The influenza A H1N1 viral
pandemic of 2009
commonly called Swine flu
was one of the major pandemics after
the Hong Kong Flu of 1968. It was officially declared by the Center for Disease
Control (CDC) and WHO as a pandemic in June 2009 and was declared to be over by
August 2010. However, in June 2011, an alert was reissued by WHO to the
Unlike the other Influenza viruses,
the H1N1 virus has the characteristic of affecting
people in all age groups. As per sources, 25% of the cases required ICU
admissions while the death rate was close to 7%.
An early detection and screening of
the condition can save the damage caused and prevent disease severity. H1N1
influenza diagnosis is considered a bit tricky and difficult compared to other
cases and types of Influenza. This is also attributed to the nature and
presentation of the signs and symptoms of the disease.
The common signs and symptoms of the H1N1 viral flu include fever
(above 100F), cold or runny nose, cough or headaches usually accompanied by
fatigue, nausea and vomiting. Chest X-rays and nasopharyngeal swabs are commonly used for detection of the
H1N1 virus pneumonia but often fail to detect the early interstitial stage of
A chest CT
scan considered the gold standard for the diagnosis of the early
interstitial stage of the influenza is not commonly used due to its cost,
radiation exposure as well as unavailability in an emergency set-up.
This difficulty in diagnosis had lead Dr. Americo Testa and his
team from Italy to explore the effectiveness of Chest Ultrasound as a
diagnostic tool. The research was conducted on 98 patients who were screened
for community-acquired pneumonia together with other co-morbidities.
Chest X-rays, laboratory tests,
Chest CT scan were conducted on patients for making a definitive diagnosis for
H1N1 influenza or pneumonia. This included 34 patients with an established
diagnosis of pneumonia, 16 with normal Chest X-ray findings and 33 patients as
A chest Ultrasound was conducted
amongst all the patients by the physician, who looked for 'interstitial
syndrome, alveolar consolidation, pleural line abnormalities and pleural
effusion' as reported by the researchers.
32 out of the 34 patients with an
established pneumonia diagnosis were found to have an abnormal lung pattern on
the Chest Ultrasound.
Interstitial syndrome pattern was
detected in the chest ultrasonographs of 15 of the 16 patients who had normal Chest X-ray
patterns and 63% of them were diagnosed with H1N1
An ultrasound pattern of Alveolar
consolidation was found in only 4 of the patients initially diagnosed with an
abnormal chest X-ray and pneumonia.
Out of the 33 controls, again 5 were detected
with an abnormal interstitial pattern in
The researchers thus
recommended the Chest
Ultrasound as an effective tool in the early
detection of H1N1 pneumonia especially in
an emergency set-up.