E U ROSU R V E I L L A N C E Vol . 14 · I ssu e 2 · 15 J an ua ry 20 09 · w w w. e urosurve illance. o rg 1 S u r v e i ll a n c e a n d o u t b r e a k r e p o r t s Lo n g -t e r m Cry p t o s p o r i d i u m t y p i n g r e v e a L s t h e a e t i o L o g y a n d s p e c i e s -s p e c i f i c e p i d e m i o L o g y o f h u m a n c r y p to s p o r i d i o s i s i n en g L a n d a n

Bendall, Gray rotavirus antigen ELISA (Rotaclone, NovoNordisk, Cambridge) (table). These results suggest that the positive reactions with the latex test were not specific for rotavirus antigen.Latex agglutination tests are generally accepted as having a specificity approaching that of electron microscopy in the diagnosis of rotavirus infection.56 Laboratories that lack the facilities for electron microscopy can rely on this method as the sole test for making the diagnosis of rotavirus infection. A test which confuses haemorrhagic colitis with rotavirus infection could be falsely reassuring to the clinicians caring for the patient, especially when the result is available a day or two before the results of bacteriological investigations. In the light of our results we recommend that positive results with the RotaScreen latex test be confirmed by some other means.We are currently looking at faecal samples collected from other patients with bloody diarrhoea to ascertain the incidence and nature of false positive reactions with this test.

Transplantation activity is increasing, leading to a growing number of patients at risk for toxoplasmosis. We reviewed toxoplasmosis prevention practices, prevalence, and outcomes for hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT; heart, kidney, or liver) patients in Europe. We collected electronic data on the transplant population and prevention guidelines/regulations and clinical data on toxoplasmosis cases diagnosed during 2010–2014. Serologic pretransplant screening of allo-hematopoietic stem cell donors was performed in 80% of countries, screening of organ donors in 100%. SOT recipients were systematically screened in 6 countries. Targeted anti-Toxoplasma chemoprophylaxis was heterogeneous. A total of 87 toxoplasmosis cases were recorded (58 allo-HSCTs, 29 SOTs). The 6-month survival rate was lower among Toxoplasma-seropositive recipients and among allo-hematopoietic stem cell and liver recipients. Chemoprophylaxis improved outcomes for SOT recipients. Toxoplasmosis remains associated with high mortality rates among transplant recipients. Guidelines are urgently needed to standardize prophylactic regimens and optimize patient management.

The LIAISON system is a fully automated system based on chemiluminescence and antigen bound to magnetic microparticles. The system allows fast and precise measurement of Toxoplasma-specific immunoglobulin G (IgG) and IgM antibody levels and measurement of the IgG avidity index even at low levels of Toxoplasma-specific IgG antibodies in a single step without manual interference. Seven European centers participated in a multicenter evaluation of the LIAISON system. The sensitivity and specificity of the LIAISON system compared to the Sabin-Feldman dye test were 99.3 and 96.8%, respectively. In a comparison of the LIAISON Toxoplasma-specific IgM assay with an immunosorbent agglutination assay, the LIAISON assay had a sensitivity of 96.7% and a specificity of 95.4%. The LIAISON IgG assay showed agreements of 91, 100, and 100% with the AXSYM IgG (Abbott), VIDAS IgG (bioMérieux), and Platelia IgG (Bio-Rad) assays, respectively. The LIAISON IgM assay showed agreements of 95% with the AXSYM IgM and Platelia IgM assays, 96% with the ISAGA IgM assay (bioMérieux), and 97% with the VIDAS IgM assay. The coefficient of correlation between the LIAISON system and the VIDAS Toxoplasma-specific IgG avidity index was 0.81. By use of the Toxoplasma-specific IgG avidity index assay with specific IgM-positive samples, the diagnosis of infection with Toxoplasma gondii in early pregnancy has been improved significantly. The LIAISON avidity assay is a valuable assay for the exclusion of recently acquired infection with T. gondii (less than 4 months) in pregnant women, and it decreases significantly the necessity for follow-up testing.Primary maternal infection with Toxoplasma gondii carries the risk of transmitting the infection to the fetus, resulting in congenital infection. Congenital infection of the fetus in women infected just before conception is extremely rare, and even during the first few weeks of pregnancy, the maternalfetal transmission rate is low (6). It is therefore essential to estimate the time of infection as precisely as possible to properly manage the risk to the fetus of a maternal infection. Low levels of Toxoplasma-specific immunoglobulin M (IgM) antibodies may be found for up to several years, and the mere demonstration of low levels of Toxoplasma-specific IgM antibodies is therefore not a sign by itself of acute infection with T. gondii (16,17). The measurement of the avidity of IgG antibodies for T. gondii infections was first demonstrated in 1989 (8, 9, 15) and since then has been further developed (4,18).A study of the diagnostic value of various tests for acute infections with T. gondii, including Toxoplasma-specific IgG, IgM, and IgA antibodies and the IgG avidity index, showed that the combination of a sensitive test for Toxoplasma-specific IgM antibodies and a Toxoplasma-specific IgG avidity assay had the highest predictive value with regard to the time of infection (23).Since previous studies showed that some individuals have low-avidity IgG antibodies many months after infection, we also tested the hypo...

Polymerase chain reaction amplification and DNA sequencing of the Toxoplasma gondii dihydropteroate synthase gene (dhps) identified 4 alleles among parasite populations from 32 cases of human toxoplasmosis. Heterologous expression and enzyme assay reveal that 3 of these alleles encode sulfadiazine (Sdz)-sensitive enzymes. The fourth, generating a highly Sdz-resistant enzyme, differs from 1 of the other 3 at only a single residue (407) of DHPS. Of interest, a fifth allele, found in a laboratory-induced Sdz-resistant line, also differs from another of these 3 drug-sensitive forms by the same single mutation that affects residue 407 of DHPS. Significantly, residues corresponding to DHPS-407 are implicated in sulfonamide resistance in other microorganisms. The human-derived allelic form encoding the Sdz-resistant enzyme was found in T. gondii associated with a fatal infection, and its presence within clinical material may have implications for sulfonamide use, particularly in cases of toxoplasmosis in which the initial response to drug treatment is poor.