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#17,963
Twenty-four hours after the first report (see here), Vietnamese media are now reporting the student infected with H5Nx has died after 8 days of treatment. Thus far, there are no new updates on the Khánh Hòa CDC website since yesterday's announcement.
The following (translated) report comes once again from VOV.vn (Voice of Vietnam), and provides an update into the epidemiological investigation.
I'll have more after the break on what we know - or think we know - about the fatality rate
Suffering from influenza A/H5, a 21-year-old male student in Khanh Hoa died
Saturday, 14:54, March 23, 2024
VOV.VN - A 21-year-old male student in a dormitory at Nha Trang University (Khanh Hoa) tested positive for influenza A/H5 with an unknown source of infection and died after 8 days of treatment.
At noon on March 23, a representative of Khanh Hoa Provincial Hospital of Tropical Diseases said that a male BD patient (21 years old, residing in Ninh Hoa town) infected with avian influenza A/H5 while being treated at the hospital died on March 23. morning of the same day.
“When we received the results of the patient being infected with influenza A/H5, we consulted with the Central Tropical Disease Hospitals, Ho Chi Minh City Tropical Diseases Hospital, and Khanh Hoa Provincial General Hospital but could not save the patient's life because of the condition. The disease has progressed seriously, the lungs have become fibrotic," said a representative of this hospital.
(SNIP previously known timeline)
According to the CDC of Khanh Hoa province, after receiving epidemiological information, the unit guided the patient's family on epidemic prevention measures, monitored health, and disinfected examination and treatment areas and transport vehicles. transfer.
In addition, the patient's family members, including his mother, aunt and sister, are also closely monitored for his health.
Rooms and suites in the dormitories at Nha Trang University, where the patient is studying, were also sprayed with Chloramin B to disinfect.
In addition, the CDC of Khanh Hoa province said that the results of five samples taken on March 21, from poultry flocks (including two samples from the chicken flock in the patient's house, one sample from the duck flock 50m away from the house, two samples from the flock of birds in the patient's house). where the patient often goes) all tested negative for the A/H5 virus.
Six patient samples from people in the same room as the patient at Nha Trang University are currently negative for influenza A/H5; Test results and daily health monitoring of people exposed to cases of influenza A/H5 infection are also stable, no suspicious symptoms of the disease have been detected.
This is the first case of influenza A/H5 recorded in Vietnam since the beginning of the year.
At this point we still don't know what clade, or even subtype, of H5 Vietnam is dealing with. The most obvious choices are:
- H5N1 clade 2.3.2.1c (which has caused recent cases/deaths in Cambodia)
- H5N6 clade 2.3.4.4h, which has reportedly caused roughly 90 infections and dozens of deaths in China since 2014
- and newer H5N1 clade 2.3.4.4b (which is currently circulating globally) but has a more limited history of infecting humans.
It is possible, but less likely, that they are dealing with some other subtype, clade, or variant. More precise laboratory results should be available in a few days.
While it is true that the fatality rate of known (i.e. hospitalized and tested) cases of H5Nx has hovered around the 50% mark, what is not known is how many mild or moderately ill cases go unidentified.
Seroprevalence studies suggest those numbers may be substantial (see Serological Analysis in Humans in Malaysian Borneo Suggests Prior Exposure to H5 Avian Influenza), which would produce a much lower CFR.
A look at H5N1 cases over the past 20 years also shows a wide disparity between the fatality rates of different countries, with Indonesia reporting a staggering 84% CFR (168 deaths out of 200 cases), while Egypt came in at 33% (120 out of 359 cases).
While the reasons aren't entirely clear, younger people (< 40) seem to be more susceptible to H5 infections while the opposite appears true for H7N9 (see H7N9: The Riddle Of The Ages).Exactly what accounts for this difference isn't known, although different clades circulating in each country - along with earlier treatment, and better medical care - are likely contributing factors. H5 is an HA Group type 1
Eight years ago, in Science: Protection Against Novel Flu Subtypes Via Childhood HA Imprinting, we looked at research which suggested the influenza HA Group type (1 or 2) you are first exposed to makes a significant, and lasting, impression on your immune system
- Those born prior to the mid-1960s were almost certainly first exposed to Group 1 flu viruses (H1N1 or H2N2)
- Those born after 1968 and before 1977 would have been exposed to Group 2 (H3N2)
- After 1977, both Group 1 and 2 viruses co-circulated, meaning the first exposure could have been to either one.
The bad news is, the virus keeps on trying.For now, the good news is that the virus has yet to figure out human physiology sufficiently to transmit efficiently from human-to-human.
