Juveniles had lower seroprevalence than adults (37% vs 82%) but similar RT-PCR detection rates (16% vs 15%).
An outbreak in a breeding herd, showed that antibodies rapidly wane, that camels become re-infected, and that outbreaks in a herd are sustained for an extended time.
Local free-roaming herds, and local farmed breeding herds including a herd of about 90 camels that were raised and bred in confinement on the Mediterranean coast were also sampled repeatedly every month.
Camels were classified as juvenile when under two years of age around when they are weaned off mother’s milk.
Phylogenetic tree of the partial Spike protein gene (around 600 bp) was constructed using MEGA 6 with bootstrap method and Kimura 2-parameter model.
The distribution of sera and nasal swabs by sampling site, age, sex and animal origin is presented in Table 1.
However, most of the evidence relating camels to MERS-Co V comes from cross-sectional studies that do not provide information on the dynamics of MERS-Co V infection in camels.
Furthermore, the majority of traded camels originate from African countries and those have not been well studied.
The dynamics of natural infection in camels are not well understood.The overall seroprevalence was 71% and RNA detection rate was 15%.Imported camels had higher seroprevalence (90% vs 61%) and higher RT-PCR detection rates (21% vs 12%) than locally raised camels.Results were only accepted if results from the positive and negative antisera were as expected.Test samples (milk and sera) were initially screened at a dilution of in duplicate.Between June 2014 and February 2016, 2825 nasal swabs, 114 rectal swabs, 187 milk samples, 26 urine samples and 2541 sera were collected from dromedary camels.