Incidence Of Crimean-Congo Hemorrhagic Fever Research Articles

Epidemiologic Features and Risk Factors for Crimean-Congo Hemorrhagic Fever in Dhi Qar Province, Iraq.

Crimean-Congo hemorrhagic fever virus (CCHFV) is endemic in Iraq, where recurrent epidemics have been constantly observed during the last five years. The present study aimed to determine the factors associated with Crimean-Congo hemorrhagic fever (CCHF) cases in Dhi Qar province during the year 2022. A test-negative case-control design was used to analyze 621 CCHF patients, of which 162 were confirmed and 459 were suspected cases. To identify the confirmed and suspected cases, reverse transcriptase polymerase chain reaction (RT-PCR) was used. Suspected patients whose PCR test results were negative were selected as the control group. Data on potential risk factors for CCHF were collected as existing data for previous years for the same geographical locations in Dhi Qar province. Logistic regression analyses were used to determine the correlation between probable risk factors and confirmed CCHF cases. The incidence rate of CCHF was 6.8% per 100,000 people. The total number of deaths was 48 for patients with a case fatality rate of 7.7%. The patients' ages ranged from one year to 65 years, with an overall mean ± SD of 36.08 ± 18.29 years. A total of 98.2% of the patients were between 15 and 65 years of age; 58% of the reported patients were male, and the male-to-female ratio was 1.4:1. Additionally, contact with raw meat, animal contact, and tick bite had the highest percentages for CCHF positivity cases. Male gender, high-risk jobs like housewives, health staff, shepherds, butchers, animal dealers, slaughterhouse workers, veterinary staff, and farmers, tick bites, and contact with raw meat were statistically significant predictors for increasing CCHF incidence in Dhi Qar province during the year 2022.

Alarming update on incidence of Crimean-Congo hemorrhagic fever in Iraq in 2023

ObjectivesIn 2021, large outbreak of Crimean-Congo hemorrhagic fever (CCHF) was reported in Iraq and cases have increased without any significant control measures. To raise awareness about the increasing cases in different regions of Iraq, hence remind the necessity to tackle contributing factors and potential outbreak interventions. MethodsThe study included 511 polymerase chain reaction-confirmed CCHF infection cases out of 1827 suspected cases from 18 Provinces from January to August 2023. Approval from the Ministry of Health for data analyzed. ResultsOut of 1827 suspected cases, 511 were confirmed positive by polymerase chain reaction. The total case fatality rate (CFR) was 12.7 with varying severity levels among provinces. Erbil had the highest CFR, 38.5, while Sulaimaniya and Anbar report no deaths. Independent t-test showed a significant difference in CFR between provinces west and south of Baghdad compared to north (P <0.05). Trend showed significant surges after Iftar and Adha holidays. ConclusionDifferences in CFR among provinces around the religious ceremonies, highlight the need for one public health intervention strategy. Increased temperatures affected vector behavior. Uncontrolled animal movement with neighboring countries is an important factor. Virus or host determinants can shape the clinical case outcomes, which need clinical and extensive laboratory studies to unravel the reasons leading to death.

Crimean-Congo Hemorrhagic Fever: Epidemiological and Epizootiological Situation in the Russian Federation in 2022, Incidence Forecast for 2023

The review presents an analysis of the epidemiological and epizootiological situation on Crimean-Congo hemorrhagic fever (CCHF) in the Russian Federation in 2022. The incidence rate of CCHF registered in 2022 (59 cases) was 1.2 times higher as compared to 2021, however, below the long-term average annual values. The mortality rate was 10.2 %, which exceeds the indicators of long-term observations (in 2012–2021 – 3.2 %). Following epizootiological survey of stationary observation points, it was found that the number of Hyalomma marginatum imago in 2022, in general, corresponded to the average long-term indicators. CCHF virus isolates circulating in Russia in 2017–2022 belonged to the genetic lines “Europe-1” (V), “Europe-2” (VI), and “Europe-3” (VII). The ratio of CCHF virus genovariants in the population on the territory of the Russian Federation in 2017–2022 didn’t change. Based on the analysis of naturalclimatic factors, the forecast for the incidence of CCHF in the Russian Federation for 2023 has been made.

