Vernon Jones's son Trystan died from meningococcal septicaemia when he was 16 - he was not admitted to hospital for vital treatment until it was too late. The grandfather-of-three, who lives near Aberystwyth, said nine-month-old baby Aleesha Evans's death echoed what his own family had been through.
"Lessons haven't been learned in the medical profession over the last 10 to 16 years. Still the alertness about [meningococcal septicaemia] is not there, but you have to be alert all the time for meningitis," he said.
Trystan died in 1992 from meningococcal septicaemia, just a day after he had been seen by a doctor.
His 72-year-old father, who has another son Osian, said: "He became ill after he had been hunting and we called the doctor out - we thought it was flu at first.
"The doctor said he was treating it as meningitis and that he would come again in the morning. That night he was quite restless and a rash appeared on him, which we had no idea what it was.
"He died at midnight on Sunday night. It was meningococcal septicaemia. The locum paediatrician didn't say anything but she looked very angry when we told her that we had seen a doctor the previous night and been given antibiotics."
Mr Jones's comments come after an inquest this week heard how nine-month-old Aleesha Evans died from meningococcal septicaemia a day after being sent home from a hospital A&E unit after two hours with Calpol.
Her mother Shiree Hanbury, from Bettws, Newport, told the Cardiff inquest that when she woke the following morning, Aleesha was "just covered in bruises."
The inquest heard that Aleesha's discharge from the Royal Gwent Hospital, in Newport, in August 2006, cost the baby her life. Coroner Mary Hassell has said she will write a report in a bid to prevent such an incident happening again.
The Western Mail last month reported how nine-year-old Caitlin Lang had received a £3.3m payout after suffering severe disabilities after vital treatment for pneumococcal meningitis was delayed by two days. An out-of-hours doctor failed to spot the first signs of the infection when Caitlin was just three months old.
There are up to 1,800 cases of meningococcal disease every year in the UK - the life-threatening condition can cause meningitis and septicaemia. Meningococcal septicaemia requires urgent admission to hospital where patients are treated with antibiotics - the Meningitis Trust said the faster treatment is started, the less likely it is to become life threatening.
Symptoms include fever with cold hands and feet, joint or muscle pain, rapid breathing, stomach cramps and diarrhoea and red or purple spots or bruises that do not fade under pressure.
The Meningitis Trust said that some 7% of people who suffer meningococcal disease will die and up to 15% of patients will be left with severe and disabling after effects.
Dr David Bailey, chairman of the Welsh GP Committee, said: "Meningococcal septicaemia is notoriously difficult and is a disease that suddenly turns overwhelming in a matter of hours. The time from when it is non-diagnosable to the time when there is no effective hospital treatment can be very short."