Role of clinical, molecular, and serological features in the diagnosis of parvovirus B19 infection in children.

BACKGROUND: Parvovirus B19(B19) is a DNA virus. The most common B19 disease is erythema infectiosum (fifth-disease). PCR and ELISA are sensitive for detecting of acute disease. However, it is not clear which test better and the relationship between laboratory tests and clinical findings. OBJECTIVE: To discuss the clinical and laboratory characteristics of pediatric patients infected with B19. STUDY DESIGN: 236 children were examined. Children with at least one positive molecular or serological test were included. Positive serum B19-DNA and/or B19-IgM was considered an acute B19 infection. RESULTS: B19DNA was detected in 80.8 % of acute cases. Serological tests were less positive. Acute B19 infection was observed in 24 patients. Only 17 patients were positive for B19 DNA, 3 for IgM and 4 for both. The sensitivity of B19 DNA is 87.5 %. However, this rate is 29.2 % for B19 IgM. CONCLUSION: B19-DNA and IgM together provide a better, highly accurate diagnosis.

Evaluation of SARS-CoV-2-Positive Patients with Suspected Reinfection.

The aim of this study was to investigate the reinfection rates and characteristics of SARS-CoV-2 in individuals with SARS-CoV-2 RNA present in their clinical specimens for COVID-19. Our data from the COVID-19 Laboratory of Istanbul University were analyzed for 27,240 cases between 27 March 2020 to 8 February 2022. Demographic characteristics, vaccination statuses, comorbidities, and laboratory findings were evaluated in cases with suspected reinfection, as determined by the presence of SARS-CoV-2 RNA at a rate of 0.3% in clinical specimens. When comparing laboratory values, leukocyte counts were lower in the second and third infections compared with the first infection (p = 0.035), and neutrophil counts were lower in the second infection (p = 0.009). Symptoms varied, with coughing being common in the first infection and malaise being common in subsequent infections. These results suggest that it is important to continue to monitor reinfection rates and develop strategies to prevent reinfection. Our results also suggest that clinicians should be aware of the possibility of reinfection and monitor patients for recurrent symptoms.

Evaluation of the Diagnostic Performance of a SARS-CoV-2 and Influenza A/B Combo Rapid Antigen Test in Respiratory Samples.

This study aimed to evaluate the performance characteristics of a rapid antigen test developed to detect SARS-CoV-2 (COVID-19), influenza A virus (IAV), and influenza B virus (IBV) (flu) compared with those of the real-time reverse transcription-polymerase chain reaction (rRT-PCR) method. One hundred SARS-CoV-2, one hundred IAV, and twenty-four IBV patients whose diagnoses were confirmed by clinical and laboratory methods were included in the patient group. Seventy-six patients, who were negative for all respiratory tract viruses, were included as the control group. The Panbio™ COVID-19/Flu A&B Rapid Panel test kit was used in the assays. The sensitivity values of the kit were 97.5%, 97.9%, and 33.33% for SARS-CoV-2, IAV, and IBV, respectively, in samples with a viral load below 20 Ct values. The sensitivity values of the kit were 16.7%, 36.5%, and 11.11% for SARS-CoV-2, IAV, and IBV, respectively, in samples with a viral load above 20 Ct. The kit's specificity was 100%. In conclusion, this kit demonstrated high sensitivity to SARS-CoV-2 and IAV for viral loads below 20 Ct values, but the sensitivity values were not compatible with PCR positivity for lower viral loads over 20 Ct values. Rapid antigen tests may be preferred as a routine screening tool in communal environments, especially in symptomatic individuals, when diagnosing SARS-CoV-2, IAV, and IBV with high caution.

Is SARS-CoV-2 viral load a predictor of mortality in COVID-19 acute respiratory distress syndrome patients?

