[s6e6] The World Turned Upside Down -

Once Claire begins to recover, Malva Christie arrives at the Big House with a shocking claim: she is pregnant and names Jamie Fraser as the father. Show S6E6 The World Turned Upside Down : r/Outlander

After multiple fatalities, the cause is eventually traced to a dead elk contaminating a local stream.

Curiously, both Claire and Tom Christie fall ill with similar symptoms, though their cases seem slightly different from the general outbreak.