Evaluation of Crimean-Congo Hemorrhagic Fever in Kermanshah (2006 - 2020)

Background: Crimean-Congo hemorrhagic fever (CCHF) is a contagious viral disease that can be transmitted through various means, including tick bites, contact with infected blood and animal tissues in slaughterhouses, and healthcare-related infections. Methods: In this study, we examined the incidence of CCHF and analyzed the demographic and clinical data of 130 patients diagnosed with CCHF in Kermanshah, a city located in western Iran, over a period of 15 years (2006 - 2020). Results: During the study, 19 cases tested positive, 66 were verisimilar, and the remaining cases (31.54%) were considered suspected. Among the positive cases, 15 patients recovered, and four died. Of those infected, 63.16% were males residing in rural areas. Additionally, 78.95% of the infected individuals had contact with domestic livestock, 26.31% had a history of contact with ticks, and 10.53% had contact with raw meat or raw liver. Furthermore, 5.26% had a history of contact with a CCHF patient. Conclusions: The highest prevalence of CCHF was observed among men aged 15 to 30 who lived in rural areas. According to the annual reports of people suffering from CCHF, health authorities should prioritize this disease in their public health programs. Since individuals who come into direct contact with livestock and livestock products are at a high risk of contracting diseases, it is important to educate them.

Explanatory models for tick-borne disease incidence (Astrakhan rickettsial fever and Crimean-Congo hemorrhagic fever)

Introduction. The study focuses on methods providing mathematical substantiation of discrepancies between actual incidence rates of Astrakhan rickettsial fever (ARF) and Crimean-Congo hemorrhagic fever (CCHF) and predicted rates due to the indirect impact of weather conditions during the current epidemic season.&#x0D; The purpose of the study was to develop explanatory models for ARF and CCHF incidence using satellite monitoring (remote sensing) data and to present the results of their practical evaluation in the Stavropol Territory and Astrakhan Region.&#x0D; Materials and methods. The materials included climate data provided by the Space Research Institute of the Russian Academy of Sciences as well as epidemiological data on CCHF and ARF incidence from 2005 to 2021. The explanatory models incorporated the Bayes theorem and Wald sequential analysis. All the calculations were completed using the Microsoft Excel 2010-based program developed by the authors.&#x0D; Results. It has been found that the greatest indirect effect on development of the CCHF epidemiological situation is produced by the normalized difference vegetation index and relative air humidity in June-July in the Stavropol Territory and by the maximum, minimum and average air temperature in October as well as the minimum air temperature in July in the Astrakhan Region. ARF incidence rates depend on the indirect effect of the annual average and average annual maximum temperature, maximum temperature and the normalized difference vegetation index in April-July. The match between explanatory model-based results and prediction model-based results ranged within 46.2-100%.&#x0D; Discussion. In addition to projecting incidence rates, which could be reached with the observed values of climatic factors in the current year, the explanatory models can be used for indirect verification of prediction models and for identification of factors causing differences in results.&#x0D; Conclusion. The practical evaluation of explanatory models confirms the prospects and benefits of the study that should be continued, involving other regions highly endemic for tick-borne infections.

