HAVVA KAYA

Dr. HAVVA KAYA

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 January 2022 in Journal of Pediatric Infectious Diseases
Verified
Journal Article
Closed access
PDF file
FYFatih Yılmaz
Fatih Yılmaz
HKHAVVA KAYA
HAVVA KAYA
MOMehmet Ozdemir
Mehmet Ozdemir
Objective Gastroenteritis is a disease that affects all age groups, especially children, and causes high mortality and morbidity in all countries. The most common agents of acute gastroenteritis are viral agents. As a result, millions of diarrhea attacks and hospital admissions occur worldwide every year due to viral gastroenteritis. This study uses the multiplex polymerase chain reaction (PCR) method to investigate the viruses that are the causative agents of viral gastroenteritis in the pediatric patient group in Konya, Turkey. Methods Stool samples of 94 patients aged 0 to 18 years sent from Emergency clinics and Pediatric outpatient clinics, Meram Medical Faculty Hospital Pediatric clinics, Konya Necmettin Erbakan University to Medical Microbiology Laboratory with a diagnosis of gastroenteritis between February and December 2018 were included in the study. Stool samples were stored at –80°C until the time of the analysis. Deoxyribonucleic acid/ribonucleic acid isolation from stool samples was performed with EZ1 Virus Mini Kit v2.0 (Qiagen, Hilden, Germany) using an automatic extraction system (BioRobot EZ1 system, Qiagen). The presence of astrovirus, rotavirus, adenovirus, norovirus (GI, GII), and sapovirus agents was investigated by the multiplex PCR method (Fast Track Diagnostics, Luxembourg) viral gastroenteritis kit. Results Viral gastroenteritis agents were detected in 56.3% of the patients. One viral agent was detected in 47 (50%) of these patients and at least two viral agents in 6 (6.3%) of them. Norovirus GII was detected in 20 (21.2%) of the children included in the study, adenovirus in 13 (13.8%), rotavirus in 11 (12.8%), astrovirus in 11 (11.7%), sapovirus in 4 (4.2%), and norovirus GI in 1 (1.06%). When the distribution of viral agents was examined by months, the most number of agents were observed (21; 35%) in May, followed by April and June (12; 20%). Considering the distribution of the prevalence of the agents by age, it was seen to be mainly between 0 and 12 months (42%). Conclusion Considering that the most common viral agent in our region is norovirus GII, it will be useful to investigate the norovirus that is not routinely examined in children who are admitted to clinics with the complaint of gastroenteritis. It will be appropriate to examine routinely adenovirus, rotavirus, and norovirus in the laboratory, especially in children with diarrhea and vomiting in the winter and spring months.

30 September 2021 in Flora the Journal of Infectious Diseases and Clinical Microbiology
Verified
Journal Article
Closed access
GAGökçe Kader Arslan
Gökçe Kader Arslan
MÖMehmet Özdemir
Mehmet Özdemir
HKHAVVA KAYA
HAVVA KAYA
BFBahadır Feyzioğlu
Bahadır Feyzioğlu
EKESMA KEPENEK KURT
ESMA KEPENEK KURT
IEİbrahim Erayman
İbrahim Erayman

