Latex Agglutination Assay Research Articles

Changes in d-dimer levels in pregnant women according to gestational week.

We performed a retrospective review of medical charts regarding blood d-dimer levels determined cross-sectionally by the latex agglutination assay in 1952 samples from 1185 women to determine changes in d-dimer levels according to the stage of pregnancy. Three of 17 women in whom further investigations were performed were found to have clinical venous thromboembolism (VTE). The median and 95th percentile values of d-dimer (μg/mL) in the 1182 women without clinical VTE, 0.54 and 2.41 at gestational week (GW) 4-13, increased gradually to 1.22 and 5.03 at GW 14-27, 1.81 and 6.18 at GW 28-35, and 2.13 and 5.85 at GW 36-42, respectively. A total of nine women (0.76%), including three women with clinical VTE, exhibited a d-dimer level >14.0μg/mL, which was well above the 99th percentile for any stage of pregnancy. Thus, 3 (33%) of the nine with a d-dimer level >14μg/mL developed clinical VTE, while none of the remaining 1176 women with a d-dimer level ⩽14μg/mL developed clinical VTE. Although further prospective studies are required, our results suggested that there is a certain cut-off d-dimer value that would allow us to differentiate between pregnant women with and without clinical VTE.

Lack of Clostridium difficile Infection in Patients Treated With Rifaximin for Hepatic Encephalopathy

The purpose of this study was to assess the incidence of Clostridium difficile infection in patients who received rifaximin for the treatment of hepatic encephalopathy (HE). Medical charts of patients who received rifaximin for the treatment of HE were reviewed. The number of patients who developed diarrhea during treatment with rifaximin and results of latex agglutination assays to detect C. difficile in stool samples were analyzed. A total of 211 patients received rifaximin for HE. Of these, 152 were treated in a university practice and 59 were treated in community practices. The mean dose of rifaximin was 1055 mg/d (range, 600 to 1600 mg/d) for a mean duration of 250 days (range, 180 to 385 d). Eighteen patients developed diarrhea during rifaximin treatment. None of these patients tested positive for C. difficile. This study demonstrates that treatment of HE with the safe, nonsystemic, gut-selective antibiotic rifaximin was not associated with the development of C. difficile infection.

Reference intervals of serum hyaluronic acid corresponding to the radiographic severity of knee osteoarthritis in women

BackgroudWhile serum levels of hyarulonic acid (sHA) is known to be useful for a burden of disease biomarker in knee OA, it is far from practical. The reference intervals must be established for biomarkers to be useful for clinical interpretation. The aim of this study was to establish the reference intervals of sHA corresponding to the radiographic severity of knee OA for elucidating whether sHA can be useful as a burden of disease marker for individual patient with knee OA.Methods372 women with Kellgren & Lawrence grade (K/L) 1 through 4 painful knee OA were enrolled in this study. The patients included 54 with K/L 1, 96 with K/L 2, 97 with K/L 3, and 118 with K/L 4. Serum samples were obtained from all subjects on the day that radiographs taken. A HA binding protein based latex agglutination assay that employed an ELISA format was used to measure sHA. Age and BMI adjusted one way ANOVA was used to set the reference intervals of sHA.ResultsThe reference intervals for sHA corresponding to the patients with K/L 4 (49.6 – 66.5 ng/ml) was established without any overlap against to those with K/L 1, 2 and 3, while those with K/L 1, 2 and 3 showed considerable overlap.ConclusionsThese results indicate that sHA can be available as a burden of disease marker for the individuals with severe knee OA (K/L 4), while it is not for those with primary to moderate knee OA (K/L 1–3).

