A couple of weeks ago we alerted readers of TropIKA.net to the publication of an important series of articles on neglected tropical diseases in the Lancet. The series continues and the following articles are now freely available (registration required).

Programmes, partnerships, and governance for elimination and control of neglected tropical diseases
Bernhard Liese, Mark Rosenberg, Alexander Schratz

Integration of control of neglected tropical diseases into health-care systems: challenges and opportunities
John O Gyapong, Margaret Gyapong, Nathaniel Yellu, Kwadwo Anakwah, George Amofah, Moses Bockarie, Sam Adjei

Mapping, monitoring, and surveillance of neglected tropical diseases: towards a policy framework
MC Baker, E Mathieu, FM Fleming, M Deming, JD King, A Garba, JB Koroma, M Bockarie, A Kabore, DP Sankara, DH Molyneux

Socioeconomic aspects of neglected tropical diseases
Lesong Conteh, Thomas Engels, David H Molyneux

Also recently published in the journal’s Seminar section is an update on human African trypanosomiasis (sleeping sickness).

The impact of sleeping sickness (human African trypanosomiasis, HAT) on ordinary families is brought home in a BBC news story that focuses on the barriers a Ugandan mother had to surmount in order to get treatment for her young daughter.

The story also describes a veterinary project in Uganda which seeks to reduce levels of infection with the trypanosome parasite in cattle. (In this part of Africa, cattle are the main reservoir of the parasite responsible for sleeping sickness in humans.) The innovative project involves private, community-based vets.

It has been reported that a search for cases of sleeping sickness (human African trypanosomiasis, HAT) in Ghana has been unable to find any active cases of the disease in humans.

Web Ghana says the search was conducted under the auspices of the Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC). Over 10,000 blood samples were taken in Western and Upper West regions but the Trypanosoma brucei parasite was found to be present in only 24 samples.

Thomas Azurago, Ghana’s HAT Programme Officer, said 57 tsetse flies were trapped during the survey in four communities in the Western Region and eight of them tested positive for the parasite. He also cautioned that there was a low awareness of the disease amongst health personnel, which could hold back efforts to complete the elimination of the disease from Ghana.

Human African trypanosomiasis (HAT, sleeping sickness) is difficult to diagnose. Presently, it requires a lumbar puncture and microscopy to search for parasites in the spinal fluid. Left untreated, HAT is fatal but most cases go undiagnosed because of poor surveillance programmes and the difficulties of performing the antiquated diagnostic technique in low-resource settings.

Efforts to improve the diagnosis of neglected infections such as HAT have been few and far between. The Foundation for Innovative New Diagnostics (FIND) is, however, making progress. It is evaluating a low-cost microscope suitable for field use and attempting to develop a molecular detection kit hat does not require a sophisticated lab or specialized personnel. More details are provided by IRIN, in an interview with Joseph Ndung’u, head of trypanosomiasis at FIND.

TropIKA.net reported earlier on the second stakeholder conference of the Drugs for Neglected Diseases initiative (DNDi) held in Nairobi. Now, an article from the IPS news service includes an interview with Marcel Tanner, chairman of DNDi’s board of directors, given during the event. He discusses the problems resulting from the lack of adequate treatments for diseases such as leishmaniasis and human African trypanosomiasis (sleeping sickness).

Using the phrase “neglected diseases, neglected people”. Marcel Tanner describes the attitude of the pharmaceutical industry towards tropical diseases that primarily affect the marginalised poor.

Trypanosomiasis, transmitted by the tsetse fly has both direct and indirect effects on human health in Africa. An article in IRIN News includes an interview with Joseph Ndung’u, head of the human African trypanosomiasis (“sleeping sickness”) programme at the Geneva-based Foundation for Innovative New Diagnostics (FIND).

Dr Ndung’u says: “Whereas the impact [of our work] on humans may not be so obvious, the link to Africa’s agriculture is what makes tsetse flies so important. With oxen to pull ploughs, you can produce 10 times more, feed yourself and your children and have enough to sell at the market.” However, he believes that the apparent drop in the number of humans affected by trypanosomiasis – from an estimated half-million a decade ago to 75,000 in 2007 according to WHO – has reduced funding for tsetse fly research, surveillance and disease control.

