Detecting Schistosoma mansoni infections among pre-school-aged children in southern Ghana: a diagnostic comparison of urine-CCA, real-time PCR and Kato-Katz assays.

BACKGROUND: In Ghana, pre-school-aged children (PSAC) are at risk of intestinal schistosomiasis and are living in need of praziquantel treatment. To better assess the infection burden within this vulnerable demographic group, we have provided a comparative assessment of the prevalence of Schistosoma mansoni in pre-school-aged children by urine circulating cathodic antigen (CCA) dipsticks, real-time PCR Taqman® faecal assays and Kato-Katz coproscopy. METHODS: In all, 190 pre-school-aged children were sampled from three endemic communities (viz. Tomefa, Torgahkope/Adakope, and Manheam) around Weija dam, Southern Ghana. Fresh stool and urine samples were collected from all participants for diagnosis. RESULTS: Among all the three communities, the urine-CCA assay recorded the highest prevalence values of 90.5% (95% CI 80.4-96.4), 87.9% (95% CI 76.7-95), and 81.2% (95% CI 69.9-89.6) in Tomefa, Torgahkope/Adakope, and Manheam respectively. Prevalence by real-time PCR was 50% (95% CI 35.5-64.5), 8% (95% CI 2.2-19.2) and 16.7% (95% CI 8.3-28.5), while by Kato-Katz was 55.6% (95% CI 42.5-68.1), 8.6% (95% CI 2.9-19) and 11.6% (95% CI 5.1-21.6) respectively. Children aged 1 year and over were found to be positive with the urine-CCA assay; by the ages of 3-4, over 50% were urine-CCA patent. The sensitivity and specificity of the POC-CCA dipsticks, when compared against the combined results of Kato-Katz/TaqMan results was found to be 84.1% (95% CI = 72.7-92.1) and 12.9% (95% CI = 6.6-22) respectively. CONCLUSIONS: We propose that the urine-CCA dipstick may be a useful rapid diagnostic tool to estimate the prevalence of intestinal schistosomiasis in PSAC, particularly in rapid identification of at-risk areas. However, our assessment has shown that it possible to record false positives when compared to combined Kato-Katz and qPCR results. To guide PSAC praziquantel treatment needs, we propose the urine CCA assay should be included in routine surveillance of intestinal schistosomiasis alongside other diagnostics such as Kato-Katz and urine filtration.

Leishmania infantum is present in vaginal secretions of naturally infected bitches at lower levels in oestrogenized bitches than in non-oestrogenized bitches.

Naturally Leishmania infantum infected bitches were divided into oestrogenized (n = 11) and non-oestrogenized (n = 6) groups. Vaginal secretions were collected for polymerase chain reaction (PCR), and vulval, vaginal and uterine tissues were collected for the immunohistochemical (IHQ) identification of L. infantum. Parasite DNA was identified in vaginal secretions of non-oestrogenized (41.8%) and oestrogenized (18.2%) bitches (P<0.05; Fisher's Exact test). IHQ was positive in vulvar dermis (23.5%) and vaginal mucosa (17.7%) but negative in endometrium of all bitches. Poor association between positive vaginal secretion PCR and tissue IHQ (Kappa index) were observed. The results showed that genital secretions are a potential source for dog contamination.

Malignant Pleural Effusion with Filariasis.

The occurrence of microfilaria in pleural fluid is rare. Filarial lung involvement occurs in the form of Tropical Pulmonary Eosinophilia with pulmonary infiltrates and peripheral eosinophilia. We report a 74-year-old male patient, non smoker who was admitted to our hospital with breathlessness and chest discomfort of two weeks duration. He had, eosinophilia and deranged renal function. X-ray chest revealed massive left sided pleural effusion. Pleural fluid analysis revealed atypical cells and pleural fluid cytology showed microfilaria (Wuchereria bancrofti), which were also found on peripheral smear.

Diagnostic value of semi-purified antigens of hydatid cyst fluid in human cystic echinococcosis.