Predicting incidence of Crimean-Congo hemorrhagic fever using satellite monitoring (remote sensing) data in the Stavropol Territory

Introduction. With the epidemiological situation for Crimean-Congo hemorrhagic fever (CCHF) remaining tense in many countries worldwide, special attention should be focused on development and improvement of risk-based epidemiological prediction methods.The aim of the study was to build a prediction model for CCHF incidence dynamics (based on the Stavropol Territory) using satellite monitoring (remote sensing) data.Materials and methods. We analyzed the climate data obtained from the Space Research Institute of the Russian Academy of Sciences as well as the data of public statistics reports on CCHF incidence from 2005 to 2021. The prediction model incorporated the Bayes theorem and Wald sequential analysis. The information content of the factors was assessed using the Kullback method.Results. Predictions for each of 26 districts were made stepwise (compared to threshold levels) to predict whether there will be at least one case of CCHF, whether the relative incidence per 100,000 population will exceed the median level (0.9 cases) or the average rate (3.5 cases) or the third quartile rate (4.7 cases). The highest values of information coefficients were obtained for soil temperature and moisture content (at depths of 10 and 40 cm), normalized relative vegetation index, relative humidity, maximum and average air temperature, relative air humidity. During the testing of the model in 2021, false-negative (erroneous) prediction was made for 2 districts.Discussion. The model proved to be most efficient in prediction of occurrence or absence of cases. More accurate quantitative prediction may be difficult due to subjective factors (including misdiagnosing CCHF cases without hemorrhagic manifestations and administering treatment for other conditions with similar symptoms).Conclusion. The tests of the model demonstrate its potential. The practical application of the prediction will make healthcare workers more alert when screening and detecting CCHF cases.

Epidemiological situation on Crimean-Congo Hemorrhagic Fever in the Russian Federation in 2021

The review presents an analysis of the epidemiological and epizootiological situation on Crimean-Congo hemorrhagic fever (CCHF) in the Russian Federation in 2021. 49 cases of CCHF were detected in 2021, which is 1.53 times higher than in 2020. The mortality rate was 6.1 %. Sporadic cases of CCHF were registered in the Stavropol Territory, Rostov, Volgograd Regions, the Republics of Dagestan and Kalmykia. The incidence rates of CCHF were below the long-term average annual values in the majority of the constituent entities. Epizootiological survey of stationary observation points has revealed that the number of Hyalomma marginatum imago corresponded to the average long-term indicators in 2021, the peak of H. marginatum activity was noted in the II–III decades of May. The proportion of Ixodidae tick pools positive for Crimean-Congo hemorrhagic fever (CCHF) virus markers exceeded the long-term average indexes in a number of regions. On the territory of the natural focus of CCHF, the circulation of the CCHF virus of the genetic lineages “Europe-1” and “Europe-3” was detected in 2021. Based on the analysis of the epidemiological data of the previous year and natural and climatic factors affecting the abundance and vital activity of H. marginatum ticks, risk-based quantitative forecast for the incidence of CCHF in the Stavropol Territory for 2022 has been compiled.

Review of the incidence of Crimean-Congo hemorrhagic fever for 16 years in 2005-2020 based on ProMED-RUS reports

Review of the incidence of Crimean-Congo hemorrhagic fever for 16 years in 2005-2020 based on ProMED-RUS reports

Epidemiological Community and Differences of Transmissive Infections in Astrakhan Region

