Zoonotic infections among veterinarians in Turkey: Crimean-Congo hemorrhagic fever and beyond

First Insight into the Prevalence of Coxiella burnetii Infection among Veterinary Medicine Students in Bulgaria

The aim of this study was to assess the prevalence of Coxiella burnetii infection among veterinary medicine students from two Bulgarian Universities, located in Sofia and Stara Zagora. Blood samples were collected from a total of 185 veterinary students for the detection of C. burnetii phase II antibodies and presence of DNA using an enzyme-linked immunosorbent assay (ELISA) and end-point PCR test. Out of all samples, 29.7% were positive for at least one C. burnetii phase II antibody marker or by the result of the PCR test. Veterinary students from Stara Zagora showed a significantly high seropositivity for Q fever (33.6%), as compared to the students in Sofia (23%; p < 0.05). Evidence of recent exposure with detection of anti-C. burnetii phase II IgM (+) antibodies was observed in 14.6% of the students under study. Seroprevalence among students in Stara Zagora was higher (15.3%). Anti-C. burnetii phase II IgG antibodies were detected in 21.6% of examined samples. Our study revealed a higher seropositivity among the male students (32.8%) as compared to females (16.0%; p < 0.05). The end-point PCR assay detected 5.9% blood samples as positive. The relative risk (RR) of Q fever exposure for male students was 40.7%, whereas it was 24.6% in females (p < 0.05). The findings from this study indicate that the C. burnetii infection is widely distributed amongst veterinary students in Bulgaria. This study emphasizes the need for improved safety protocols and infection control measures in veterinary training programs.

Exploring veterinary students' awareness and perception of zoonoses risks, infection control practices, and biosecurity measures in Ethiopia

Universities and colleges are often regarded as playing a key role in educating veterinarians and animal health workers who advise farmers on herd health and animal husbandry. However, to date, studies examining veterinary students' knowledge of zoonotic diseases of public health importance and the source of this knowledge, as well as their preparedness to respond to these diseases, have focused on the Global North rather than the Global South. This study takes Ethiopia as a case study in exploring veterinary medicine students' knowledge of zoonosis risks, infection control practices and biosecurity measures, recognizing that it is imperative to reconcile national-level veterinary education curricula with emerging global trends, such as One Health-focused training. This training advocates for a collaborative, interdisciplinary response at local, national, and international levels to the adverse impact of zoonotic diseases on animal health and productivity, and human and environmental health. Data for this study were collected through a pre-tested online questionnaire administered to 154 veterinary students from several universities in Ethiopia. The findings of this study suggest veterinary students were aware of the public health risks posed by zoonoses and the important role that collaboration between the disciplines of human and animal health can play in addressing zoonoses and emerging health risks. However, students demonstrated poor knowledge of the need to adopt infection control measures (ICPs) and biosecurity measures to reduce occupational risks and prevent within and between herd transmission of infection. Moreover, students' vaccination rates against zoonotic diseases associated with occupational risks, such as rabies, were low. The results of this study suggest that there are currently gaps in Ethiopia's veterinary curriculum and that enhancing veterinary students' access to information regarding infection control practices and biosecurity measures could contribute to reducing their future occupational exposure to zoonoses. This study highlights the policy implications of the current veterinary medicine curriculum in Ethiopia and the scope for aligning the curriculum with important global initiatives, such as One Health-focused training.

Do birds play a role in the transmission of Toscana virus? Initial isolation results from birds in northernmost Türkiye

AIMS

Recent research has prioritized emerging and re-emerging diseases that affect human and animal health, particularly to describe how these diseases enter countries and determine their transmission cycles. Given that migratory birds play a significant role in spreading infections, the present study analysed their migration paths and specimens to investigate Orthoflavivirus, Orthonairovirus, Alphavirus and Phlebovirus in birds in Samsun province, Türkiye.

METHODS AND RESULTS

For these viruses, 312 samples from 56 birds were analysed using RT-PCR and qRT-PCR. Toscana virus (TOSV) was identified in 14 birds (four mallards, five partridges, four quails and one pigeon), representing 25% of the birds sampled. Genotype B was reported in all 14 birds. After inoculating the positive tissues in cell cultures, TOSV was isolated from the organs of pigeons, mallards and partridges.

CONCLUSIONS

This is the first time TOSV has been isolated in cell culture from birds and indicates that they may play a role in spreading TOSV in Türkiye. The results also suggest that TOSV might be carried between countries by migratory birds.

