Hong Kong flu spread: Timely interventions required

Flu casualties have been reported more in rural areas due to lack of medicines and prompt health services. In fact almost all flu patients in Jajarkot and Kalikot died due to lack of lifesaving medicines and health care providers

As of January this year, dozens of people have died and thousand others required urgent treatment in a completely unexpected outbreak of viral fever outbreak in Jajarkot and Kalikot districts. Samples from patients were sent to the National Public Health Laboratory, Kathmandu to identify the cause of the outbreak. Influenza virus A (H3N2), commonly known as “Hong Kong Flu”, was found to be responsible for this febrile outbreak. This is the first major and fatal outbreak of influenza virus this year in Nepal.

Influenza, commonly known as “flu”, is a highly contagious respiratory illness caused by viruses. There are four types of influenza viruses called A, B, C and D. Of these, flu A and B are commonly known to cause human illnesses and large epidemics in almost every season.

In Nepal, influenza virus often increases its activity during winter months and rainy season. Currently, both A and B type viruses are circulating in Nepal. Influenza A is known for causing large epidemics and even pandemic (beyond borders) in humans.

Influenza A is divided into subtypes — A (H1N1), A (H2N2), A (H3N2), A (H5N1), A (H1N1)pdm09, A (H7N9). Among these subtypes, A (H3N2) and A (H1N1)pdm09 are currently circulating in Nepal. Influenza A (H1N1)pdm09 was previously known as Swine Flu, while A (H3N2) is popularly known as Hong Kong Flu in Nepal. Influenza B is divided into two lineages — Yamagata (B/Yamagata) and Victoria (B/Victoria).

Influenza B type activity is increasing unexpectedly in Kathmandu and elsewhere across the country this winter. However, it is not known which one of two influenza B lineages is circulating in Nepal. In fact, government or private laboratories in Nepal do not further elaborate this virus to identify its lineage. Yamagata lineage, also known as Japanese Flu, is rapidly spreading in Europe. It is indeed crucial to know the lineage in order to recommend appropriate vaccine.

According to media reports, more than 100 people have died from influenza related complications and thousand others have been infected across the UK since the start of flu season this year. The virus has been identified as A (H3N2) and is dubbed “Australian Flu’ in the UK. It is said that this epidemic could be the worst outbreak in 50 years. Scientists have estimated that currently available vaccine is only 10-30 per cent effective against this year’s flu strain. Similarly, type B virus known as Japanese Flu (Yamagata lineage) is also reported to be spreading together with A (H3N2) in the UK. Physicians therefore have urged the UK government to provide the vaccine that includes both A (H3N2) as well as Yamagata strains of type B virus.

Samples from current epidemic areas of Nepal also show that A (H3N2) and type B virus are responsible for outbreaks and deaths. It shows similar trends of the flu virus activities in the UK and Nepal.

Infectious diseases spread from one country to the other very easily due to rapid globalisation, human migration and international travels. A (H1N1)pdm09 Swine Flu had reached Nepal two months after it first emerged in the US in 2009.

Sudden onset of high-grade fever, cough, sore throat, muscle or body ache, fatigue, diarrhoea and vomiting are the key symptoms of flu. Symptoms usually develop one to three days after the virus infection and last usually up to 10 days. Most of the patients do not seek advice in the early stage, while self-medication practices are very common in Nepal.

People with influenza like illness (ILI) must go through laboratory testing for the confirmation of virus. ILI includes fever more than 100.4 degrees Fahrenheit and cough for 10 days. However, it is always better to visit the hospital to identify virus using PCR testing within 3 days of the onset of illness. The government offers this testing for free to those who are suspected of having flu or fulfil the ILI criteria.

Antiviral drug known as Oseltamivir is used to treat either confirmed or suspected flu cases and is provided by the government free of cost. It is, however, recommended for those in risk groups.

People in risk groups include pregnant women at any stage of pregnancy, children under five, elderly people who are above 65 years of age, immuno compromised persons and people who have illnesses like asthma, chronic obstructive pulmonary disease, chronic bronchitis and heart disease.

In the current Jajarkot and Kalikot flu outbreaks, people above 65 years of age or children under five are being admitted to hospitals. The fatality rate is also high among individuals in these groups.

Preventive measures such as vaccination are the best option to protect people from flu related complications. It is, however, unfortunate that most people in Nepal are unaware about flu vaccines.

Casualties have been reported more in rural areas than in urban centres due to lack of medicines, prompt health or disease information and healthcare workers and hospitals. In fact almost all flu patients in Jajarkot and Kalikot died due to lack of lifesaving medicines and health care providers.

Flu has yet to peak so precautionary measures, including vaccination, are urgently required to prevent flu deaths and hospitalisations.

Pun is coordinator of the Clinical Research Unit at Sukraraj Tropical and Infectious Disease Hospital