Did Healthmap issue an alert about Ebola before the WHO announced an outbreak had been confirmed
(question heavily paraphrased)
Yes (probably).
Their alert was probably issued on the basis that one or more healthcare workers had blogged about their concerns that the illness they were confronting might be Ebola.
It seems the WHO wait for reports and confirmation before issuing announcements of an outbreak.
(reference - see text of article linked in question)
Did a computer algorithm predict the 2014 Ebola outbreak
No.
The linked article is entitled "How A Computer Algorithm Predicted West Africa’s Ebola Outbreak Before It Was Announced" and goes on to discuss Healthmap.
The claim appears to be that Healthmap computer algorithms predicted an Ebola outbreak 9 days before the WHO announced it.
However Healthmap made no prediction saying something like "there will be an Ebola outbreak in West Africa in 9 days time"
Healthmap issues alerts about recent historical events, it does not issue predictions about future events.
So the claim that Healthmap computer algorithms made a prediction is false.
The article in question appears to be an entry on a personal blog written by "a doctoral student working on my PhD in Social and Behavioral Health"
The body of the article doesn't attempt to support its headline. The claim in the headline may not be a serious or notable claim.
The body of the article supports a claim that Healthmap announced possible cases of Ebola in West Africa before the WHO did. The article claims that Healthmap did this because Healthmap picks up on mentions of diseases in the personal blogs of healthworkers rather than only relying on official formal reports via national health agencies.
So how did a computer algorithm pick up on the start of the outbreak before the WHO? As it turns out, some of the first health care workers to see Ebola in Guinea regularly blog about their work. As they began to write about treating patients with Ebola-like symptoms, a few people on social media mentioned the blog posts.
HealthMap, a team of researchers, epidemiologists and software developers at Boston Children's Hospital founded in 2006, is an established global leader in utilizing online informal sources for disease outbreak monitoring and real-time surveillance of emerging public health threats. The freely available Web site 'healthmap.org' and mobile app 'Outbreaks Near Me' deliver real-time intelligence on a broad range of emerging infectious diseases for a diverse audience including libraries, local health departments, governments, and international travelers.
So its subject is near real-time monitoring of reports of health problems.
You can sign up for email alerts. These are shown graphically on it's front page. A summary on that page counts numbers of alerts under various categories including "Ebola(1543)"
At the Healthmap website I can find no predictions of future events.