Neglected Tropical Diseases - Sustaining the

Drive

Dr. Rajesh Karyakarte MD

Professor and Head,Department of Microbiology,Government Medical College, Akola,Maharashtra, India

MAHAMICROCON 2014

NTDs – Introduction-1

Neglected tropical diseases (NTDs) are caused by diverse pathogens, majority being parasites

Associated with: poverty and deprived environments in tropics

NTDs also anchor large populations in poverty

NTDs – Introduction-2

Most of the NTDs are ancient and have plagued humanity for centuries

NTDs disappear as living conditions and hygiene improve

NTDs affect an estimated 100 Crore people living in: Remote rural areas and Urban slums of tropical countries

NTDs – Introduction-3

NTDs are found in places with low socio-economic progress, where: Substandard housing, Lack of access to safe water and

sanitation, Filthy environments, and Abundant insects and other vectors contribute to efficient transmission of

infection

WHO’s Initiative

In 2007, WHO launched a “Global Plan to Combat Neglected Tropical Diseases 2008–2015”

In 2010, the first WHO report on neglected tropical diseases, “Working to overcome the global impact of neglected tropical diseases” was released

In 2013, the second WHO report on neglected tropical diseases, “Sustaining the drive to overcome the global impact of neglected tropical diseases” was released

WHO Report-1

In all 17 NTDs have been profiled in the first WHO report on neglected tropical diseases

Some NTDs comprise separate infections and thus separate diseases

For example, soil-transmitted helminthiases include: Ascariasis Trichuriasis Hookworm diseases

WHO Report-2

NTDs are endemic in 149 out of 260 (57.30%) countries and territories

Of these,

At least 100 countries are endemic for 2 or more NTDs

And 30 countries are endemic for 6 or more NTDs

Parasitic NTDs

ParasiticChagas disease (American trypanosomiasis)

Cysticercosis

Dracunculiasis (guinea-worm disease)

Echinococcosis

Human African trypanosomiasis (sleeping sickness)

Leishmaniasis

Lymphatic filariasis (elephantiasis)

Schistosomiasis (bilharziasis)

Onchocerciasis (river blindness)

Foodborne trematode infections

Soil-transmitted helminthiasis

Bacterial and viral NTDs

BacterialTrachomaBuruli ulcer (Mycobacterium ulcerans infection)Leprosy (Hansen disease)Endemic treponematoses

ViralDengueRabies

Nine NTDs (of 17) plague India Dengue Rabies Leprosy Trachoma Cysticercosis Echinococcosis Leishmaniasis Lymphatic Filariasis Soil transmitted helminthiasis Yaws and Guinea worm infection -

eliminated

NTDs – Anchor poor in poverty-1

Onchocerciasis and trachoma cause blindness

Leprosy and lymphatic filariasis cause deformation that hinder: Economic productivity and Normal social life

Buruli ulcer maim patients when limbs have to be amputated to save their life

NTDs – Anchor poor in poverty-2

Human African trypanosomiasis (sleeping sickness) severely debilitates before it kills, and mortality approaches 100% in untreated cases

Without post-exposure prophylaxis, rabies causes acute encephalitis and is always fatal

NTDs – Anchor poor in poverty-3

Leishmaniasis, in its various forms:

Cause deep and permanent scars or Entirely destroys the mucous

membranes of the nose, mouth and throat In its most severe form, it attacks the internal organs and is rapidly fatal, if untreated

NTDs – Anchor poor in poverty-4

Chagas disease damages heart of young adults, reducing the labor force

Severe schistosomiasis: Decreases school attendance, Contributes to malnutrition, and Impairs the cognitive development of

children

NTDs – Anchor poor in poverty-5

Guinea-worm disease debilitates the agricultural work force, during peak season, due to excruciating pain

Dengue affects mostly poor, urban populations; it is also the leading cause of hospital

admissions in several countries

NTDs – Consequences-1

The consequences of NTDs are very costly for societies and for health care, for example: Intensive care is required for dengue

hemorrhagic fever and clinical rabies Surgery and prolonged hospital stays is

necessary for Chagas disease and Buruli ulcer

NTDs – Consequences-2

The consequences of NTDs are very costly for societies and for health care, for example: Rehabilitation for leprosy and lymphatic

filariasis Cumbersome administration of toxic drugs

for sleeping sickness and leishmaniasis Expensive post-exposure immunization for

Rabies that is not affordable in many Asian and African countries

NTDs - Common features-1

A proxy for poverty and disadvantage NTDs have an enormous impact on individuals,

families and communities in developing countries in terms of ▪ disease burden ▪ quality of life▪ loss of productivity▪ aggravation of poverty ▪ high cost of long-term care

They constitute a serious obstacle to socioeconomic development and quality of life at all levels

NTDs - Common features-2

Affect populations with low visibility and little political voice NTDs affect low-income and politically

marginalized people living in rural and urban areas

NTDs are concentrated in remote rural areas or urban slums

NTDs are linked to poverty hence offer little incentive to industry to invest in developing new or better products for a market that cannot pay

NTDs - Common features-3

Do not travel widely NTDs generally do not spread widely,

and so present little threat to the inhabitants of high-income countries

Distribution of NTDs is restricted by climate, vectors and reservoir hosts to the tropics

