Aykut Özkul

Prevalence, Distribution, and Host Range of Peste des petits ruminants virus, Turkey

Peste des petits ruminants virus (PPRV, genus Morbillivirus), which causes a severe disease in sheep and goats, has only recently been officially declared to be present in Turkey. We carried out a study to determine the prevalence, distribution, and host range of PPRV in Turkey. A total of 1,607 animals, reared in 18 different locations, were monitored for the presence of antibodies to PPRV and the related virus of large ruminants, Rinderpest virus (RPV). Only two farms had animals that were free of antibody responses to either disease. Prevalence for PPRV infection varied (range 0.87%–82.6%) and was higher in sheep (29.2%) than in goats (20%). The overall antibody responses to PPRV and RPV were 22.4% and 6.28%, respectively. Two PPRVs of lineage 4, which comprises many other PPRVs whose origins are in the Middle East, the Arabian Peninsula, and southern Asia, were isolated from Turkish sheep.

Bone generation on PHBV matrices: an in vitro study

Bone formation was investigated in vitro by culturing rat marrow stromal osteoblasts in biodegradable, macroporous poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) matrices over a period of 60 days. Foams were prepared after solvent evaporation and solute leaching. PHBV solutions with different concentrations were prepared in chloroform: dichloromethane (1:2, v/v). In order to create a matrix with high porosity and uniform pore sizes, sieved sucrose crystals (300-500 microm) were used. PHBV foams were treated with rf-oxygen plasma (100 W 10 min) to modify their surface chemistry and hydrophilicity with the aim of increasing the reattachment of osteoblasts. Osteoblasts were isolated from rat bone marrow and seeded onto PHBV foams. The cell density on and in the foams was determined with MTS assay. MTS results showed that osteoblasts proliferated on PHBV. Twenty-one days after seeding of incubation, growth of osteoblasts on matrices and initiation of mineralization were observed by confocal laser scanning microscopy. Increasing ALP and osteocalcin secretion during 60 days confirmed the osteoblastic phenotype of the derived stromal cells. SEM, histological evaluations and confocal laser scanning microscopy showed that osteoblasts could grow inside the matrices and lead to mineralization. Cells exhibited spindle-like morphology and had a diameter of 10-30 microm. Based on these, it could confidently be stated that PHBV seems to be a promising polymeric matrix material for bone tissue engineering.

The impact of Crimean-Congo hemorrhagic fever virus on public health.

Climatic, environmental and economic changes, as well as the steadily increasing global trade and personal mobility provide ample opportunities for emerging pathogens with zoonotic potential to spread to previously unaffected countries. Crimean-Congo hemorrhagic fever virus (CCHFV) is considered to be one of the major emerging disease threats spreading to and within the European Union following an expanding distribution of its main vector, ticks of the genus Hyalomma. Every year more than 1000 human CCHF cases are reported from countries of southeastern Europe and Turkey. CCHFV can cause high case fatality rates and can be transmitted from human to human. There are no vaccine prophylaxis and therapeutic interventions available at present. Several EU-funded research projects focus currently on CCHFV which highlights the awareness for this problem at the European level. As public health deals with questions of prevention on a population level rather than healing and health on an individual level, the analysis of existing data plays a fundamental role to minimize its epidemic potential, by reducing infection risks, and to manage disease outbreaks. This review gives a summary of the current knowledge and data with focus at the interface between public health and CCHFV. Based on this knowledge, guidelines for the risk classification of a region and for outbreak prevention are given. This review will assist decision makers and public health authorities in understanding risk scenarios and in deciding on effective countermeasures, as well as human and veterinary scientists by highlighting existing gaps in knowledge.

A viral infection of the hand commonly seen after the feast of sacrifice: human orf (orf of the hand).

