AFRICA: Detecting stealth sleeping sickness

Photo: IAEA

Often known for its decimation of African livestock, the tsetse fly also infects humans (file photo)

DAKAR, 14 July 2009 (IRIN) - Tens of thousands of people in Africa who are infected with trypanosomiasis, also known as sleeping sickness, go undiagnosed because the only way to detect the deadly infection is through blood exams and a painful expensive lower back puncture, according to the Geneva-based Foundation for Innovative New Diagnostics (FIND).

“It is incredibly difficult now to detect the infection,” Joseph Ndung'u, FIND’s head of trypanosomiasis programme, told IRIN. “The parasite numbers are low. We are required to puncture the lumbar region [lower back] and examine the spinal fluid through a microscope in order to determine whether parasites have entered the brain.” 

Once the infection - transmitted by the tsetse fly - penetrates  the brain, it can attack the central nervous system.

FIND is evaluating a microscope that is expected to cost several times less than microscopes currently used for diagnoses. “This new microscope can be used in the field and does not require an expensive laboratory with a darkroom,” said Ndung'u.

The NGO is also researching molecular detection that does not require a sophisticated lab or specialized personnel, as well as a rapid test, which Ndung'u told IRIN is “highly feasible”.

“Right now, there must be a good technician to draw out the spinal fluid carefully, a microscope, centrifuge and someone who is able to count the number of white blood cells…Endemic areas are not likely to have all this,” said Ndung'u.

If caught early, trypanosomiasis can be cured within a week of hospitalization, said the FIND scientist. “But when the disease progresses to an advanced stage and parasites have entered the brain, the only available medication can be toxic in up to 10 percent of patients.”

The arsenic-based Melarsoprol is one of the drugs currently used for advanced infections.

World Health Organization (WHO) estimates 80 percent of late-stage trypanosomiasis patients who do not respond to treatment, die. “The medicine is toxic and a lot of effort has been put in an unsuccessful search for a safer medication,” said Ndung’u.

The moment you start ignoring a disease is when it turns into an epidemic

FIND’s Ndung'u said that while surveillance has improved and helped reduce human deaths, the disease has typically resurged after occasional dips. “The moment you start ignoring a disease is when it turns into an epidemic.”

Trypanosomiasis epidemics have taken place in Uganda and the Congo Basin between 1896 and 1906 and in a number of African countries in 1920 and 1970.

FIND’s Ndung'u told IRIN that more than 90 percent of infections are currently reported in the Democratic Republic of Congo. “This sleeping sickness disease is like a sleeping giant. It goes underreported, especially during periods of conflict, and by the time it receives national attention, a large proportion of the population is infected.”

The FIND scientist cited reports in recent years in which there was a more than 30-percent prevalence in some endemic countries.

Ndung'u told IRIN that the sleeping sickness disease prevalence is “grossly underestimated” because many areas have no surveillance, and not all countries report trypanosomiasis infections and deaths.

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