Qinghai H5N1 Confirmed in Cluster in Lagos Nigeria
Recombinomics Commentary
January 30, 2007
Four Nigerians are suspected to have died from H5N1 bird flu, but tests on three of the victims were inconclusive and the virus was confirmed scientifically in only one case, a senior health official said on Wednesday.
Abdulsalam Nasidi, a bird flu expert at the health ministry, said the three inconclusive cases were the mother of the confirmed case in Lagos, a poultry worker in northeastern Taraba state and one person in far northeastern Borno state.
The above comments describe four suspect H5N1 cases in Nigeria. The confirmed cases (22F) is the daughter of a suspect case. The disease onset dates strongly suggest the index case infected the confirmed case. This cluster was in Lagos, Nigeria.
The other two suspect cases are a distinct locations in Nigeria, suggested human infections may be markedly higher than the four cases described above. Poultry outbreaks have been widespread in Nigeria.
The confirmed case is the first in western Africa. However, sequences of H5N1 from Nigeria, as well as neighboring countries (Niger, Ivory Coast, Burkino Faso, and Cameroon) support multiple introductions of H5N1 into the region. However, many of these sequences carry Qinghai polymorphisms that are found in human and poultry isolates in Egypt and Djibouti, raising serious questions about human H5N1 infections in western Africa.
The above confirmation suggests a significant commitment is needed. Samples have been sent to Mill Hill in London, and the Capua lab in Rome for confirmation. However, the inconclusive results suggests on site testing would be useful.
In the past, the WHO has set up a mobile lab in Azerbaijan, with personal and technical support by NAMRU-3. The description and location of the suspect cases dictate a similar response. Recently the NAMRU-3 lab discovered the Tamiflu resistance marker, N294S, in a family cluster in Gharbiya, Egypt.
The high case fatality rate in Egypt and Nigeria also raise questions about widespread Tamiflu resistance, which can also be addressed by mobile labs at appropriate locations.
The suspect case in Borno state is near Lake Chad, which is adjacent to Niger, Nigeria, Chad, and Cameroon.
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