Impacto del cribado de cáncer colorrectal mediante análisis inmunológico en una zona básica de salud urbana

ObjectiveTo describe the results of implementing a pilot screening program, in the Castilla y León, for colorectal cancer (CRC) with the faecal occult blood test (iFOBT) using a quantitative immunological latex agglutination assay. MethodsThe study population included 4930 persons between 50-69 years from the Basic Health Area of Medina del Campo. Colonoscopy was performed on those who had a positive iFOBT. The rates of participation were calculated, positivity, acceptance of colonoscopy, detection of lesions, percentages and predictive positive value (PPV) of the test. ResultsA total of 2241 (46.33%) people took part. There were 138 (6.15%) positive iFOBT. The rate acceptance of the colonoscopy was 99.27%. CRC was detected in 12 patients (91.66% in early stages), a high risk adenoma (HRA) in 42, and a low risk adenoma (LRA) in 34. The rates of detection were for CRCwas 5.35‰, 18.74‰ for HRA, 15.17‰ for LRA, and 39.26‰ for all kinds of adenoma. The PPV was 8.69% for CCR, 30.43% for HRA and 24.63% for LRA. ConclusionsThe CRC screening program is feasible in our context. The iFOBT indicators are superior to those of other studies performed using the classic test. The high rates of detection of CRC, and all kinds of adenoma would be enough to justify the study. These together with the diagnosis of CRC in the early stages could lead to a reduction of the mortality.

Cross-Reactivity of the Anti-Human D-dimer Monoclonal Antibody 1C9-6F10 to Canine Fibrin Degradation Products

The cross-reactivity of the anti-human D-dimer antibody 1C9-6F10 to the canine D-dimer was evaluated by western blotting using purified canine fibrinogen, fibrin degradation products (XDPs) and plasma from a dog with suspected disseminated intravascular coagulation (DIC). The antibody cross-reacted with canine XDPs and plasma from the dog with suspected DIC. A latex agglutination assay using 1C9-6F10 measured the canine XDPs in dogs. In conclusion, the antibody 1C9-6F10 cross-reacted to the canine D-fragment with high specificity, but lower affinity compared with the human D-dimer. The latex agglutination assay using the 1C9-6F10 antibody was used to measure canine plasma D-dimer concentrations.

Clinical Utility of the Cryptococcal Antigen Lateral Flow Assay in a Diagnostic Mycology Laboratory

Background Cryptococcus neoformans causes life-threatening meningitis. A recently introduced lateral flow immunoassay (LFA) to detect cryptococcal antigen (CRAG) is reportedly more rapid and convenient than standard latex agglutination (LA), but has not yet been evaluated in a diagnostic laboratory setting.MethodsOne hundred and six serum, 42 cerebrospinal fluid (CSF), and 20 urine samples from 92 patients with known or suspected cryptococcosis were tested by LA and LFA, and titres were compared. Results were correlated with laboratory-confirmed cryptococcosis. Serial samples were tested in nine treated patients.ResultsTwenty-five of 92 patients had confirmed cryptococcosis; all sera (n = 56) from these patients were positive by LFA (sensitivity 100%, 95% confidence interval (CI) 93.6–100%) compared with 51/56 positive by LA (sensitivity 91.1%, 95% CI 80.7–96.1%). Fifty sera from 67 patients without cryptococcosis tested negative in both assays. While LA yielded more false negative results (5/56) this did not reach statistical significance (p = 0.063). Nine CSF samples from patients with cryptococcal meningitis yielded positive results using both assays while 17/18 urine samples from patients with cryptococcosis were positive by the LFA. The LFA detected CRAG in C. gattii infection (n = 4 patients). Agreement between titres obtained by both methods (n = 38 samples) was imperfect; correlation between log-transformed titres (r) was 0.84. Turn-around-time was 20 minutes for the LFA and 2 h for LA. The cost per qualitative sample was 18USD and 91 USD, respectively and per quantitative sample was 38USD and 144USD, respectively.ConclusionsQualitative agreement between the LFA and LA assays performed on serum and CSF was good but agreement between titres was imperfect. Ease of performance of the LFA and the capacity for testing urine suggest it has a role in the routine laboratory as a rapid diagnostic test or point-of-care test.