NTDs rarely affect travelers, exceptional example being, outbreaks of dengue

NTDs - Common features-4

Cause stigma and discrimination, especially of girls and women Many NTDs cause disfigurement and disability,

leading to stigma and social discrimination In some cases, their impact disproportionately

affects girls and women, whose marriage prospects may diminish or who may be left vulnerable to abuse and abandonment

Some NTDs contribute to adverse pregnancy outcomes

NTDs – Common features-5

Have an important impact on morbidity and mortality A large body of evidence, published in

peer-reviewed medical and scientific journals, has demonstrated that NTDs adversely affect morbidity and mortality

This refutes the once-widespread assumptions held by the international community

NTDs – Common features:6

Are relatively neglected by research Research is needed to develop new

diagnostics and medicines, and to make accessible interventions to prevent, cure and manage the complications of all NTDs

NTDs - Common features:7

Can be controlled, prevented and possibly eliminated using effective and feasible solutions WHO’s Strategies: 1. Preventive chemotherapy; 2. Intensified case-management;3. Vector control;4. The provision of safe water, sanitation and hygiene;

and 5. Veterinary public health using the one-health concept

These strategies make control; prevention and even elimination of several NTDs feasible at a low cost

Preventive chemotherapy Mass distribution of seven broad-

spectrum anthelminthic medicines: Albendazole, Diethylcarbamazine, Ivermectin, Levamisole, Mebendazole, Praziquantel, and Pyrantel

Preventive chemotherapy WHO recommends these medicines

because of their: Ease of administration and Efficacy Excellent safety profiles and Minimal side-effects

Preventive chemotherapy Preventive chemotherapy is the main

intervention for controlling: Lymphatic filariasis, Onchocerciasis, Schistosomiasis, and Soil-transmitted helminthiases

Intensified case-management It is the principal strategy for

controlling and preventing those NTDs: Where no medicines are available for

preventive chemotherapy That are asymptomatic for long periods That require confirmation of diagnosis

because of the toxicity of medicines

Intensified case-management WHO recommends this intervention

strategy for prevention and control of: Buruli ulcer, Chagas disease, Human African trypanosomiasis, Leishmaniasis (in its cutaneous,

mucocutaneous and visceral forms), Leprosy, and Yaws

Vector control

Vector-borne diseases account for about 16% of the estimated global burden of communicable diseases

The judicious use of pesticides is important for the control of vector-borne diseases

Vector control

Most NTDs involve vector transmission: Insects: ▪ Dengue, ▪ Chagas disease, ▪ Human African trypanosomiasis, ▪ Leishmaniasis, ▪ Lymphatic filariasis and onchocerciasis;

Snails:▪ Foodborne trematodiasis, and ▪ Schistosomiasis;

Crustaceans: ▪ Dracunculiasis, and ▪ Foodborne paragonimiasis

Safe water, sanitation and hygiene

Statistics compiled by the United Nations reveal that: 900 million people lack access to safe

drinking-water, and 2500 million lack access to appropriate

sanitation

Until this situation improves, many NTDs and other communicable diseases will not be eliminated, and certainly not eradicated

Veterinary public health

Veterinary public health is defined as the sum of all contributions to the physical, mental and social well-being of humans through an understanding and application of veterinary sciences

In 2008, a new concept, known as “one health”, was defined as “the collaborative effort of multiple disciplines to attain optimal health for humans, animals, and our environment”.

Veterinary public health

NTDs with a zoonotic component: Cysticercosis, Echinococcosis, Foodborne trematodiasis, Human African trypanosomiasis, Leishmaniasis, and Rabies

DALYs

DALYs: Disability-Adjusted Life Years

Developed to assess: Quantitative and comparative burden of

individual diseases on human life

DALYs give an estimate of the sum of years of potential life lost due to: Premature mortality and The productive life lost

DALYs, 2004

Neglected tropical disease

DALYs (in thousands)

Human Africantrypanosomiasis

1673

Chagas disease 430Schistosomiasis 1707Leishmaniasis 1974Lymphatic filariasis 5941Onchocerciasis 389Ascariasis 1851Trichuriasis 1012Hookworm disease 1092

The global burden of disease: 2004 update. Geneva, World Health Organization, 2008.

Economic burden

WHO’s conservative assessment: Lymphatic filariasis causes a loss of almost US$

1 billion a year in lost productivity The annual expenditure for rabies prevention

and control exceeds US$ 1 billion Cysticercosis: The estimated social monetary

cost in India: US$ 15.27 million Dengue fever: The average total economic

burden in India was estimated at US$29.3 million (Cost in private health sector is 4 times this sum)

Costs of interventions

How many DALYs can be averted by the investment in control gives a proper cost benefit ratio The cost of treating a patient with

lymphatic filariasis using ivermectin and albendazole (both donated) ranges from US$ 0.05 to 0.10

While the cost of the DALYs averted is reckoned to be US$ 5.90

References

1) Working to overcome the global impact of Neglected Tropical Diseases: First WHO report on Neglected Tropical Diseases ISBN 978 92 4 156409 0 (NLM Classification: WC 680)

2) Sustaining the drive to overcome the global impact of Neglected Tropical Diseases: Second WHO report on Neglected Tropical Diseases

ISBN 978 92 4 156454 0 (NLM Classification: WC 680)

THANK YOU !