Seroprevalence of Crimean Congo Hemorrhagic Fever Virus in Occupational Settings: Systematic Review and Meta-Analysis

Crimean Congo Hemorrhagic Fever (CCHF) Virus can cause a serious human disease, with the case fatality ratio previously estimated to be 30-40%. Our study summarized seroprevalence data from occupational settings, focusing on the following occupational groups: animal handlers, abattoir workers, farmers, healthcare workers, veterinarians, rangers, and hunters. Systematic research was performed on three databases (PubMed, EMBASE, MedRxiv), and all studies reporting seroprevalence rates (IgG-positive status) for CCHF virus were retrieved and their results were reported, summarized, and compared. We identified a total of 33 articles, including a total of 20,195 samples, i.e., 13,197 workers from index occupational groups and 6998 individuals from the general population. Pooled seroprevalence rates ranged from 4.751% (95% confidence intervals (95% CI) 1.834 to 11.702) among animal handlers, to 3.403% (95% CI 2.44 to 3.932) for farmers, 2.737% (95% CI 0.896 to 8.054) among rangers and hunters, 1.900% (95% CI 0.738 to 4.808) for abattoir workers, and 0.644% (95% CI 0.223-1.849) for healthcare workers, with the lowest estimate found in veterinarians (0.283%, 95% CI 0.040-1.977). Seroprevalence rates for abattoir workers (odds ratio (OR) 4.198, 95% CI 1.060-16.464), animal handlers (OR 2.399, 95% CI 1.318-4.369), and farmers (OR 2.280, 95% CI 1.419 to 3.662) largely exceeded the official notification rates for CCHF in the general population. CCHF is reasonably underreported, and pooled estimates stress the importance of improving the adherence to personal protective equipment use and appropriate preventive habits.

Changing Disease Course of Crimean-Congo Hemorrhagic Fever in Children, Turkey

Crimean-Congo hemorrhagic fever (CCHF), endemic in certain regions of the world, is listed as a priority disease with pandemic potential. Since CCHF was first identified in Turkey, children have been known to experience milder disease than adults. However, during the COVID-19 pandemic, we observed an unusually severe disease course, including hemophagocytic lymphohistiocytosis (HLH). We examined cytokine/chemokine profiles of 9/12 case-patients compared with healthy controls at 3 time intervals. Interferon pathway-related cytokines/chemokines, including interleukin (IL) 18, macrophage inflammatory protein 3α, and IL-33, were elevated, but tumor necrosis factor-α, IL-6, CXCL8 (formerly IL-8), and cytokines acting through C-C chemokine receptor 2 and CCR5 were lower among case-patients than controls. Interferon pathway activation and cytokines/chemokines acting through CCR2 and CCR5 improved health results among children with severe CCHF. Children can experience severe CCHF, including HLH, and HLH secondary to CCHF can be successfully treated with intravenous immunoglobulin and steroid therapy.

Development of a protective inactivated vaccine against Crimean-Congo hemorrhagic fever infection

Crimean-Congo hemorrhagic fever (CCHF) is an emerging zoonotic infectious disease caused by Crimean-Congo hemorrhagic fever virus (CCHFV). The first clinical CCHF infection was described in 1944 in the Crimean Peninsula, exclusively in humans, with case-fatality rates exceeding 30%. The increasing number of cases, high mortality rate, and lack of effective therapy make CCHF a serious threat to public health and a potential bioterrorism agent. The present study evaluated the development, immunogenicity, and immune response durations for cell-culture-derived inactivated vaccine (CCVax) formulations in comparison with those of mouse-brain-derived vaccine (MBVax) formulations. In this study, the Kelkit06 CCHF virus strain was propagated in both suckling mice and Vero E6 cells, and purified with a sucrose gradient. Formalin-inactivated vaccine candidates were formulated at various doses [low dose (LD), 5 μg; medium dose (MD), 10 μg; high dose (HD), 20 μg)] and mixed with an alum adjuvant. BALB/c mice received the same doses of the vaccine formulations three times at 3-week intervals. The humoral endpoint IgG responses were evaluated and compared for the MBVax and CCVax treatments. The duration of the presence of IgG and neutralizing antibody (Ab) titers was evaluated and compared until up to 1 year after immunization. The humoral IgG responses indicated that the CCVax and MBVax candidates enhanced the IgG endpoint titers in a dose-dependent manner, which were induced more strongly in all the CCVax groups than in the MBVax mice. The fold changes in neutralizing Ab levels were also found to be higher in the CCVax groups: between 2- and 7.6-fold after the second week of the last immunization. The neutralization titers peaked 4 months after immunization in all the vaccine-receiving groups, but these were still comparable at the end of the first year. The CCVax formulations induced higher IgG and neutralizing Ab titers at all the measured time points. In this study, we showed that cell-culture-purified and formalin-inactivated vaccine candidates induced strong and robust immunity in vaccinated mice dose-dependently, more so than mouse-brain-derived vaccines.