C0315 Comparison of different D-dimer assays in normal pregnancy

Background: Normal pregnancy is associated with hypercoagulation state and activation of fibrinolysis. D-dimer is an important test of activation of haemostasis. D-dimer concentration progressively increases during normal pregnancy. It is important to establish normal deviations of D-dimer for physiological pregnancy with different assays. Methods: The citrate plasmas of 117 healthy pregnant women at the age of 19 till 40 yearswere evaluated. D-dimer levels weremeasured by ELISA (“Asserachrom D-DI”, Diagnostica Stago, France), quantitative immunoturbidimetric latex agglutination assay (“Auto Blue D-dimer 400”, England) and semi quantitative latex agglutination assay (“DDimer Test”, Diagnostica Stago, Roche, France). STATISTICA 6.0 was used. Results are given as median (Me) with 95% confidence intervals (CI) for each gestational period. A Pb0.05 was considered statistically significant. Results: Results of the ELISA-method were increased both between I and II trimesters (172.45-1109.75 ng/ml FEU vs 244.40-1268.00 ng/ml FEU respectively; pb0.01) and II and III trimesters (244.40-1268.00 ng/ ml FEU vs 512.25-1891.50 ng/ml FEU respectively; pb0.01). Parameters of the quantitative immunoturbidimetric latex agglutination assay were significantly high between I and II trimesters (6.90-468.55 ng/ml vs 57.00-1434.50 ng/ml) only. The results of the latex testwere reported in three categories: normal (b500 ng/ml FEU), positive (500-3000 ng/ml FEU) and over positive (N3000 ng/ml FEU). High D-dimer level was in 68.2% of pregnant women even in I trimester. In II and III trimesters positive and over positive results were increased to 82.4% and 90.9% respectively whereas normal results were 17.6% and 9.1% respectively. Comment: It is recommended that D-dimer be estimated by themost informative ELISA. This quantitative assay adequately evaluates D-dimer level in each trimester of pregnancy.

Updates in Immunoassays: Introduction

1. Deborah Josko, Ph.D. MLT (ASCP) M,SM[⇑][1] 1. Department of Clinical Laboratory Sciences, Medical Laboratory Science Program, University of Medicine and Dentistry of New Jersey, Scotch Plains, NJ <!-- --> 1. Address for Correspondence: Deborah Josko, Ph.D. MLT(ASCP)M, SM , Department of Clinical Laboratory Sciences, Medical Laboratory Science Program, University of Medicine and Dentistry of New Jersey, 1776 Raritan Road, Scotch Plains, NJ 07076. (908) 889-2422. joskotda{at}umdnj.edu 1. Discuss the evolution and development of immunoassays. 2. Explain the principle of various immunoassays used in diagnosis. 3. List emerging methodologies in the area of immunological assays. 4. Describe the importance of immunoassay testing in the clinical laboratory. The immune system is one of the most intricate and complex systems of the human body. The cascade of events that occurs at both the cellular and molecular level from the moment foreign matter enters the body is astounding. Once antibodies are synthesized by plasma cells in response to the invading entity, medical laboratory professionals have the ability to measure and identify the type of antibody present by a variety of immunological assays. Detection methods range from rapid latex agglutination assays to enzyme, fluorescent and chemiluminescent assays that can measure both IgM and IgG levels qualitatively and quantitatively. Immunoassays have evolved considerably when compared to some of the earlier methods of identifying antigen/antibody complex formation. The Ouchterlony double immunodiffusion assay developed in the 1940s by Swedish immunologist Örjan Ouchterlony1 is one of the older methods where both antigen and antibody diffuse through a semi-solid gel independently of each other resulting in a precipitation line if the specific antigen/antibody complex is formed (identity pattern).2 This assay can take up to 48 hours to completely diffuse and render a positive result. To improve turn-around times, assays were designed using electrical currents during the diffusion process to speed up the reaction time. One method developed by Grabar and Williams in 1953 was the rocket immunoelectrophoresis technique.3 In this assay, antigen is added to an appropriate medium, then subjected to an electrical current where protein fractions are separated according to size. Antiserum is then placed in a trough cut into the gel and allowed… ABBREVIATIONS: ANA - anti-nuclear antibody; CBC - complete blood count; CDC - Centers for Disease Control and Prevention; CLIA - chemiluminescent immunoassay; CMV - cytomegalovirus; CRP - C-reactive protein; DFA - direct fluorescent antibody; EIA - enzyme immunoassay; ELFA - enzyme-linked fluorescent assay; ELISA - enzyme-linked immunosorbent assay; FIA - fluorescent immunoassay; HCG - human chorionic gonadotropin; HIV - human immunodeficiency virus; IFA - indirect fluorescent assay; IgG - immunoglobulin G; IgM – immunoglobulin M; RSV - respiratory syncytial virus. 1. Discuss the evolution and development of immunoassays. 2. Explain the principle of various immunoassays used in diagnosis. 3. List emerging methodologies in the area of immunological assays. 4. Describe the importance of immunoassay testing in the clinical laboratory. [1]: #corresp-1

