Analytical evaluation of nine serological assays for diagnosis of syphilis.

BACKGROUND: The diagnosis of syphilis is most frequently dependent on antibody detection with serological assays. Assays for both treponemal and non-treponemal antibodies are needed to provide a sensitive and specific diagnosis. For decades, a first screening has been done with non-treponemal assays, followed by treponemal. However, in recent years, following laboratory automation, the reverse sequence screening algorithms have been developed, using a treponemal assay as the initial screening test. OBJECTIVE: To evaluate serological assays for treponemal and non-treponemal antibodies, to use in reverse algorithm screening of syphilis. MATERIAL AND METHODS: Six treponemal assays (one IgM-specific assay), two non-treponemal assays and one novel dual point-of-care (POC) assay for serological diagnosis of syphilis were evaluated. Serum samples from Guinea-Bissau and Sweden were examined, as well as two performance panels and samples from blood donors. Sensitivity and specificity were calculated for each assay, using different assays as gold standard test. RESULTS: The Macro-Vue RPR Card test was the most sensitive non-treponemal test and the TrepSure Anti-Treponema EIA Screen and the SeroDia TP-PA were the most sensitive and specific treponemal assays. Among the automated assays, both the Liaison Treponema Screen and Architect Syphilis TP showed high sensitivity, however, the former had clearly higher specificity. CONCLUSIONS: In resourced settings, where the reverse sequence algorithm is preferred for screening, an automated treponemal immunoassay for initial screening subsequently followed by the TrepSure test or TP-PA assay as a second treponemal assay appear highly effective. Finally, a quantitative highly sensitive non-treponemal assay, e.g. the Macro-Vue RPR Card test, could then be used as a supplementary test to evaluate activity of the syphilis infection.

Foodborne Illness Among School Children in Ga East, Accra.

BACKGROUND: A food borne illness was reported in Ga-East district of Greater Accra Region among school children in May, 2007 after eating food provided at school. The objective of the investigation was to determine the source, mode of contamination and the causative agent. METHODS: A case-control study was conducted, cases were schoolchildren with abdominal symptoms and controls were children of the same sex and class without any symptom during the same period. The school children were selected by systematic sampling. Food handlers and the children were interviewed by a structured questionnaire. Food handlers were physically examined and their stools and blood examined. The kitchen for food preparation was inspected. Risks of food borne infection from the foods eaten were determined using attack rates. RESULTS: The minimum, peak and maximum incubation periods were 2, 11 and 61 hours respectively. The source was rice and groundnut soup (with the highest attack rate difference). Stool and blood samples of food handlers were not infective. Storage facility for food items was poor. No food samples were available for organism isolation. A protocol to prevent such outbreaks was nonexistent. CONCLUSION: The short incubation period and symptoms presented suggest an infective origin. The storage of the meat may potentially have been the point of contamination. The study showed that the schoolchildren ate contaminated food although the investigation could not determine the causative agent. Protocols to prevent such outbreaks need to be developed for the schools.

Preoperative CT angiography versus Doppler ultrasound mapping of abdominal perforator in DIEP breast reconstructions: A randomized prospective study.

Is there a difference in surgery time and complication rate when Doppler ultrasound (US) is used for the preoperative mapping of perforators in comparison with computer tomography angiography (CTA)? Women who were candidates for breast reconstruction using the deep inferior epigastric perforator (DIEP) free flap were enrolled in a prospective randomized study. The operating time was 249 ± 62 min (mean ± SD) in the CTA group (n = 32) and 255 min ± 75 in the US group (n = 31)--hence a difference of 6 min on average. No flaps were lost. Sixteen complications occurred in 15 patients: seven in the CTA group and nine in the US group. Complications were remedied without delay and all patients came through with a favorable reconstruction. Preoperative mapping of perforators with US is satisfactory enough provided the microsurgery team has proper experience in breast reconstruction with the DIEP flap.

Performance of Liaison XL automated immunoassay platform for blood-borne infection screening on hepatitis B, hepatitis C, HIV 1/2, HTLV 1/2 and Treponema pallidum serological markers.