Cystic Echinococcosis (CE) is an infection caused by the larval stage of Echinococcus granulosus. The diagnosis of this disease has been problematic. Serological tests detecting antibodies against E. granulosus are the most popular and mainly use the crude Hydatid Cyst Fluid (HCF) or its components, Ag 5 and B. However, the diagnostic value of these tests is limited by the problems of specificity and/or sensitivity. The use of purified HCF antigens could be more helpful in the serodiagnosis of CE compared to the whole HCF. In the present study, we have evaluated the diagnostic value of semi-purified antigens using ELISA tests. Our results have shown that the 53 KDa antigen gave the best specificity (97.5%) and sensitivity (80%). We have also used Western Blot technique to analyze the serological profile against HCF. The results have confirmed that the most immunogenic component of HCF is the Ag 5.

Detection of Toxoplasma gondii DNA in horse meat from supermarkets in France and performance evaluation of two serological tests.

In France, some cases of severe toxoplasmosis have been linked to the consumption of horse meat that had been imported from the American continent where atypical strains of Toxoplasma gondii are more common than in Europe. Many seroprevalence studies are presented in the literature but risk assessment of T. gondii infection after horse meat consumption is not possible in the absence of validated serological tests and the unknown correlation between detection of antibodies against T. gondii and presence of tissue cysts. We performed magnetic-capture polymerase chain reaction (MC-PCR) to detect T. gondii DNA in 231 horse meat samples purchased in supermarkets in France and evaluated the performance and level of agreement of the modified agglutination test (MAT) and enzyme-linked immunosorbent assay (ELISA) in the meat juices. The serological tests lacked sensitivity, specificity, and agreement between them, and there was no correlation with the presence of T. gondii DNA in horse meat, raising concerns about the reliability of T. gondii seroprevalence data in horses from the literature. T. gondii DNA was detected in 43% of horse meat samples but the absence of strain isolation in mice following inoculation of more than 100 horse meat samples suggests a low distribution of cysts in skeletal muscles and a low risk of T. gondii infection associated with horse meat consumption. However, to avoid any risk of toxoplasmosis, thorough cooking of horse meat is recommended.

Biological roles of cysteine proteinases in the pathogenesis of Trichomonas vaginalis.

Human trichomonosis, infection with Trichomonas vaginalis, is the most common non-viral sexually transmitted disease in the world. The host-parasite interaction and pathophysiological processes of trichomonosis remain incompletely understood. This review focuses on the advancements reached in the area of the pathogenesis of T. vaginalis, especially in the role of the cysteine proteinases. It highlights various approaches made in this field and lists a group of trichomonad cysteine proteinases involved in diverse processes such as invasion of the mucous layer, cytoadherence, cytotoxicity, cytoskeleton disruption of red blood cells, hemolysis, and evasion of the host immune response. A better understanding of the biological roles of cysteine proteinases in the pathogenesis of this parasite could be used in the identification of new chemotherapeutic targets. An additional advantage could be the development of a vaccine in order to reduce transmission of T. vaginalis.

Importancia del estudio del balance del contenido vaginal (BACOVA) en el control preventivo de las trabajadoras sexuales / Importance of studying the balance of vaginal content (BAVACO) in the preventive control of sex workers

El objetivo de este trabajo fue estudiar a un grupo de 229 trabajadoras sexuales de Comodoro Rivadavia (Chubut), atendidas en centros públicos de salud de dicha ciudad, mediante la aplicación del método conocido como balance del contenido vaginal (BACOVA). Este método comprende el estudio morfológico de la microbiota vaginal, como así también de la reacción infamatoria. Incluye el análisis del contenido vaginal en fresco y por tinciones de Gram y de Giemsa, de modo de integrar la exploración de todo el panorama biológico. El 35,37 % de estas mujeres presentó microbiota normal (MN); el 15,72 %, microbiota intermedia (MI); el 23,14 %, vaginosis bacteriana (VB) y el 10,48 %, vaginitis microbiana inespecífca (VMI). Los casos de vaginitis por levaduras y por Trichomonas vaginalis comprendieron el 8,30 % y 6,99 % de las mujeres, respectivamente. Se observó el desplazamiento de la MN hacia una MI, que se correspondió con el predominio de bacterias corineformes. Por otra parte, no se reconoció un marcado desequilibrio del contenido vaginal ante la colonización e infección por levaduras o por T. vaginalis: el 48 % de los casos de estas vaginitis convencionales no presentaron reacción infamatoria vaginal (RIV). El 24,89 % de los casos de MN presentaron una signifcativa RIV, y en más del 50 % de las mujeres se diagnosticaron disfunciones vaginales en ausencia de sintomatología. Estos resultados se podrían asociar a un incremento del riesgo gineco-obstétrico, lo que afecta la salud sexual y reproductiva de la población estudiada.