A Genome-Wide CRISPR-Cas9 Screen Reveals the Requirement of Host Cell Sulfation for Schmallenberg Virus Infection

Schmallenberg virus (SBV) is an insect-transmitted orthobunyavirus that can cause abortions and congenital malformations in the offspring of ruminants. Even though the two viral surface glycoproteins Gn and Gc are involved in host cell entry, the specific cellular receptors of SBV are currently unknown. Using genome-wide CRISPR-Cas9 forward screening, we identified 3'-phosphoadenosine 5'-phosphosulfate (PAPS) transporter 1 (PAPST1) as an essential factor for SBV infection. PAPST1 is a sulfotransferase involved in heparan sulfate proteoglycan synthesis encoded by the solute carrier family 35 member B2 gene (SLC35B2). SBV cell surface attachment and entry were largely reduced upon the knockout of SLC35B2, whereas the reconstitution of SLC35B2 in these cells fully restored their susceptibility to SBV infection. Furthermore, treatment of cells with heparinase diminished infection with SBV, confirming that heparan sulfate plays an important role in cell attachment and entry, although to various degrees, heparan sulfate was also found to be important to initiate infection by two other bunyaviruses, La Crosse virus and Rift Valley fever virus. Thus, PAPST1-triggered synthesis of cell surface heparan sulfate is required for the efficient replication of SBV and other bunyaviruses.IMPORTANCE SBV is a newly emerging orthobunyavirus (family Peribunyaviridae) that has spread rapidly across Europe since 2011, resulting in substantial economic losses in livestock farming. In this study, we performed unbiased genome-wide CRISPR-Cas9 screening and identified PAPST1, a sulfotransferase encoded by SLC35B2, as a host entry factor for SBV. Consistent with its role in the synthesis of heparan sulfate, we show that this activity is required for efficient infection by SBV. A comparable dependency on heparan sulfate was also observed for La Crosse virus and Rift Valley fever virus, highlighting the importance of heparan sulfate for host cell infection by bunyaviruses. Thus, the present work provides crucial insights into virus-host interactions of important animal and human pathogens.

Seroprevalence of Crimean-Congo hemorrhagic fever in humans in the World Health Organization European region: A systematic review

BACKGROUND

Crimean-Congo hemorrhagic fever (CCHF) is an emerging infectious disease caused by a Nairovirus. CCHF is a tick-borne disease that is predominantly associated with Hyalomma ticks and have a widespread distribution in Africa, Asia and Europe. CCHF usually presents as a subclinical disease, but in some cases, it may present as a hemorrhagic fever with a high mortality rate. This systematic review of the literature was performed to identify the available evidence on the prevalence of CCHF in the European Region of the World Health Organization, based on seroprevalence (IgG antibodies).

METHODOLOGY

A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement protocol. PubMed, Embase, and the Web of Science were used for the search (up to January 31, 2019), combining the following MeSH terms: ["Crimean-Congo haemorrhagic fever" OR "Crimean-Congo hemorrhagic fever virus" OR "Congo-Crimea" OR "Crimea-Congo"] AND ["Europe"] AND ["epidemiology" OR "seroprevalence"]. The abstracts were screened. Subsequently, full-text articles were selected and reviewed based on the PICOS (Population-Intervention-Comparison-Outcomes-Study type) criteria by two independent reviewers for inclusion in the final analysis. The data were qualitatively synthesized without quantitative pooling due to the heterogeneity in the study populations and methodologies.

PRINCIPAL FINDINGS

Thirty articles (9 from western Europe, 18 from central Europe and 3 from eastern Europe) were included in the analysis. All articles were cross-sectional studies (descriptive studies).

