Recombinomics Commentary 06:50
April 13, 2009
“On the other hand, all the patients had exposure to diseased or dead poultry, and they likely contracted infection from that source and not from human carriers. Furthermore, there has been no evidence of
onward transmission of infection to family members.
Several of the children are still in critical condition, and all may not survive.”
The above comments at ProMED are curious. They are made in association with another English language report raising concerns associated with the H5N1 cases in Egypt. The concerns center on the concentration of confirmed cases in toddlers, between the ages of 1 ½ and 2 ½, as well as the mild nature of the cases. None of the confirmed cases in 2009 have died and 10/12 cases are toddlers. Moreover, the cases not only recover, but the courses are mild.
Only one of the 10 toddler cases was in critical condition, and that case along with nine other toddlers has been discharged. The three cases that are currently hospitalized include two toddlers, and both have been characterized as being in “good general condition”. There was no indication that these two cases or any of the seven other cases were ever in critical condition or had developed pneumonia or had been placed on a respirator. Moreover, the most recent case, who was not a toddler, was said to be improving, reducing the likelihood of death. Thus, it is clear that there is little likelihood that any of the confirmed H5N1 cases in toddlers will die, and survival is in question for only one of the 12 confirmed cases.
This low case fatality rate is similar to the cases in the spring of 2007. Those cases were generally older and were large children between the ages of 3 and 10. Among this group, 16/17 survived and again the cases were mild and few developed pneumonia or were placed on a respirator. There was little evidence to suggest this low case fatality rate was tied to prompt oseltamivir treatment because the 10 cases prior to the mild cases in 2007 were fatal and the cases between the mild cases in 2007 and the mild case in 2009 involved patients in critical condition and most of those cases also died.
Thus, the mild cases involving children in 2007 and toddlers in 2009 has raised concerns that H5N1 has been spreading via mild cases and this spread has produced protective immunity in older cases, resulting in a high concentration of toddler cases in 2009.
This concern has been increased by the lack of testing of patients that have symptoms but no connection to dead and dying poultry, as well as the high number of patients hospitalized with symptoms and poultry contact. Less than 1% of these patients are PCR positive, raising concerns of a high number of false negatives among these hospitalized patients.
Similarly, the detection of H5N1 in two cousins who were next door neighbors and developed symptoms four days apart raise additional concerns that there was onward transmission to a relative, linkages to dead or dying poultry notwithstanding. There have been no H5N1 confirmed poultry deaths reported near the Beheira households of the cousins (see updated map) and these has also been no confirmed poultry deaths in Qena (see updated map), the location of H5N1 infected toddler confirmed prior to the Behiera cousins. The lack of reports of confirmed poultry deaths near these recent confirmed cases has raised concerns further.
Therefore the comments in ProMED, which extend the number of commentaries denying human to human transmission of H5N1, continue to be hazardous to the world’s health.