Detection of non-polio and polio enteroviruses in Acute Flaccid Paralysis surveillance in Turkey.

Poliomyelitis was a disease feared worldwide, striking suddenly and paralysing mainly children for life. Monitoring of suspected cases of poliomyelitis is carried out with Acute Flaccid Paralysis (AFP) surveillance in Turkey. This study examines national data of AFP surveillance and the epidemiology of enteroviruses (EV) in Turkey from 2000 to 2019 and gives an overview of the detected serotypes of EVs. A total of 13,640 samples collected from patients with 5216 AFP pre-diagnosed cases (2 samples from each patient) and 3,208 contacts, during a 20-year period (2000-2019) were investigated. All isolated polioviruses were tested for their wild or vaccine origin according to the WHO recommended protocol by PCR and sequencing analysis were performed. Enterovirus positivity was detected in a total of 915 cases, which were identified as 204 Sabin-like polio virus (SLPV) and 711 non-polio enterovirus (NPEV). Of the 204 SLPV, 141 (69.1%) AFP were detected in patients and 63 (30.9%) were detected in samples taken from their contacts. Of the 711 NPEVs, 516 (72.5%) were from AFP cases and 195 (27.5%) were detected in samples taken from their contacts. It is concluded that the reason for the higher detection rate of NPEV in samples from AFP pre-diagnosed cases is attributed to the polio vaccination rates reaching 97% between 2008 and 2019 in Turkey. The most frequently detected NPEV serotypes were Coxackie A24, B3, and Echo 30. This retrospective study is the first comprehensive study in Turkey to evaluate the results of the AFP surveillance in the last 20 years.

[Investigation of adenovirus isolation frequency from the stool samples of patients suspected with acute flaccid paralysis]. / Akut flask paralizi süpheli olgularin diski örneklerinden adenovirus izolasyon sikliginin arastirilmasi.

Although adenoviruses (AdVs) generally cause upper respiratory tract infections, conjunctivitis/epidemic keratoconjunctivitis, gastroenteritis and pneumonia, they can lead to the involvement of central nervous system. Acute flaccid paralysis (AFP) is a type of seizure, characterized by rapid and sudden onset of extreme weakness in hands and feet, including (less frequently) weakness of respiratory and swallowing, representing with decreased muscle tone, especially in children below 15-year-old. The major viral cause of AFP is polioviruses, however non-polio enteroviruses, mumps virus, rabies virus and flaviviruses can also be responsible for AFP. The data of some recent studies have pointed out the probable aetiological role of AdVs in AFP. The aim of this study was to investigate the frequency of AdVs from stool samples of AFP-suspected patients and their contacts. A total of 6130 stool samples from patients (age range: 0-15 years) prediagnosed as AFP (n= 3185) and their contacts (n= 2945), which were sent to our laboratory from the health care centers located at different regions of Turkey for the monitorization of poliomyelitis as part of national AFP surveillance programme, between 2000-2014, have been retrospectively evaluated in terms of adenovirus isolation frequency. Samples were analyzed according to the algorithm recommended by World Health Organization and inoculated in Hep-2, RD, and L20B cell lines for cultivation. Apart from enteroviruses, in case of the presence of characteristic cytopathic effects for AdVs observed in L20B cells were confirmed by a commercial Adeno agglutination kit (Diarlex Adeno; Orion Diagnostica, Finland). It was noted that AdVs have been isolated from 1.6% (97/6130) of the samples, and out of positive samples 76.3% (74/97) were from AFP-suspected cases, while 23.7% (23/97) were from their contacts. Accordingly the frequencies of AdVs from AFP-suspected cases and their contacts were found as 2.3% (74/3185) and 0.8% (23/2945), respectively. The frequencies of Adenovirus positivity between the patients and their contacts were statistically significant (Z-Score 4.8347; p< 0.05). It was determined that 52.6% of the detected AdVs among AFP-suspected cases were between 1-4 age group and the positivity was 1.6 times more among males than the females. Although the data of this study are in agreement with the studies that support the relationship of AdVs with AFP, it is obvious that further molecular and clinical studies are needed.

[Serotype distribution of enteroviruses isolated from paediatric cases prediagnosed as aseptic meningitis between 2001-2004 period]. / 2001-2004 yillari arasinda aseptik menenjit ontanili pediatrik olgulardan izole edilen enterovirus serotiplerinin dagilimi.

Enteroviruses have major clinical and public health importance and are one of the leading causes of aseptic meningitis. There are many diseases with similar clinical symptoms and cerebrospinal fluid (CSF) findings of aseptic meningitis, thus virus isolation and identification is crucial for definitive diagnosis. Virological diagnosis is nonetheless important to distinguish between induced meningitis and other treatable causes of disease with a similar clinical picture. A total of 249 samples obtained from 246 cases (age range: 0-15 years), prediagnosed as aseptic meningitis, were sent to Virology Laboratory of Refik Saydam Hygiene Center. The patients were followed at Department of Pediatric Infectious Diseases in the Social Security Hospital, Ankara, Turkey, between 2001 and 2004. Stool (n: 180), CSF (n: 54) and throat swab (n: 15) samples have been inoculated to RD (rhabdomyosarcoma), Hep-2 (human epithelioma) and L20B (transgenic mice) cell lines, and followed up for the presence of cytopathic effects. A total of 95 enterovirus strains were isolated from 85 (34.6%) cases, and serotyped by using RIVM (National Institute of Public and the Environment, Nederlands) antisera with microneutralization method. As a result, the most frequently isolated types were found as echovirus type 30 (n: 24) and coxsackievirus type B (n: 19), which were most frequently isolated between July to October. This is the first report from Turkey for aseptic meningitis cases due to echovirus type 25 (n:3), 18 (n:2), 14 (n:1), 13 (n:4), 11 (n:6), 9 (n:1), 6 (n:9), 5 (n:1), 4 (n:1) and coxsackievirus type A9 (n:1).

[Sensitivities of various cell cultures for the isolation of enteroviruses]. / Enteroviruslarin izolasyonunda degisik hücre kültürlerinin duyarliliklari.

In the present study, the sensitivities of HEp-2 (human epithelioma), RD (rhabdomyosarcoma) and L20B (mouse cells, that have receptors for human polioviruses) cell cultures have been evaluated and compared, for the isolation and identification of enteroviruses from the stool and cerebrospinal fluid samples of patients with acute flask paralysis and aseptic meningitis, which were examined between the years 1999-2000, in Refik Saydam Institute of Hygiene Center, Virology, Tissue Culture and Enterovirus Laboratory. Of a total of 1663 samples, 131 viral strains were isolated, and 120 of them were identified as enteroviruses, and 11 as adenoviruses. The isolation rates of 48 Sabin-like polioviruses from HEp-2, RD and L20B cell lines were found similar, as 83.3%, 87.5% and 91.6%, respectively. All of 47 Echovirus strains were isolated from RD cells, all of 13 Coxsackie type B strains were isolated from HEp-2 cells, and all of 12 non-polio enteroviruses were isolated from RD cells. All of 11 adenovirus strains that have been grown in Hep-2 cells, were thought to be occasionally isolated due to the passage of viruses to gastrointestinal tract, and excreted via stool, thus having no clinical significance for these patients. As a result, it was concluded that, all of these three cell lines and especially L20B were sensitive for polioviruses, RD cell line being more sensitive for Echovirus, and HEp-2 cell line being more sensitive for Coxsackie type B virus strains.