The aim of this work was to study the vaginal microenvironment in sex workers from Comodoro Rivadavia, Chubut. For that purpose, BAVACO procedures were applied. A total of 229 female sex workers attended public health centers. Vaginal secretions were analyzed by Gram and Giemsa stains. The following results were obtained: normal microbiota 35.37 %, intermediate microbiota 15.72 %, bacterial vaginosis 23.14 %, microbial nonspecifc vaginitis, Donders'"aerobic vaginitis" 10.48 %, yeast vulvovaginitis 8.30 %, and trichomoniasis 6.99 %. The intermediate microbiota was characterized by a decrease in the number of lactobacilli and the presence of diphtheroid bacilli cell types. The population studied shared increased values of vaginal dysfunctions. These results are considered risk factors for obstetric and gynecologic diseases.

Diagnostic yield of double-balloon enteroscopy with intestinal juice analysis for intestinal strongyloidiasis.

Strongyloidiasis is relatively common in tropical and subtropical areas. Most patients with Strongyloides stercoralis hyperinfection are immunocompromised, most commonly from corticosteroids or human T-cell lymphoma virus type 1 (HTLV-1) infection. We encountered a patient with HTLV-1 infection accompanied by paralytic ileus, in whom strongyloidiasis in the duodenum and jejunum was disclosed by esophagogastroduodenoscopy (EGD) and double-balloon enteroscopy (DBE). Until the age of 7 years, he lived on Amami-Oshima Island, Japan, where both S. stercoralis and HTLV-1 are endemic. EGD and peroral DBE disclosed white villi, edematous mucosa, and the disappearance of folds in the duodenum and jejunum. Biopsy specimens from the white villi in the duodenum and jejunum revealed S. stercoralis larvae. In both duodenal and jejunal juice, the rhabditiform larvae moved around. Because the larvae invade the lymph vessels, resulting in lymphangiectasia in edematous enteritis, the appearance of white villi may reflect villous atrophy/destruction and mucosal edema. Although our patient revealed no eosinophilia and negative stool specimens for parasites or ova, EGD and DBE with multiple biopsies and intestinal juice analysis are valuable diagnostic tools for strongyloidiasis.

High-speed gel microelectrophoresis, a new and easy approach for detection of PCR-amplified microbial DNA from environmental and clinical samples in microgels using conventional equipment.

AIMS: Microelectrophoresis allows the detection of DNA bands using minimal amounts of sample in a short time, but commonly requires the use of special equipment which is not available in all laboratories. This fact has limited the application of this technique in microbiology despite its advantages. In this work, we describe a new approach to perform gel microelectrophoresis, named high-speed gel microelectrophoresis (HSGME), and its application for rapid detection of bacteria, protozoa and viruses in clinical, vegetal and environmental samples. METHODS AND RESULTS: Aliquots of 0.4-1 microl of PCR product were loaded in 2 cm 1% agarose microgels and electrophoresed at high voltage (125 V cm(-1)) in conventional submarine horizontal mini-slabs. By using HSGME, single-DNA bands obtained after specific-PCR useful in diagnosis of different diseases caused by micro-organisms were detected in 5 min. CONCLUSIONS: HSGME is a rapid and easy procedure applicable to detection of microbial genes, which is carried out using conventional equipment and thus can be performed in any research and diagnostic laboratory. SIGNIFICANCE AND IMPACT OF THE STUDY: The performance of HSGME saves up to 90% time, material and energy costs, as well as laboratory hazardous wastes including carcinogenic agents used for visualizing DNA bands.

Quantitative detection of Toxoplasma gondii DNA in human body fluids by TaqMan polymerase chain reaction.