Identification of mecA genes in environmental Staphylococcal isolates

Background: In the past Hospital isolates of Staphylococcus aureus (MRSA) were considered more drug resistant than community acquired strains. However community acquired MRSA strains have now have developed drug resistance commensurate to Hospital strains. The question arise as to what environmental factors have led to this development, is it just the widespread use of antibiotics in the non-hospital environment or are there potentially other factors. Recently, increased attention has been paid to multidrug-resistant coagulase-negative Staphylococci (MRCNS) in hospitals. These strains are recognized as opportunistic pathogens in the immuno- suppressed and hospital strains are also a potential reservoir for mecA genes. This current study was to investigate antibiotic resistance in Staphylococci isolated from a non-hospital environment in common use by humans, in this case from public washrooms. Methods: Swabs taken from public washrooms were analysed. Staphylococci were identified using the Bruker MALDI-TOF biotyper system. The minimum inhibitory concentrations (MIC) of Staphylococcal isolates against 30 antibiotics, including oxacillin, erythromycin, amoxicillin, and vancomycin were determined using the MicroScan Walkway 96 plus automated system (Simens Healthcare Diagnostics, CA, USA). For methicillin resistant Staphylococcal isolates, a rapid latex agglutination assay kit was used to determine PBP2’ according the manufacturer's instructions (Oxoid, Basingtoke, UK). Genomic DNA of the isolates was prepared and mec complex was determined by polymerase chain reaction (PCR). Results: 33% of Staphylococcal isolates (both coagulase-positive and coagulase-negative) were multidrug resistant, including non-β-lactam antibiotics such as fusidic acid, gentamycin, erythromycin, chloramphenol. MICs for oxacillin varied from 0.75 to 64 mg/l. The presence of mecA was confirmed in all MRSA and MRCNS isolates. Moreover, we determined mec complexes were widely spread between isolates and represented all classes (A, B,C,C1,D) of mec complexes. Conclusion: We have demonstrated that non-healthcare establishments such as washrooms are potential reservoir for antibiotic resistant Staphylococci. Using combination of PBP2’ agglutination test and PCR methods we have shown that all methicillin resistant environmental staphylococci isolates carried mecA. Such a wide-spread presence of drug resistance determinants in these human environments is a potential source to aid the spread, sustainability and development of drug-resistance both in hospitals and community strains.

