Detection of antibodies to Trypanosoma cruzi among blood donors in the southwestern and western United States. II. Evaluation of a supplemental enzyme immunoassay and radioimmunoprecipitation assay for confirmation of seroreactivity

BACKGROUND: Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi, is endemic to Latin America and may be transmitted in the United States via blood donated by infected immigrants. Blood- borne pathogens such as T. cruzi require supplemental testing for confirmation of seroreactivity. STUDY DESIGN AND METHODS: A study was undertaken to determine an optimal scheme for confirmation of seroreactivity in repeatedly reactive samples identified by the Chagas antibody enzyme immunoassay (EIA). The procedure for initial confirmation involves three purified antigens coated onto three separate polystyrene beads and uses an EIA format. If the sample is reactive with two of three or three of three antigens, it is confirmed as seroreactive. If none or one of three beads is reactive, the sample is indeterminate and subjected to a radioimmunoprecipitation assay (RIPA). The RIPA must demonstrate characteristic bands at 32, 34, and 90 kDa. RESULTS: When tested with sera from persons with potentially cross-reactive diseases (n = 39) or against a presumed negative population from southeast Wisconsin (n = 289), the confirmatory EIA had a specificity of 100 percent. Sensitivity was 100 percent (28/28) with xenodiagnosis-positive sera and 97.6 percent (80/82) with chagasic sera from Latin America. The RIPA showed a specificity of 100 percent in EIA- nonreactive samples (n = 100) and a sensitivity of 100 percent with both xenodiagnosis-positive (28/28) and chagasic (82/82) sera. CONCLUSION: The confirmatory EIA and the RIPA together provide a highly specific and sensitive means of confirming seroreactivity for antibodies to T. cruzi.     

Serum Serotonin Abnormality in Depression

Background

Serotonin plays an important role in treatment of depression. We evaluated the clinical correlates of plasma serotonin levels in depressed patients before and after treatment.

Methods

Study sample comprised of 40 patients diagnosed on ICD-10 diagnostic criteria, and an equal number of healthy matched controls. Subjects were evaluated on Beck''s Depression Inventory (BDI) and Suicide Ideation Scale (SIS), before and after the treatment. Blood samples were collected from all the cases and controls before starting the antidepressant medication with selective serotonin reuptake inhibitors (SSRI''s). Serum serotonin levels were measured before and after treatment.

Result

Significant differences in scores before and after the intervention on BDI, SIS and serotonin levels of cases and controls (p<.000) were noted. Correlation between the serum serotonin levels before and after the treatment, and between the rating scales did not reveal significant association (p > 0.05). Patients with suicidal intentions had lower levels of serotonin. The scores changed after intervention.

Conclusion

Treatment with SSRI''s had shown significant changes in clinical conditions. However these changes did not relate significantly with serum serotonin levels.Key Words: Serotonin, Depression, Selective serotonin reuptake inhibitors     

Validation of MCADD newborn screening

Medium‐chain acyl‐CoA dehydrogenase deficiency (MCADD) represents a potentially fatal fatty acid β‐oxidation disorder. Newborn screening (NBS) by tandem mass spectrometry (MS/MS) has been implemented worldwide, but is associated with unresolved questions regarding population heterogeneity, burden on healthy carriers, cut‐off policies, false‐positive and negative rates. In a retrospective case‐control study, 333 NBS samples showing borderline acylcarnitine patterns but not reaching recall criteria were genotyped for the two most common mutations (c.985A>G/c.199C>T) and compared with genotypes and acylcarnitines of 333 controls, 68 false‐positives, and 34 patients. c.985A>G was more frequently identified in the study group and false‐positives compared to controls (1:4.3/1:2.3 vs. 1:42), whereas c.199C>T was found more frequently only within the false‐positives (1:23). Biochemical criteria were devised to differentiate homozygous (c.985A>G), compound heterozygous (c.985A>G/c.199C>T), and heterozygous individuals. Four false‐negatives were identified because our initial algorithm required an elevation of octanoylcarnitine (C₈) and three secondary markers in the initial and follow‐up sample. The new approach allowed a reduction of false‐positives (by defining high cut‐offs: 1.4 μmol/l for C₈; 7 for C₈/C₁₂) and false‐negatives (by sequencing the ACADM gene of few suspicious samples). Our validation strategy is able to differentiate healthy carriers from patients doubling the positive predictive value (42→88%) and to target NBS to MCADD‐subsets with potentially higher risk of adverse outcome. It remains controversial, if NBS programs should aim at identifying all subsets of all diseases included. Because the natural course of milder variants cannot be assessed by observational studies, our strategy could serve as a general model for evaluation of MS/MS‐based NBS.     

Italian healthcare workers' views on mandatory vaccination

Background  

Mandatory vaccination has contributed to the success of immunisation programmes but voluntary vaccination allows people to be responsible for their own health. There are benefits from both policies and the arguments between them remain subject to debate within and without the scientific community, both nationally and internationally. The aim of this study is to assess the opinions of those who actually work in the Vaccination Service.     

Aboriginal nursing education in Canada: an update

Canada does not have enough aboriginal nurses and aboriginal nursing faculty. Consequently, there is an inadequate number of nurses to meet both on- and off-reserve and community health care staffing needs. In 2002, Health Canada asked the Canadian Association of University Schools of Nursing to facilitate a national task force that would examine aboriginal nursing in Canada. The task force engaged in an extensive literature review, conducted a national survey of nursing programs, and explored recruitment and retention strategies. In 2007, the association prepared an update on the current status. In this article, the authors review the progress made during the intervening five years in the recruitment, retention and education of aboriginal nursing students.     

Managing environmental sensitivity: an overview illustrated with a case report

While the adverse impact of certain environmental agents is well established and affect individuals in a predictable dose-dependent manner, the validity of some exposure syndromes, such as environmental sensitivity, attributed to the influence of environmental chemicals in low, usually harmless doses, is less certain. Diagnosis of environmental sensitivity is subjective, and both standard medical and complementary and alternative treatment often fails to provide clinically meaningful functional gains. Existing evidence suggests that in many individuals with these syndromes, psychosocial factors play a prominent role. In this article we present an approach to managing patients presenting with sensitivities to environmental agents that includes identifying and managing organic disease, obtaining a thorough biopsychosocial history, confirming a diagnosis, and developing a rehabilitative process that focuses on support and improvements in function. A case of multiple chemical sensitivity illustrates this approach.     

A systematic review of the epidemiology of somatisation disorder and hypochondriasis

BACKGROUND: This paper reviews current knowledge regarding the prevalence and associated features of somatisation disorder and hypochondriasis in population-based and primary care samples. METHOD: A systematic review of the literature, which used a standardised definition of somatisation disorder or hypochondriasis and which examined the characteristics and associated features of these disorders in population-based samples or primary care settings. RESULTS: In population-based studies the prevalence of somatisation disorder and hypochondriasis was too low to examine associated features reliably. In studies using abridged criteria, a clear female predominance was not found in either disorder; there was a consistent relationship with few years of education. There was a close relationship with anxiety and depressive disorders, with a linear relationship between numbers of somatic and other symptoms of distress in several studies, including longitudinal studies. No studies showed that these symptom clusters fulfil the criteria of characteristic onset, course and prognosis required to merit the status of discrete psychiatric disorders. CONCLUSIONS: On existing evidence, somatisation disorder and hypochondriasis cannot be regarded as definite psychiatric disorders. There is some evidence that numerous somatic symptoms or illness worry may be associated with impairment and high health care utilisation in a way that cannot be solely explained by concurrent anxiety and depression, but further research using population-based samples is required.