Seroprevalence of Middle East Respiratory Syndrome Corona Virus in dromedaries and their traders in upper Egypt

Abstract

Introduction: Camel trade in Egypt depends mainly on importation. Seemingly healthy imported camels are responsible for the ingress of serious diseases into Egypt. A striking example of this concerning public health globally is the Middle East respiratory coronavirus (MERS-CoV) which causes case fatalities of over 34%. Here, we determined the seroepidemiological situation of the MERS-CoV in imported camels and their traders in Upper Egypt. Methodology: Sera of sixty-three dromedaries and twenty-eight camel traders were recruited (January 2015-December 2016). The age, gender, and sampling locality of each sampled camel and human were obtained. Semi-quantitative anti-MERS-CoV IgG ELISAs which utilize the purified spike protein domain S1 antigen of MERS coronavirus (MERS-CoV S1) were used to detect specific IgG antibodies against the virus. Results: The data showed that 58.73% of imported camels and 25% of traders had antibodies specific to MERS-CoV. Interestingly, like seroreactive camels, all seropositive humans were apparently healthy without any history of developing severe respiratory disease in the 14 days prior to sampling. Having specific antibodies among the examined camel sera was significantly different (P < 0.0001) in relation to various sampling localities, gender and age groups. In contrast, the seropositivity rate of MERS-CoV IgG in humans did not differ significantly by any of the studied factors. Conclusions: The current study provides the first serological evidence of occupational exposure of humans to MERS-CoV in Africa. Additionally, it reports that imported camels could be implicated in introducing MERS-CoV into Egypt. Accordingly, application of strict control measures to camel importation is a priority.

Sex-Bias in COVID-19: A Meta-Analysis and Review of Sex Differences in Disease and Immunity

“…Studies in wild bats, known reservoirs for pathogenic coronaviruses, have shown either similar seropositivity in males and females 44 , or higher seropositivity in female animals 45 . Similar studies in dromedary camels, the main reservoir host for MERS-CoV, showed higher seropositivity in females 46,47 . A possible explanation for the higher rate of seropositivity in females is the higher risk of exposure: the close proximity of female dromedaries to their highly susceptible calves puts them at repeated risk of infection 47 , while pregnant bats collect to stay warm during roosting season 45 .…”

Sex-bias in COVID-19: a meta-analysis and review of sex differences in disease and immunity

“…Seropositivity in these reservoir animals, which act as hosts for viral pathogens but generally do not display symptoms, has been investigated with sampling studies.Studies in wild bats, known reservoirs for pathogenic coronaviruses, have shown either similar seropositivity in males and females45 , or higher seropositivity in female animals46 . Similar studies in dromedary camels, the main reservoir host for MERS-CoV, showed higher seropositivity in females47,48 . A possible explanation for the higher rate of seropositivity in females is the higher risk of exposure: the close proximity of female dromedaries to their highly susceptible calves puts them at repeated risk of infection48 , while pregnant bats collect to stay warm during roosting season 46 .2.…”

“…Similar studies in dromedary camels, the main reservoir host for MERS-CoV, showed higher seropositivity in females47,48 . A possible explanation for the higher rate of seropositivity in females is the higher risk of exposure: the close proximity of female dromedaries to their highly susceptible calves puts them at repeated risk of infection48 , while pregnant bats collect to stay warm during roosting season 46 .2. SEX DIFFERENCES IN OTHER INFECTIONSSex differences in response to infection occur at all ages with a generally higher burden of bacterial, viral, fungal and parasitic infections in human males.…”

The COVID-19 pandemic: implications for the cytology laboratory

“…6 MERS-CoV probably also originated from bats, 17 but the intermediate hosts are dromedary camels. Camel to human transmission of MERS-CoV may occur through contact with camels, unpasteurized camel milk, and medicinal use of camel urine, 19 but human to human transmission of the virus also occurs and has been documented in health care workers. 20 MERS has a much higher case fatality rate (about 35% for the 2500 patients with clinical infections 21,22 ).…”

“…42 Because bronchoalveolar lavage (BAL) fluid is sometimes obtained for viral identification [43][44][45] and is occasionally positive when nasopharyngeal and oropharyngeal swab samples are negative, 46 an aliquot may also be sent to the cytology laboratory. However, the cytologic findings of BAL samples of patients with COVID- 19 are not yet reported. In patients with MERS, cytological examination of BAL fluid reportedly showed high numbers of neutrophils and macrophages.…”