"In the past week we have seen a slight dip in suspect cases. On average we have one new case every day and a death every two or three days," said Dr. Fortunat Mtumba, health minister for the affected Western Kasai region.
Those being admitted either have Ebola, an incurable disease characterised by massive internal bleeding, or the Shigella strand of infectious dysentery which is treatable by antibiotics, he said.
In the past four months there have been 170 fatalities from 378 cases of either Ebola or shigellosis, Mtumba said. A previous tally from September 14 put the number of fatalities at 169 from 376 patients.
Ebola kills 50 to 90 percent of those it infects. For shigellosis the mortality rate is around 40 percent. The World Health Organisation (WHO) confirmed the two outbreaks on September 11.
Ebola victims suffer high fever, severe dehydration and bleed under the skin and in severe cases from the mouth, ears and eyes. The virus is highly infectious for those who come into contact with a victim's body fluids.
Ebola has killed some 450 people in the DRC since 1976, and 1,200 people across Africa in the same period. It last swept DR Congo in 1995, then known as Zaire, claiming 245 lives out of the 315 registered cases.
The survival rate can be increased by quarantine and swift treatment of symptoms.
The first cases of the latest outbreak were detected in April around the village of Kanungu, 300 kilometres (185 miles) from the provincial capital Kananga. Five cases of Ebola and one of Shigella had since been confirmed by international laboratories.
The medical charity Doctors Without Borders (MSF) has sent extra staff and equipment and has set up an isolation centre at Kampungu, where eight people have died out of 25 hospitalised since the start of September.
"At the moment we have seven people in isolation, including three in a serious condition. Three people died at the end of last week," MSF spokeswoman Pascale Zintzen told AFP.
The WHO is also sending a team to the area, as is US-based Centers for Disease Control and Prevention.