Orf of the hand is an uncommon zoonotic infection caused by a dermotropic DNA virus that belongs to the Parapoxvirus genus of the family Poxviridae. It is transmitted to humans through contact with infected sheep and goats and is reported as an occupational disease. We report nine cases of human orf seen in the hands of individuals, who were not occupationally exposed, after the feast of sacrifice in Turkey. Three cases were teachers and six out of the nine were housewives. We observed musculoskeletal complications and misdiagnoses. It is important to consider human orf in the differential diagnosis of hand lesions to prevent overtreatment and complications.

Molecular epidemiology of Crimean-Congo hemorrhagic fever virus in Turkey: Occurrence of local topotype

The goal of this study was to investigate the molecular epidemiology of Crimean-Congo hemorrhagic fever virus (CCHFV) in Turkey. The study was performed on a total of 48 confirmed human CCHF cases from 2006 to 2008. The majority of the CCHF viral strains in Turkey were found to belong to the European lineage. Local CCHF viral strains are grouped into two main clusters, which can be further divided into two sub-groups. We also identified an AP92-like virus causing clinical disease in Corum (a mid-Anatolian province). Phylogenetic analysis revealed that the most recent CCHFV infections were caused by intrinsic (or native) CCHF viral strains, which we identified as the local topotype. Comparison of deduced amino acid sequences of S-segment RNAs indicated that the local topotype was derived from viruses of previous years, most likely by a low rate recombination. No genetic differences, based on S- and M-segment RNA sequences, were found between human and tick viral isolates. This data suggest that replication of CCHFV in the tick vector, whether Rhiphicephalus spp. or Hyalomma spp., has no effect on the viral genomic structure.

Serological evidence of West Nile Virus (WNV) in mammalian species in Turkey

In this study, the sera collected from a variety of mammalian species (ass-mules, cat, cattle, dog, horse, human and sheep) in 10 representative provinces of Turkey, were surveyed for the presence of neutralizing antibodies to West Nile virus (WNV). Overall, 1 of 40 (2.5%) ass-mules, 4 of 100 (4%) cattle, 43 of 114 (37.7%) dogs, 35 of 259 (13.5%) horses, 18 of 88 (20.4%) humans and 1 of 100 (1%) sheep, tested positive for WNV-neutralizing antibodies. The results indicate that a wide range of mammals are exposed to a West Nile-related virus and this could contribute to the long-term survival of this virus in the absence of overt disease.

Natural Peste des Petits Ruminants Virus Infection: Novel Pathologic Findings Resembling Other Morbillivirus Infections

The present study describes pathologic and virologic findings in 15 sheep and 6 goats that died of natural peste des petits ruminants virus infection in Turkey. Pathologic findings included erosiveulcerative stomatitis, fibrino-necrotic tracheitis, bronchointerstitial pneumonia, multifocal coagulation necroses in the liver, and severe lymphocytolysis in lymphoid tissues. Syncytial cells were conspicuous, especially in the oral mucosa, pulmonary alveoli, liver, and lymphoid tissues. In addition to the typical tissue distribution, eosinophilic intracytoplasmic and/or intranuclear inclusions were observed in epithelial cells lining the renal pelvis and abomasal mucosa. Immunolabeling of the viral antigen was observed in the kidney, brain, rumen, abomasum, heart, and myocytes of the tongue besides its more typical locations. In this study, we report and describe in detail the first peste des petits ruminants endemic in Kirikkale Province, Central Anatolia of Turkey. In conclusion, these previously unreported pathologic findings in natural peste des petits ruminants virus infection establish a basis for resemblance to other morbillivirus infections, such as canine distemper and distemper of sea mammals. Reverse transcriptase-polymerase chain reaction analyses indicated that the 448-bp genome fragment was amplified in 18 cases (18/21, 85.7%). Phylogenetic analysis showed that viruses belong to lineage 4 in the peste des petits ruminants virus common phylogenetic tree.

