Countries endemic for human African trypanosomiasis (HAT), also known as sleeping sickness, continue to report fewer cases, indicating that the disease is well on course for elimination as a public health problem by the end of this year.
The latest data show that only 980 cases were reported to the World Health Organization (WHO) in 2019, which include the numbers for both the rhodesiense1 and gambiense2 forms of the disease.
“There were 864 cases of gambiense HAT, which is the chronic
and more prevalent form of the disease, last year compared with 953
cases in 2018 representing a drop of 9% in one year,” said Dr José Ramón Franco-Minguell, Medical Officer, WHO Department of Control of Neglected Tropical Diseases. “It follows the sustained downward trend of the past 20 years.”
The total combined number of both forms of the disease in 2018 was 977 cases. The slight increase in cases is due to a higher number of rhodesiense HAT cases (the lesser prevalent disease form) in Malawi.3
In 2000, there were 26 550 confirmed cases reported to WHO. Sustained control efforts reduced the number to below 10 000 for the first time in 50 years in 2009 – a reduction that continued to 7129 cases in 2010, 2800 in 2015 and now to its current
level, which represents a 96% reduction during the past 20 years.
“This achievement is largely due to the hard work and efforts
of national control programmes and to an array of committed stakeholders
and the support of WHO,” said Dr Gerardo Priotto, Medical Officer, WHO Department of Control of Neglected Tropical Diseases. “Added
to this is the long-standing collaboration of Sanofi and Bayer
HealthCare who have generously donated medicines and facilitated other
initiatives, including training of personnel to improve control and
patient-screening activities over the past 20 years.”
WHO cautions that the world should not repeat the mistakes of the past and become prematurely complacent.
“Elimination as a public health problem in 2020 is an intermediate step,” said Dr Franco-Minguell. “We
need to do much more to reach the sustainable elimination of
transmission (zero cases) for gambiense HAT in 2030 as targeted in the
new WHO NTD road map.”
Achieving the 2030 goals will require maintaining the commitment of disease‐endemic countries and of donors as well as integrating control activities into health systems. These efforts should be supported by the development of improved tools, adoption
of innovative disease control approaches and effective coordination of work by stakeholders to ensure synergy of efforts.
1Trypanosoma brucei rhodesiense HAT (r‐HAT) is a zoonotic disease transmitted by tsetse flies from wild and domestic animals. It is found in eastern and southern Africa.
2Trypanosoma brucei gambiense HAT (g‐HAT) is mainly an anthroponotic disease that accounts for more than 98% of all HAT cases. It is found mainly in western and central Africa.
3In Malawi, an important increase in the number of cases was reported in the last months
of 2019 around Vwaza Marsh and Nkhotakota wildlife reserves, where the diversity of wild animals is considered to be the main potential reservoir of the disease.
4WHO provides the antitrypanosomal medicines free of charge to endemic
countries through public–private partnerships with Sanofi (pentamidine, melarsoprol, eflornithine and fexinidazole) and with Bayer HealthCare (suramin and nifurtimox). The medicines are conditioned and shipped in collaboration with MSF-Logistics.