Relevance. The territory of the Astrakhan region hosts natural foci of severe infections of arbovirus etiology – Crimean-Congo hemorrhagic fever (CCHF) and Astrakhan fever (spotted fever resembling the Mediterranean spotted fever, Astrakhan spotted fever (ASF). The long-term average incidence of CCHF and ASF in the Astrakhan region is to 11 and 135 times higher, respectively, than the average incidence in the Russian Federation. Aims. To present, based on epidemiological data, a comparative characterization of transmissible infections of CCHF and ASF in the Astrakhan region. Materials &amp; Methods. The main method of the study was epidemiological. The data for 2000−2016 of primary medical documentation Ф.058/у «Emergency notification of infectious disease, food, acute occupational poisoning, unusual reaction to vaccination», federal statistical observation Ф. 2 «Information on infectious and parasitic diseases», Ф. 357/у «Epidemiological examination card of infectious disease focus», Ф. .003/у «Medical card of inpatient patient», presented by Center of hygiene and epidemiology in Astrakhan region. For retrospective epidemiological analysis, we studied the absolute and intensive morbidity indicators (per 100 ths population), by age, professional groups, and among the urban and rural population. Based on the average long-term morbidity indicators of the population, a mapping of the territory of the Astrakhan region was carried out. The influence of natural and climatic conditions on the epidemic process of CCHF and ASF was assessed by meteorological data (amount of precipitation, air temperature, etc.). Materials of long-term observation over 11 districts of Astrakhan region and Astrakhan city were analyzed, including data on the spread of Ixodid ticks, population contact with them (according to the attendance of people to treatment-and-prophylactic organizations of the region). Statistical data processing was carried out using the method of straight-line alignment of dynamic series of morbidity indicators, calculation of the average annual rate of decrease/increase. Correlation analysis was used to assess the direction and strength of the relationship between the indicators, and quantitative dependence between epidemic process characteristics. Differences between the indicators were considered to be reliable if p &lt; 0.05. Results. During the analyzed period 151 cases of CCHF and 3951 cases of ASF were identified. By 2016. CCHF was registered in all 11 districts of the region and the area of foci covered 44,000 km2 and 44,100 km2, respectively. There are no differences significantly affecting the epidemic process of CCHF and ASF, so preventive measures are mainly aimed at controlling the vectors of the pathogens of these infections. The comprehensive study of the territory of Astrakhan region carried out in 2000–2016 revealed expansion of CCHF and ASF areal of disease (by 11.8% and 23.4% respectively) and determined the territories with the highest risk of infection, which allowed to increase and redistribute the volumes of acaricide treatments of the territories with the highest infection risk and ensure the decrease of CCHF and ASF morbidity rates. Conclusion. As a result of the comprehensive study conducted in 2000–2016 in the territory of Astrakhan region, the expansion of CCHF and ASF areal of disease was revealed (by 11.8% and 23.4% respectively) and the areas of highest infection risk were identified, which allowed to increase and redistribute the volume of acaricide treatments of the areas of highest infection risk and ensure the reduction of CCHF and ASF morbidity.

Is the Reduced Incidence of Crimean-Congo Hemorrhagic Fever Related to the Preventive Measures of COVID-19?

Is the Reduced Incidence of Crimean-Congo Hemorrhagic Fever Related to the Preventive Measures of COVID-19?

Seroprevalence of Crimean Congo Hemorrhagic Fever in cows by ELISA in Mosul city

Crimean-Congo hemorrhagic fever (CCHF) is described as a tick-borne viral zoonosis highly prevalent in Africa, Asia, Russia and the Balkans within the distribution range of ticks that belong to the genus Hyalomma. This research aimed to verify the seroprevalence of CCHF in cows employing Indirect enzyme-linked immunosorbent assay (I-ELISA) in Mosul city / Iraq, to ​​examine some epidemiological risk factors related to the incidence of CCHF. From October 2019 - September 2020, one hundred eighty-four blood samples were taken from 3-8-year-old cattle of both sexes, from several management systems and origins, from various parts in Mosul city, 10 ml of blood was taken from the jugular vein in test tubes without anticoagulant to obtain the sera for I-ELISA test, while epidemiological data were obtained by interviewing the farm-owners. I-ELISA was applied to detect the antibodies of CCHF in the serum. The overall seroprevalence of CCHF in cows was 40/184 (21.7%). As for the risk factors associated with increased seroprevalence of the disease, an increase in seroprevalence rates was observed at ages 6, 7 and 8 years 30.5%, among females 26.3% and imported animals 27.5%. which showed that the serological prevalence in indoor feeding and outdoor feeding, was not significantly different (p<0.05). This study concluded that there is a higher seroprevalence of CCHF in Mosul city along with many risk factors related to its incidence.