Current Status of Human Arboviral Diseases in Turkey

Infections caused by viruses transmitted via blood-feeding arthropods (arthropod-borne or arboviruses) have gained considerable attention and importance during the last decades due to their resurgence, impact on public health, and changing epidemiologic features. The complex transmission cycles affected by environmental, technological, and ecological changes place arboviral infections in the realm of emerging and reemerging infections that intermittantly reappear in epidemic form or display tendency to extend beyond endemic zones. A number of previously undetected arboviral diseases have emerged in Turkey during the last decade, although, in some cases, serologic evidence has been provided earlier. Since Crimean-Congo hemorrhagic fever first emerged in Turkey in 2002, there are now more than 4400 laboratory-confirmed cases of the disease. In addition, convincing evidence has accumulated to suggest that pathogenic flaviviruses, including West Nile virus, are in circulation. Recent studies have also revealed human exposure, central nervous system infections, and outbreaks of febrile diseases by sandfly fever viruses. In this study, reports published in local and international journals on surveillance and epidemiology of medically important arboviruses and associated diseases from Turkey have been reviewed, and current data on tick, mosquito, and sandfly vectors are incorporated.

Chitosan based delivery systems for mucosal immunization against bovine herpesvirus 1 (BHV-1)

Bovine herpesvirus 1 (BHV-1), is a major pathogen of cattle which causes serious infections, including infectious bovine rhinotracheitis (IBR)/infectious pustular vulvovaginitis (IPV). At present, BHV-1 is still a serious threat to animal health and productivity in Turkey, hence to develop a more efficient and economical vaccine system against BHV-1 is certainly an important necessity. A mucosal vaccination strategy would provide both mucosal and systemic immune responses to protect disease progression and transmission. However, vaccination through mucosal membranes requires adjuvants/delivery systems in order to enhance the immunogenicity of the antigens. Chitosan, which is a biodegradable, biocompatible and bioadhesive natural polysaccharide, has been shown to be promising both as a delivery system and an adjuvant for mucosal vaccination. In this study, microparticles with appropriate size (<10μm), positive surface charge and high loading efficiency (∼95%) were prepared for mucosal delivery of BHV-1, using various types of chitosan with different molecular weight and solubility. Particles were shown to be taken up by the cells, mostly around the nucleus, whereas with aggregates which were bigger in size were adsorbed at the surface. Furthermore, gel formulations with a suitable viscosity which would provide easy application and remain on the mucosa for extended period of time were also developed with a high zeta potential indicating a stable system. Both the BHV-1 loaded microparticle and gel formulations were shown to maintain cell viability and antigen integrity. Chitosan-based formulations are suggested as promising adjuvant/delivery systems for mucosal immunization against BHV-1.

Distribution of G (VP7) and P (VP4) genotypes of group A bovine rotaviruses from Turkish calves with diarrhea, 1997-2008.

Group A rotaviruses are major enteric pathogens of calves. In order to investigate the genetic diversity of bovine rotaviruses (BRVs), a collection of 53 BRVs, detected from diarrheic calves from several Turkish geographical areas, between 1997 and 2008 was analyzed by RT-PCR for specificities of the outer capsid proteins VP7 (G type) and VP4 (P type), for the first time. Overall, G6 was the predominant G type, detected in 40/53 samples (75.4%), while P[11] was the predominant P type, detected in 52/53 samples (98.1%). The most common VP7/VP4 combinations were G6P[11] (60.3%) and G10P[11] (24.5%). Mixed infections were identified in 7/53 samples (13.2%). In the VP7 region the G6P[11] viruses were similar to other ones detected worldwide, forming an independent G6 lineage, distantly related to the G6 gene of the vaccine G6P[1] strain NCDV (90.1% amino acid identity), and suggesting that G6P[11] viruses represent a genetically stable BRV strain. The study of G and P type diversity is pivotal to understand the efficacy of the existing rotavirus vaccines and to provide the basis of future prophylaxis tools against rotaviral diarrhea of calves.