A survey of Toxoplasma gondii antibodies by latex agglutination assay in dairy goats in Northern Tanzania

Food-borne parasitic diseases, such as toxoplasmosis, are increasingly becoming a global food safety concern. A cross-sectional study was conducted to investigate seroprevalence and risk factors of Toxoplasma gondii seropositivity in apparently healthy, unvaccinated dairy goat flocks reared under mixed smallholders, northern Tanzania between April and October 2011. Flock- and animal-level data were collected using a questionnaire. Sera (n = 337) collected from goats aged ≥ 6 months and from 102 flocks, respectively, were analyzed using modified Eiken latex agglutination test. A flock was classified as T. gondii seropositive if at least one animal tested positive. Titers considered diagnostically significant (≥ 1:16) were detected in 19.3 % of goats and 45.17 % of flocks, respectively. The antibody levels ranged from 1:16 to 1:2,048 and among the seropositive goats, the proportion of high antibody levels (≥ 1:2,048), suggestive of acute infection, was 1.5 %. The study revealed that goats raised in Babati are at a lower risk of acquiring T. gondii infection (P = 0.00209) than those which are raised in Arumeru district. The prevalence of T. gondii antibody was significantly higher in crossbred (24.7 %) and Saanen (24.4 %) breed goats than in local (14.3 %) and Toggenburg (12.1 %) and in females than in males (P = 0.043). No significant difference was observed among goats kept under various husbandry practices. The relatively high seroprevalence detected in this study suggests that toxoplasmosis may be posing a significant animal and human health risk and that the consumption of goat meat may play a role in the transmission of the disease to humans.

Latex Agglutination Assays for Detection of Non-O157 Shiga Toxin–Producing Escherichia coli Serogroups O26, O45, O103, O111, O121, and O145

Latex agglutination assays utilizing polyclonal antibodies were developed for the top six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups. Rabbit antisera were affinity purified through protein A/G columns, and the isolated immunoglobulins (IgGs) were covalently immobilized onto polystyrene latex particles. The resulting latex-IgG complex had a protein (IgG) load of 0.20 to 0.28 mg/ml in a 1% latex suspension. Optimum conditions for the agglutination assay consisted of utilizing 20 μm l of latex-IgG reagent containing 2.0 to 2.8 μm g IgG in a 0.5% latex suspension. Agglutination or flocculation was observed almost instantly after mixing the colonies with the latex-IgG, indicating STEC strains. More than 100 target and nontarget strains were tested in more than 3,000 test replicates. All target organisms produced positive results, but three antisera (anti-O26, anti-O103, and anti-O145) cross-reacted with some other STECs. The anti-O103 and anti-O145 latex reagents cross-reacted with O26 strains, and the anti-O26 cross-reacted with O103 strains. The latex-IgG reagents are stable for at least 1 year and are easy to prepare. These agglutination assays can be used for identification of presumptive non-O157 STEC colonies from agar media. The techniques used to prepare the latex reagents also can be utilized for testing other STEC serogroups, other E. coli serotypes, or other pathogens to ensure safe foods to consumers.

Comparison of methods for the detection of coliphages in recreational water at two California, United States beaches

Methods for detection of two fecal indicator viruses, F+ and somatic coliphages, were evaluated for application to recreational marine water. Marine water samples were collected during the summer of 2007 in Southern California, United States from transects along Avalon Beach (n=186 samples) and Doheny Beach (n=101 samples). Coliphage detection methods included EPA method 1601 - two-step enrichment (ENR), EPA method 1602 - single agar layer (SAL), and variations of ENR. Variations included comparison of two incubation times (overnight and 5-h incubation) and two final detection steps (lysis zone assay and a rapid latex agglutination assay). A greater number of samples were positive for somatic and F+ coliphages by ENR than by SAL (p<0.01). The standard ENR with overnight incubation and detection by lysis zone assay was the most sensitive method for the detection of F+ and somatic coliphages from marine water, although the method takes up to three days to obtain results. A rapid 5-h enrichment version of ENR also performed well, with more positive samples than SAL, and could be performed in roughly 24h. Latex agglutination-based detection methods require the least amount of time to perform, although the sensitivity was less than lysis zone-based detection methods. Rapid culture-based enrichment of coliphages in marine water may be possible by further optimizing culture-based methods for saline water conditions to generate higher viral titers than currently available, as well as increasing the sensitivity of latex agglutination detection methods.

