Untreated malaria in Guinea surged as a result of the Ebola scare and probably caused far more deaths than the dreaded haemorrhagic fever itself, doctors reported Wednesday.

Tens of thousands shunned seeking help for malaria, fearing infection from people with Ebola or confinement if they showed feverish symptoms, the experts said.

Researchers led by Mateusz Plucinski from the US Centers for Disease Control and Prevention (CDC) looked at figures from 120 clinics in December 2014, when the Ebola outbreak in Guinea was at its peak.

Sixty clinics were in prefectures that had been most affected by Ebola and the 60 others in places where the disease had not been reported.

They compared this with data for attendance at these clinics in 2013 and malaria incidence from 2011 and 2014.

The number of outpatient visits in December fell by 11 percent and the tally of patients receiving malaria treatment fell by 24 percent for oral drugs and by 30 percent for injectable drugs, they found.

The falls were far greater in Ebola-affected areas. Out-patient attendance there plummeted by 42 percent in certain age groups, and the number of treated malaria cases dropped by as much as 69 percent.

But even districts which had not recorded a single case of Ebola saw substantial declines in reported malaria cases and treatment.

Malaria facilities were also badly affected by staff shortages, the study found.

Extrapolated nationwide, around 74,000 likely cases of malaria were not treated, said the study, published in The Lancet Infectious Diseases.

"It is difficult to put an exact figure on the number of excess malaria deaths," Plucinski told AFP.

"However, our study and a recently modelling analysis suggest that the number of excess malaria deaths in Guinea are likely substantially larger than number of deaths from Ebola virus disease."

Previous investigations into "uncomplicated" malaria have found that around three to 30 percent of untreated cases progress to severe malaria, depending mainly on the age of the patient. Of these cases, between 45 and 73 percent will die.

According to the World Health Organization (WHO), as of June 14, there had been 27,305 confirmed, probable and suspected cases of Ebola in Guinea, Liberia and Sierra Leone, of which 11,169 were fatal.

In Guinea, there had been 3,674 cases, 2,444 of them fatal.

"One problem is that the early symptoms of malaria -- fever, headache and body aches -- mimic those of Ebola," said Plucinski.

"(...) Our data suggest that since the start of the Ebola epidemic, people with fevers have avoided clinics for fear of contracting Ebola or being sent to an Ebola treatment centre."

"Malaria control efforts and care delivery must be kept on track during an Ebola epidemic so that progress... is not jeopardised and Ebola outbreak response is not impeded," he said.

Evidence from Sierra Leone and Liberia suggests it is "very likely" they too were devastatingly affected, said Plucinski.

In April, research based on a broad-ranging computer model, published in The Lancet, suggested an additional 11,000 deaths from malaria may have occurred in the three countries.

A further 3,900 deaths may have occurred through disruption to the supply of insecticide-treated bednets, it added.