Antimicrobial resistance prevalence of Escherichia coli and Staphylococcus aureus amongst bacteremic patients in Africa: a systematic review.

OBJECTIVES: Antimicrobial resistance (AMR) is a global concern among infectious diseases. Bloodstream infections can potentially become life-threatening if they become untreatable with conventional antimicrobials. This review aims to provide an understanding of the AMR prevalence and trends of common bacteremic pathogens, namely Escherichia coli and Staphylococcus aureus in the World Health Organization (WHO) Africa region. METHODS: PubMed and Google Scholar were searched using relevant keywords for published human studies (excluding case reports and reviews) reporting bacteremic AMR data on the pathogens of interest between 2008 and 2019. Two reviewers independently screened the articles against a pre-defined eligibility criterion. Data extraction and analysis were achieved with different platforms: Covidence, Excel, R version 3.6.3, and QGIS v3.4.5. The pooled prevalence, 95% confidence intervals, and I2 index (a measure of heterogeneity) were calculated for the various pathogen-antibiotic combinations. RESULTS: Five hundred sixty-two papers were retrieved, with 27 papers included in the final analysis. Only 23.4% (11/47) of member states of the WHO African region had reports on AMR in bacteremia. The Clinical and Laboratory Standards Institute (CLSI) (78.5%) was the most common standard used in the region. For E. coli, the pooled resistance was: cefotaxime (42%), imipenem (4%), meropenem (0%), and colistin (0%). For S. aureus, the calculated pooled resistance was cloxacillin (34%), oxacillin (12%), and vancomycin (0%). There was a high degree of variation across studies (I2 > 90%). CONCLUSION: The pooled resistance rates indicate a concerning degree of methicillin-resistant and Extended Spectrum-ß-lactamase-producing pathogens. The paucity of AMR data also presents challenges for a comprehensive understanding of the situation in the region. Continent-wide and standardized surveillance efforts therefore need strengthening.

Antimicrobial resistance among bacteria isolated from urinary tract infections in females in Namibia, 2016-2017.

BACKGROUND: The emergence of antimicrobial resistance (AMR) among bacterial pathogens demands a local understanding of the epidemiological situation. This information is needed both for clinical treatment decision-making purposes as well as for the revision of current care guidelines. Clinical AMR data from Namibia is sparse, whilst urinary tract infections remain not only widespread but they disproportionally affect females. This paper aims to describe the national antimicrobial resistance situation of major bacterial uropathogens in females within the 14 Namibian regions. METHOD: Retrospective countrywide information on clinical urine cultures performed in females in Namibia in 2016-2017 was obtained from the national public health laboratory, Namibia Institute of Pathology (NIP). The data set included both microbiological findings as well as antimicrobial susceptibility test (AST) results. The AST was done as per the Clinical and Laboratory Standards Institute (CLSI) guidelines. Resistance to 3rd generation cephalosporins was indicative of Extended Spectrum-ß-lactamase (ESBL) production. Data analysis was done with WHONET using expert interpretation rules. RESULTS: In total, 22,259 urinary cultures were performed, of which 13,673 (61.4%) were culture positive. Gram-negative bacterial species accounted for 72.6% of the findings. The most common pathogens identified were Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. Most of these were from young females, with a median age ranging from 28 to 32 years for the various pathogens. Resistance to ampicillin was 77.7% in E. coli and 84.9% in K. pneumoniae. In E. coli, resistance to 1st line empiric therapy antibiotic, nitrofurantoin, was below 13%, except for one region that showed 59.2% resistance. Resistance to third generation cephalosporin (3GC) was used as a proxy for ESBL production. By year 2017, 3GC resistance was 22%, 31.4% and 8.3% for E. coli, K. pneumoniae and P. mirabilis, respectively. CONCLUSION: We report high resistance to ampicillin, quinolones and sulfamethoxazole-trimethoprim amongst E. coli. Resistance rates to third-generation cephalosporins was also concerningly high at 22%. Resistance to carbapenems was low. However, superiority of nitrofurantoin was found, which provides rational support for the usefulness of nitrofurantoin as an empiric therapy regimen for the treatment of urinary tract infections in this setting.

Leucocyte protein Trojan, a possible regulator of apoptosis.