Extremely high salivary β2-microglobulin and Na+ levels in a Sjögren syndrome patient

Extremely high salivary β2-microglobulin and Na+ levels in a Sjögren syndrome patient

Application of a point-of-care test for the serodiagnosis of typhoid fever in Nigeria and the need for improved diagnostics

There is an urgent need for affordable point-of-care diagnostics for the differentiation of febrile illnesses and the confirmation of typhoid in endemic countries. Blood samples were collected from febrile patients with clinical suspicion of typhoid and screened for typhoid fever using the Widal and Typhi Dri Dot tests, while stool and blood samples were screened for Salmonella Typhi using the culture method as well as PCR as a confirmatory test. A high proportion of febrile patients from Lagos with clinical suspicion of typhoid fever reacted positively in a simple and rapid latex agglutination assay for typhoid fever, indicating that this illness is a common and presumably under-diagnosed health problem in this metropolis. Seropositivity was 19.2% in the rapid test compared with 22.9% in the classical Widal test. The confirmation of typhoid in these seropositive patients appeared cumbersome because of negative blood cultures and low DNA yield in molecular testing. A review of the literature revealed that in Nigeria seroprevalence rates can be high in the normal population and that pathogens other than S. Typhi are often isolated from the blood of seropositive febrile patients. The simplicity and the relatively high specificity (97.8%) of the rapid test as determined in a study performed in Indonesia calls for a further validation of this promising test for use in Africa.

Molecular Characterization ofBacillus cereusToxigenic Strains Isolated from Different Food Matrices in Jordan

Bacillus cereus is increasingly recognized as one of the causative agents of food poisoning in different parts of the world. In this study, molecular characterization of B. cereus toxigenic strains isolated from food in Jordan was performed. A total of 202 food samples were collected from local markets and restaurants. B. cereus was found in 23.3% (47) of the food samples. The hemolytic enterotoxin hblA, hblC, and hblD were detected in 40.4%, 36.5%, and 75% of the isolates, respectively. Combination of all three hbl genes was detected in 19 isolates (36.5%). The nonhemolytic enterotoxin nheA, nheB, and nheC were detected in 61.5%, 92.3%, and 92.3% of the isolates, respectively. All three nhe genes were detected in 27 isolates (51.9%). The six enterotoxin genes (hemolysin BL [HBL] and NHE complexes) were detected in 25% of isolates. The cytK gene was detected in 53.8% of B. cereus isolates, whereas the bceT gene was detected in 69.2%. Only four emetic toxin-producing isolates were found to carry all the three genes of NHE complex, but none of the HBL complex ones. The B. cereus Enterotoxin-Reversed Passive Latex Agglutination assay results were strongly correlated with molecular detection of the L(2) part of the HBL complex (p≤0.01). This study demonstrated the occurrence of potentially enterotoxic and emetic toxic B. cereus isolates in the food samples analyzed from Jordan.

Validation of the Dri-Dot Latex agglutination and IgM lateral flow assays for the diagnosis of typhoid fever in an Egyptian population

Laboratory confirmation of typhoid fever is essential for appropriate medical treatment. Blood culture is a standard test for diagnosis of typhoid fever, but well-equipped diagnostic facilities to perform culture are seldom available in endemic areas. We retrospectively compared 2 diagnostic field tests, a latex agglutination Dri-Dot assay and an IgM Lateral Flow assay, to blood culture, in patients with clinically diagnosed typhoid fever. Sensitivity of the Dri-Dot was 71.4%, and specificity was 86.3% for samples collected at time of first diagnosis. Sensitivity and specificity of IgM Lateral Flow were 80% and 71.4%, respectively. A major limitation of these serologic tests is the limited sensitivity at the early stage of the disease. Performing both tests in parallel increased sensitivity to 84.3%, but decreased specificity to 70.5%. There was a trend towards improved diagnostic performance using either assay over a longer duration of illness. These rapid, point-of-care assays for typhoid fever provide easy-to-interpret results in typhoid-endemic countries and may be most useful in patients presenting 1 week after symptom onset.

