Detection of West Nile virus genome and specific antibodies in Iranian encephalitis patients.

West Nile virus (WNV) is a mosquito-borne flavivirus which circulates in birds, horses and humans. An estimated 80% of WNV infections are asymptomatic. Fewer than 1% of infected persons develop neuroinvasive disease, which typically presents as encephalitis, meningitis, or acute flaccid paralysis. This study was conducted from January 2008 to June 2009 in Isfahan, Iran. Patients attending the emergency department with fever and loss of consciousness were consecutively included. Cerebrospinal fluids (CSF) were initially analysed through bacteriology and biochemistry examinations, resulting in those with evidence of meningitis being excluded. Patients' CSF and serum were diagnosed by serological and molecular assays. A total of 632 patients with fever and loss of consciousness were tested by CSF analyses. Samples of the remaining patients (39·4%) were referred for WNV investigation. Three (1·2%) of the patients were positive for both serum and CSF by RT-PCR, and six (2·4%) were positive only for IgG antibodies. History of insect bite, and blood transfusion and transplantation were risk factors for being positive by RT-PCR (P=0·048) and being IgG positive (P=0·024), respectively. The results of this study showed that the prevalence of West Nile fever is low in patients with encephalitis.

Mice orally immunized with a transgenic plant expressing the glycoprotein of Crimean-Congo hemorrhagic fever virus.

While Crimean-Congo hemorrhagic fever (CCHF) has a high mortality rate in humans, the associated virus (CCHFV) does not induce clinical symptoms in animals, but animals play an important role in disease transmission to humans. Our aim in this study was to examine the immunogenicity of the CCHFV glycoprotein when expressed in the root and leaf of transgenic plants via hairy roots and stable transformation of tobacco plants, respectively. After confirmatory analyses of transgenic plant lines and quantification of the expressed glycoprotein, mice were either fed with the transgenic leaves or roots, fed the transgenic plant material and injected subcutaneously with the plant-made CCHFV glycoprotein (fed/boosted), vaccinated with an attenuated CCHF vaccine (positive control), or received no treatment (negative control). All immunized groups had a consistent rise in anti-glycoprotein IgG and IgA antibodies in their serum and feces, respectively. The mice in the fed/boosted group showed a significant rise in specific IgG antibodies after a single boost. Our results imply that oral immunization of animals with edible materials from transgenic plants is feasible, and further assessments are under way. In addition, while the study of CCHF is challenging, our protocol should be further used to study CCHFV infection in the knockout mouse model and virus neutralization assays in biosafety level 4 laboratories.

Molecular epidemiology of Crimean- Congo hemorrhagic fever virus genome isolated from ticks of Hamadan province of Iran.

BACKGROUND & OBJECTIVES: Crimean-Congo hemorrhagic fever (CCHF) virus is a tick-borne member of the genus Nairovirus, family Bunyaviridae. CCHFV has been isolated from at least 31 different tick species. The virus is transmitted through the bite of an infected tick, or by direct contact with CCHFV-infected patients or the products of infected livestock. This study was undertaken to study the genetic relationship and distribution of CCHFV in the tick population of Hamadan province of Iran. METHOD: In this study, RT-PCR has been used for detection of the CCHFV genome. RESULTS: This genome was detected in 19.2% of the ticks collected from livestock of different regions of the Hamadan province in western Iran. The infected species belonged to Hyalomma detritum, H. anatolicum, Rhipicephalus sanguineus and Argas reflexus. With one exception, genetic analysis of the virus genome isolates showed high sequence identity to each other. Even though they clustered in the same group with the strain circulating in Iran, they had a closer relationship to the Matin strain. INTERPRETATION & CONCLUSION: Vector control programs should be applied for reducing population density of potential tick vectors in this province. Further surveys are indicated in this region to provide a better view of the distribution and epidemiology of the virus.

Phylogenetic analysis in a recent controlled outbreak of Crimean-Congo haemorrhagic fever in the south of Iran, December 2008.

Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease with a high mortality rate in humans. The CCHF virus is transmitted to humans through the bite of Ixodid ticks or contact with blood or tissues of CCHF patients or infected livestock. In December 2008, a re-emerging outbreak of CCHF occurred in the southern part of Iran. Five people were hospitalised with sudden fever and haemorrhaging, and CCHF was confirmed by RT-PCR and serological assays. One of the cases had a fulminant course and died. Livestock was identified as the source of infection; all animals in the incriminated herd were serologically analysed and more than half of them were positive for CCHFV. We demonstrated that two routes of transmission played a role in this outbreak: contact with tissue and blood of infected livestock, and nosocomial transmission. Phylogenetic analyses helped to identify the origin of this transmission. This outbreak should be considered as a warning for the national CCHF surveillance system to avoid further outbreaks through robust prevention and control programmes.

Crimean-Congo hemorrhagic fever in Iran and neighboring countries.

Crimean-Congo hemorrhagic fever (CCHF) is a zoonotic viral disease that is asymptomatic in infected livestock, but a serious threat to humans. Human infections begin with nonspecific febrile symptoms, but progress to a serious hemorrhagic syndrome with a case fatality rate of 2-50%. Although the causative virus is often transmitted by ticks, livestock-to-human and human-to-human transmissions also occur. The disease is one of the most widely distributed viral hemorrhagic fevers occurring in Africa, the Middle East, Asia, and some parts of Europe. In this study, we have focused on the CCHF situation in Iran and neighboring countries and provide evidence of over 5000 confirmed cases of CCHF in a single period/season.

Surveillance and laboratory detection system of Crimean-Congo haemorrhagic fever in Iran.

Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease with a high mortality rate in humans. The CCHF virus (CCHFV) is transmitted to humans through the bite of Ixodid ticks or by contact with blood or tissues of infected livestock. In addition to zoonotic transmission, CCHFV can be spread from person to person and is one of the rare haemorrhagic fever viruses able to cause nosocomial outbreaks in hospitals. Crimean-Congo haemorrhagic fever is a public health problem in many regions of the world such as Eastern Europe, Asia, the Middle East and Africa. In addition to clinical symptoms, the diagnosis of CCHF is based on the use of serological tests for the detection of immunoglobulin M and immunoglobulin G antibodies and on the use of molecular tools such as RT-PCR. From 1970 to 1978, serological and epidemiological studies were performed in humans and in livestock of Iran. After two decades and observations of CCHF in some provinces of Iran, a CCHF surveillance and detection system was established in 1999, leading to a dramatically decreased mortality rate from 20% (year 2000) to 2% (year 2007).