Trojan is a leucocyte-specific protein, cloned from chicken embryonic thymocyte cDNA library. The molecule is a type I transmembrane protein with an extracellular CCP domain, followed by two FN3 domains. Its cytoplasmic tail is predicted to possess a MAPK docking and a PKA phosphorylation sites. Trojan has been proposed to have an anti-apoptotic role based on its differential expression on developing thymocyte subpopulations. Using a chicken cell line, our in vitro studies showed that upon apoptosis induction, Trojan expression rises dramatically on the surface of surviving cells and gradually decreases towards its normal levels as cells recover. When sorted based on their expression levels of Trojan, cells with high expression appeared less susceptible to apoptotic induction than those bearing no or low levels of Trojan on their surface. The mechanism by which the molecule exerts its function is yet to be discovered. We found that cells overexpressing Trojan from a cDNA plasmid show elevated steady-state levels of intracellular calcium, suggesting the molecule is able to transmit cytoplasmic signals. The mechanistic nature of Trojan-induced signalling is a target of future investigation. In this article, we conducted a series of experiments that suggest Trojan as an anti-apoptotic regulator.

A Decrease in Temperature and Humidity Precedes Human Rhinovirus Infections in a Cold Climate.

Both temperature and humidity may independently or jointly contribute to the risk of human rhinovirus (HRV) infections, either through altered survival and spread of viruses in the environment or due to changes in host susceptibility. This study examined the relationship between short-term variations in temperature and humidity and the risk of HRV infections in a subarctic climate. We conducted a case-crossover study among conscripts (n = 892) seeking medical attention due to respiratory symptoms during their military training and identified 147 HRV cases by real-time PCR. An average temperature, a decline in daily ambient temperature and absolute humidity (AH) during the three preceding days of the onset (hazard period) and two reference periods (a week prior and after the onset) were obtained. The average daily temperature preceding HRV infections was -9.9 ± 4.9 °C and the average AH was 2.2 ± 0.9 g/m³. An average (odds ratios (OR) 1.07 (95% confidence interval (CI) 1.00-1.15)) and maximal (OR 1.08 (1.01-1.17)) change in temperature increased the risk of HRV infections by 8% per 1 °C decrease. An average (OR 1.20 (CI 1.03-1.40)) and maximal decrease (OR 1.13 (CI 0.96-1.34)) in AH increased the risk of HRV infection by 13% and 20% per 0.5 g/m³ decrease. A higher average temperature during the three preceding days was positively associated with HRV infections (OR 1.07 (CI 1.00-1.15)). A decrease rather than low temperature and humidity per se during the preceding few days increases the risk of HRV infections in a cold climate. The information is applicable to populations residing in cold climates for appropriate personal protection and prevention of adverse health effects.

Surface expression, peptide repertoire, and thermostability of chicken class I molecules correlate with peptide transporter specificity.

The chicken major histocompatibility complex (MHC) has strong genetic associations with resistance and susceptibility to certain infectious pathogens. The cell surface expression level of MHC class I molecules varies as much as 10-fold between chicken haplotypes and is inversely correlated with diversity of peptide repertoire and with resistance to Marek's disease caused by an oncogenic herpesvirus. Here we show that the average thermostability of class I molecules isolated from cells also varies, being higher for high-expressing MHC haplotypes. However, we find roughly the same amount of class I protein synthesized by high- and low-expressing MHC haplotypes, with movement to the cell surface responsible for the difference in expression. Previous data show that chicken TAP genes have high allelic polymorphism, with peptide translocation specific for each MHC haplotype. Here we use assembly assays with peptide libraries to show that high-expressing B15 class I molecules can bind a much wider variety of peptides than are found on the cell surface, with the B15 TAPs restricting the peptides available. In contrast, the translocation specificity of TAPs from the low-expressing B21 haplotype is even more permissive than the promiscuous binding shown by the dominantly expressed class I molecule. B15/B21 heterozygote cells show much greater expression of B15 class I molecules than B15/B15 homozygote cells, presumably as a result of receiving additional peptides from the B21 TAPs. Thus, chicken MHC haplotypes vary in several correlated attributes, with the most obvious candidate linking all these properties being molecular interactions within the peptide-loading complex (PLC).

Characterization of the avian Trojan gene family reveals contrasting evolutionary constraints.

