Well you would, since your [message] field is
"message" => " <Parameter ID="512" EventID="498" Name="Iteration" //DisplayName="Iteration" Type="Int" StorageUnit="" DisplayUnit="" DisplayScale="" //FormatString="" ServiceCategory="None" MaxLogInterval="00:00:00" //AbsoluteMinimum="-1.7976931348623157E+308" //AbsoluteMaximum="1.7976931348623157E+308" />\r"
That matches the health_id and event_id in your event.
I wonder if your problem is that you are consuming the XML line by line. You may need a multiline codec. Read this post and the posts linked to.