Evaluation of seroprevalence and clinical and laboratory findings of patients admitted to health institutions in Gümüşhane with suspicion of Crimean-Congo hemorrhagic fever

Background/aimTo determine the seroprevalence and evaluate clinical findings and laboratory results of patients prediagnosed with Crimean-Congo hemorrhagic fever (CCHF) in Gümüşhane.Materials and methodsIncluded in the cross-sectional study were 362 patients (162 female, 200 male) between 0 and 94 years of age, who were followed up after receiving a preliminary diagnosis of CCHF between January 2011 and December 2019. Anamnesis, age, sex, clinical findings, laboratory results, epidemiological and clinical evaluations, severity criteria, risk factor reviews, and a comparison of the suspected negative cases with positive cases were analyzed retrospectively. Patients included in the study were evaluated as RNA-positive by polymerase chain reaction (PCR) or IgM-positive by ELISA.ResultsOf the 362 patients admitted to health institutions with a preliminary diagnosis of CCHF, 242 were diagnosed as CCHF-positive (66.9%). Moreover, 196 of those CCHF-positive patients (81%) were admitted to health institutions during the summer months. Statistical analyses revealed a significant relationship between the incidence of CCHF and patients who had been in contact with animals, lived in rural areas, and had engaged in farming and animal husbandry. In addition, fever, headache, diffuse bodily pain, nausea and vomiting, diarrhea, fever of 38 °C or higher, tachycardia, elevated ALT/AST, creatine kinase (CK), and lactate dehydrogenase (LDH) levels, leukopenia, and thrombocytopenia were detected in the CCHF-positive patients. Significant relations were found between this disease and these symptoms. However, there was no significant relationship between the statistical evaluation of the disease and bloody diarrhea, bodily bruises, rash, unconsciousness, gingival bleeding, hypotension, epistaxis, petechiae, splenomegaly, ecchymosis, hematuria, maculopapular rash, gastrointestinal system complaints, anemia, or elevation of the international normalized ratio and activated partial thromboplastin time duration, separately. ConclusionOf the 362 patients, 66.9% (242) of those who received a preliminary diagnosis of CCHF were indeed CCHF-positive in Gümüşhane. It was concluded that CCHF remains an important endemic disease in Gümüşhane. In addition, elevated ALT/AST, CK, and LDH levels, leukopenia, and thrombocytopenia in patients presenting with headache, fever, fever of 38 °C or higher, generalized body pain, nausea/vomiting, diarrhea, and tachycardia will play a pivotal role in the preliminary diagnosis of CCHF.

The effect of climate variables on the incidence of Crimean Congo Hemorrhagic Fever (CCHF) in Zahedan, Iran

BackgroundThe Crimean-Congo Hemorrhagic fever (CCHF) is endemic in Iran and has a high fatality rate. The aim of this study was to investigate the association between CCHF incidence and meteorological variables in Zahedan district, which has a high incidence of this disease.MethodsData about meteorological variables and CCHF incidence was inquired from 2010 to 2017 for Zahedan district. The analysis was performed using univariate and multivariate Seasonal Autoregressive Integrated Moving Average (SARIMA) models and Generalized Additive Models (GAM) using R software. AIC, BIC and residual tests were used to test the goodness of fit of SARIMA models, and R2 was used to select the best model in GAM/GAMM.ResultsDuring the years under study, 190 confirmed cases of CCHF were identified in Zahedan district. The fatality rate of the disease was 8.42%. The disease trend followed a seasonal pattern. The results of multivariate SARIMA showed the (0,1,1) (0,1,1)12 model with maximum monthly temperature lagged 5 months, forecasted the disease better than other models. In the GAM, monthly average temperature lagged 5 months, and the monthly minimum of relative humidity and total monthly rainfall without lag, had a nonlinear relation with the incidence of CCHF.ConclusionsMeteorological variables can affect CCHF occurrence.