"Trojan" is a leukocyte-specific, cell surface protein originally identified in the chicken. Its molecular function has been hypothesized to be related to anti-apoptosis and the proliferation of immune cells. The Trojan gene has been localized onto the Z sex chromosome. The adjacent two genes also show significant homology to Trojan, suggesting the existence of a novel gene/protein family. Here, we characterize this Trojan family, identify homologues in other species and predict evolutionary constraints on these genes. The two Trojan-related proteins in chicken were predicted as a receptor-type tyrosine phosphatase and a transmembrane protein, bearing a cytoplasmic immuno-receptor tyrosine-based activation motif. We identified the Trojan gene family in ten other bird species and found related genes in three reptiles and a fish species. The phylogenetic analysis of the homologues revealed a gradual diversification among the family members. Evolutionary analyzes of the avian genes predicted that the extracellular regions of the proteins have been subjected to positive selection. Such selection was possibly a response to evolving interacting partners or to pathogen challenges. We also observed an almost complete lack of intracellular positively selected sites, suggesting a conserved signaling mechanism of the molecules. Therefore, the contrasting patterns of selection likely correlate with the interaction and signaling potential of the molecules.

Sequence of a complete chicken BG haplotype shows dynamic expansion and contraction of two gene lineages with particular expression patterns.

Many genes important in immunity are found as multigene families. The butyrophilin genes are members of the B7 family, playing diverse roles in co-regulation and perhaps in antigen presentation. In humans, a fixed number of butyrophilin genes are found in and around the major histocompatibility complex (MHC), and show striking association with particular autoimmune diseases. In chickens, BG genes encode homologues with somewhat different domain organisation. Only a few BG genes have been characterised, one involved in actin-myosin interaction in the intestinal brush border, and another implicated in resistance to viral diseases. We characterise all BG genes in B12 chickens, finding a multigene family organised as tandem repeats in the BG region outside the MHC, a single gene in the MHC (the BF-BL region), and another single gene on a different chromosome. There is a precise cell and tissue expression for each gene, but overall there are two kinds, those expressed by haemopoietic cells and those expressed in tissues (presumably non-haemopoietic cells), correlating with two different kinds of promoters and 5' untranslated regions (5'UTR). However, the multigene family in the BG region contains many hybrid genes, suggesting recombination and/or deletion as major evolutionary forces. We identify BG genes in the chicken whole genome shotgun sequence, as well as by comparison to other haplotypes by fibre fluorescence in situ hybridisation, confirming dynamic expansion and contraction within the BG region. Thus, the BG genes in chickens are undergoing much more rapid evolution compared to their homologues in mammals, for reasons yet to be understood.

Decline in temperature and humidity increases the occurrence of influenza in cold climate.

BACKGROUND: Both temperature and humidity may independently or jointly contribute to the risk of influenza infections. We examined the relations between the level and decrease of temperature, humidity and the risk of influenza A and B virus infections in a subarctic climate. METHODS: We conducted a case-crossover study among military conscripts (n = 892) seeking medical attention due to respiratory symptoms during their military training period and identified 66 influenza A and B cases by PCR or serology. Meteorological data such as measures of average and decline in ambient temperature and absolute humidity (AH) during the three preceding days of the onset (hazard period) and two reference periods, prior and after the onset were obtained. RESULTS: The average temperature preceding the influenza onset was -6.8 ± 5.6°C and AH 3.1 ± 1.3 g/m3. A decrease in both temperature and AH during the hazard period increased the occurrence of influenza so that a 1°C decrease in temperature and 0.5 g decrease per m3 in AH increased the estimated risk by 11% [OR 1.11 (1.03 to 1.20)] and 58% [OR 1.58 (1.28 to 1.96)], respectively. The occurrence of influenza infections was positively associated with both the average temperature [OR 1.10 per 1°C (95% confidence interval 1.02 to 1.19)] and AH [OR 1.25 per g/m3 (1.05 to 1.49)] during the hazard period prior to onset. CONCLUSION: Our results demonstrate that a decrease rather than low temperature and humidity per se during the preceding three days increase the risk of influenza episodes in a cold climate.

Plasma B-type natriuretic peptide (BNP) in acute Puumala hantavirus infection.

