Chikungunya arthritis - should we expect it to become more common in Portuguese rheumatology?

Chikungunya virus is known to cause acute disease characterized by fever, rash, myalgias, conjunctivitis and arthritis, having potential to cause chronic musculoskeletal disease, namely persistent arthritis. The area of spread of the virus in the world has been increasing and the migratory flows make the occurrence of Chikungunya induced chronic arthritis more and more scattered. Data regarding the experience of Portuguese rheumatology centres in identifying and treating chronic ChikV induced arthritis are not available. The authors describe the diagnosis and treatment aspects of three cases of "imported" Chikungunya induced chronic arthritis, briefly discuss its approach in the light of current knowledge and alert to the possibility this situation may become more prevalent in the Portuguese rheumatology setting.

Multi-character population study of the vir subtelomeric multigene superfamily of Plasmodium vivax, a major human malaria parasite.

Plasmodium vivax, the most widely distributed human malaria parasite, contains the subtelomeric multigene vir superfamily corresponding to circa 10% of its coding genome. In this work, we used a multi-character strategy to study the vir gene repertoire circulating in natural parasite populations obtained directly from 32 human patients from endemic regions of Brazil and Sri Lanka. Cladistic analysis confirmed the existence of vir subfamilies, which varied in size and allele polymorphisms. Moreover, different motifs, protein domain, and secondary structures were predicted for each subfamily. Of importance, not all vir sequences possess a recognizable Pexel motif recently shown to be important, though not essential, signal for transportation to the cell membrane of infected red blood cells. Furthermore, subfamilies A and D display common structural features with the recently described P. falciparum SURFIN and Pfmc-2tm subtelomeric multigene families. These results suggest that VIR proteins can have different subcellular localizations and functions. This is the first study on a population level of the P. vivax vir subtelomeric multigene superfamily.

Plasmodium vivax: allele variants of the mdr1 gene do not associate with chloroquine resistance among isolates from Brazil, Papua, and monkey-adapted strains.

We describe here the sequence of the Plasmodium vivax mdr1 gene from 10 different isolates differing in chloroquine sensitivity. The deduced amino acid sequence of PvMDR1 shares more than 70% similarity with other malarial MDR proteins and it displays consensus motifs of an ABC family transporter including two transmembrane domains and two ATP binding cassettes. Similarity and dendrogram analyses revealed that sequences could be grouped according to their geographical origin. Within each geographical group however, no correlation was found between chloroquine resistance and specific mutations.