Writing large amounts of data to a csv file - vb.net

Question

I couldn't find anything specific to this so here goes.
I have a For Each loop where I want to write values to a csv file. Currently, I use a WriteToFile function:
Public Sub WriteToFile(stuff as string, morestuff as string, moremorestuff as string))
Dim strFile As String = "\\SomeServer\somefilepath\WriteTo.csv"
Try
If System.IO.File.Exists(strFile) = True Then
'rename with startdate and enddate. Always want to create new
Dim objWriter As New System.IO.StreamWriter(strFile, True)
objWriter.WriteLine(Stuff & "," & MoreStuff & "," & Moremorestuff)
objWriter.Close()
Else
Dim writeFile As IO.StreamWriter
writeFile = IO.File.CreateText(strFile)
writeFile.WriteLine("Stuff" & "," & "MoreStuff" & "," & "MoreMoreStuff")
writeFile.WriteLine(Stuff & "," & MoreStuff & "," & MoreMoreStuff)
writeFile.Close()
End If
Catch ex As Exception
MessageBox.Show("An error has occured in the WriteToFile subroutine: " & ex.ToString) ' & vbCrLf & strPlugin & vbCrLf & strVersion)
End Try
End Sub
Rather than closing the StreamWriter after every record is written, is there a way to keep it open? Or should it be kept open?
I made some changes and came up with this. However, using this code, how would I create a header in the csv file?
If cur.Count > 0 Then
Using writer As System.IO.StreamWriter = New IO.StreamWriter("C:\Temp\UWConditions.csv")
For Each lrdata As LoanReportData In cur
loan = session.Loans.Open(lrdata.Guid)
If Not IsNothing(loan) Then
For Each condition As UnderwritingCondition In loan.Log.UnderwritingConditions
Title = condition.Title.Replace(",", "")
Desc = condition.Description.Replace(",", "")
UWName = loan.Session.Users.GetUser(loan.Fields("UWID").Value).FullName.Replace(",", "")
writer.WriteLine(lrdata("Loan.LoanNumber") & "," & Title & "," & Desc & "," & UWName)
Next
loan.Close()
End If
Next
End Using
End If