BACKGROUND: Nephropathia epidemica (NE) is a haemorrhagic fever with renal syndrome (HFRS) caused by Puumala hantavirus (PUUV). Acute infection causes transient kidney injury, permeability disorder, and fluid retention, for example. METHODS: B-type natriuretic peptide (BNP) and N-terminal peptide (NT-proBNP) during NE were investigated; disease severity and development of clinical symptoms were considered. RESULTS: Mean concentrations were 80.2 pg/mL and 55.2 pg/mL for BNP, and 2362.5 pg/mL and 1057.0 pg/mL for NT-proBNP in males and females, respectively. Hospitalization was 6.3 versus 5.2 days (P = 0.01) and 5.9 versus 4.4 days (P = 0.01) for patients with elevated BNP (> 100 pg/mL) or NT-proBNP (> 300 pg/mL), respectively, compared to those with normal peptide concentrations. Weight change during hospitalization was -2.8 or -0.3 kg (P <0.05) in patients with elevated or normal BNP, respectively. Heart rate (r = -0.46, P = 0.001 and r = -0.37, P = 0.01), creatinine clearance (r = -0.46, P = 0.001 and r = -0.56, P = 0.000), blood haemoglobin concentration (r = -0.55, P = 0.000 and r = -0.52, P = 0.000), and C-reactive protein (r = -0.47, P = 0.001 and r = -0.36, P = 0.01) measured when the peptide samples were collected correlated with BNP and NT-proBNP, respectively. In addition, anterior chamber depth of eye and plasma BNP (r = -0.39, P < 0.05) displayed a correlation. CONCLUSIONS: BNP and NT-proBNP levels are associated with severity of several clinical features of acute NE.

International recommendations for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies.

Anti-nuclear antibodies (ANA) are fundamental for the diagnosis of autoimmune diseases, and have been determined by indirect immunofluorescence assay (IIFA) for decades. As the demand for ANA testing increased, alternative techniques were developed challenging the classic IIFA. These alternative platforms differ in their antigen profiles, sensitivity and specificity, raising uncertainties regarding standardisation and interpretation of incongruent results. Therefore, an international group of experts has created recommendations for ANA testing by different methods. Two groups of experts participated in this initiative. The European autoimmunity standardization initiative representing 15 European countries and the International Union of Immunologic Societies/World Health Organization/Arthritis Foundation/Centers for Disease Control and Prevention autoantibody standardising committee. A three-step process followed by a Delphi exercise with closed voting was applied. Twenty-five recommendations for determining ANA (1-13), anti-double stranded DNA antibodies (14-18), specific antibodies (19-23) and validation of methods (24-25) were created. Significant differences between experts were observed regarding recommendations 24-25 (p<0.03). Here, we formulated recommendations for the assessment and interpretation of ANA and associated antibodies. Notably, the roles of IIFA as a reference method, and the importance of defining nuclear and cytoplasmic staining, were emphasised, while the need to incorporate alternative automated methods was acknowledged. Various approaches to overcome discrepancies between methods were suggested of which an improved bench-to-bedside communication is of the utmost importance. These recommendations are based on current knowledge and can enable harmonisation of local algorithms for testing and evaluation of ANA and related autoantibodies. Last but not least, new more appropriate terminologies have been suggested.

Influenza C virus infection in military recruits--symptoms and clinical manifestation.

Due to the lack of rapid diagnostic tests, clinical features of Influenza C virus infections are poorly characterized. Respiratory infections in military recruits in eastern Finland were monitored between July 2004 and December 2005 in order to study the epidemiology and clinical picture of infections caused by this virus. Blood samples were obtained at entry and at the end of the military service, and during each episode of respiratory infection to measure antibody responses against 10 viral and 2 bacterial pathogens. If possible, sputum samples were collected during the acute phase of respiratory infection episodes. Symptoms of the episodes were recorded for comparison of the clinical picture caused by various infectious agents. Infection with influenza C virus was detected in 38 of 892 young men during their service. The virus usually caused a mild upper respiratory tract infection. Most typical clinical features of influenza C virus infection were cough, rhinitis, and hoarseness. A striking difference to infections caused by influenza A virus was the lack of fever. Influenza C virus is an important cause of a respiratory tract infection in army conscripts. Infections with this virus are usually mild but can be complicated in some cases.

TIM-family molecules in embryonic hematopoiesis: fetal liver TIM-4(lo) cells have myeloid potential.