OBJECTIVE: Viral load varies during infection and is higher during the initial stages of disease. Given the importance of the intensive care unit (ICU) in the late stages of COVID-19 infection, analyzing cycle threshold values to detect viral load upon ICU admission can be a clinically valuable tool for identifying patients with the highest mortality risk. METHODS: This was a retrospectively designed study. Patients older than 18 years who tested positive for SARS-CoV-2 PCR and had a PaO2/FiO2 ratio <200 were included in the study. The patient population was divided into two groups: survivors and non-survivors. RESULTS: Two hundred patients were included in the study. In non-survivors, age, relevant ICU admission scores, and procalcitonin levels were significantly higher whereas PaO2/FiO2 ratios and cycle threshold levels were significantly lower than in survivors. CONCLUSION: Viral load at ICU admission has significant prognostic value. In combination with age, comorbidities, and severity scores, viral load may assist clinicians in identifying individuals who need more intensive monitoring. Increased awareness may improve outcomes by allowing the more effective monitoring and treatment of patients. More prospective studies are needed to determine how a high viral load worsens disease and how to avoid irreversible results.

Helicobacter pylori-miRNA interaction in gastric cancer tissues: First prospective study from Turkey.

Helicobacter pylori (H. pylori) is involved in the etiology of gastric cancer (GC). miRNAs are short RNAs that regulate gene expression by marking mRNAs for degradation. miRNAs are involved in tumorigenesis, metastasis, and cell proliferation. We aimed to investigate the miRNA expression profiles of tissues from H. pylori (+) and (-) GC patients. Forty GC patients, 20 H. pylori (+) and 20 H. pylori (-), and a healthy control group were included. The miRNA expression levels were investigated by microarrays and quantitative RT-PCR. We detected 9 upregulated and 4 downregulated miRNAs by microarray. We selected 5 upregulated and 5 downregulated miRNAs for the quantitative RT-PCR assay. The relative fold changes of miRNAs in the cancerous tissue and non-tumor mucosa specimens of H. pylori (+) GC patients for hsa-miR-194 were 4.24- and 3.83-fold higher, respectively, whereas the hsa-miR-145 expression levels were downregulated 0.33-fold and 0.43-fold, respectively, in the same group. The presence of H. pylori significantly upregulated hsa-miR-194 and downregulated hsa-miR-145 expression levels in H. pylori (+) GC cases, compared to H. pylori (-) GC cases. Regional differences in the virulence of H. pylori strains may also be involved in the up- or downregulation of miRNA expression levels.

Comparison of new and classical point mutations associated with clarithromycin resistance in Helicobacter pylori strains isolated from dyspeptic patients and their effects on phenotypic clarithromycin resistance.

PURPOSE: We aimed to investigate the presence of three recently identified point mutations (A2115G, G2141A and A2144T) of the 23 S rRNA gene and compare them with the three most frequently encountered point mutations (A2142G, A2142C and A2143G) in Helicobacter pylori strains in Turkey. METHODOLOGY: A total of 63 patients (mean 47.08±12.27) were included. The E-test method (for clarithromycin) was used for the clarithromycin antimicrobial susceptibility test of isolated H. pylori strains. Real-time PCR was used to detect the point mutations. RESULTS: A total of 24 out of 63 H. pylori strains (38.1%) were detected as clarithromycin resistant (>0.5 mg l-1 ). The new A2115G (n:6, 25%), A2144T (n:7, 29.1%) and G2141A, 8 (n:8, 33.3%) mutations and the classical A2142G (n:8, 33.3%) and A2143G (n:11, 45.8%) point mutations were detected in the 24 clarithromycin-resistant strains. The A2144T point mutation had the highest median MIC value (3 mg l-1 ) amongst the new mutations, but the classical mutations (A2142G and A2143G) had the highest median MIC values (256 mg l-1 ) overall. The presence of the A2115G (OR:31.66), A2144T (OR:36.92) or G2141A (OR:28.16) mutations increased the likelihood of clarithromycin resistance in H. pylori strains by 31.66-, 36.92- and 28.16-fold (ORs), respectively, according to the binary logistic regression analysis. CONCLUSION: We concluded that classical mutations of the 23 S rRNA gene resulted in higher clarithromycin MIC values than new mutations. These new point mutations caused moderate elevations in the MIC values of clarithromycin-resistant H. pylori strains.

The Prevalence of Cyclospora cayetanensis and Cryptosporidium spp. in Turkish patients infected with HIV-1.