OBJECTIVES: Aim of the study was to evaluate performance of a new fully automated platform, DiaSorin-LIAISON® XL (DiaSorin S.p.A, Vercelli, Italy), in blood donor screening, specifically for hepatitis B surface antigen (HBsAg), hepatitis B core antibodies (anti-HBc), hepatitis C antibodies (anti-HCV), HIV p24 antigen, HIV antibodies, human T-lymphotropic virus types 1 and 2 (HTLV-1/2) and Treponema pallidum antibodies. BACKGROUND: In screening for such viral and bacteriological blood-borne infections, sensitivity and specificity are of utmost importance. METHODS: Sensitivity was evaluated using selected panels of samples previously analysed on the Abbott Architect immunoanalyser (Abbott Laboratories, Abbott Park, IL, USA)--the gold standard for this evaluation. These samples were confirmed positive for HBsAg, anti-HBc, anti-HCV, HIV Ag/Ab, anti-HTLV-1/2 and antibodies to T. pallidum, respectively. Specificity analysis was assessed by analysing blood donor samples previously run on the Architect platform and found non-reactive for each marker. A total of 1·100 donor samples (both new and regular donors) were tested. Previously, non-specific reactive samples were also run for every tested marker, as well as samples with autoimmune antibodies and antibodies to other infections. RESULTS: Three hundred seventy-eight samples positive for the tested markers (HBsAg n = 51, anti-HBc n = 52, anti-HCV n = 75, anti-Treponema n = 55, anti-HIV-1 n = 79, anti-HIV-2 n = 25, anti-HIV 1/2 n = 3, anti-HTLV-1 n = 28 anti-HTLV-2 n = 10) were tested and found positive, suggesting a high sensitivity. A number of 342-1100 negative blood donors (depending on marker) have been tested, with very good specificity for the markers tested, ranging between 99·5 and 100%, respectively. CONCLUSIONS: The LIAISON® XL platform demonstrated very high sensitivity for the markers tested and the specificity necessary to fulfil the stringent requirements for blood donor screening.

Shifting from presumptive to test-based management of malaria - technical basis and implications for malaria control in Ghana.

The presumptive approach was the World Health Organisation (WHO) recommended to the management of malaria for many years and this was incorporated into syndromic guidelines such as the Integrated Management of Childhood Illnesses (IMCI). In early 2010 however, WHO issued revised treatment guidelines that call for a shift from the presumptive to the test-based approach. Practically, this implies that in all suspected cases, the diagnosis of uncomplicated malaria should be confirmed using rapid test before treatment is initiated. This revision effectively brings to an end an era of clinical practice that span several years. Its implementation has important implications for the health systems in malaria-endemic countries. On the basis of research in Ghana and other countries, and evidence from program work, the Ghana National Malaria Control Program has issued revised national treatment guidelines that call for implementation of test-based management of malaria in all cases, and across all age groups. This article reviews the evidence and the technical basis for the shift to test-based management and examines the implications for malaria control in Ghana.

Patterns of health service utilization at a medical school clinic in Ghana.

BACKGROUND: The University of Ghana Medical School (UGMS) Clinic provides healthcare service which is free at point of service to students, staff, retired staff and dependents of staff of the College of Health Sciences. However, since 1983, no in-depth review of health service provision or utilization has been undertaken. This study reviewed client characteristics, utilization and disease patterns at the clinic and also compared the disease patterns to that of other primary health facilities nationwide. METHODS: This was an analytical cross-sectional study undertaken at the UGMS clinic in Korle-Bu. It was a retrospective review of records of all clients attending the facility from January 2002 to December, 2004. RESULTS: More males than females attended the clinic and majority (63.9%) of clients were between 15-44 years (median age was 26 years). Dependents of staff constituted the highest attendants (41%) to the clinic. Among staff, junior staffs were in the majority. Malaria, respiratory tract infection and musculoskeletal pain were the most common conditions seen. Overall, 83% of clients were treated and discharged per visit without the need for review visits. CONCLUSION: Dependents of staff used the facility the most and they live in many different part of the city of Accra, and to ask them to attend the clinic for care is not efficient. It will be better to provide or supplement their securing of insurance so that they could access health care close to their homes and save time and attention to students and staff.

Performance of three automated fourth-generation combined HIV antigen/antibody assays in large-scale screening of blood donors and clinical samples.

Since the introduction in the mid-1980s, HIV testing has gradually improved both in terms of sensitivity and specificity. The so-called fourth generation of tests, combined HIV antigen/antibody assays, has now been introduced. This study compares three automated combined assays with older third-generation antibody assays in large-scale screening. Serum samples from routine screening of blood and plasma donors and clinical samples were investigated for specificity evaluation. Three fourth-generation combination assays from one manufacturer were compared with three older third-generation antibody assays from the same manufacturer. More than 40 000 samples per assay were included. For sensitivity, selected panels of confirmed HIV-1- and HIV-2-positive samples as well as seroconversion samples (HIV-1) from commercial panels and also from patients who appeared during the evaluation were used. The specificities of the fourth-generation tests were 99.91% (AxSYM), 99.95% (ARCHITECT) and 99.97% (PRISM) after repeated testing. Some specificity variation between reagent batches was observed. All HIV-1-positive samples were reactive by the three fourth-generation systems. HIV-1 seroconversion samples and panels were reactive earlier than by antibody-only tests. As for HIV-2 samples, AxSYM failed to detect one (n = 40), whereas PRISM and ARCHITECT detected all (n = 16 for PRISM and n = 52 for ARCHITECT). The new HIV antigen/antibody combination assay systems were found to have high sensitivity and specificity. The instruments provided a rational and easy way of testing at large scale.

