The Epidemiological Features and Pathogen Spectrum of Respiratory Tract Infections, Istanbul, Türkiye, from 2021 to 2023.

Respiratory tract infections (RTIs) can lead to both recurrent seasonal epidemic outbreaks and devastating pandemics. The aim of this study was to evaluate the epidemiologic characteristics and pathogen spectrum of RTIs using a multiplex RT-PCR panel. A total of 9354 cases with suspected RTIs between February 2021 and July 2023 were included in this study. A total of 11,048 nasopharyngeal and oropharyngeal samples from these patients were analyzed for 23 respiratory tract pathogens using multiplex RT-PCR. H. influenzae and S. pneumoniae were considered as colonizing bacteria. At least one pathogen was detected in 70.66% of the samples; viral pathogens were detected in 48.41% of the samples, bacterial pathogens were detected in 16.06% of the samples, and viral + bacterial pathogens were detected in 35.53% of the samples. The most frequently detected viral pathogen was rhinovirus/enterovirus (RV/EV) (19.99%). Interestingly, in 2021, respiratory syncytial virus A/B showed atypical activity and replaced RV/EV as the most prevalent pathogen. Human bocavirus, H. influenzae, and S. pneumoniae were detected at higher rates in males (p: 0.038, p: 0.042, and p: 0.035, respectively), while SARS-CoV-2 and B. pertussis were detected at higher rates in females (p < 0.001 and p: 0.033). RTIs were found at higher rates in children (p < 0.001). SARS-CoV-2 and human coronaviruses 229E were detected at higher rates in adults (p < 0.001 and p: 0.001). This comprehensive study with a large sample size investigating RTI pathogens was the first in Türkiye. Understanding the current viral circulation using multiplex RT-PCR panels enables clinicians to predict the most likely pathogens affecting patients and contributes to patient management, in addition to anticipating potential threats.

Molecular investigation of Blastocystis sp. and its subtypes in cancer patients under chemotherapy in Aegean region, Turkey.

Blastocystis sp. is a common enteric protist found in humans and many other animals. Although the clinical relevance of Blastocystis sp. is currently fully unknown for humans, the prevalence of Blastocystis and subtypes are investigated in immunocompetent individuals presenting with symptoms like diarrhea or immunocompromised individuals including cancer patients. In this comprehensive study, the prevalence of Blastocystis sp. and subtypes were investigated in patients (n=94) with different types of malignant solid tumors using PCR targeting SSU rDNA gene and sequencing. All patients were undergoing chemotherapy and had diarrhea. According to obtained results, 46 patients were found to be Blastocystis positive and the molecular prevalence was detected as 48.9%. Among the positive specimens, 43 (43/46; 93.5%) of them were successfully subtyped. ST4 was the most predominant subtype and detected in 24 (55.8%) patients, followed by ST1 (11 patients, 25.6%) and ST3 (8 patients, 18.6%). In the colon cancer group, which had the highest number of patients, Blastocystis sp. was detected with a higher prevalence rate of 61.5% compared with the prevalence rate (48.9%) of all patients. Interestingly, ST3 was not detected in any of this patient group in contrast to ST4 and ST1. In conclusion, high prevalence of the Blastocystis in the immunocompromised patient groups shows the susceptibility of this patient group against any other infectious agents.

Cryptosporidium spp. during chemotherapy: a cross-sectional study of 94 patients with malignant solid tumor.

BACKGROUND: Cryptosporidium spp. is a protozoan parasite that infects many vertebrate animals, including humans. Since Cryptosporidium spp. can cause chronic life-threatening diarrhea and severe malabsorption in immunocompromised patients, we investigated the prevalence of this parasite among patients undergoing chemotherapy for malignant solid tumors. OBJECTIVE: Investigate the prevalence of Cryptosporidium spp. in stool samples. DESIGN: Cross-sectional. SETTING: Tertiary care. PATIENTS AND METHODS: Stool samples were collected from adult patients with malignant solid tumors receiving chemotherapy and diarrhea. Cryptosporidium spp. prevalence was determined using Ziehl-Neelsen staining, ELISA, and real-time PCR targeting of the COWP gene. MAIN OUTCOME MEASURE: The prevalence of Cryptosporidium spp. in patients undergoing chemotherapy for malignant solid tumors. SAMPLE SIZE: 94 RESULTS: The prevalence was 2.1% (2/94), 5.3% (5/94), and 5.3% (5/94) as detected by Ziehl-Neelsen staining, real-time PCR and ELISA, respectively. The prevalence reached 8.5% (8/94) using all results obtained from the three methods. Among eight positive stool samples, four were positive by at least two different methods (Ziehl-Neelsen staining-ELISA or ELISA-real-time PCR) whereas the remaining four were positive by either ELISA or real-time PCR. CONCLUSION: These findings show the risk of cryptosporidiosis in cancer patients and the necessity to use at least two diagnostic methods during the diagnosis of cryptosporidiosis to reach more accurate and trustworthy results. LIMITATIONS: Further studies with a larger sample size are recommended. CONFLICT OF INTEREST: None.

Radiation therapy for biliary tract tumors: the joint experience of three centers.

BACKGROUND/AIM: This study presents the joint experience of three centers in the treatment of patients with biliary tract tumors with radiation therapy (RT). MATERIALS AND METHODS: The records of 27 patients were retrospectively reviewed. All of the patients who had undergone surgical resection received postoperative adjuvant RT, whereas all of the patients who had not undergone a surgical resection received RT with palliative intent. Twenty patients with adequate performance status were treated with RT and chemotherapy, while the remaining seven patients were treated with RT alone. RESULTS: Follow-up ranged from 1 to 44 months. Local control was not achieved in 10 out of 11 patients who had received RT with palliative intent. Systemic failure was observed in eight patients at 5 to 16 months. Fifteen patients died due to disease-related causes at 1 to 22 months. At 2 years, overall survival was 33% and disease-free survival was 19%. A surgical resection with curative intent predicted improved local failure-free survival and improved disease-free survival. CONCLUSION: Since local recurrence is still the leading cause of failure following postoperative RT and the outcome following palliative RT is far from satisfactory, the indications, the target volume, and the doses for RT should be reconsidered.