Nigerian child holds up a chicken outside the family home in Todo village

Recent research findings that Nigeria may have been hit repeatedly by different strains of bird flu are raising concern, as the West African country struggles to deal with the outbreak.

It has been about five months since the deadly H5N1 bird flu strain was first detected in Nigeria. Despite repeated government assurances that its containment measures are working, experts say the outbreak is far from over.

Dr. Bala Mohammed is the secretary general of the Nigerian Veterinary Association.

"There has been some kind of a resurgence in Taraba and Lagos. And except for some few people who believe bird flu had gone, but for those on the job, the heat is on. We have new cases in Lagos and Taraba," Mohammed says.

Researchers say Nigeria may have been hit by different strains of bird flu, raising the risk of human contagion. Experts warn that, unless the Nigerian outbreak is effectively dealt with immediately, there is now a real chance that the virus could become transmissible among humans, leading to the possibility of a pandemic.

Food and Agriculture Organization representative in Nigeria Helder Muteia says surveillance is being stepped up to get a clearer picture of the current outbreak.

"We have designed an active surveillance program, because we have to know. Until this moment, we had a very passive surveillance strategy," Muteia says. "So, let us have an active surveillance. That means to go to the field and to find out what is going on there, instead of waiting for people to announce any outbreak. So, we are starting very soon an active surveillance to know exactly what is going on."

Nigerian veterinarians are pushing for radical changes in efforts to stem the bird flu outbreak as Dr. Mohammed explains.

"A whole lot of problems that I feel will have to be sorted out. Until the issue of surveillance, compensation, decontamination ... until things are done properly, until regulatory agencies collaborate, until we get either remotely or actively get the farmers to report cases, we would not get out of the problem," Mohammed says.

The World Health Organization says bird flu has infected 223 people since December 2003, killing more than 130 worldwide, primarily in Southeast Asia.