The geographic distribution of cases of Crimean-Congo hemorrhagic fever: Kastamonu, Turkey

Crimean-Congo Hemorrhagic Fever, Spain, 2013-2021

Crimean-Congo hemorrhagic fever (CCHF) is a viral infectious disease for which distribution of the main vector, Hyalomma spp. ticks, is expanding. We analyzed all 10 cases of CCHF diagnosed in Spain during 2013-2021; case-patient median age was 56.5 years, and 7 were men. We identified CCHF virus genotypes III and V. Six case-patients acquired the infection in urban areas. Sixty percent of patients were infected in summer and 40% in spring. Two patients met criteria for hemophagocytic syndrome. Seven patients survived. The epidemiologic pattern of CCHF in Spain is based on occasional cases with an elevated mortality rate. Genotype III and, to a less extent also genotype V, CCHF circulates in humans in a common geographic area in Spain. Those data suggest that the expansion pathways are complex and may change over time. Physicians should remain alert to the possibility of new CCHF cases.

Risk factors associated with sustained circulation of six zoonotic arboviruses: a systematic review for selection of surveillance sites in non-endemic areas

Arboviruses represent a significant burden to public health and local economies due to their ability to cause unpredictable and widespread epidemics. To maximize early detection of arbovirus emergence in non-endemic areas, surveillance efforts should target areas where circulation is most likely. However, identifying such hotspots of potential emergence is a major challenge. The ecological conditions leading to arbovirus outbreaks are shaped by complex interactions between the virus, its vertebrate hosts, arthropod vector, and abiotic environment that are often poorly understood. Here, we systematically review the ecological risk factors associated with the circulation of six arboviruses that are of considerable concern to northwestern Europe. These include three mosquito-borne viruses (Japanese encephalitis virus, West Nile virus, Rift Valley fever virus) and three tick-borne viruses (Crimean-Congo hemorrhagic fever virus, tick-borne encephalitis virus, and louping-ill virus). We consider both intrinsic (e.g. vector and reservoir host competence) and extrinsic (e.g. temperature, precipitation, host densities, land use) risk factors, identify current knowledge gaps, and discuss future directions. Our systematic review provides baseline information for the identification of regions and habitats that have suitable ecological conditions for endemic circulation, and therefore may be used to target early warning surveillance programs aimed at detecting multi-virus and/or arbovirus emergence.

Evaluation of Crimean-Congo hemorrhagic fever suspected cases admitted to a secondary care hospital in Kastamonu, Turkey between 2014-2017

Background

Crimean-Congo hemorrhagic fever (CCHF) is an endemic zoonosis in Kastamonu, Turkey. Clinical and laboratory findings may not be specific in the early phase of the disease, hence bringing a challenge to the clinician.

Objective

We aimed to distinguish CCHF cases among all suspected cases by comparing them with non-CCHF cases with respect to characteristics during admission.

Methods

Cases with a presumptive diagnosis of CCHF at a secondary care hospital in Kastamonu in between 2014–2017 were evaluated, retrospectively. CCHF and non-CCHF cases were compared with respect to their clinical, laboratory and epidemiological characteristics during admission.

Results

Among 76 suspected patients, CCHF was found in 46.1% of them. Four-year fatality rate was 9.6% in CCHF cases. The frequency of headache, nausea/vomiting, leukopenia, thrombocytopenia less than 50x109/L, AST-ALT and LDH elevation, tick bites and contact with blood or body fluids of animals in CCHF cases were significantly higher than in non-CCHF cases (p<0.05).

Conclusion

Headache and nausea/vomiting accompanied with leukopenia, thrombocytopenia less than 50x109/L, AST-ALT and LDH elevations raise the possibility of CCHF in endemic regions especially when there is a history of tick bite and contact with blood or body fluids of animals.

