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PLoS Med. Influenza in Africa
PLoS Medicine: Influenza in Africa (Extracts, edited)
Influenza in Africa
Maria Yazdanbakhsh and Peter Kremsner argue that there needs to be better awareness, surveillance, and clinical management of common febrile diseases in Africa, especially influenza.
Formal Correction: This article has been formally corrected to address the following errors.
Maria Yazdanbakhsh 1*, Peter G. Kremsner 2,3
1 Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands,
2 Medical Research Unit, Albert Schweitzer Hospital, Lambarene, Gabon,
3 Institute for Tropical Medicine, University of T?bingen, T?bingen, Germany
Citation: Yazdanbakhsh M, Kremsner PG (2009) Influenza in Africa. PLoS Med 6(12): e1000182. doi:10.1371/journal.pmed.1000182
Published: December 15, 2009
Copyright: ? 2009 Yazdanbakhsh, Kremsner.
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: No specific funding was received for this piece.
Competing interests: The authors have declared that no competing interests exist.
Abbreviations: HI, haemagglutination inhibition
* E-mail: M.yazdanbakhsh@lumc.nl
Provenance: Not commissioned; externally peer reviewed.
Summary Points
* Influenza activity displays a seasonal pattern in temperate areas with marked peaks in the winter, but influenza is present all year round throughout the tropics.
* A well-established network of surveillance systems, World Health Organization (WHO) Flu Net, is in place in Europe and North America, providing continuous data on influenza burden and spread of viral types and subtypes.
* Recent threats of pandemic influenza are prompting the establishment of active monitoring in parts of Southeast Asia and Latin America.
* But prevalence and incidence of influenza in most tropical countries, especially in Africa, are largely unknown, and improved surveillance is needed.
* Similarly, little information on influenza vaccine efficacy in tropical Africa is available, and clinical trials are needed.
How Little We Know
Whereas in Europe and North America most of the influenza cases are reported between December and March, in tropical and subtropical regions such as in Brazil [1] or in Hong Kong [2] cases are seen throughout the year. Epidemic peaks in the tropical areas mostly occur in between those found in the Northern and Southern hemispheres. A recent survey over 7 years in Brazil showed that annual peaks of influenza cases occurred in association with the rainy seasons [3]. Important reports on spatial and temporal data that describe the global circulation of influenza highlight the fact that there is virtually no data from Africa [4],[5]. Indeed, until recently, the burden of influenza in Africa was believed to be negligible. However, sporadic reports from the Gambia [6], Senegal [7], Congo [8], Madagascar [8], Kenya [9], Ivory Coast [10], and from Gabon [11], have indicated that influenza is circulating and may be causing epidemics regularly. The study in Gabon recorded extremely high levels of antibodies to influenza A H3N2 virus in schoolchildren [11]. The haemagglutination inhibition (HI) antibodies to this influenza A virus at titers of 1,530 (ranging from 80 to 17,920) indicated that the virus had been circulating within the community in the recent past. In addition, almost all children, had anti-H1N1 HI titers above 40, while 40% showed antibodies to influenza B with HI titers of 40 or above, again highlighting the fact that multiple influenza virus strains are present in the region. The recent swine flu pandemic provides an interesting example. In the WHO influenza A (H1N1 swine flu) update of May 2009, many countries, but none in Africa, reported virus victims [12]; whereas two reports appeared in October 2009 that showed data on confirmed swine flu cases from South Africa [13] and Kenya [14], indicating that the virus was circulating in Africa, but because of the lack of a rigorous surveillance system, it was not reported as readily.
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<cite cite="http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1000182">PLoS Medicine: Influenza in Africa</cite>
Maria Yazdanbakhsh and Peter Kremsner argue that there needs to be better awareness, surveillance, and clinical management of common febrile diseases in Africa, especially influenza.
Formal Correction: This article has been formally corrected to address the following errors.
Maria Yazdanbakhsh 1*, Peter G. Kremsner 2,3
1 Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands,
2 Medical Research Unit, Albert Schweitzer Hospital, Lambarene, Gabon,
3 Institute for Tropical Medicine, University of T?bingen, T?bingen, Germany
Citation: Yazdanbakhsh M, Kremsner PG (2009) Influenza in Africa. PLoS Med 6(12): e1000182. doi:10.1371/journal.pmed.1000182
Published: December 15, 2009
Copyright: ? 2009 Yazdanbakhsh, Kremsner.
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: No specific funding was received for this piece.
Competing interests: The authors have declared that no competing interests exist.
Abbreviations: HI, haemagglutination inhibition
* E-mail: M.yazdanbakhsh@lumc.nl
Provenance: Not commissioned; externally peer reviewed.
Summary Points
* Influenza activity displays a seasonal pattern in temperate areas with marked peaks in the winter, but influenza is present all year round throughout the tropics.
* A well-established network of surveillance systems, World Health Organization (WHO) Flu Net, is in place in Europe and North America, providing continuous data on influenza burden and spread of viral types and subtypes.
* Recent threats of pandemic influenza are prompting the establishment of active monitoring in parts of Southeast Asia and Latin America.
* But prevalence and incidence of influenza in most tropical countries, especially in Africa, are largely unknown, and improved surveillance is needed.
* Similarly, little information on influenza vaccine efficacy in tropical Africa is available, and clinical trials are needed.
How Little We Know
Whereas in Europe and North America most of the influenza cases are reported between December and March, in tropical and subtropical regions such as in Brazil [1] or in Hong Kong [2] cases are seen throughout the year. Epidemic peaks in the tropical areas mostly occur in between those found in the Northern and Southern hemispheres. A recent survey over 7 years in Brazil showed that annual peaks of influenza cases occurred in association with the rainy seasons [3]. Important reports on spatial and temporal data that describe the global circulation of influenza highlight the fact that there is virtually no data from Africa [4],[5]. Indeed, until recently, the burden of influenza in Africa was believed to be negligible. However, sporadic reports from the Gambia [6], Senegal [7], Congo [8], Madagascar [8], Kenya [9], Ivory Coast [10], and from Gabon [11], have indicated that influenza is circulating and may be causing epidemics regularly. The study in Gabon recorded extremely high levels of antibodies to influenza A H3N2 virus in schoolchildren [11]. The haemagglutination inhibition (HI) antibodies to this influenza A virus at titers of 1,530 (ranging from 80 to 17,920) indicated that the virus had been circulating within the community in the recent past. In addition, almost all children, had anti-H1N1 HI titers above 40, while 40% showed antibodies to influenza B with HI titers of 40 or above, again highlighting the fact that multiple influenza virus strains are present in the region. The recent swine flu pandemic provides an interesting example. In the WHO influenza A (H1N1 swine flu) update of May 2009, many countries, but none in Africa, reported virus victims [12]; whereas two reports appeared in October 2009 that showed data on confirmed swine flu cases from South Africa [13] and Kenya [14], indicating that the virus was circulating in Africa, but because of the lack of a rigorous surveillance system, it was not reported as readily.
(...)
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