Albino children
Many South Africans use them and the services they offer are very similar. But in the Tanzanian capital of Dar es Salaam they confront you everywhere you look.
You find posters advertising them hanging in trees, nailed to fences, in bus terminals, on electric pylons, in public toilets and on the walls of hotels and shops.
They are waganga – traditional healers. The increase in the number of advertisements in every corner of the capital indicates the heavy reliance, almost worshipful attitude that ordinary Tanzanians feel towards them.
Their adverts are often crude, scribbled in marker pen on cardboard or scrap wood. Cellphone numbers are usually offered below and the names – mostly nicknames – are placed above in capital letters.
Services offered range from general good fortune, educational, business success and wealth enhancement to cures for infertility, HIV and Aids. Love charms and the power to tie the knot with the love object – often in 30 days – feature prominently.
Among the best-known healers are Bibi (grandmother) Maajabu and various maDokta (doctors; abbreviated to Dk), such as Dk Nkuba, Dk Mbuyu from Nigeria and Dk Mbalala.
To test the claims of Dk Nkuba, I told him of a cousin who was doing badly at school.
"Yes, you can come. I can cure him in just one hour," was the response.
I also travelled to Rukwa, in southwestern Tanzania, where traditional healers sell lightning.
Entering his compound, I found Dk Chimwaga sitting outside with his two wives.
I told him: "We're here for revenge – someone stole a large amount of money from us."
Dk Chimwaga: "How? Do you want to make him mad or die?
"We want him to die by lightning."
"Fine. There are two types of lightning; one which requires magic using scraps of wood and the other a new cup and plate. It's only 40000 (about R240)."
We didn't take the deal.
Probably the best-known mganga is "Professor" Majimarefu, who is famous throughout East Africa and owns a number of houses in the town of Tanga.
The wealthiest was undoubtedly Sheikh Yahya Hussen, who died in 2011 but whose son, Maalim Hassen, continues the family business.
The standard price is a coconut, or the equivalent of 200 Tanzanian shillings (about R12). But if the service is more valuable – for example, a political position or being top of the class – the charge can be a large sum of money (for example Tsh100000), a goat, a white sheet or a black chicken.
Religious faith and a belief in witchcraft are by no means mutually exclusive. Tanzanians are a religious people, and many of those who consult traditional healers are devout Catholics or Muslims.
A report by the Pew Research Centre on beliefs in sub-Saharan Africa found that 93% of Tanzanians believe in witchcraft, compared with 27% in Kenya, 29% in Uganda and 37% in Nigeria.
Of the 19 African states surveyed, the only country that came close to Tanzania was Cameroon, with a score of 78%.
The belief system is not always a benign one. In 2007 Tanzania was gripped by a wave of albino killings, apparently based on the belief that the body parts of albinos are magically charged and can be used to attain wealth.
Some people believe that having sex with an albino woman cures Aids, resulting in a rash of rapes.
To date there have been 78 documented attacks on albinos, resulting in 62 murders.
As in South Africa, the belief in witchcraft can also result in attacks on elderly people, particularly old women perceived to be witches.
A report from the Legal and Human Rights Centre indicates that, between January 2010 and June 2011, 241 old women were killed for this reason.
Tanzania's minister of national affairs, Emmanuel Nchimbi, has addressed the growing tendency of trying to harness the power of witchcraft in realising dreams of success.
"We need to preach about education, instead of the power of traditional healers. Tanzanians must stop depending on them," he said.
Ernest Kimiya, a director of the Albinism Society, attacked the "illogical thinking which … brings albino killings and escalates conflict in Tanzania".
Women are the core customers, and many of their requests to traditional healers revolve around love and marriage. Typically, they want to maintain a relationship, get married, or weave a spell of attraction over some unsuspecting male.
The men who seek their services are generally looking for wealth, a political position or promotion at work.
"Women are the ones who usually come to see us. In a month when you receive 15 customers, at least nine will be women," said Nkuba. "It doesn't matter if they're married. They'll do anything the herbalist tells them to control their lovers.
"For your information, men consume many different things without knowing it. Sometimes we give women houseflies to put in the men's food."
Another herbalist, Bibi Maajabu, offers various concoctions and charms to win the affection of a lover – known as juju. One method of ensuring the fidelity of a husband is to give the wife a charmed ballpoint pen. She must get her spouse to place the top on the pen to lock in his affections.
Another medicine designed to ensure fidelity is nasa ("stuck" in Kiswahili), which is placed under the mattress. If the husband is unfaithful, the charm will ensure that he and his lover stick together during sex and can only be separated by the traditional healer.
Ussu Mallya, the director of the country's Gender Networking Programme, says that, to break the hold of the healers, Tanzanians must learn what really makes the world go round and how to solve their "life puzzles".
Florence Majani is an intern with amaBhungane, the M&G Centre for Investigative Journalism