Pathogenic leptospires can be causative agents of reproductive problems in pigs. Cultures of uteri and kidneys from two pig herds in New South Wales and Victoria (Australia) yielded five strains identified as Leptospira on morphological and cultural grounds. Phenotypic characteristics (growth at 13 and 30 "C, growth in the presence of 8-azaguanine) were intermediate between those of pathogenic and saprophytic leptospires. No crossagglutination was observed with reference antisera representing the 24 pathogenic serogroups and the main saprophytic ones. Antiserum against one of the strains did not agglutinate reference strains representative of any serogroup. This provided evidence of a new serovar, designated hurstbridge. Genomic characterization of the five strains was achieved using five molecular approaches. Mapped restriction site polymorphisms in the rrs (165 rRNA) gene were not related to those of any reference strains. Arbitrarily primed PCR fingerprints suggested clonality of the five strains. The strains all showed an identical and unique PFGE profile. PCR, using primers specific for the rrs gene of pathogenic leptospires, amplified corresponding sequences from the strains. DNA-DNA hybridization (and reciprocal experiments) using the S1 nuclease/TCA method was performed between one of the strains and the reference strains of Leptospira species. The homology ranged from 0 to 36% (the latter being with Leptospira inadan thus satisfying the criterion of a new species, Leptospira fainei (type strain BUT 63. Phylogenetic analysis of 165 rRNA sequences showed that L. fainei and L. inadai formed a clade separate from the previously recognized 'saprophyte and ' pathogen ' clades.

A proficiency testing scheme for the leptospirosis microscopic agglutination test was provided to 37 laboratories in 23 countries in 2002 (round 1) and to 60 laboratories in 34 countries in 2003 (round 2). Thirty-four laboratories participated in both rounds. Each panel consisted of five rabbit serum samples, four of which were antisera raised against pathogenic serovars of Leptospira. One of these samples was a mixture of two different antisera. The rates of false-negative results, calculated on the basis of the assumption that serovars within a serogroup will cross-react, were 11% for round 1 and 14% for round 2. There were regional differences in the rates of false-negative results. The titers reported by laboratories testing for the same sample with the same serovar varied widely. Laboratories that had previously participated in round 1 reported fewer false-negative results in round 2 than new participants (10 and 21%, respectively [P = 0.002]) and reported 0.56 false-negative results per participant, whereas new participants reported 1.23 false-negative results per participant (P = 0.041). Laboratories that had previously participated also reported fewer false-negative results in round 2 than in round 1 when samples common to both rounds were tested (5 and 15%, respectively [P = 0.028]). The titers reported by the new participants were, on average, lower than those reported by the laboratories that had participated previously (P = 0.019) and were significantly more variable (P = 0.001). Analysis of these results suggests a positive impact of proficiency testing on the testing performance of the participating laboratories.

Brucella-specific antibodies of different immunoglobulin classes were quantitatively evaluated with respect to their efficiency in serological tests for bovine brucellosis. IgM reacted more efficiently than IgG1 and IgG2 in both the Rose Bengal plate test and serum agglutination test. The complement fixation test was found to be slightly more sensitive to IgM than to IgG1 and did not react to IgG2. IgM was, however, partly inactivated when heated at 60 degrees C. in the presence of serum.

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Immunoassays for detecting HIV infection perform better than other serological assays. HIV immunoassays are presented in a number of different formats: instrument-based, plate, rapid assays and as immunoblots. HIV immunoassays for screening and diagnosis are now in their fourth generation; an assay generation meaning that significant modifications to the assay format have led to a significant enhancement in quality. Although still not perfect, they are now of exceptionally high quality if conducted properly. Most problems relate to how the assays are performed. Many laboratories, especially in high human development index (HDI) countries, manage testing within functioning quality-management systems, but this is not true of laboratories in low HDI countries or in many medium HDI countries. Simple rapid tests for HIV are being used increasingly, and create special challenges for assuring quality. Users of HIV immunoassays are learning that a poorer assay used well has better outcomes than a splendid assay performed poorly. Experience highlights the importance of conducting HIV testing within quality-managed systems and according to international standards, but testing quality and laboratory quality management must be funded adequately.