The Role of Molecular Tests in the Diagnosis of Disseminated Histoplasmosis

Histoplasmosis is an emerging fungal disease, with global distribution. The disseminated form of the disease is a more severe infection, generally associated with AIDS. Classic diagnostic methods for histoplasmosis consist of microscopy, culture, and histopathology. More recently, the importance of Histoplasma antigen detection has dominated the literature on histoplasmosis diagnosis, but the relevance of molecular assays has not been as much studied. Here we describe the results of a systematic literature review focusing on studies that mainly compared immunological techniques (Histoplasma urine antigen detection) with molecular tests for the diagnosis of histoplasmosis. In addition to the review of comparative studies using such diagnostic techniques, the literature on polymerase chain reaction (PCR) tests in patients with disseminated histoplasmosis is also summarized. Two studies reported the comparison between immunological and molecular methods applied simultaneously for the diagnosis of disseminated histoplasmosis. PCR demonstrates a satisfactory performance assisting in the detection of Histoplasma spp. DNA in clinical samples.

New guidelines for the diagnosis and treatment of neurocysticercosis: a difficult proposal for patients in endemic countries

INTRODUCTION

Recent guidelines for the diagnosis and treatment for neurocysticercosis (NC) from the Infectious Disease Society of America/American Society of Tropical Medicine and Hygiene were developed to be used in the United States and Canada, where only a small fraction of NC cases occur. Areas covered: The paper discusses the strengths and weakness of the proposed guidelines. Expert commentary: Although these new guidelines bring much needed attention to a neglected parasitic disease, some of the recommendations made are based on insufficient and/or inadequate evidence. The authors only recommend one specific immunological assay for use in the diagnosis of NC, when evidence clearly supports other options. The authors strongly recommend dual-anthelminthic for patients with multiple active parenchymal cysts on the basis of one clinical trial that was stopped early. The authors recommend surgical removal of cysts in the fourth ventricle and long-term treatment for subarachnoid NC despite their own admission that there is little evidence to support these recommendations. We propose that clinicians should approach some of the recommendations in the new guidelines with caution and call for the establishment of gold-standard guidelines that can be used and adapted for the diagnosis and treatment of patients with NC worldwide.

Monitoring of occupational and environmental aeroallergens-- EAACI Position Paper. Concerted action of the EAACI IG Occupational Allergy and Aerobiology & Air Pollution

Exposure to high molecular weight sensitizers of biological origin is an important risk factor for the development of asthma and rhinitis. Most of the causal allergens have been defined based on their reactivity with IgE antibodies, and in many cases, the molecular structure and function of the allergens have been established. Significant information on allergen levels that cause sensitization and allergic symptoms for several major environmental and occupational allergens has been reported. Monitoring of high molecular weight allergens and allergen carrier particles is an important part of the management of allergic respiratory diseases and requires standardized allergen assessment methods for occupational and environmental (indoor and outdoor) allergen exposure. The aim of this EAACI task force was to review the essential points for monitoring environmental and occupational allergen exposure including sampling strategies and methods, processing of dust samples, allergen analysis, and quantification. The paper includes a summary of different methods for sampling and allergen quantification, as well as their pros and cons for various exposure settings. Recommendations are being made for different exposure scenarios.

A review on diagnostic and preventive aspects of cystic echinococcosis and human cysticercosis

Cystic echinococcosis and human cysticercosis have recently been included in the list of "neglected tropical diseases" by the World Health Organization (WHO). Both are zoonoses which are prevalent throughout the world and lead to considerable mortality, morbidity, and economic losses as well. This review deals with the disease burden of these two neglected cestode infections. Diagnostic modalities with their specific advantages and disadvantages have also been discussed. Recent developments in immunodiagnostic assays for the two diseases have been dealt with. Various control strategies including the use of veterinary vaccines have been highlighted.

Long-term serological evaluation of patients with cystic echinococcosis treated with benzimidazole carbamates

Seeking better immunological markers indicating the long-term outcome of cystic echinococcosis (CE) after chemotherapy we studied 23 patients receiving albendazole, clinically followed for 8 years, and grouped ultrasonographically according to therapeutic outcome. Antibody responses against a partially purified fraction of hydatid fluid (HFF) and antigen B (AgB) were evaluated by indirect haemagglutination (IHA), ELISA and immunoblotting (IB). Although IHA titres varied over the course of treatment, differences in mean antibody titres to HFF between groups were significant only at 4 years (P = 0.031). IgG isotype expression remained unchanged during follow-up whereas IgE expression decreased in patients with cured or stable disease. AgB disclosed higher IgG4 expression (P < 10(-4); P = 0.025) and lower IgG1 expression than HFF (P < 10(-4); P = 0.022). IHA antibody titres were higher in patients with progressive than in those with cured or stable disease, even in those with the same cyst type. ELISA isotype profiles differed between groups, particularly for type CE 3, 4 and 5 cysts: higher serum IgG1 and IgG3, lower IgG4 and IgE in patients with cured or stable disease. Although combined serological testing provides scarce information on the long-term outcome of CE after chemotherapy it may be useful for reviewing in a retrospective study the outcome of a cyst and for assessing the host-parasite relationship.