IRIN also spoke to Jorge Hendrichs, the head of a joint FAO and International Atomic Energy Agency (IAEA) project which seeks to control tsetse flies by releasing males sterilised by irradiation. He describes tsetse as “the poverty fly”.

“Why,” asks Jorge Hendrichs, “are there lush green areas with very hungry poor people? Look closer and you will notice women working the land with their bare hands. There are simply no animals in the poorest rural areas of Africa. Tsetse have killed the cattle that would have pulled plough sin the fields or transported food to the market.”

A family of proteins that helps influence the development of the parasite that causes sleeping-sickness (human African trypanosomiasis, HAT) has been identified in a study (1) reported in Nature. The authors argue that the protein family will prove a useful biomarker and may aid in the development of new treatments.

Keith Matthews and colleagues at the University of Edinburgh, UK show that the PAD (proteins associated with differentiation) family of proteins helps the parasite, Trypanosoma brucei, respond to specific environmental cues that influence its form — the parasites have a complex life cycle, and exist in different forms in mammalian and insect hosts.

The proteins are expressed on the surface of the transmission-competent ‘stumpy-form’ parasites in the bloodstream. When PAD expression is abolished, the ability to change shape in response to key environmentalcues is diminished.

A commentary (2) on the study has been published in the same issue of Nature.

References
1. Dean S, Marchetti R, Kirk K, Matthews KR (2009). A surface transporter family conveys the trypanosome differentiation signal. Nature; 459(7244):213-217.
2. Shadan S (2009). Microbiology: Signals for change. Nature; 459(7244):175.

The Journal of the American Medical Association (JAMA) is one of the world’s most highly rated general medical journals but is not noted for the level of attention it gives to the infectious diseases of poverty, compared for example to PLoS Medicine or the Lancet. However, a recent article in JAMA’s Medical News & Perspectives section, “Attention Sought for Neglected Diseases”, makes an interesting read.

The article uses human African trypanosomiasis (HAT; sleeping sickness) as an example of a disease where, “Doctors and nurses in the field are forced to care for patients with treatments that are largely archaic, toxic, ineffective; some are unaffordable and some are nonexistent.” The words are those of Sophie Delaunay, executive director of the US section of Médecins Sans Frontières.

The article goes on to refer to the work of the Drugs for Neglected Diseases Initiative (DNDI) and of the Neglected Tropical Disease Control Program of RTI International. Mary Linehan of RTI notes the particular difficulties of finding treatments for the three kinetoplastid diseases (HAT, Chagas disease and leishmaniasis). She says that available treatments have not been adapted to conditions in affected countries: “They require heavy management of the patient, which is very difficult to ensure in remote settings”.

Examples are briefly given of the public-private partnerships which are now seeking to develop new treatments.

JAMA is not an open-access journal but for those with access to a library with a JAMA subscription, the article may be read here.

Medical research in Angola, in southwestern Africa, will receive a major boost with the opening of a new research centre in Bengo province. A report from allAfrica.com says the centre will conduct research on a number of conditions including: malaria, TB, HIV/AIDS, filariasis, schistosomiasis, trypanosomiasis and viral haemorrhagic fevers.

The centre, known as CISA, is sponsored by Angolan government, Portugal and the Calouste Gulbenkian Foundation. Portugal’s Health Ministry and the Agostinho Neto University Medicine Faculty are partners in the project.

In a recent TropIKA.net review of new research on human African trypanosomiasis (HAT, sleeping sickness), it was noted that the great majority of cases of this disease, which is fatal if not treated, are never reported. HAT is also a disease that is of little interest to the media.

It is therefore encouraging to see a report in Uganda’s New Vision of a briefing given to journalists by Director of Health Services, Dr Samuel Ojok, concerning the HAT situation in Dokolo District. It seems that the health services, with WHO support, are acting appropriately to contain the spread of the disease in the area. The interest of the media is also commendable as it will increase awareness and aid control efforts.

However, the situation which Dr Ojok describes is very worrying. There have been 120 cases and 18 deaths recently. Dr Ojok said the disease spread to the district in 2004, following the arrival of infected animals from the Busoga region for sale by businessmen. Many cases had presented in a confusing form and as people were generally unaware of the symptoms they often delayed seeking health care.

The experience of Dokolo District is yet another demonstration that more needs to be done to control this disease, and of the need for increased research efforts.