31 December 2024 in Archives of Rheumatology
Verified
Journal Article
Open access
PDF file
MKMehmet Karabey
Mehmet Karabey
HKHAVVA KAYA
HAVVA KAYA
ACAlperen Ceylan
Alperen Ceylan
KKKadir Kaba
Kadir Kaba
MOMehmet Ozdemir
Mehmet Ozdemir
BFBahadır Feyzioğlu
Bahadır Feyzioğlu
Objectives: The study aimed to investigate the possible effects of coronavirus disease 2019 (COVID-19) on autoantibodies. Patients and methods: Samples of 89,108 individuals (29,033 males, 60,075 females; median: 36 years; range, 0 to 96 years) who underwent autoimmune testing between January 2017 and May 2022 were retrospectively analyzed. The prepandemic period was defined as May 1, 2017, to March 20, 2020, while the pandemic period was defined as March 20, 2020, to May 31, 2022. Results: Of the participants, 0.55% were of foreign nationality. The positivity rate was 18.12%. Autoantibody positivity rates, when analyzed by sex, were higher in females for antinuclear antibody (ANA), antimitochondrial antibody (AMA), anti-liver kidney microsomal (LKM) antibody, immunoglobulin A (IgA) anti-gliadin antibody, anti-endomysial antibody A, anti-ribosomal P protein antibody, anti-Sjögren’s syndrome A (anti-SSA), anti-Sjögren’s syndrome B (anti-SSB), anti-Smith/ribonucleoprotein (anti-SM/RNP), anti-SM, and c-ANCA (cytoplasmic antineutrophil cytoplasmic antibody). When the prepandemic period was compared with the pandemic period, AMA, anti-LKM antibody, IgA anti-gliadin antibody, anti-endomysial antibody A, and anti-SM/RNP levels were higher in the prepandemic period, while ANA was higher during the pandemic. Additionally, statistically significant differences were found in the distributions of ANA, AMA, anti-LKM antibody, IgA anti-gliadin antibody, anti-endomysial antibody A, anti-ribosomal P protein antibody, anti-SM, anti-SSA, and c-ANCA across the years. Conclusion: This study could not establish a cause-effect relationship between the changing autoantibody levels during the COVID-19 pandemic and severe acute respiratory syndrome coronavirus 2 infection due to the lack of results from the same patients across different periods. Nonetheless, we believe the quantitative seroprevalence changes in such a large sample of autoantibody screening results over a five-year period, including the pandemic, are valuable.

2 January 2024 in Journal of Molecular Virology and Immunology
Verified
Journal Article
Open access
HKHAVVA KAYA
HAVVA KAYA
MKMehmet Karabey
Mehmet Karabey
ÖAÖzge Metin Akça
Özge Metin Akça
BFBahadır Feyzioğlu
Bahadır Feyzioğlu
MOMehmet Ozdemir
Mehmet Ozdemir
KKKadir Kaba
Kadir Kaba
After the declaration of the COVID-19 pandemic by the World Health Organization (WHO), various restrictions were implemented, and face-to-face education was suspended in schools. In some countries, COVID-19 vaccines emergency use authorization has been granted for the pediatric age group. This study aimed to investigate COVID-19 antibody level in children who have not been vaccinated against COVID-19. A total of 1,000 pediatric patients aged 0-12 years, unvaccinated against COVID-19, admitted to Necmettin Erbakan University Medical Faculty Hospital Pediatrics clinics with different symptoms between October 2020 and April 2022 were included in this study. SARS-CoV-2 S total antibody levels were tested by ELISA method from the sera samples of these children. Of the children included in the study, 535 (53.5%) were male and 465 (46.5%) were female. Anti-SARS-CoV-2 S total Ig positivity rates were 75.9% in girls and 78.5% in boys and the difference between them was not statistically significant (p>0.05). When the anti-SARS-CoV-2 S total Ig positivity rates of children were evaluated according to years, 23 (43.4%) in 2020, 183 (60%) in 2021, and 567 (88.3%) in 2022 was found positive. The difference between antibody results by years was found to be statistically significant (p<0.001). Median value of SARS-CoV-2 antibody levels of patients with positive antibody test in 2020 46 AU/ml (min 5, max: 214 AU/ml), in 2021 130 AU/ml (min:1, max: 250 AU/ml), and in 2022 it was found to be 250 AU/ml (min:1, max: 250 AU/ml). When the antibody levels of patients with anti-SARS-CoV-2 S Ig total positive were evaluated, the difference between years was found to be statistically significant (p<0.05). In our study, it was determined that the rate of SARS-CoV-2 S total antibody positivity reached 90% in unvaccinated children aged 12 and younger. Determining the SARS-CoV-2 antibody status of children aged 12 and under who unvaccinated against COVID-19 in our country will both give information about immunization by natural immunity and will be effective in deciding and planning the need for COVID-19 vaccination for children.

