Nine babies died at a Johannesburg hospital from a disease attacking the intestines of infants, only a few months before a klebsiella outbreak killed six newborns in a Vosloorus hospital.
The outbreak of necrotising enterocolitis at the Rahima Moosa Mother & Child Hospital in Coronationville - which infected 41 babies between mid-March and July - was kept under wraps.
The cause is still unknown, despite extensive testing of babies' samples, nurses' hands, hospital surfaces and even formula milk powder.
The disease, which damages the intestines of babies and can cause parts of their gut to die, affects premature babies and occurs from time to time, said Professor Nelesh Govender, head of the Centre for Opportunistic, Tropical and Hospital Infections at the National Institute for Communicable Diseases (NICD).
"Premature newborn babies are at high risk for a variety of infections in hospitals because of their immature immune systems," said Govender. When cases start to mount, investigations are needed, he said.
In mid-March a paediatrician described as "astute" by Govender called on the NICD to investigate the cause.
Between mid-March and mid-May, 30 babies got sick at Rahima Moosa hospital and six died. Another three babies died within weeks.
The NICD was unable to find the cause. It is notoriously difficult to do so, and the disease is not always infectious.
Tests found bacterial and fungal infections in about half of the sick babies.
But almost half of those who got sick had no bacteria or fungal infections, according to NICD documents.
By July 20 there were 41 cases in total - 37 premature babies and four full-term babies.
The NICD staff went into Rahima Moosa hospital and strengthened infection control procedures in the ICU and wards for premature babies.
This included insisting on nurses, mothers, cleaners and doctors doing regular hand-washing and disinfecting their hands between seeing patients.
Swabs were taken of nurses' and mothers' hands, but no links to the outbreak were found.
The NICD said after the infection control was strengthened, the number of cases declined by mid-May.
Govender said: "The decline of cases is welcomed but unexplained."
Guy Richards, professor of critical care at Wits University, said following strict hand-hygiene principles in busy hospitals was a global problem.
"It is something that is rapidly forgotten no matter what you do."
Tests of hospital formula were also done by the NICD, and two types of bacteria were found in the powdered milk used in the hospital.
But Govender said: "The laboratory results for milk samples obtained as part of this outbreak investigation do not warrant further investigation."
The NICD does not know if milk played a role as it does not have enough data.
"In summary, the results of a comprehensive outbreak investigation did not identify the precise cause of this outbreak."
A paediatrician who spoke to the Sunday Times, asking not to be named, said infectious-disease outbreaks would keep happening across the province due to overcrowded wards.
He said doctors were at their "wits' end" as neonatal ICU units were all overcrowded.
In the klebsiella outbreak, six babies died of the 11 who were infected at Vosloorus's Thelle Mogoerane Hospital.
Gauteng health spokesperson Lesemang Matuka conceded that the province's hospitals were "severely overcrowded". He said hospitals, staff and resources had not expanded to keep up with the doubling of the Gauteng population over the past 14 years.
"We are a victim of our own success," said Matuka, a reference to what he said was a huge number of pregnant mothers travelling to Gauteng to use the province's hospitals.
Health minister Aaron Motsoaledi, commenting on the klebsiella outbreak, said that Gauteng needed six more hospitals to cope with the number of babies born in the province...