Abstract:
Background: Coronaviride is a large family of viruses that cause a variety of diseases in humans and other animals. Recently, a novel coronavirus not previously seen in humans is identified in a resident of the Middle East.
Aims: There is growing evidence that the Camelus dromedarius are host species for the virus and play an important role as a source of human infection. Therefore, the authors decided to detect coronaviruses in dromedary camels in two high risk area of Iran using a RT-PCR assay.
Methods: In this study, nasal swab specimens are collected from 98 camels (Camelus dromedarious) traditionally reared in Southeast and Northwest of Iran. The Detection of pancoronavirus is carried out using Reverse transcription polymerase chain reaction (RT-PCR).
Results, and Conclusions: Pancoronavirus RNA is detected in 7 cases among 98 nasal swab samples. Among these, four positive samples belong to Azerbaijan province, Northwest of Iran
and three positive samples taken from Southeast of Iran. Results of this study help to raise hypothesis about the extent of transmission and risk factors for human infection and public health in Iran.
Introduction:
Coronaviride is a large family of viruses that cause a variety of diseases in humans, from the common cold to severe acute respiratory syndrome (SARS). These viruses additionally cause disease in a wide variety of animal species (Drosten et al. 2003; Kuiken et al. 2003; Perlman and Netland
2009; Vabret et al.2006; Vabret et al. 2008; WHO 2013). In late 2012, a novel coronavirus not previously seen in human was identified in a resident of the Middle East [need reference]. The Coronavirus now has been known as the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) (Bermingham et al. 2012; U Buchholz 2013; Van Boheemen et al.2012; Zaki et al. 2012). According to the World Health Organization (WHO), global cases counted for Middle East Respiratory Syndrome (MERS) were 1,599 laboratory-confirmed cases until October 2015 [need reference]. It includes at least 574 deaths (case fatality rate 36%) since the first cases reported in September 2012 (WHO 2015).
There is evidence that the dromedary camels are host species for the virus and they play a role as a source of human infection (WHO 2013). An investigation in Egypt, utilizing Reverse transcription polymerase chain reaction (RT-PCR), detected MERSCoV in 3.6% (4 of 110) ostensibly salubrious dromedary camels in an abattoir [Need reference if it is not Chu et al.2014]. Genetic sequence of the viruses demonstrate minimum differences from a reference strain antecedently taken from a human case (Chu et al.2014).
Viral culture is a standard test for diagnosis of respiratory infections [need reference]. However, as it is difficult to grow coronaviruses in cell culture, RT-PCR has been developed to obtain more sensitivity and rapid diagnostic results [need reference]. This pancoronavirus assay is a useful tool for screening sample collections for the presence of all known coronaviruses (Mo''s 2005;Zaki et al. 2012).
As Iran recently reported its sixth human MERS-CoV case and its fifth death from the disease, it is vital to evaluate the situation of the infection in camels as a source of the virus. Therefore, the authors decided to detect coronaviruses in dromedary camels in two high risk area of Iran using a RT-PCR assay.
Discussion:
The recent fatal human infections caused by the MERSCoV, resulted an excruciating interest in the revelation of coronaviruses in humans and farm animals. The first study carried out to investigate that camels are a possible source and reservoir of the virus [Need Reference]. It was predicated on positive serological results from 50 serum tests taken from dromedary camels in Oman where the outcomes demonstrate a high titer of neutralizing antibodies against MERS-CoV (Reusken et al. 2013).
Camels infected with MERS-CoV may not show any clinical signs [need reference]. Therefore, it is not possible to know, an animal in a farm, market, race track or slaughterhouse is excreting the virus and able to infect humans through their nasal discharges, faeces, and potentially in their milk and urine [need reference]. The virus may also be found in the organs and meat of infected animals (WHO 13 June 2014).
Camelus dromedarius is increasingly recognized as natural reservoir for human coronaviruses [Need reference]. A pancoronavirus RT-PCR assay is a felicitous method to test esse of all coronaviruses in clinical samples. Besides expeditious screening for several pathogens in one assay, it supplies the possibility to identify aforetime unknown coronaviruses.
In recent studies, researchers test the sera of sheep, cattle, goats and camels from the Middle East and some other regions for the presence of antibodies against the MERS-CoV [Need Reference which studies]. Interestingly, it was observed that results taken from all camels live in the Middle East were positive for the mentioned antibodies [where did you mention antibodies? anti-MERS-CoV antibodies] (with quite high antibody titers) [Need Reference]. However, no anti-MERS-CoV antibodies were found in any of the other tested animals (Reusken et al. 2013).
Results of previous studies also show that humans who had interaction with camels developed a higher seroprevalence than those without contact [Need Reference]. However, they do not necessary have to develop disease, but are likely to transmit the pathogen (M''ller et al. 2015). A recent study show that identical MERS-CoV RNA fragments were detected in an air sample amassed from the barn of a camel that shared homogeneous MERS-CoV with an infected person (Azhar et al. 2014).
On June 11th, 2014, the World Health Organization (WHO) reports that Kuwait has found the virus in five camels. They also confirm the first two MERS-CoV cases in Iran (WHO 2014). According to the WHO recent report, all of the patients who died from MERS-CoV were resident of Kerman province, Iran [Need reference]. Therefore, our research group designed a study to focus on detection of coronaviruses in camels in Kerman province, Iran.
However, The Ministry of Health and Medical Education of Iran reports that the mentioned patients had no contact with animals, or consumed raw camel products before their illness, but they had close contact with Umrah pilgrims who had influenza-like illness. Previous studies confirm high similarity of MERS-CoVs carried by humans and camels (Abdulaziz N. Alagaili and Lisa E.Hensley 2014; Haagmans et al. 2014) and support the hypothesis that human MERS-CoV infection may be acquired directly from camels.
The first reported case of coronavirus infection in Camelus deromedarius in Iran raises the possibility that a significant proportion of cases might be infected, or will be infected in the future and so improve the hypothesis about the extent of transmission and risk factors for human infection and public health.
Conclusion:
In conclusion, the implementation of a continuous veterinary surveillance program for detecting coronoviruses in dromedary camels may aid our understanding of the transition method of coronaviruses infections. [I think it is not your conclusion. Your conclusion is that you find virus in camels and it can increase the risk of human infection. You did not consider transition of virus from camel to human].
Ethical approval:
All ethical considerations utilizing animals were considered conscientiously, and the experimental protocolwas approved by the Ethics Committee of KUMS, Kerman, Iran.
Conflict of interest:
The authors declare that we have no conflict of interest.