Vidarbha Journal of Internal Medicine < Volume 19 < July 2015
Influenza H1N1 - Revisited
Chand D A
1Associate Professor, Medicine,
Govt. Medical College, Nagpur
Address for Correspondence -
Dr. Deepti Chand
E-mail :
dachand@gmail.com
Deadly 1918 influenza pandemic was the first of the two pandemics involving H1N1 influenza virus. It
infected 500 million people across the world in three waves and killed 50 to 100 million of them, making
it one of the deadliest natural disasters in human history. In April 2009, human infection with a new
strain of this virus was confirmed in Mexico and within weeks, the infection had spread to other parts
of the world. Hardest hit regions were Southeast Asia and Africa. World Health Organization (WHO)
declared this new strain of swine-origin H1N1 as a pandemic. Later on August 10, 2010, the WHO
declared the H1N1 influenza pandemic over, stating that worldwide flu activity had returned to typical
seasonal patterns. In the ensuing years since the 2009-10 pandemic, both case and death burden had
remained fairly stable and manageable . However in India we witnessed the resurgence of H1N1
influenza in the first quarter of 2015 with the worst kind of infection and fatalities.
In India the H1N1 virus had killed 981 people in 2009 and 1763 in 2010. The mortality decreased in
2011 to 75. It claimed 405 lives in 2012 and 699 lives in 2013. In 2014, a total of 218 people died from the
H1N1 flu. As on 15th April 2015, the number of people affected in India has been over 35,077 and a
death toll of 2167 in the first three and half months of 2015 itself . The worst affected States have been
Gujarat and Rajasthan. Maharashtra had 4075 positive cases with 478 deaths till 20th April?15. 594
cases were positive in Nagpur region with case fatality of 120. In the original article published in
this issue of VJIM, Government Medical College, Nagpur witnessed 156 admissions of H1N1 positive
patients, all in Category C of which 86 were direct admissions and 70 were referred patients after
admissions outside.
Patients presenting after 5 days of symptom onset had a mortality of 43% as
compared to 27% in those presenting within 5 days of symptom onset. Young and economically
productive age group has been the most affected. Of the referred patients the mean duration of
hospitalization outside was 2.05 days in Survivors as compared to 3.98 days in Non-Survivors (p=HS).
The mortality observed in direct admissions was 24% as compared to 45% in referred patients.
66.66% of patients affected had co-morbid conditions like diabetes, hypertension, IHD, obesity
and pregnancy . So a high mortality rate was observed even in patients who reported early in the
disease course.
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http://vjim.org/pdf/vol19/influenza-h1n1-revisited.pdf