Opportunistic infections such as cryptosporidiosis and cyclosporiasis are commonly encountered in patients with acquired immunodeficiency syndrome (AIDS). We investigated the existence of opportunistic protozoans that significantly affect the quality of life in HIV-1 infected patients using conventional and molecular methods. The study group comprised 115 HIV-1 positive patients. In the identification of Cyclospora cayetanensis and Cryptosporidium, the formol-ether precipitation method was used and smears were evaluated in optical microscope by staining modified Ziehl-Neelsen (ZN). The primers and probes used for PCR were Heat shock protein 70 for C. cayetanensis and the oocysts wall protein for Cryptosporidium spp.. Cyclospora and Cryptosporidium spp. oocysts were detected in one and two patients, respectively, by staining, whereas we detected C. cayetanensis in three patients out of 115 (2.6%) by PCR, and Cryptosporidium spp. in a further three patients (2.6%). C. cayetensis was detected in patients with CD4 counts of 64 cells/µm, 182 cells/µm and 287 cells/µm, respectively. Cryptosporidium spp. was detected in patients with CD4 counts of 176 cells/µm, 241 cells/µm and 669 cells/µm. As conclusion, PCR method is faster and more sensitive than microscopic methods and to screen intestinal pathogens routinely in patients infected with HIV should not be neglected in developing countries like Turkey.

Neopterin and Soluble CD14 Levels as Indicators of Immune Activation in Cases with Indeterminate Pattern and True Positive HIV-1 Infection.

BACKGROUND: We aimed to evaluate the roles of the plasma immune activation biomarkers neopterin and soluble CD14 (sCD14) in the indirect assessment of the immune activation status of patients with the indeterminate HIV-1 (IHIV-1) pattern and a true HIV-1-positive infection (PCG). METHODS: This cross-sectional and descriptive study included eighty-eight patients with the IHIV-1 pattern, 100 patients in the PCG, and 100 people in a healthy control group (HCG). Neopterin and sCD14 levels were determined by competitive and sandwich ELISA methods, respectively. RESULTS: Mean neopterin and sCD14 levels among those with the IHIV-1 pattern were significantly lower than among the PCG (p < 0.001 and p = 0.001, respectively), but they were similiar to those in the HCG (p = 0.57 and p = 0.66, respectively. Mean neopterin and sCD14 levels among the PCG were found to be significantly higher than among those with the IHIV-1 pattern (p < 0.001 and p = 0.001, respectively) and among those in the HCG (p = 0.001, p < 0.001, respectively). Neopterin did not have adequate predictive value for identifying those in the PCG (area under the curve [AUC] = 0.534; 95% CI, 0.463-0.605; p = 0.4256); sCD14 also had poor predictive value but high specificity (100%) for identifying those in the PCG (AUC = 0.627; 95% CI, 0.556-0.694; p = 0.0036). CONCLUSIONS: While low levels of these two biomarkers were detected among those with the IHIV-1 pattern, they were found in high levels among those in the PCG. These two markers obviously cannot be used as a sceening test because they have low sensitivies. Taken together, we suggest that neopterin and sCD14 may be helpful because they both have high specificity (92%-100%) as indirect non-specific markers for predicting the immune activation status of individuals, whether or not they have true positive HIV-1.

Investigation of intestinal parasites in pig feces that are also human pathogens.

A total of 238 pig fecal specimens were collected from pig farms in Corlu (Tekirdag), Ayazma, and Arnavutköy (Istanbul) during the summer. Out of the 238 pig specimens, 105 were from pigs younger than 6 months and 133 from pigs older than 6 months. These were investigated for intestine parasites in particular the ones that are human pathogens. Cryptosporidium spp. was detected In 21 fecal specimens (8.8%), Giardia spp. in 9 (3.7%), Balantidium coli cysts in 4 (1.6%) and Ascaris suum eggs in 9 (4.1%). Giardia lamblia were found in 8 (7.6%) of 105 pigs younger than 6 months, Cryptosporidium spp. in 12 (11.4%), Balantidium coli cysts in 2 (1.5%). In the pigs older than 6 months Giardia lamblia were found in 1 (0.7%), Cryptosporidium spp. in 9 (6.7%), Balantidium coli cysts in 2 (1.5%). and Ascaris suum eggs in 9 (6.7%). The difference in the rate of G. lamblia (p=0.01) in pigs less than 6 months and of A. suum in those over 6 months was found to be statistically significant (p=0.005). Our results revealed that pigs are important sources of these parasites.