23 December 2022 in Journal of Molecular Virology and Immunology
Verified
Journal Article
Closed access
HKHAVVA KAYA
HAVVA KAYA
MPMehmet Parlak
Mehmet Parlak
MBMustafa Zahir Bakıcı
Mustafa Zahir Bakıcı
HGHüseyin Güdücüoğlu
Hüseyin Güdücüoğlu
YBYasemin Bayram
Yasemin Bayram
Disinfection of contaminated material, surface and body parts with appropriate substances is one of the most effective practices in preventing the infection-colonization of Vancomycin-Resistant Enterococci (VRE). In this study, 1/10 and 1/100 dilutions of 5% sodium hypochlorite, 4% concentration of chlorhexidine gluconate and 0.1% and 0.5% concentrations of Akacid plus’s efficacy against VRE strains at 1, 5, 15 and 30 minutes was tested. Sixty-nine vancomycin-resistant E. faecium strains isolated from different body samples between 2012 and 2014 were included in the study. The BD Phoenix 100® fully automated system was used for the identification of strains and detection of vancomycin resistance. Quantitative Suspension Test method EN 1276 (March 2010) was used to evaluate the bactericidal activities of chemical disinfectants and antiseptics used in European Union countries in the investigation of disinfectant susceptibility of VRE strains. Five log10 decrease (105) in the number of bacteria in the initial test suspension between the number of bacteria after using the disinfectant indicates that the disinfectant is effective. In this study, it has been determined that a 1/10 dilution of 5% sodium hypochlorite (bleach) is the most effective disinfectant on VREs in all minutes and conditions. Effectiveness of 1/100 dilution of bleach has a significant decrease in dirty conditions. Akacid plus was not effective on all strains in any contact times we tested. It has been observed that Akacid plus is the disinfectant least affected by the changes in environmental conditions in all minutes. Chlorhexidine gluconate (4%) was ineffective in clean and dirty conditions in just 1 minute, while from the 5th minute, its effectiveness was found to be statistically at the same level as the 1/10 dilution of bleach. There was no decrease in the activities of chlorhexidine due to the changing environmental conditions. In conclusion, it has been determined that a 1/10 dilution of 5% sodium hypochlorite (bleach) is the most effective disinfectant on VREs in all minutes and conditions, but dirty environmental conditions cause a significant decrease in the effectiveness of sodium hypochlorite. In addition, it was observed that the effectiveness of all disinfectants and antiseptics on VREs increased as the contact time with the substances increased.

23 October 2026 in Viruses
Verified
Journal Article
Open access
PDF file
GTGöknur Yapar Toros
Göknur Yapar Toros
EOEbru Oruc
Ebru Oruc
BEBaşak Erarslan
Başak Erarslan
SCSabahat Ceken
Sabahat Ceken
ESEmine Merve Savaş
Emine Merve Savaş
ISIrfan Sencan
Irfan Sencan
Background: Viral infections of the respiratory tract in patients with hematological disorders show a similar seasonal pattern to that of the normal population; however, these infections are an important cause of morbidity and mortality in this group of patients. This study evaluated the clinical and laboratory characteristics and outcomes of proven respiratory viral infections (RVIs) and identified risk factors for in-hospital mortality in patients with hematologic malignancies (HM) and hematopoietic stem cell transplant (HSCT) recipients followed at our center. Methods: A single-center, retrospective cohort study comprising patients with HM and HSCT who were diagnosed with RVIs was conducted between January 2023 and June 2025 at a tertiary health center. Patient information was retrospectively collected from the hospital electronic medical records. Baseline mortality predictors were identified using LASSO-penalized logistic regression with 10-fold cross-validation and bootstrap-based selection stability. Clinical deterioration markers were assessed using Firth-penalized logistic regression. Results: A total of 98 patients were included, of whom 19 (19.4%) died in hospital. Serum albumin was the most stable predictor and the only variable retained in the parsimonious model; each 1 g/L increase was associated with lower odds of all-cause in-hospital mortality (OR, 0.82; 95% CI, 0.73–0.91; p < 0.001). The optimism-corrected C-index was 0.828. In univariable analyses, ICU transfer and markers of respiratory deterioration, which reflect the clinical course rather than baseline risk, were associated with higher mortality. Coinfection was also associated with higher mortality (45.5% vs. 16.1%, p = 0.035). Conclusions: In this cohort of patients with HM and HSCT recipients with RVIs, organ dysfunction indicators, clinical worsening, and coinfection were associated with all-cause in-hospital mortality, and lower serum albumin was the most stable independent predictor. These findings highlight the importance of early identification of high-risk patients and close monitoring for respiratory deterioration and coinfections.