&lt;p class="Body"&gt;&lt;strong&gt;Preliminary Investigation on the Genetic Diversity and Population Structure of &lt;em&gt;Hyalomma marginatum &lt;/em&gt;(Acari: Ixodidae) in Turkey&lt;/strong&gt;&lt;/p&gt;

The hard tick Hyalomma marginatum Koch, 1844 is the main vector of Crimean Congo hemorrhagic fever (CCHF). Although this disease is a serious public health concern in Turkey, there is still no information about population structure and genetic diversity of this tick species. In this study, the genetic structure of H. marginatum populations collected from nine different locations of Turkey were evaluated using five microsatellite markers. A total of 75 H. marginatum samples were collected from domestic animals and genotyped. We hypothesized that localities which have high CCHF incidence rates (Bayburt, Amasya and Tokat) might be genetically distinct from the localities with low incidence rates. All approaches used in this study (DAPC, STRUCTURE and FST) showed low levels of genetic diversity. Although, no genetic pattern was observed between localities that can be associated with CCHF incidence rates, there was moderate genetic differentiation between Igdir and Tekirdag populations (FST = 0.142) and also between Igdir and Mugla populations (FST = 0.128). DAPC confirmed this finding, as Igdir, Mugla and Tekirdag populations were found to be genetically different when compared to other populations. The mechanisms underlying overall observed low genetic variation and only moderate differentiation between some of these populations should be investigated in further studies in the context of other host-parasite-vector system regulating factors such as antropogenic transports of livestock, environmental conditions and the role of migratory routes of birds.

CRIMEAN-CONGO HEMORRHAGIC FEVER IN THE MIDDLE EAST: HISTORY AND FACTS

Crimean-Congo Hemorrhagic Fever (CCHF) is the highest widespread, tick-borne viral hemorrhagic fever that affect humans. This virus is endemic in many areas in the world, such as Africa, Asia, and Europe. Nowadays, the incidence of CCHF is increasing rapidly in several countries of the middle-east, with several outbreaks and sporadic cases in human of CCHF, that are reported in several countries in this region.

Space-time epidemiology of Crimean-Congo hemorrhagic fever (CCHF) in Iran

Iran, as an endemic country of Crimean-Congo hemorrhagic fever (CCHF), has been suffering from severe health issues and substantial economic burdens imposed by the disease. We analyzed monthly and yearly spatial and temporal distributions of CCHF to better understand the epidemiology of the disease in Iran. A cross-sectional survey was performed on 1027 recorded cases between 2000 and 2014. Global Moran’s I analysis was applied to statistically evaluate the spatial pattern of the disease. Additionally, spatial and space-time scan statistics were used to study the presence of possible spatial and space-time hotspots. Global Moran’s I analysis proved that the incidence of the disease is strongly clustered in Iran (p<0.01). Purely spatial scan statistics identified that there were three clusters in the eastern, southern and western parts of the country. Through space-time analysis, we found that the highest incidence of CCHF occurred in the eastern parts of the country between 2006 and 2012. Monthly clusters, which include cities with lower (average) temperatures, had been occurring in relatively short periods. The distribution of CCHF incidence in this country is spatially and temporally clustered. The majority of the clusters emerged during the critical years of 2009 and 2013. Summer is the predominant period for the formation of CCHF clusters.

Обзор эпидемической ситуации по Крымской геморрагической лихорадке в Российской Федерации в 2015 г. и прогноз на 2016 г

This paper presents analysis of epidemiological situation on Crimean-Congo hemorrhagic fever (CCHF) in Russia in 2015; summarized are the results of epidemiological survey of the territory of the natural CCHF focus in the south of the European part of Russia. In 2015, the Russian Federation reported 139 cases of CCHF. The most significant increase in the incidence of CCHF occurred in the Stavropol Territory and Rostov Region. Identified was CCHF case in Voronezh city imported from the Crimean Federal District. Marked is the involvement of new administrative areas in the epidemic core of the natural focus. The aggravation of the epidemiological situation in the South of Russia was mainly due to the favorable for dissemination of ticks, H. marginatum, climatic conditions in winter 2014-2015. In 2016, in the case of successful Ixodids wintering, as well as ineffectively exercised acaricide treatments, the numbers of H. marginatum may increase compared to 2015, which may become the cause of augmented incidence among the population.