CONCLUSIONS

The highest seroprevalence of CCHF is found in central and eastern European countries. Southern and western Europe countries, such as Greece and Spain, have low levels of endemicity, but the spread of the infection, which is associated with climate change, is a possibility that we should keep in mind. Further studies, especially larger seroprevalence studies in humans and animals, are needed to establish the current status of the CCHF epidemiology and to generate standardized guidelines for action in the region.

Study on Toxoplasma Gondii, Leptospira Spp., Coxiella Burnetii, and Echinococcus Granulosus Infection in Veterinarians from Poland

Introduction

Exposure to zoonotic factors in veterinary practice is closely related to the nature of the work. The main aim of the study was to determine the risk of selected zoonotic infections among the occupational group of veterinarians in Poland.

Material and Methods

Blood samples of 373 veterinarians (162 males and 211 females) from 12 provinces of Poland were collected by the venipuncture of a forearm for serological tests. Commercial immunoenzymatic tests (ELISA) were used for detection of specific IgG antibodies to Echinococcus granulosus, IgM and IgG to Leptospira spp., and IgM, IgA, and I and II phase IgG to Coxiella burnetii. Enzyme-linked fluorescence assays (ELFA) were used to detect IgM and IgG antibodies to Toxoplasma gondii.

Results

Positive results were found in 209 (56.0%) veterinarians for at least one of the examined diseases. The overall proportion of participants found to have specific Toxoplasma gondii antibodies in the IgM and/or IgG assays amounted to 44.5%. The presence of Coxiella burnetii antibodies was found in 16 (4.3%) subjects, while Leptospira spp. antibodies were detected in 63 (16.9%) veterinarians. Among the 373 veterinarians examined, no Echinococcus granulosus antibodies were found.

Conclusion

Results of the study seem to indicate a slightly elevated risk of Toxoplasma gondii infection and a moderate risk of infection with Leptospira spp. and Coxiella burnetii in veterinarians.

Seroprevalence of Crimean-Congo Hemorrhagic Fever in Turkey's Van Province

Crimean-Congo hemorrhagic fever (CCHF) is an endemic tick-borne viral disease that affects both animals and humans. This study aims to determine the seroprevalence of CCHF in Turkey's Van province using analysis of blood samples obtained from people living in the region. Blood specimens were taken from healthy subjects living in Van province and some of the surrounding villages between January and July 2012. Blood samples were initially tested using a CCHF virus (CCHFV) IgM IgG kit for anti-CCHFV IgG, followed by anti-CCHFV IgM determination of any IgG positive blood samples. IgM-positive specimens were re-confirmed using real-time polymerase chain reaction (qPCR). One hundred and 7 men and 261 women were included in the study. Fifty-three blood specimens (14.4%) were anti-CCHFV IgG positive, and 2 of these were anti-CCHFV IgM positive. Two blood samples with anti-CCHFV IgM seropositivity tested negative using qPCR, indicating chronic infections. Locality, sex, and a history of tick bites did not significantly affect anti-CCHFV IgG seropositivity. Although the incidence of anti-CCHFV IgG in blood specimens was 14.4%, no deaths have yet been reported in Turkey's Van province. It is imperative that clinical CCHFV tests be implemented for people at high risk of developing CCHFV-related complications.

Brucellosis in Occupationally Exposed Groups

INTRODUCTION

In India, high incidence of human brucellosis may be expected, as the conditions conducive for human brucellosis exist. Limited studies have been undertaken on human brucellosis especially in occupationally-exposed groups.

AIM

To estimate prevalence of anti-brucellar antibodies, evaluate the clinical manifestations, risk factors and Knowledge, Attitude and Practices (KAP) levels about brucellosis among occupationally exposed groups.

MATERIALS AND METHODS

Blood samples were collected from 2337 occupationally exposed individuals. The serum samples were screened for the presence of anti-brucellar antibodies by Rose Bengal Plate Test (RBPT), Serum Agglutination Test (SAT) and 2-Mercaptoethanol test (2-ME). Clinical manifestations, risk factors and KAP levels were evaluated by personal interview using a structured questionnaire.

RESULTS

Seroprevalence of brucellosis by RBPT, SAT and 2-ME test was 9.46%, 4.45% and 3.64 % respectively. Clinical symptoms resembling brucellosis were seen in 91 subjects. The major risk factors were animal exposure in veterinarians and abattoirs, both animal exposure and raw milk ingestion in farmers and shepherds, exposure to raw milk and its ingestion in dairy workers and exposure to Brucella culture in laboratory workers. Except laboratory workers, few veterinarians and dairy workers none had heard about brucellosis. KAP levels regarding brucellosis were too poor in all the groups except laboratory workers.

