Influenza surveillance in Western Turkey in the era of quadrivalent vaccines: A 2003-2016 retrospective analysis

Human influenza is predominantly caused by influenza A virus (IAV) - A/H1N1 and/or A/H3N2 - and influenza B virus (IBV) - B/Victoria and/or B/Yamagata, which co-circulate each season. Influenza surveillance provides important information on seasonal disease burden and circulation, and vaccine content for the following season. To study the circulating influenza subtypes/lineages in western Turkey. Community-based sentinel surveillance results during 2003-2016 (weeks 40-20 each season; but week 21, 2009 through week 20, 2010 during the pandemic) were analyzed. Nasal/nasopharyngeal swabs from patients with influenza-like illness were tested for influenza virus and characterized as A/H1N1, A/H3N2, or IBV. A subset of IBV samples was further characterized as B/Victoria or B/Yamagata. Among 14,429 specimens (9,766 collected during interpandemic influenza seasons; 4,663 during the 2009-2010 pandemic), 3,927 (27.2%) were positive. Excluding the pandemic year (2009-2010), 645 (27.4%) samples were characterized as A/H1N1 or A/H1N1/pdm09, 958 (40.7%) as A/H3N2, and 752 (31.9%) as IBV, but the dominant subtype/lineage varied widely each season. During the pandemic year (2009-2010), 98.3% of cases were A/H1N1/pdm09. IBV accounted for 0-60.2% of positive samples each season. The IBV lineages in circulation matched the vaccine IBV lineage >50% in six seasons and <50% in four seasons; with an overall mismatch of 49.7%. IBV cases tended to peak later than IAV cases within seasons. These results have important implications for vaccine composition and optimal vaccination timing. Quadrivalent vaccines containing both IBV lineages can reduce B-lineage mismatch, thus reducing the burden of IBV disease

A review of the experience of childhood hepatitis A vaccination in Saudi Arabia and Turkey : implications for hepatitis A control and prevention in the Middle East and North African region

In most countries of the Middle East and Northern African (MENA) region, a high hepatitis A virus (HAV) endemicity has been documented. Few others, such as Saudi Arabia and Turkey, are transitioning from high to intermediate endemicity. There is a paucity of recently published HAV disease burden that could be useful to inform or strengthen relevant national hepatitis A vaccination policy and other prevention strategies in the region. This review summarizes information on HAV epidemiology before and after the implementation of a childhood hepatitis A vaccination program in Saudi Arabia and Turkey. In both countries, a clear shift in the age of first HAV exposure has been documented, with more homogeneous trends across regions in Saudi Arabia compared to Turkey. Utilizing the experience of Saudi Arabia and Turkey with hepatitis A vaccination, countries in the region are encouraged to foster discussions on potential vaccination strategies suitable for their own setting

Herpes Zoster Burden of Disease and Clinical Management in Turkey: A Comprehensive Literature Review

Abstract Introduction Herpes zoster (HZ), or shingles, is caused by the reactivation of varicella zoster virus (VZV) and typically presents as an acute, painful dermatomal rash, but can lead to long-term, distressing complications such as postherpetic neuralgia (PHN). Increasing trends in HZ cases are evident globally among the aging population; however, reviews investigating the epidemiology and clinical management of HZ in Turkey are lacking. Therefore, a literature review of local studies in Turkey was conducted to identify the data available and identify gaps in the literature. Methods Literature searches were carried out in PubMed and local journals to retrieve published articles that reported surveillance data, seroepidemiology, patient outcomes, or clinical management related to HZ or VZV in Turkey until April 30, 2022. Studies included primary data reports, case studies, secondary data reviews, and epidemiological studies in healthy or at-risk populations; HZ was the primary focus of the review. Results No studies reported VZV or HZ epidemiological data at a national level. One large retrospective study in Istanbul reported that HZ incidence rates significantly increased in adults 18–44 years of age between 2011 and 2019. Four single-center studies reported the proportion of dermatological patients with HZ at 0.43–1.56%. PHN was the most common reported complication, occurring in 8–58.9% of patients with HZ. However, out of 39 identified case reports, HZ ophthalmicus was the most frequently reported complication. Two studies highlighted poor disease awareness and risk perception of HZ among Turkish citizens. Conclusion Overall, there were limited comprehensive epidemiological data on HZ in Turkey. However, the abundance of case studies on HZ complications indicates a strong disease presence and diverse clinical management in Turkey. Further research will be important to understand the impact of HZ, increase disease awareness, and support the introduction of new preventative strategies