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

The purpose of this study was to analyze the epidemiological characteristics of cases diagnosed with Crimean-Congo Hemorrhagic Fever (CCHF) with the help of Geographic Information Systems (GIS) and to establish an epidemiological risk map. Data for 434 cases diagnosed with CCHF between 01.01.2004 and 31.12.2013 were subjected to statistical analysis SPSS 13.0 software. A digital map of Kastamonu was transferred onto ArcGIS 10.0 software in order to establish a risk map for CCHF. The highest cumulative incidence of CCHF is 41.29/10,000, and in people living at altitudes of 1001–1200meters. ROC analysis of altitudes above sea level of residences with CCHF cases revealed an area under the curve of 74.5% (95% CI: 0.72-0.76, p<0.05). At a cut-off point of 836.5 meters, sensitivity was 0.74 and specificity 0.76. Cumulative incidence of CCHF was significantly positively correlated with number of animals per head (r=0.76) and area of agricultural land per head (r=0.59) (p<0.05). No significant correlation was determined between cumulative incidence and forested area percentages. This study reveals that both men and women living at more than 836.5 meters above sea level and working in agriculture and animal husbandry are at risk of CCHF between May and July. Detailed examination of the ecology of vector ticks is now needed in order to fully determine the epidemiology of the disease.

Spatial cluster analysis of human cases of Crimean Congo hemorrhagic fever reported in Pakistan.

BackgroundCrimean Congo hemorrhagic fever (CCHF) is a tick-borne viral zoonotic disease that has been reported in almost all geographic regions in Pakistan. The aim of this study was to identify spatial clusters of human cases of CCHF reported in country.MethodsKulldorff’s spatial scan statisitc, Anselin’s Local Moran’s I and Getis Ord Gi* tests were applied on data (i.e. number of laboratory confirmed cases reported from each district during year 2013).FindingsThe analyses revealed a large multi-district cluster of high CCHF incidence in the uplands of Balochistan province near it border with Afghanistan. The cluster comprised the following districts: Qilla Abdullah; Qilla Saifullah; Loralai, Quetta, Sibi, Chagai, and Mastung. Another cluster was detected in Punjab and included Rawalpindi district and a part of Islamabad.ConclusionWe provide empirical evidence of spatial clustering of human CCHF cases in the country. The districts in the clusters should be given priority in surveillance, control programs, and further research.Electronic supplementary materialThe online version of this article (doi:10.1186/2049-9957-4-9) contains supplementary material, which is available to authorized users.

Crimean-Congo hemorrhagic fever and its relationship with climate factors in southeast Iran: a 13-year experience.

Crimean-Congo hemorrhagic fever (CCHF) is endemic in southeast Iran. In this study we present the epidemiological features of CCHF and its relationship with climate factors in over a 13-year span. Surveillance system data of CCHF from 2000 to 2012 were obtained from the Province Health Centre of Zahedan University of Medical Sciences in southeast Iran. The climate data were obtained from the climate organization. The seasonal auto-regression integrated moving average (SARIMA) model was used for time series analysis to produce a model as applicable as possible in predicting the variations in the occurrence of the disease. Between 2000 and 2012, 647 confirmed CCHF cases were reported from Sistan-va-Baluchistan province. The total case fatality rate was about 10.0%. Climate variables including mean temperature (°C), accumulated rainfall (mm), and maximum relative humidity (%) were significantly correlated with monthly incidence of CCHF (p <0.05). There was no clear pattern of decline in the reported number of cases within the study's time span. The first spike in the number of CCHF cases in Iran occurred after the first surge of the disease in Pakistan. This study shows the potential of climate indicators as predictive factors in modeling the occurrence of CCHF, even though it has to be appreciated whether there is any need for a practically applicable model. There are also other factors, such as entomological indicators and virological finding that must be considered.