The mystery of rare diseases

The mystery of rare diseases
by Shyama Ghosh, Ph.D.
Science Editor - Incidence and Prevalence Database, Clarivate Analytics
Life Sciences Connect

If everyone with rare diseases lived in one country, it would be the world’s third most populous country. Yet for many, rare diseases remain a mystery. Approximately 50% of people affected by rare diseases are children, with almost a third of the children with rare disease not surviving their 5th birthday. International definitions for rare diseases vary, so a disease may be considered rare in Europe but not in the U.S. Moreover, of the roughly 7,000 rare diseases known to date, only an estimated 350 rare diseases are responsible for affecting 80% of all rare disease patients.

Some diseases initially classified as rare may outgrow this categorization. One significant example is Lyme disease. In the last 20 years, there has been a 320% increase in Lyme cases worldwide. What steps need to be taken to curb the rapid spread of this rare condition? In October 2015, Brazil encountered an unusual increase in babies born with low head circumference. Amid concerns that epidemics of rare conditions such as the Zika virus disease may occur sporadically and unpredictably in Latin America, should large populations be vaccinated in anticipation of a Zika epidemic? What impact would such strategies have for the international traveler visiting such disease prone areas?

In the U.S., the September 2016 Congressional stopgap spending bill included $1.1 billion for Zika virus research. Globally, scientists joined collaborative efforts to build up research programs for speedy and effective answers. Yet, even if the Zika virus crosses from mother to baby through the placenta, similar to the West Nile virus and other viruses, its capacity to cause infant brain damage would be novel. Zika persists in the fetus for a long period, as confirmed by its detection in stillborn babies with microcephaly. Why are some women and babies apparently vulnerable to adverse effects, while a vast majority of other women infected with Zika deliver healthy babies?

Finally, if there is a link between Zika and microcephaly, the number of fetuses affected by the condition could soar as the virus spreads. What would then be the best manner to support the often impoverished families at risk, given that the babies are prone to seizures and may continue life in a vegetative state?

 

Urgent need to raise awareness

In the case of the Ebola virus disease, the question remains whether there is an ongoing risk of human transmission and another outbreak as long as the bat reservoir exists in Africa. Even though the prevalence of several rare diseases is skewed or somewhat inexact over time, there is an urgent need to raise awareness about these conditions.

This blog post is adapted from the introduction to Raising Awareness of Rare Diseases, a new report from Clarivate Analytics. Drawing extensively from data in Cortellis Clinical Trials Intelligence and the Incidence and Prevalence Database, both from Clarivate, the report endeavors to raise awareness for these conditions by elaborating on the number of affected patients worldwide, the causes for these diseases, the aid obtained from patient advocacy organizations and rare disease-specific organizations and the current market scenario regarding rare diseases.

It includes an epidemiological introduction to rare diseases, and a deeper look at specific concerns surrounding several rare conditions – Lyme disease, Zika infection, prion disease, Ebola infection and Chikungunya infection – as well as the researchers, biopharma companies and patient advocacy organizations worldwide that are striving to make a difference.

Read the full report here.

Click here to learn more about the global disease epidemiology data from the Incidence and Prevalence Database and here for in-depth trials analysis from Cortellis Clinical Trials Intelligence.

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