Human African Trypanosomiasis ( sleeping sickness)

Ankita Desai

HUMAN AFRICAN TRYPANOSOMIASIS (SLEEPING SICKNESS)

Disease 2007 US$ 2008 US$2008 Nominal US$

2007%

2008%

2007 Rank

2008 Rank

HIV/AIDS 1,083,018,193 1,164,882,551

1,215,841,708 42.3 39.4 1 1

Malaria 468,449,438 541,746,356 565,985,827 18.3 18.3 2 2

Tuberculosis 410,428,697 445,927,582 467,538,635 16.0 15.1 3 3

Kinetoplastids

125,122,839 139,207,962 145,676,517 4.9 4.7 4 4

Kinetoplastids include Sleeping sickness.

Approximately 400 mil l ion people are at r isk of contracting a kinetoplastid disease.

Distribution of funds for sleeping sickness

Human African Trypanosomiasis = “sleeping sickness”Early stage vs. late stage

WHAT IS HAT?

Tsetse fly is a vector

HOW DOES ONE CONTRACT HAT?

Trypanosoma brucei gambiense – chronicTrypanosoma brucei rhodesiense – acute; infects

cattle and humans

WHAT CAUSES DISEASE?

Nucleus

Kinetoplast (circular DNA inside mitochondrion)

Flagella for movement

STRUCTURE OF TRYPANOSOME

TRANSMISSION/THE PARASITE’S LIFE CYCLE

36 African countries & ~ 60 million people at risk in 1996.

WHO estimate: b/w 50,000 and 70,000 people are infected.

WHO DOES IT AFFECT?

HAT mainly affects the most productive age group (15 to 45 years).

At risk if near/on: forest trails water collection points in

forests Riverbanks forest edges surrounding

plantations

Flies are attracted by large moving objects and by CO2 which is why they often feed on animals and humans

WHO IS MOST SUSCEPTIBLE?

Look for inflammation of the brain and its covering, the meninges

Tests include the following: Blood smear Cerebrospinal fluid tests Complete blood count (CBC) Lymph node aspiration

HOW TO DETECT HAT

drug treatment Melarsoprol Eflornithine (T. gambiense only)

Nifurtimox (used with Eflornithine)

HOW CAN WE CURE INFECTED PERSONS?

PROBLEM OF RELAPSE AND POTENTIAL DRUG RESISTANCE

Year

TotalNorthern Central Southern

No. treated

No. (%) relapsed

No. treated

No. (%) relapsed

No. treated

No. (%) relapsed

No. treated

No. (%) relapsed

2001 708 90 (12.7) 1,154 284 (24.6)

506 46 (9.1) 2,368 420 (17.7)

2002 572 56 (9.8) 799 180 (22.5)

135 36 (26.7) 1,506 272 (18.1)

2003 362 57 (15.7) 570 171 (30.0)

119 39 (32.8) 1,051 267 (25.4)

Total 1,642 203 (12.4)

2,523 635 (25.2)

760 121 (15.9)

4,925 959 (19.5)

Melarsoprol relapse rates in second-stage human African trypanosomiasis patients, Equateur Nord Province, 2001–2003

WHO suggests supplying people with tsetse fly traps

HOW CAN THE DISEASE BE PREVENTED?

QUESTIONS?