The bout of influenza that affected a lot of people towards the end of 2022 and the New Year has nothing to do with the Covid-19 virus and nor is it in any way related to vaccination.

The bout of flu which intensified during the rainy season left children and adults sick and weak, with many narrating how severe it was and the impact it had on their bodies.

Common signs and symptoms included a strong cough, fever, headache, inflammation of the tonsils and general body malaise. The nature of the influenza left many wondering if it was a normal cold or not.

"I could not go to work for two days and previously I had never failed to work because of the flu. It didn’t feel like a normal cold because I would feel feverish every evening,” explained Madeline Uwabyaye, 42, a patient at Kigali Medical Centre (KMC).

Uwabaye felt feverish on New Year’s eve and was confined to bed on January 1. Assouma Mugwaneza, a nurse at a local clinic explained that the majority of the patients that came in at the beginning of the year were mainly people with influenza who thought they had contracted malaria.

"Some say they took medicine but the flu wasn’t responding quickly and they thought they had malaria. Majority returned negative results for malaria,” said Mugwaneza.

Other people affected by the respiratory tract viral infection showed signs which include loss of appetite, general nausea and pain when coughing or sneezing. To many, the flu was more aggressive than they had ever experienced.

"Many people here in the market said that it was related to the vaccines we took, others said it could be Covid-19 in a different form,” said Augustin Kananga, a trader in Kimironko market.

But according to Prof. Claude Mambo Muvunyi, Director General of the Rwanda Biomedical Centre, there was nothing unusual with the flu escalated by the rainy season, and affected many people. Muvunyi also said the bout of flu had nothing to do with Covid-19 vaccines as some people had thought and was not associated with the pandemic.

"Influenza is a seasonal epidemic. So, it is the season and it's not only in Rwanda but even Europe and America where they are in winter. We didn’t see anything unusual despite many people feeling that it was aggressive and widespread,” Muvunyi said.

Nonetheless, the Rwanda Biomedical Centre was doing surveillance to best understand this strain of influenza.

"This influenza cannot be associated with vaccines or Covid-19. There are many factors of how one reacts to it, mainly dependent on one's immune system,” Muvunyi said.

"The seriousness varied from one person to another but most of the signs we saw were typical signs of influenza,” he said, adding that the on-going surveillance will determine whether the strains are different.

"We started doing surveillance three weeks ago and it will provide us with data which will inform us better on the nature of the influenza. But, so far, we have not had any cases of severe sickness or hospitalisation.”

Why it was widespread

Muvunyi said the reason they believe it was widespread is because during the Covid-19 period when people wore face masks, cases of flu became minimal.

"We think that now that people are no longer wearing face masks, many got exposed to the influenza virus. That is why it is advised that people in the high-risk group should continue to wear face masks, much as they are no longer mandatory,” he explained.

When people who contract flu wear masks immediately, he noted, they minimize the chances of infections. Muvunyi said that flu was not widespread in the past two years or so because of Covid-19 preventive measures.

"The same recommendations to prevent Covid-19 are the same that limit the spread of influenza; including washing hands with soap regularly and proper hygiene.”

Muvunyi said that after such a bout, people develop herd immunity and the influenza no longer becomes a threat even as the seasons change. In December, the Ministry of Health explained that the bout of flu sweeping across the country was exacerbated by the cold weather.

"Our data show an increase in seasonal flu cases during the rainy season. National laboratory surveillance testing shows that the H3N2 influenza virus remains the most prevalent in Rwanda,” reads a statement from the Ministry. People with flu-like symptoms are advised to seek treatment and avoid spreading the virus as the surveillance on the situation continues.

Last month, the World Health Organisation (WHO) warned that the 2022-2023 influenza (flu) season epidemic would affect many parts of the world, causing respiratory syncytial virus (RSV), at a time when the Covid-19 was exhibiting signs of resurfacing. The UN health agency indicated that some places, especially Europe, were experiencing increasing circulation of influenza and RSV, which together with Covid-19, were expected to have a high impact on the health services and populations during winter.

The virus was detected in 23 countries in Europe, which reported Severe Acute Respiratory Infection (SARI) data. Hospitalised patients were diagnosed mostly with type B viruses (85%), with children aged four years and younger being the most often affected.

The WHO called for increased inoculation, particularly for the unvaccinated groups and use of personal protective equipment, even when they are not mandatory.