Feb 1, 2013
WHO confirms 5 recent H5N1 cases in Cambodia
The World Health Organization (WHO) today confirmed five cases of H5N1 avian flu that were reported in Cambodia in the past week, four of which were fatal. The illnesses are the world's first H5N1 cases this year. The sole surviving patient is an 8-month-old boy from Phnom Penh, who the WHO said had only mild flu-like symptoms before recovering. The others were a 17-year-old girl from Takeo province (earlier reports said she was 15), a 9-year-old girl from Kampot province, and a 35-year-old man and 17-month-old girl, both from Kong Pisey district in Kampong Speu province. The agency did not say whether those two cases shared any connection. Disease-onset dates ranged from Jan 9 to 15. Four of the five patients had contact with sick or dead poultry before they became ill. The WHO update said rapid-response teams are investigating close contacts and seeing if there are any epidemiologic links among the patients. The number of WHO-confirmed cases in Cambodia since 2005 has now reached 26, of which 23 have been fatal. The global count now stands at 615 H5N1 cases and 364 deaths.
Feb 1 WHO report
Feb 1 WHO global H5N1 case count
Researchers find most asthma patients had uncomplicated pH1N1 course
Asthma, the most common underlying medical condition in patients hospitalized for pandemic H1N1 influenza (pH1N1), was associated with an uncomplicated flu course unless pneumonia was present at admission, according to a study published yesterday in BMC Infectious Diseases. The patient population comprised 473 patients 2 years of age or older who were hospitalized with pH1N1 in 2009. As determined through patients charts, 137 (29%) had asthma. Those with asthma were significantly more likely than those without to be 2 to 17 years of age (39% vs 30%, P = 0.04), to be black (29% vs 18%, P <0.01), and to have chronic obstructive pulmonary disease (13% vs 9%, P = 0.04). However, the asthmatic pH1N1 patients were less likely than nonasthmatics to have pneumonia (37% vs 47%, P = 0.05), to need mechanical ventilation (13% vs 23%, P = 0.02), or to die of flu (4% vs 10%, P = 0.04). Asthmatic patients who were admitted to the intensive care unit (ICU) or who died, however, were more likely to have pneumonia (60% versus 27%, P < 0.01) or acute respiratory distress syndrome (24% versus 0%, P < 0.01) than survivors not admitted to the ICU.
Jan 31 BMC Infect Dis abstract
High prevalence of HA mutation in Mexican patients with severe pH1N1
Mexican researchers confirm reports from elsewhere that an amino acid mutation at hemagglutinin (HA) position 222 of the pH1N1 flu virus was associated with increased severity and death during the 2009 pandemic. Their study was published yesterday in Virology Journal. Respiratory samples from 50 patients hospitalized with severe pH1N1 and 27 ambulatory patients with mild pH1N1 in Mexico City were studied during the second pandemic wave (September 2009 to April 2010). Fourteen (28%) of the patients with severe disease had a nonaspartic acid residue at D222, compared with none of the patients with mild disease. These patients had a higher mortality rate than those without (71.4% versus 22.2%, P = 0.0008). In addition, 12 patients with severe disease had a G222 substitution alone or coexisting with N222 and D222 substitutions; 8 of these patients died. In a second phase of the study, the researchers cultured 4 of 14 viruses from the patients with severe disease and infected mice intranasally with them. Two viruses containing the G222 mutation were fatal in the mice; a third with the G222 mutation plus a virus with a D222 mutation caused mild disease in the animals.
Jan 31 Virol J abstract