Disclosing the diagnosis of pediatric HIV infection: mothers' views.

ISSUES AND PURPOSE: The stigma of HIV infection creates barriers to disclosure. The purpose of this study was to identify to whom biological and foster mothers disclose the diagnosis of HIV infection, discuss their rationale, and describe the recipient's reactions. DESIGN AND METHODS: A descriptive, qualitative study included biological (n = 9) and foster (n = 11) mothers of children with HIV infection. RESULTS: Three themes emerged from the data: Telling for support, determining who should know, and telling children. These themes were present for both biological and foster mothers. PRACTICE IMPLICATIONS: It is important for nurses to realize that parental disclosure of the diagnosis of HIV infection is a long-term, age-appropriate process that will take place over many discussions and time, and should have the support of the interdisciplinary team. Additional psychological support also should be available.

Family experiences when a child is HIV-positive: reports of natural and foster parents.

The purpose of this exploratory study was to examine issues reported by natural and foster parents when caring for a child 3 years of age or younger with vertically transmitted HIV-disease. Issues common to both groups, and specific to the natural and foster parents were explored. The issues discussed by the natural mothers included guilt, their relationship with their infected child, and the effects of their HIV infection on their family. Issues discussed by foster mothers included their decision to foster a HIV-positive child, characteristics of their HIV- positive foster children, fears of transmission, and the effect of the HIV-positive foster child(ren) on their natural family. Issues common to both sets of mothers include disclosure, support, preparation for the HIV-positive child's death, and life in general. The experiences of these families are important to describe in order for pediatric nurses to give accurate, sensitive, and culturally appropriate care.

The use of aqueous two-phase systems to concentrate and purify bovine leukemia virus outer envelope protein gp51.

Enzootic bovine leucosis is a chronic lymphoproliferative disease of cattle. The causative agent, bovine leukemia virus (BLV), is related to the human retroviruses HTLV-I and -II. The external env-protein of BLV, a glycoprotein of 51 kDa, carries neutralizing epitopes and should be an essential component in a vaccine against the virus. Problems have been encountered with the concentration and purification of intact virions of BLV and other retroviruses. During centrifugation procedures the external env-proteins are to a great extent detached and consequently poorly recovered with the virion particles. Therefore, other methods are sought to obtain a high yield of the external glycoproteins. The use of two-phase systems based on water soluble polymers is described for the extraction of BLV-gp51 from culture medium. Several polymer systems were tested and the results showed that some were attractive for large scale application. The classical combination dextran-polyethylene glycol gave promising results; a partition coefficient of about 0.02 was obtained for the distribution of the gp51 between the top and combined inter- and bottom phases. In a single extraction step it was possible to obtain 45% of the glycoprotein in a small volume bottom phase and at the same time about 15-fold purified. That should be compared with a recovery of less than 20% with the conventional centrifugation procedures. It is concluded that extraction in phase systems based on water soluble polymers is a methodology well suited for the concentration and purification of BLV-gp51.

Concentration and purification of feline leukaemia virus (FeLV) and its outer envelope protein gp70 by aqueous two-phase systems.

The major protective antigens of retroviruses are considered to be their glycosylated envelope proteins. However, the methods commonly employed to enrich and purify virus from culture media such as pelleting and density-gradient centrifugation result in a low recovery of the viral external glycoproteins. This is an obvious drawback when the virus is intended for use in a vaccine. In search for alternative methods to concentrate and purify FeLV, we have attempted extraction in two-phase systems based on water-soluble polymers (Albertsson PA., Biochem Biophys Acta 1958; 27: 378-395). A variety of polymer systems was tested. Some of them seem attractive for a large-scale concentration of the virus and/or its glycoprotein. The distribution between the phases of two FeLV proteins, the outer envelope protein, gp70, and the gag protein, p27, was determined. With a system composed of dextran sulfate and polyvinyl alcohol both the glycoprotein and the gag protein were almost completely recovered in the lower phase which constitutes about 3% of the total system in weight. The two proteins were more than 40-fold purified as calculated on protein basis. The proteins can be extracted readily.