CONCLUSION

Brucellosis most of the times was missed or misdiagnosed. Regular screenings for brucellosis and awareness programmes to increase KAP levels are necessary to control brucellosis in occupationally exposed groups.

Risk factors for occupational brucellosis among veterinary personnel in Turkey

Veterinarians and veterinary technicians are at risk for occupational brucellosis. We described the risk factors of occupational brucellosis among veterinary personnel in Turkey. A multicenter retrospective survey was performed among veterinary personnel who were actively working in the field. Of 712 veterinary personnel, 84 (11.8%) had occupational brucellosis. The median number of years since graduation was 7 (interquartile ranges [IQR], 4-11) years in the occupational brucellosis group, whereas this number was 9 (IQR, 4-16) years in the non-brucellosis group (p<0.001). In multivariable analysis, working in the private sector (odds ratio [OR], 2.8; 95% confidence interval [95% CI], 1.55-5.28, p=0.001), being male (OR, 4.5; 95% CI, 1.05-18.84, p=0.041), number of performed deliveries (OR, 1.01; 95% CI, 1.002-1.02, p=0.014), and injury during Brucella vaccine administration (OR, 5.4; 95% CI, 3.16-9.3, p<0.001) were found to be risk factors for occupational brucellosis. We suggest that all veterinary personnel should be trained on brucellosis and the importance of using personal protective equipment in order to avoid this infection.

Clinical symptoms and laboratory findings supporting early diagnosis of Crimean-Congo hemorrhagic fever in Iran

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic disease, which is usually transmitted to humans by tick bites or contact with blood or other infected tissues of livestock. Patients suffering from CCHF demonstrate an extensive spectrum of clinical symptoms. As it can take considerable time from suspecting the disease in hospital until reaching a definitive diagnosis in the laboratory, understanding the clinical symptoms and laboratory findings of CCHF patients is of paramount importance for clinicians. The data were collected from patients who were referred to the Laboratory of Arboviruses and Viral Hemorrhagic Fevers at the Pasteur institute of Iran with a primary diagnosis of CCHF between 1999 and 2012 and were assessed by molecular and serologic tests. Referred patients were divided into two groups: patients with a CCHF positive result and patients with a CCHF negative result. The laboratory and clinical findings of these two groups were then compared. Two-thousand five hundred thirty-six probable cases of CCHF were referred to the laboratory, of which 871 cases (34.3%) were confirmed to be CCHF. Contact with infected humans and animals increased the CCHF infection risk (P < 0.001). A tick bite was not a risk factor. Fever; bleeding, vomiting, leucopoenia, thrombocytopenia, and increases in alanine transaminase (ALT) and aspartate transaminase (AST) levels were also indicative of CCHF infection. Accurate and speedy diagnosis of CCHF and appropriate treatment play an important role in patient survival and the application of the findings of this study can prove helpful as a key for early diagnosis.

Crimean-Congo hemorrhagic fever: seroprevalence and risk factors among humans in Achaia, western Greece

BACKGROUND

The Crimean-Congo hemorrhagic fever virus (CCHFV) presents a wide distribution, with the Balkan Peninsula being among the endemic regions. To date, only one CCHF case has been reported in Greece; however, based on seroprevalence data, there is evidence that CCHFV circulates in the country. Achaia is a prefecture in western Greece that has not previously been studied for CCHFV.

OBJECTIVES

The aim of this study was to estimate the seroprevalence of CCHFV in humans in Achaia Prefecture, Greece, and to assess possible factors playing a role in seropositivity.

METHODS

A total of 207 serum samples from people of all age groups, from both urban and rural areas, were prospectively collected and tested for IgG antibodies against CCHFV.

RESULTS

The overall seroprevalence was 3.4%, with significant differences among municipalities. An agro-pastoral occupation, contact with sheep and goats, former tick bite, increasing age, and living at an altitude of ≥400 m, on specific land cover types, were significantly associated with CCHFV seropositivity.

CONCLUSIONS

A relatively high seroprevalence was detected in a previously unstudied region of Greece, where CCHFV infection seems to occur mainly through tick bites. Further investigations are needed to identify the circulating CCHFV strains in Greece, in order to gain a better understanding of CCHFV ecology and epidemiology in the country.

