyl-a(1-3)galactose (anti-GaG) antibody values in patients with American cutaneous leishmaniasis (ACL), chronic Chagas' disease, and Trypanosoma rangeli infections compared with normal subjects or with patients suffering from any of 15 other infectious diseases. The specificity of the GaG antibodies was determined by inhibition enzyme-linked immunosorbent assays, which revealed that several a-galactosyl-but not 0-galactosyl-bearing sugars blocked absorption of GaG antibodies to the specific antigen used. GaG antibodies were mainly distributed between immunoglobulin classes G and M in three Kinetoplastida infections studied, with a lower increase in reactivity detected in immunoglobulin A. Absorption of highly reactive GaG antibodies with purified murine laminin and nidogen, two basement membrane proteins, almost abolished GaG reactivity, suggesting the identity of anti-GaG with laminin and nidogen antibodies previously reported as elevated in Kinetoplastida infections. In ACL, GaG antibodies were detected in 71% of patients having skin lesions with a clinical evolution time of 0.5 month. This percentage increased with the time of evolution of skin lesions, reaching 93% in lesions older than 3 months, and tended to decrease inversely to the induration diameter in the skin leishmanin test. It is proposed that similar epitopes may exist on kinetoplast protozoa and that the determination of GaG antibodies may be a highly sensitive assay for the detection of humoral responses to Kinetoplastida infections.

Interspecies transmission is an important mechanism of evolution and contributes to rotavirus A (RVA) diversity. In order to evaluate the detection frequency, genetic diversity, epidemiological characteristics and zoonotic potential of RVA strains in faecal specimens from humans and animals cohabiting in the same environment in the department of Cusco, Peru, by molecular analysis, 265 faecal specimens were obtained from alpacas, llamas, sheep and shepherd children, and tested for RVA by RT‐PCR. Genotyping was performed by multiplex PCR and sequence analysis. Rotavirus A was detected in 20.3% of alpaca, 47.5% of llama, 100% of sheep and 33.3% of human samples. The most common genetic constellations were G3‐P[40]‐I8‐E3‐H6 in alpacas, G1/G3‐P[8]‐I1‐E1‐H1 in llamas, G1/G3/G35‐P[1]/P[8]‐I1‐E1‐H1 in sheep and G3‐P[40]‐I1/I8‐E3‐H1 in humans. The newly described genotypes P[40] and P[50] were identified in all host species, including humans. Genotyping showed that the majority of samples presented coinfection with two or more RVA strains. These data demonstrate the great genetic diversity of RVA in animals and humans in Cusco, Peru. Phylogenetic analysis suggested that the strains represent zoonotic transmission among the species studied. Due to the characteristics of the human and animal populations in this study (cohabitation of different host species in conditions of poor sanitation and hygiene), the occurrence of zoonoses is a real possibility.