Endemic and emerging arboviral diseases of livestock in Nigeria: a review

Arthropod-borne viruses (arboviruses) are the largest biologic group of vertebrate viruses and constitute important emerging infectious disease agents globally. Arthropod transmission provides a way for viruses to cross species barriers since the same arthropod may bite animals that rarely or never come into close contact in nature. In Nigeria, arboviruses have, over several decades, caused severe diseases in livestock resulting in great economic losses and, sometimes, infection of humans leading to morbidity and mortality. In the present review, a computerized search of existing literature was conducted using the Google search engine and PubMed electronic database to identify and review relevant publications on arboviral diseases of livestock in Nigeria. The keywords used were 'arbovirus', 'arthropod-borne viral diseases' or 'livestock diseases' and 'Nigeria' while the Boolean operator 'OR' was used to combine and narrow the searches. Additional information was obtained by searching the veterinary libraries for journals not listed in the database. The available publications were thereafter reviewed and findings qualitatively described. Our findings revealed that although there were several studies on arboviruses and the livestock diseases they cause in Nigeria, most of such reports were made four to six decades ago, with only a few reported recently. Consequently, the true economic and public health impact of these diseases are likely to be underestimated, mainly due to under-reporting or lack of awareness of them. Thus, it is essential to update information on arboviral diseases in Nigeria in order to increase awareness of the diseases and facilitate their prompt identification and reporting. The importance of routine surveillance for arbovirus livestock diseases and sentinel herd monitoring as basis for development of an early warning and alert system to prevent future outbreaks is discussed.

Spatial cluster analysis of Crimean-Congo hemorrhagic fever virus seroprevalence in humans, Greece

Crimean-Congo hemorrhagic fever (CCHF) is a viral disease transmitted to humans by bite of infected ticks or by direct contact with blood or tissues of viremic patients or livestock. The present cross-sectional meta-analysis study is based on previous data which have shown that the human CCHFV seroprevalence in specific regions of Greece is high (> 5%). In the absence of human cases, it has been suggested that a non- or low-pathogenic strain is circulating in the country causing asymptomatic infections. A spatial cluster analysis was performed to assess the geographical variations in CCHFV seropositivity and to identify the risk factors. The overall CCHFV seroprevalence is 3.8%, with significant rate difference between the eastern and western part of the country. Apart the risk factors described in previous studies (age, sex, tick bite, agropastoral activities), the altitude, the land cover type and the transitional woodland/shrub land per person, as well as the number of livestock per person, and specifically the number of goats, sheep and cattle per person, were shown to affect significantly the seroprevalence. Tick studies are needed to identify the circulating strains and unravel the mystery of CCHF epidemiology in Greece.

Various clinical conditions can mimic Crimean-Congo hemorrhagic fever in pediatric patients in endemic regions

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease with high mortality. Many disorders can mimic CCHF. It is important to recognize the condition and to perform differential diagnosis in endemic countries. Twenty-one children aged 18 years or less with a preliminary diagnosis of CCHF were retrospectively evaluated. Real-time PCR and a confirmatory indirect immunofluorescence assay for negative results were performed. The diagnoses determined that 9 patients had (42.9%) CCHF; 7 patients had (33.3%) viral upper respiratory tract infections (URTI); 2 patients had (9.5%) brucellosis; 1 patients had (4.7%) periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome episode; 1 patient had (4.7%) cerebral palsy, diabetes insipidus, acute gastroenteritis, and hypernatremic dehydration; and 1 patient had (4.7%) cellulitis after a tick bite. The mean age of patients with CCHF was greater than that of the other patients (116.1±53.6 vs. 94.1±52.1 months, p=0.02). Seventeen (81%) of the children included had a history of tick bites, 2 (9.5%) had a history of contact with a patient with CCHF, and 2 (9.5%) had no exposure, but were living in an endemic region. Three patients had an underlying disorder: cerebral palsy and diabetes insipidus, epilepsy, or PFAPA. All of the children experienced fever. Other frequent symptoms were malaise, diarrhea, vomiting, and abdominal pain, but none of these differed statistically between the patient groups. CCHF patients had a longer mean duration of symptoms (10.56±1.42 vs. 6.75±3.62 days, p=0.008) and a longer mean length of hospitalization (8.00±2.08 vs. 3.58±1.56 days, p<0.001) than the other patients. At laboratory examination, patients with CCHF had statistically significant lower leukocyte and platelet counts, more prolonged coagulation parameters, and greater AST, ALT, LDH, and CK levels than the other patients. No mortality or complications occurred in the study. Both infectious causes, such as URTI, cellulitis, and brucellosis, and non-infectious causes may resemble CCHF. Although they are not pathognomonic, some indicators, including a longer symptom duration and hospitalization, cytopenia, elevated liver enzymes, creatine kinase and prolonged coagulation parameters, were found to be in favor of CCHF.

Crimean-Congo hemorrhagic fever in Turkey: Current status and future challenges

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease of humans that affects a wide geographic area of Africa and Eurasia, including Turkey, Iran, Pakistan, Afghanistan and Russia. Since the first detection of CCHF cases in Turkey in 2002, more than 9700 patients have been reported, with an overall mortality rate just under 5%. This article assesses the present epidemiological situation of CCHF in Turkey, with an updated literature review, describes national practices and summarizes lessons learned in preparation for future outbreaks.