Crimean-Congo hemorrhagic fever: history, epidemiology, pathogenesis, clinical syndrome and genetic diversity

Crimean-Congo hemorrhagic fever (CCHF) is the most important tick-borne viral disease of humans, causing sporadic cases or outbreaks of severe illness across a huge geographic area, from western China to the Middle East and southeastern Europe and throughout most of Africa. CCHFV is maintained in vertical and horizontal transmission cycles involving ixodid ticks and a variety of wild and domestic vertebrates, which do not show signs of illness. The virus circulates in a number of tick genera, but Hyalomma ticks are the principal source of human infection, probably because both immature and adult forms actively seek hosts for the blood meals required at each stage of maturation. CCHF occurs most frequently among agricultural workers following the bite of an infected tick, and to a lesser extent among slaughterhouse workers exposed to the blood and tissues of infected livestock and medical personnel through contact with the body fluids of infected patients. CCHFV is the most genetically diverse of the arboviruses, with nucleotide sequence differences among isolates ranging from 20% for the viral S segment to 31% for the M segment. Viruses with diverse sequences can be found within the same geographic area, while closely related viruses have been isolated in far distant regions, suggesting that widespread dispersion of CCHFV has occurred at times in the past, possibly by ticks carried on migratory birds or through the international livestock trade. Reassortment among genome segments during co-infection of ticks or vertebrates appears to have played an important role in generating diversity, and represents a potential future source of novel viruses. In this article, we first review current knowledge of CCHFV, summarizing its molecular biology, maintenance and transmission, epidemiology and geographic range. We also include an extensive discussion of CCHFV genetic diversity, including maps of the range of the virus with superimposed phylogenetic trees. We then review the features of CCHF, including the clinical syndrome, diagnosis, treatment, pathogenesis, vaccine development and laboratory animal models of CCHF. The paper ends with a discussion of the possible future geographic range of the virus. For the benefit of researchers, we include a Supplementary Table listing all published reports of CCHF cases and outbreaks in the English-language literature, plus some principal articles in other languages, with total case numbers, case fatality rates and all CCHFV strains on GenBank.

Presence of antibodies against genogroup VI norovirus in humans

Background

Noroviruses are important enteric pathogens in humans and animals. Recently, we reported a novel canine norovirus (CaNoV) in dogs with diarrhea belonging to a new genogroup (GVI). No data are available on exposure of humans to this virus.

Methods

Sera from 373 small animal veterinarians and 120 age-matched population controls were tested for IgG antibodies to CaNoV by a recombinant virus like particle based enzyme-linked immunosorbent assay.

Results

Antibodies to CaNoV were found in 22.3% of the veterinarians and 5.8% of the control group (p < 0.001). Mean corrected OD₄₅₀ values for CaNoV antibodies were significantly higher in small animal veterinarians compared to the control group.

Conclusions

These findings suggest that CaNoV may infect humans and small animal veterinarians are at an increased risk for exposure to this virus. Additional studies are needed to assess if this virus is able to cause disease in humans.

The seroprevalance of Crimean-Congo haemorrhagic fever in people living in the same environment with Crimean-Congo haemorrhagic fever patients in an endemic region in Turkey

Crimean-Congo haemorrhagic fever (CCHF) is endemic in Turkey, and since 2004 many cases have been reported from different regions of Turkey. There are limited data about the seroprevalence of the disease in household members of patients or persons sharing the same environment. We evaluated seroprevalence of CCHF in the immediate neighbourhood and in household members of patients living in the same environment as confirmed cases of CCHF in an endemic area of Turkey. A total of 625 healthy subjects [mean (s.d.) age: 42·3 (18·4) years, 58·7% females] without a past history of CCHF infection included in this case-control, retrospective study were evaluated in terms of sociodemographic characteristics, risk factors for CCHF via a study questionnaire, while serum analysis for CCHF virus (CCHFV) IgG antibodies was performed by ELISA. Anti-CCHFV IgG antibodies were positive in 85 (13·6%) participants. None of the seropositive individuals had a history of symptomatic infection. Regression analysis revealed that animal husbandry [odds ratio (OR) 1·84, 95% confidence interval (CI) 1·09-3·11], contact with animals (OR 2·31, 95% CI 1·08-5·10), contact with ticks (OR 3·45, 95% CI 1·87-6·46), removing ticks from animals by hand (OR 2·48, 95% CI 1·48-4·18) and living in a rural area (OR 4·05, 95% CI 1·65-10·56) were associated with increased odds of having IgG seropositivity, while being a household member of a patient with prior CCHF infection had no influence on seropositivity rates. This result also supports the idea that CCHF is not transmitted person-to-person by the airborne route.

