Copyright © Françoise Herrmann
The theme
for UN World Health Day 2014 is Preventing vector-borne disease.
Vector-borne diseases are transmitted through a vector that is an organism such
as insects, mosquitoes, tics and flies. These organisms transmit pathogens and
parasites from one infected person (or animal) to another, causing serious
diseases in human populations [WHO (1)].
The most
deadly vector-born disease is malaria, transmitted through mosquitos carrying
the plasmodium parasite, causing an
estimated 627,000 deaths in 2012.
The
fastest growing vector borne disease is dengue, also transmitted through
mosquitos carrying one of four dengue virus serotypes. There is no vaccine or
specific treatment for dengue. The most severe form of this disease is
hemorrhagic dengue fever, which causes severe bleeding as a lethal
complication. It is estimated that
dengue puts about 40% of the world population at risk. [WHO (2)]
Other
vector-borne diseases include, for example:
· Chagas disease
Life-threatening condition transmitted through triatomine bugs, contaminated food, infected blood transfusion
Life-threatening condition transmitted through triatomine bugs, contaminated food, infected blood transfusion
·
Chikungunya
Viral disease transmitted to humans by infected mosquitoes
Viral disease transmitted to humans by infected mosquitoes
·
Congo-Crimean haemorrhagic fever
Severe illness caused by a number of viruses
Severe illness caused by a number of viruses
·
Dracunculiasis
Infection caused by drinking-water containing water fleas that have ingested Dracunculus larvae
Infection caused by drinking-water containing water fleas that have ingested Dracunculus larvae
·
Human African trypanosomiasis
Glossina-borne parasitic infection, fatal without prompt diagnosis and treatment
Glossina-borne parasitic infection, fatal without prompt diagnosis and treatment
·
Leishmaniasis
Infection is caused if bitten by female sandflies
Infection is caused if bitten by female sandflies
·
Lymphatic filariasis
Infection occurs when filarial parasites are transmitted to humans through mosquitoes
Infection occurs when filarial parasites are transmitted to humans through mosquitoes
·
Lyme disease
Disease caused by infected ticks
Disease caused by infected ticks
·
Onchocerciasis
Parasitic disease caused by the filarial worm onchocerca volvulus
Parasitic disease caused by the filarial worm onchocerca volvulus
·
Schistosomiasis
Parasitic disease caused by trematode flatworms of the genus
Parasitic disease caused by trematode flatworms of the genus
·
Yellow fever
Viral disease transmitted via aedes mosquitoes
Viral disease transmitted via aedes mosquitoes
·
Most of
the vector-borne diseases listed above are also considered Neglected Tropical Diseases (NTDs), that is,
a group of diseases for which there are currently no available treatments,
even though the figures associated with each of the diseases are staggering [NTDs, (1)].
It is “a conversation in progress”, bringing
together many players and institutions (public, private, philanthropic and
civil society), to endeavor to include unprofitable drug development for these
diseases on the agenda of large pharmaceutical companies, whether for the discovery
of new drugs, or the reformulation of orphan
drugs (drugs that are patented, and often already tested, but that were
abandoned and never marketed).
Indeed, for those confronted with these
diseases, or their outbreaks, in the field, such as Doctors without borders/Médecins
sans frontières and other NGOs, or civil society groups, there is a feeling of total
helplessness without treatments, and indignation, by way of comparison, that
cures and treatments for every possible complaint exist in the west (Balasegaram,
2014). Witnesses of the NTDs are well aware that pharmaceutical companies are
business enterprises who claim they are compelled to recoup the cost of drug
development. But these witnesses in the field, fighting NTDs, also deplore that some of the
larger drug companies simply back out of drug development for NTDs, arguing that
none of their clients in poverty-stricken or underdeveloped countries can
afford the costs of treatment. (Balasagaram, 2014).
Consequently,
this polarization of interests between the desperate need for NTD treatments,
and the balance sheets of “Big Pharma” or large western pharmaceutical agendas,
is increasingly seen as a fruitless
dead-end. Smaller R&D agendas, such as those of OneWorldHealth, targeting NTD
drug development, invoking partnerships between government agencies,
philanthropic players and private enterprise, appear far more resourceful and
successful in developing or retargeting drugs, and producing treatments at a
fraction of the costs, thus engaging in purposeful and life-saving action
(Hale, Woo & Lipton, 2005).
At the
end of the day… various stakeholders also point out that the scales may
eventually tip “more naturally”. On the one hand, the realization that in an
interconnected world, the risk of these diseases looms in the west also will
promote action in favor of prevention [WHO (3); Chneiwess, 2013]. And, on the
other hand, the threat of drug resistance to common bacterial infections in the
west will most certainly redirect pharmaceutical agendas towards the
development of new types of antibiotics.
In the
interim – and it is a sad irony that no such interim or waiting period exists for those impacted by the spread of
parasites or vector-borne NTDs --, here are some of the staggering figures
associated with 10 vector-borne NTDs:
·
4% of the drugs developed worldwide target NTDs,
whereas these diseases account for 10% of the diseases worldwide
·
1 billion people worldwide are threatened by NTDS,
and 30,000 people die each day from these diseases. (Touraine, M., 2014 - Institut Pasteur webcast)
-----
Even though change is slow, it is also heartening to see that today, the world is celebrating the prevention of vector-borne diseases that include many NTDs, and thus that such diseases are no longer completely neglected, although much remains to be accomplished so that the statistics are no longer shameful. Consistent efforts by such multilateral groups as United to combat NTDs and what is referred to as the 2012 London Declaration, action has begun [NTDs,(2)].
References
Balasegaram, M. (Winter 2014). Drugs of the poor, drugs for the rich.
Alert, vol. 15, No. 1.
Chneiweiss, H. (2013) Preface in Biotehcnologie: Quelle Limites? Quo
vadis Homo sapiens ? by Bernard Fontaine. Paris : France : L’Harmattan.
Hale, V. Woo, K and H. Levens Lipton (July 2005.)
Oxymoron no more: the potential for non-profit pharmaceutical companies to
deliver on the promise of medicines for the developing world. Health Affairs,
24(4), pp. 1057-1063. http://content.healthaffairs.org/content/24/4/1057.full
Institut Pasteur webcast
http://www.who.int/neglected_diseases/Paris_2014_webcast/en/
NTDs (1) – Neglected Tropical Diseases
http://unitingtocombatntds.org/why-ntds
NTDs (2) Uniting to combat NTDs - Report
http://unitingtocombatntds.org/report/delivering-promises-driving-progress-second-report-uniting-combat-ntds
Touraine, M. (April, 2014) Webcast presentation
on the occasion of World Health Day 2014 at the institute Pasteur in Paris. http://www.who.int/neglected_diseases/Paris_2014_webcast/en/
WHO (1) - World Health Day 2014
http://www.who.int/campaigns/world-health-day/2014/en/
WHO (2) - About vector borne diseases
http://www.who.int/campaigns/world-health-day/2014/vector-borne-diseases/en/
WHO (3) Europeans
at risk of vector borne diseases too.
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