New flu scare

A new influenza virus that previously caused disease only in animals has crossed the species barrier to infect humans and is now threatening to spill out of eastern China, reports Sanchita Sharma.

A new killer influenza virus that previously caused disease only in animals has crossed the species barrier to infect 43 and kill eleven people in China. Since March 31, influenza A (H7N9) infections have been reported from Beijing, Shanghai and the eastern provinces of Zhejiang, Jiangsu and Anhui.

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“We do not have any instances of sustained human-to-human transmission yet. In following up the more than 600 contacts of confirmed cases, we may find some very limited transmission among close contacts,” Gregory Härtl, Department of Communications, Director-General’s Office, World Health Organisation, Geneva, told HT. “WHO does not advise any travel or trade restrictions,” he added.

Four years ago almost to the day, Mexico reported the world’s first case of H1N1 in April 2009. Over the past six years, the world saw two other brand new influenza pandemics, SARS that peaked in 2003, and influenza A H5N1 (bird flu) in 2005 and 2006.

Apart from severe pneumonia, symptoms include fever, cough, and shortness of breath. The WHO recommends that people wash their hands frequently and eat well-cooked meats.

“No vaccine is currently available, though preliminary test results provided by the WHO Collaborating Centre in China suggest that anti-viral medicines — neuraminidase inhibitors oseltamivir and zanamivir — help treat it, as they do other new influenza viruses such as influenza A H1N1 (popularly referred to as swine flu) and influenza A H5N1 (bird flu),” says Dr Sushum Sharma, director, Preventive Health programme at Max Healthcare.

In India, oseltamivir is the standard line of treatment for H1N1. Devendra Mahapatra, 27, was given a week’s dose when he was hospitalised with a cold symptoms and fever after a work trip to Pune in October 2009, when H1N1 peaked in India. “I had to wear a mask all the time, except while eating and drinking,” he says. Within days, two of my colleagues who were also on the trip tested positive, so we all ended up on the same ward.”

As in the H1N1, if the new virus starts spreading from person-to-person, instead of from animals to humans, and may continue to mutate, it would continue to infect thousands and become harder to contain. One sneeze can infect dozens who in turn infect hundreds and thousands, triggering a pandemic within days, says the global infectious diseases watchdog. It has the potential to cause a pandemic like the Hong Kong flu of 1968, which killed one million people worldwide. Or even a Spanish flu pandemic in 1918 that killed 50 million people.

The numbers are scary all right, more so when you consider that all it takes to kill are symptoms of fever, lethargy, runny nose and a sore throat.

Viruses jumping from animals to humans is not a new phenomenon. On average, one new disease has emerged every year over the past 20 years, mainly in Africa and Asia, with as many as 75% infectious diseases that have infected humans over the past 30 years having originated in animals (zoonoses). Among some infections currently thriving among humans are influenza A from wild birds, HIV from chimpanzees, plague from rodents, hepatitis B from apes, malaria from macaques and dengue from primates.

The problem with H7N9 is that it causes a mild illness in birds, which makes detection difficult as the birds appear healthy. “Extensive animal investigations are on-going. Many types of animals are being looked at. So far, poultry and pigeon samples are known to have tested positive,” said Härtl.

So, what can you do to protect yourself? Well, for a start, adopt good hygiene. Apart from protecting you from all influenza viruses — including H1N1 that killed 344 people in India last year — it will also protect you from other debilitating infections, such as tuberculosis.