Lethal Crimean-Congo hemorrhagic fever virus infection in interferon α/β receptor knockout mice is associated with high viral loads, proinflammatory responses, and coagulopathy

Crimean-Congo hemorrhagic fever (CCHF) is a widely distributed viral hemorrhagic fever characterized by rapid onset of flu-like symptoms often followed by hemorrhagic manifestations. CCHF virus (CCHFV), a bunyavirus in the Nairovirus genus, is capable of infecting a wide range of mammalian hosts in nature but so far only causes disease in humans. Recently, immunocompromised mice have been reported as CCHF disease models, but detailed characterization is lacking. Here, we closely followed infection and disease progression in CCHFV-infected interferon α/β receptor knockout (IFNAR(-/-)) mice and age-matched wild-type (WT) mice. WT mice quickly clear CCHFV without developing any disease signs. In contrast, CCHFV infected IFNAR(-/-) mice develop an acute fulminant disease with high viral loads leading to organ pathology (liver and lymphoid tissues), marked proinflammatory host responses, severe thrombocytopenia, coagulopathy, and death. Disease progression closely mimics hallmarks of human CCHF disease, making IFNAR(-/-) mice an excellent choice to assess medical countermeasures.

Seroepidemiological survey for Coxiella burnetii antibodies and associated risk factors in Dutch livestock veterinarians

Since 2007, Q fever has become a major public health problem in the Netherlands and goats were the most likely source of the human outbreaks in 2007, 2008 and 2009. Little was known about the consequences of these outbreaks for those professional care providers directly involved. The aim of this survey was to estimate the seroprevalence of antibodies against C. burnetii among Dutch livestock veterinarians and to determine possible risk factors. Single blood samples from 189 veterinarians, including veterinary students in their final year, were collected at a veterinary conference and a questionnaire was filled in by each participant. The blood samples were screened for IgG antibodies against phase I and phase II antigen of C. burnetii using an indirect immunofluorescent assay, and for IgM antibodies using an ELISA. Antibodies against C. burnetii were detected in 123 (65.1%) out of 189 veterinarians. Independent risk factors associated with seropositivity were number of hours with animal contact per week, number of years graduated as veterinarian, rural or sub urban living area, being a practicing veterinarian, and occupational contact with swine. Livestock veterinarians should be aware of this risk to acquire an infection with C. burnetii. Physicians should consider potential infection with C. burnetii when treating occupational risk groups, bearing in mind that the burden of disease among veterinarians remains uncertain. Vaccination of occupational risk groups should be debated.

Epidemiological survey of Crimean-Congo hemorrhagic fever virus in Yunnan, China, 2008

OBJECTIVES

We aimed to determine the seroprevalence of Crimean-Congo hemorrhagic fever virus (CCHFV) infection in Yunnan Province, China.

MATERIALS AND METHODS

One thousand six hundred and fifty-seven human serum samples and 1280 ticks (Hyalomma asiaticum) were collected from five counties (Menglian, Menghai, Lancang, Mengla, and Ximeng). Serum samples were analyzed independently by indirect immunofluorescence assay and Western blotting to detected CCHFV antibody. The ticks were examined by reverse transcriptase-polymerase chain reaction (RT-PCR) to detect virus RNA.

RESULTS

The CCHFV IgG positivity was 3.4% (57/1657). A multivariate analysis was performed, and variables that increased the chance of infection were found to include history of tick bite or contact (odds ratio (OR) 16.6, 95% confidence interval (CI) 7.5-37.0) and age>30 years (OR 6.8, 95% CI 1.6-28.2). The RT-PCR positive rate for ticks was 14.3% (6/42).

CONCLUSIONS

The five counties (Menglian, Menghai, Lancang, Mengla, and Ximeng) in Yunnan are areas with the potential for CCHF outbreaks. Residents should protect themselves against tick bites and the surveillance of CCHFV in this region should be improved.