Rotavirus infection in a tertiary hospital: laboratory diagnosis and impact of immunization on pediatric hospitalization

Background and objectivesRotavirus (RV) is the main etiological agent of diarrhea in childhood; its laboratory diagnosis is crucial to guide the clinical management and prevention of its spread. RV immunization was introduced in Brazilian 6-month-old children in 2006. The present study was aimed to evaluate three methodologies used for human RV detection in stool samples obtained from patients hospitalized due to gastroenteritis in a teaching hospital and report the impact of RV immunization in hospitalization by diarrhea. Methods293 stool samples collected in the 2001-2008 period were analyzed by enzyme immunoassay (EIA), latex agglutination (LA) and polyacrylamide gel electrophoresis (PAGE). ResultsRotavirus was detected in 34.8% of samples by LA assay, 28.3% of samples by EIA assay and in 25.6% of samples by PAGE assay. Considering the PAGE method as gold standard, the sensitivity, specificity and accuracy of EIA were 94.6%, 94.4% and 94.5%, and to LA were 82.6%, 81.6% and 81.9%, respectively. ConclusionsThese results indicate that antigen detection by EIA is a rapid, sensitive and specific method, and could be used in large-scale applications for screening stool samples suspected of RV infection. This study showed decreased incidence of RV infection in hospitalized children prior to the implementation of the national immunization program against RV.

Short Communication: Low seroprevalence of cryptococcal antigenaemia in patients with advanced HIV infection enrolling in an antiretroviral programme in Ghana

To determine the prevalence of cryptococcal antigenaemia in a clinic population with advanced HIV infection, with a view to giving antifungal therapy to those testing positive. Serum samples from adults with CD4 count <100 cells/mm(3) presenting to a large HIV clinic in Kumasi, Ghana, were tested retrospectively for cryptococcal antigenaemia using a latex agglutination assay, and clinical and demographic data extracted from case notes. Of 92 samples tested, two were positive thus giving a prevalence of 2% (95% CI, 0-5.2%). The prevalence of cryptococcal antigenaemia in patients with advanced HIV infection enrolling in an antiretroviral programme appears to be low in Kumasi, suggesting that the value of routine testing of outpatients diagnosed with advanced HIV infection may be limited in this population.

44-jähriger Patient mit kulturnegativer, purulenter Perikarditis

We report about a patient with purulent pericarditis due to Neisseria meningitidis pretreated with antibiotics. Clinical signs were suggestive of pericardial tamponade. Cultures from blood and pericardial aspirate remained negative. Broad-range polymerase chain reaction from pericardial fluid detected Neisseria sp.. Latex agglutination assay from pleural fluid showed positive reaction with meningococcal antigen serogroup C. Meningococcal pericarditis without meningitis is a rare manifestation. Non-culture based diagnostic methods in patients with such severe infections and negative cultures play an important role.

The Liposome PCR Assay Is More Sensitive than the Vibrio cholerae Enterotoxin and Escherichia coli Heat-Labile Enterotoxin Reversed Passive Latex Agglutination Test at Detecting Cholera Toxin in Feces and Water

Practical detection of cholera toxin (CT) by a liposome PCR (LPCR) immunoassay was compared to that of an established V. cholerae enterotoxin and Escherichia coli heat-labile enterotoxin reversed passive latex agglutination (VET-RPLA) assay. LPCR detected CT in the range of 10 pg/ml to 100 ng/ml in simulated feces and environmental water. Detection by VET-RPLA required at least 4 to 19 ng/ml CT.