Trans-membrane (or T cell) immunoglobulin and mucin (TIM) molecules are known regulators of immune response whose function in hematopoiesis is unknown. Earlier, we found that tim-1 and tim-4 are expressed by CD45(+) cells in the para-aortic region of chicken embryo. Because the para-aortic region is a known site for hematopoietic stem cell (HSC) and hematopoietic progenitor cell (HPC) differentiation and expansion, we hypothesize that TIM molecules have a role in hematopoiesis. To study this role further, we analyzed TIM expression more precisely in chicken para-aortic region and mouse fetal liver hematopoietic cells. Additionally, we examined the hematopoietic potential of TIM-4(+) mouse fetal liver cells with a colony-forming assay. tim-1 gene expression was detected in chicken and mouse embryos in the aorta-gonads-mesonephros-region at the time of HSC emergence, whereas tim-3 mRNA was widely expressed in different tissues. tim-4 expression was restricted to fetal liver CD45(+)F4/80(+) cells. Moreover, two TIM-4(+) populations were distinguished: F4/80(hi)TIM-4(hi) and F4/80(lo)TIM-4(lo). F4/80(hi)TIM-4(hi) cells had no hematopoietic potential and were morphologically similar to mature macrophages, suggesting that they are yolk sac-derived macrophages. Instead, many of the F4/80(lo)TIM-4(lo) cells were c-kit(+) and Sca-1(+) and had primitive morphology and multilineage colony-forming ability. In addition, F4/80(lo)TIM-4(lo) cells included a considerable population expressing ER-MP12, a known marker for macrophage colony-forming cells and other myeloid progenitors. We conclude that TIM molecules are expressed in embryonic hematopoietic tissues in chicken and mouse and that in fetal liver, TIM-4 is expressed by myeloid progenitor cells.

Can social support alleviate inflammation associated with childhood adversities?

OBJECTIVE: Childhood adversities have been linked to elevated high-sensitivity C-reactive protein (hsCRP), which has been associated with increased morbidity. Low social support has been reported to worsen the prognosis in heart disease and cancer, and high social support has been linked to lower hsCRP. We hypothesized that social support could be a mediating factor between childhood adversities and hsCRP. METHODS: The sample was drawn from the data of the nationwide Health and Social Support Study (HeSSup Study) to which 25,898 Finns had responded in 1998. The cohort was stratified into groups of high and low social support, and the study group consisted of 100 women in both groups. Additionally, we invited a randomly drawn group of 50 subjects and a group of 62 women who had reported depressive symptoms. Of the 312 women, 116 participated in the study. RESULTS: Social support score (Social Support Questionnaire, SSQ) was lower when the number of adverse experiences in childhood was high (r = - 0.251, P = 0.007). hsCRP and SSQ were inversely associated (r = - 0.188, P = 0.046). In the adjusted general linear model, the level of social support was significantly associated with hsCRP and there was a statistically significant interactive effect of small effect size of childhood adversities and the level of social support on hsCRP (ES = 0.123, P = 0.004). CONCLUSION: This finding suggests that childhood adversity may affect social relationships and that high social support may attenuate the health risks caused by childhood adverse experience.

Serum 1,25(OH)D level increases after elimination of periodontal inflammation in T1DM subjects.

OBJECTIVES: The aim of the present study was to investigate associations between serum concentrations of vitamin D metabolites, 25-hydroxyvitamin D [25(OH)D], and its active form, 1,25-dihydroxyvitamin D [1,25(OH)D], and the severity of chronic periodontitis. SUBJECTS AND DESIGN: Presence of dental plaque, probing pocket depth (PD), and attachment level in 80 type 1 diabetes mellitus subjects were recorded. The serum levels of 25(OH)D, 1,25(OH)D, ultrasensitive C-reactive protein, IL-6, TNF-α, high-density lipoprotein cholesterol, and glycosylated hemoglobin (percentage) were determined. Multivariate regression models were used to explore the associations between serum 25(OH)D (nanomoles per liter) and 1,25(OH)D (picomoles per liter) levels and periodontal health status. INTERVENTION: Antiinfective periodontal therapies were delivered and the clinical examination and laboratory analyses were repeated 8 weeks after the therapies. RESULTS: A statistically significant association was found between the serum level of 1,25(OH)D (odds ratio 1.06, 95% confidence interval 1.02-1.11) and periodontal health at the baseline; subjects with a high level were more likely to belong to the group of no or mild periodontitis. The serum level of 1,25(OH)D showed a statistically significant increase after antiinfective periodontal therapy in both no or mild (P = .001) and moderate or severe periodontitis (P < .001) subjects. The association between serum 25(OH)D level and periodontal health was negligible. CONCLUSION: This study has shown a significant positive association between the serum 1,25(OH)D level and periodontal health status. To what extent this association is causal in nature remains to be confirmed.