OBJECTIVE: A new quantitative polymerase chain reaction (real-time PCR) was designed to detect Toxoplasma DNA in human body fluid samples. METHODS: Real-time fluorescence detection of amplification product formation on the basis of the TaqMan-System was established with Toxoplasma 18S rDNA as a target gene. RESULTS: The method provides a high sensitivity comparable to conventional nested PCR procedures and generates quantitative data when detecting toxoplasmic DNA in human blood, cerebrospinal or amniotic fluid. Moreover, data were obtained investigating blood samples from an immunocompromised patient with reactivated toxoplasmosis after allogeneic bone marrow transplantation, monitoring the therapeutic effect. CONCLUSIONS: The potential application of this method to detect Toxoplasma DNA in body fluids and to follow the development of parasitemia under therapy could be demonstrated.

Fluorescence techniques for diagnosing intestinal microsporidiosis in stool, enteric fluid, and biopsy specimens from acquired immunodeficiency syndrome patients with chronic diarrhea.

OBJECTIVE: To evaluate three fluorescent chitin stains for detecting microsporidia spores in specimens from acquired immunodeficiency syndrome (AIDS) patients with chronic diarrhea. METHODS: We compared the Fungifluor, Calcofluor White, and Fungiqual A fluorochrome stains for identifying Enterocytozoon bieneusi and Septata intestinalis spores in stool, intestinal fluid, biopsy imprints, and paraffin biopsy sections. The modified chromotrope trichrome stain was used as the standard light microscopic technique for stool and fluid specimens. Stained and unstained paraffin sections and fluid preparations were also evaluated. Multiple specimens from 50 consecutive symptomatic AIDS patients and archival material from known microsporidia-positive AIDS patients were analyzed. RESULTS: Spores of E bieneusi and S intestinalis fluoresce brightly with all three fluorochrome stains in all of the types of diagnostic specimens. Fluorescing debris and the much larger fungal forms were readily distinguished. Spores were equally well detected in unfixed and formalin-fixed stool specimens, but were not as well detected after sodium acetate-acetic acid, polyvinyl acetate, and ethanol fixation. Bouin's tissue fixative gave a higher background staining than formalin. Spores were readily detected in archival paraffin sections and stool preparations, even when the specimens had been stained previously. Repeat fluorochrome staining was possible. The methods also could detect extraintestinal parasites in paraffin sections. CONCLUSION: The three fluorescent chitin stains are sensitive and rapid methods for detecting microsporidia spores in stool, intestinal fluid, biopsy imprint, and tissue specimens, even from archived material.

Paragonimiasis in a cystic breast mass: case report and implications for examination of aspirated cyst fluids.

We report a case of paragonimiasis diagnosed by fine-needle aspiration of a breast mass in a middle-aged Korean female with a history of breast silicone injections. Although parasitoses have been discovered by aspiration of cyst fluid in otherwise sterile sites (i.e., liver and lung), the cystic presentation in the breast of a middle-aged female complicated the diagnosis in this case. Some authors have argued against the routine cytologic examination of nonbloody cyst fluids in premenopausal women, but this protocol may lead to a false negative diagnosis in the rare instance of a parasitic cyst. While microscopic examination of breast cyst fluid is probably not warranted in every patient, it may be useful in patients at risk for unusual cystic lesions, especially if clinical and mammographic signs of fibrocystic change are absent.

Special laboratory examinations for parasitic infections.

Besides the routine procedures used for the diagnosis of parasites, there are a number of other diagnostic techniques available for the recovery and identification of parasites. Most laboratories do not routinely offer all of these techniques, but many are relatively simple and inexpensive to perform. This article discusses these techniques and their clinical relevance.

High efficacy of praziquantel in the treatment of 22 patients with Clonorchis/Opisthorchis infections.

In a prospective clinical study, the efficacy of praziquantel in the treatment of 22 patients with Clonorchis/Opisthorchis infections was investigated. The dose regimen was 90 mg per kg bodyweight, divided into three equal doses given on consecutive days. Parasitological, clinical, routine haematological and biochemical parameters were followed up for twelve months. Twenty patients (91%) had no detectable egg excretion in the feces or duodenal fluid after one treatment only. Two patients required repeated treatments and a different dose regimen. No serious side effects were observed. Praziquantel proved to be a safe and effective drug for therapy of Clonorchis/Opisthorchis infections.