In WHO's expanded definition of an infodemic:
1. "an acute outpouring of information, including potentially misleading or inaccurate information": this certainly means the problem is the volume and velocity of information, and that it includes good and bad information (in which the bad is a further problem). So the first component is sheer volume and the second is that some of it is bad.
2. "This abundance of information also includes misinformation, disinformation and rumors": here the word "also" does the same thing. In other words, the abundance of information includes both accurate information and mis/disinformation etc.
That the volume of information is the first problem has been recognized by other fora (e.g., KM4Dev), and of course the bad information is universally recognized as being a problem.
For me the importance of having a focus on the sheer volume of information is to prompt the financing and development of modern (probably AI-driven) classification and sorting systems capable of managing terabytes of data. These are currently missing, but could be developed provided there is enough demand for them. Librarians throughout the world would be the managers of such systems. The problem of sorting good information from bad information is also crucial, but will take rather longer to solve - if ever.
HIFA profile: Chris Zielinski: As a Visiting Fellow in the Centre for Global Health, Chris leads the Partnerships in Health Information (Phi) programme at the University of Winchester. Formerly an NGO, Phi supports knowledge development and brokers healthcare information exchanges of all kinds. Chris has held senior positions in publishing and knowledge management with WHO in Brazzaville, Geneva, Cairo and New Delhi, with FAO in Rome, ILO in Geneva, and UNIDO in Vienna. Chris also spent three years in London as Chief Executive of the Authors Licensing and Collecting Society. He was the founder of the ExtraMED project (Third World biomedical journals on CD-ROM), and managed the Gates Foundation-supported Health Information Resource Centres project. He served on WHO’s Ethical Review Committee, and was an originator of the African Health Observatory. Chris has been a director of the World Association of Medical Editors, UK Copyright Licensing Agency, Educational Recording Agency, and International Association of Audiovisual Writers and Directors. He has served on the boards of several NGOs and ethics groupings (information and computer ethics and bioethics). UK-based, he is also building houses in Zambia. chris AT chriszielinski.com
His publications are at www.ResearchGate.net and https://winchester.academia.edu/ChrisZielinski/ and his blogs are http://ziggytheblue.wordrpress.com and https://www.tumblr.com/blog/ziggytheblue