It is very difficult to assess the accuracy of the numbers of victims in news reports such as the one in the OP IME.
While there is undoubtedly a market for human body parts in some African belief systems (e.g. Muti) there is also a huge problem of innocent people being tortured and killed as a result of being accused of being witches, wizards and sorcerers by dangerous groups of hysterical people, usually lead by pastors and church leaders.
There is a long and inglorious history of collective panics about Satanists, witches, even Jews who were believed to sacrifice children and drink their blood. One example of the myth of the Protocols of the Elders of Zion, another is the Satanic Panic that kicked off in the US, the UK and New Zealand where many children were traumatised having been forcibly removed from their families by deluded social workers.
My understanding re Muti is that, even though evil people exist in reality who do murder and mutilate people (the victims are usually children and albinos), such people are regarded with the same level of hatred and fear that say paedophile child abusers are regarded here. This last point is important as it is definitely not a situation where whole villages or countries engage in such terrible practices, as one might believe if you read some of the more sensationalist news reports.