Issue No. 19
Excerpt:
Data from previous years have shown a peak in the number of outbreaks/cases during the January-March period in both poultry outbreaks (Figure 11) and human cases (Figure 4), although there is a decreasing trend in the height of the peak as years go by.
A similar, although not so evident trend, is observed when looking at the number of countries reporting outbreaks (Figure 10). As expected, during January 2010 we
have seen an increase in the total number of outbreaks and countries affected. January constitutes the peak so far (both in terms of number of outbreaks and number of affected countries) since the previous January-March period.
Against the decreasing trend observed since 2004, it seems that the peak height in January 2010 is very similar in magnitude to that of 2009.
Moreover, in terms of number of outbreaks, 2010 has already surpassed the peak of 2009, which was also reached one month later (February 2009).
This may be partially explained by the implementation of more intensive surveillance programmes in countries such as CAHO in Egypt, together with the fact that vaccination of backyard poultry was stopped in July 2009). It may also be related with a reduction on the efficacy of control programmes in endemic countries (fatigue).
During January 2010, H5N1 HPAI has re-surfaced in several countries, where the disease was believed to have been eliminated (without vaccination): Cambodia, Nepal and Israel.
It is still too early to evaluate whether these are reintroductions, where wild birds and hunting/poaching play a significant role, or whether the virus was circulating
undetected by surveillance programmes.
In the cases of Bangladesh and India, that had reported no outbreaks in the
second half of the year, a new wave of cases has been observed since the beginning of 2010.
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