Elevated cerebrospinal fluid neopterin concentration is associated with disease severity in acute Puumala hantavirus infection.

Nephropathia epidemica (NE) caused by Puumala hantavirus (PUUV) is the most common hemorrhagic fever with renal syndrome (HFRS) in Europe. The infection activates immunological mechanisms that contribute to the pathogenesis and characteristics of the illness. In this study we measured cerebrospinal fluid (CSF) neopterin concentration from 23 acute-phase NE patients. We collected data on kidney function, markers of tissue permeability, haemodynamic properties, blood cell count, length of hospitalisation, inflammatory parameters, and ophthalmological properties. The neopterin levels were elevated (> 5.8 nmol/L) in 22 (96%) NE-patients (mean 45.8 nmol/L); these were especially high in patients with intrathecal PUUV-IgM production (mean 58.2 nmol/L, P = 0.01) and those with elevated CSF protein concentrations (mean 63.6 nmol/L, P < 0.05). We also observed a correlation between the neopterin and high plasma creatinine value (r = 0.66, P = 0.001), low blood thrombocyte count (r = -0.42, P < 0.05), and markedly disturbed refractory properties of an eye (r = 0.47, P < 0.05). Length of hospitalisation correlated with the neopterin (r = 0.42, P < 0.05; male patients r = 0.69, P < 0.01). Patients with signs of tissue oedema and increased permeability also had high neopterin concentrations. These results reinforce the view that PUUV-HFRS is a general infection that affects the central nervous system and the blood-brain barrier.

Serum osteoprotegerin and periodontal destruction in subjects with type 1 diabetes mellitus.

AIM: Besides their role in bone metabolism, receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) are also known to be associated with inflammation. We explored associations between the extent/severity of periodontitis and circulating levels of sRANKL and OPG and their ratio using a cross-sectional study design. SUBJECTS & METHODS: The extent of periodontal inflammation and tissue destruction and the serum levels of sRANKL (pg/ml) and OPG (pg/ml) were determined in 80 subjects with type 1 diabetes mellitus (T1DM). Plaque-, age-, gender-, smoking-, HbA1c- and body mass index-adjusted associations between periodontal parameters and serum sRANKL, OPG and their ratio were studied using multiple linear regression analysis. RESULTS: Adjusted regression analyses of all the subjects indicated a significant positive association between AL ≥ 4 mm and severity of periodontitis and the level of serum OPG. A major drop in the strength and statistical significance of the above association was observed when the analyses included only non-smokers. Serum sRANKL level and sRANKL/OPG ratio were not associated with periodontitis. CONCLUSION: Our observations suggest that serum OPG may be an indicator of periodontal tissue destruction in T1DM.

Comparison of antigen and two molecular methods for the detection of Clostridium difficile toxins.

BACKGROUND: Clostridium difficile (CD) is considered an important cause of diarrhoea associated with the antimicrobial treatment of infections. The pathogenicity of CD is due to toxins A and B, produced by toxigenic CD strains. METHODS: We evaluated 3 methods for detecting CD toxins: the RIDASCREEN® enzyme immunoassay (EIA) (R-Biopharm)--one detecting toxins directly in the stool specimens and another detecting toxins from isolated CD strains--and 2 molecular methods, the illumigene™ loop-mediated isothermal amplification (LAMP) assay (Meridian) and RIDA®GENE polymerase chain reaction (PCR) assay (R-Biopharm), as direct identification methods from stool specimens. Toxigenic culture (TC) was used as the reference method. RESULTS: Altogether 884 stool samples were analyzed, of which 253 (29%) were positive by TC. Six hundred and seventy-two specimens were tested by RIDASCREEN EIA, 430 were tested with the illumigene LAMP assay, and 212 were tested with the RIDA GENE PCR assay. CD toxin A and B antigen tests by EIA were very insensitive, both directly from stool specimens (2 series; 57-61%) and in isolated CD strains (53%); consequently the negative predictive value remained low (84-93% and 91%, respectively). Specificity, however, was very good at 98-100%. The 2 molecular methods detected CD toxin genes excellently and equally, resulting in sensitivities, specificities, and positive and negative predictive values of 98%, 100%, 100%, and 98%, respectively. CONCLUSIONS: Both molecular assays were easy to use, rapid, sensitive, and specific for the detection of toxigenic CD strains.