Seroprevalence of Q fever in a district located in the west Black Sea region of Turkey

Q fever is a worldwide zoonosis caused by Coxiella burnetii. In Turkey, it has been reported from the late 1940s that Q fever is endemic in humans and animals. Our objective was to evaluate the seroprevalence in Samsun Tekkeköy (north Turkey), where an outbreak of Q fever occurred in 2002. In this cross-sectional study, subjects were selected by the random proportional sampling method. All subjects were healthy with no specific symptoms and tested by the microimmunofluorescent antibody test. In total, we tested 407 subjects; 33 (8.1%) of them were identified as past evidence of infection and 22 (5.4%) were considered as evolutive form of Q fever (17 acute and five chronic forms). The seroprevalence was significantly higher among people over 30 years of age, hunters, and slaughters than the others (p = 0.001, p = 0.034, and p = 0.006, respectively). We found 13.5% seropositivity among healthy subjects, confirming that Q fever is prevalent in our region and is often asymptomatic.

A review of published reports regarding zoonotic pathogen infection in veterinarians

OBJECTIVE

To identify published reports regarding zoonotic pathogen infection among veterinarians.

DESIGN

Literature review.

PROCEDURES

The PubMed electronic database of medical literature published between 1966 and November 2007 was searched. Clinical case reports and reports of outbreak investigations were also identified through searches of the literature outside of PubMed and searches of references listed in included articles. Reports eligible for inclusion included controlled and uncontrolled studies examining seroprevalence of animal pathogens in veterinarians, serosurveys involving veterinarians, and reports of zoonotic pathogen infections causing clinical illness.

RESULTS

66 relevant articles were identified. This included 44 seroepidemiologic studies (some examined > 1 pathogen), 12 case reports, 3 outbreak investigations, and 7 self-reported surveys (including 4 related to personal protective equipment use). Of the 44 seroepidemiologic studies, 37 (84%) identified an increased risk of zoonotic pathogen infection among veterinarians, and 7 (16%) identified no increased risk or a decreased risk. Surveys also documented that veterinarians often failed to use recommended personal protective equipment.

CONCLUSIONS AND CLINICAL RELEVANCE

Our review indicated that veterinarians had an increased risk of infection with a number of zoonotic pathogens. It also suggested that veterinarians may inadvertently serve as biological sentinels for emerging pathogens and could potentially spread zoonotic pathogens to their families, community members, and the animals for which they provide care. Professional and policy measures should be implemented to reduce the risk that veterinarians will become infected with, or transmit, zoonotic pathogens.

Crimean-Congo hemorrhagic fever virus in high-risk population, Turkey

In the Tokat and Sivas provinces of Turkey, the overall Crimean-Congo hemorrhagic fever virus (CCHFV) seroprevalence was 12.8% among 782 members of a high-risk population. CCHFV seroprevalence was associated with history of tick bite or tick removal from animals, employment in animal husbandry or farming, and being >40 years of age.

Crimean-Congo hemorrhagic fever: five patients with hemophagocytic syndrome

Three pediatric and two adult Turkish patients with Crimean Congo Hemorrhagic Fever (CCHF) induced hemophagocytic syndrome (HPS) were admitted to Ondokuz Mayis University Hospital, which is in the Middle Black Sea Region of Turkey. All of them had remarkable hemophagocytosis in the bone marrow with severe bleeding symptoms along with the other known clinical and laboratory findings of CCHF. We would like to present these patients and to discuss the pathophysiology and the effect of acquired HPS on the severity of the disease.

Crimean-Congo hemorrhagic fever

PURPOSE OF REVIEW

Crimean-Congo hemorrhagic fever is a tick-borne viral zoonosis with the potential of human-to-human transmission, affecting wide areas in Asia, Southeastern Europe, and Africa. Hemorrhagic manifestations constitute a prominent symptom of late stage disease with case fatality rates from 10% to 50%. The purpose of this article is to review recent literature on Crimean-Congo hemorrhagic fever with emphasis on its epidemiology and management.

RECENT FINDINGS

Climate and environmental changes may affect Crimean-Congo hemorrhagic fever epidemiology and trigger community outbreaks. Risk factors for acquisition of infection have been well studied. In the hospital, high-risk activities include interventions for gastrointestinal bleeding and needle stick injuries. Reverse transcription-polymerase chain reaction may rapidly diagnose Crimean-Congo hemorrhagic fever with high sensitivity and specificity. Ribavirin is the only promising therapeutic agent currently available but case-control studies have not been conducted. Recently, the Mx proteins have been found to act against Crimean-Congo hemorrhagic fever virus and deserve further research.

SUMMARY

Clinicians should be aware of the potential of importation of Crimean-Congo hemorrhagic fever cases from endemic areas and nosocomial transmission. Studies on the efficacy of ribavirin are needed.