April 19, 2023
Do we need to be concerned about avian flu?
Everyone has noticed that the prices of eggs and poultry have gone up. One reason is the continued spread of avian flu. So, what is avian flu? Should we be worried?
What is avian flu?
Avian influenza, also known as bird flu, is a highly contagious viral infection that affects both domestic and wild birds. There are several strains of bird flu, among which H5N1 and H7N9 are more worrisome due to the possibility of transmission from birds to humans. While this rarely happens, H5N1 is a highly pathogenic virus. Since 1997, outbreaks of this strain and a few infections in humans have occurred in Asia, Africa, and Europe. H5N1 can infect mammals that eat the dead bird cadavers. Such infections could increase the risk of mutations in the virus that could make it more transmissible to humans. Recently, there has been a spillover of the H5N1 virus into harbor and gray seals in New England. You can read more about the risk of future mutations in the H5N1 strain of virus in this post by the Global Virus Network.
While very rare, it is possible for people who come into close contact with infected birds, bird saliva or feces to get infected. According to the Centers for Disease Control and Prevention’s latest update on H5N1, 58 million poultry birds in more than 46 states been infected. So far, one human case has been reported in the United States. Between December 2022 and March 2023, 24 countries in Europe reported H5N1 cases in domestic and wild birds.
The symptoms of avian flu
The symptoms of avian flu vary. Infected birds can experience diarrhea, respiratory problems, and a sudden drop in egg production. In severe cases, they may die.
Most people infected with bird flu will experience very mild symptoms, such as fever, cough, vomiting, sore throat, and diarrhea, according to the World Health Organization. A few patients may develop more severe symptoms, such as pneumonia, difficulty breathing, respiratory failure, and even death. The fatality rate for humans from infection with H5N1 or H7N9 is much higher than that of seasonal flu infection.
Prevention and treatment
Preventing bird flu is crucial. While most people are at low risk of contracting bird flu, people who handle birds should take precautions. Proper measurements include isolating infected birds, sterilizing equipment, monitoring bird populations for signs of disease, wearing protective gear, and washing hands frequently. If you suspect you are sick, please seek medical attention immediately.
There are also vaccines for birds, although they are not always effective.
In humans, antiviral drugs such as neuraminidase inhibitors (oseltamivir, zanamivir) can be used to treat bird flu. They are most effective when taken within 48 hours of the onset of symptoms. Seasonal influenza vaccines do not fully protect against bird flu infection, but they do reduce the risk.
Although we have developed a deep understanding of how bird flu interacts with its host, we still have a long way to go to better understand the evolving bird flu and develop new antiviral drugs and vaccines to fight different strains of bird flu. Closely monitoring virus outbreaks is critical to prevent them from becoming the next pandemic.
Christian Brèchot, MD, PhD
Senior Associate Dean for Research in Global Affairs, USF Health Morsani College of Medicine
Associate Vice President for International Partnerships and Innovation, USF
Professor, Department of Internal Medicine
President, Global Virus Network
Linman Li, MBA, MPH, PMP, CPH
Director, USF- GVN Center
USF Health Morsani College of Medicine
Vice President, Global Virus Network
February 2, 2023
Will 2023 be a New Year for COVID-19?
China lifted its zero-epidemic policy in December 2023. Since then, a huge number of people in the country have been infected with SARS-CoV-2 — around one billion. From December 1, 2022 to January 23, 2023, a total of 10,165 valid COVID-19 genome sequences, all of which are omicron variants, have been reported in China, according to data released by the Chinese Center for Disease Control and Prevention. with a total of 24 novel Omicron strains. The main strains were BA.5.2, causing 70.2% of infections, and BF.7, causing 28.3%. (Other omicron subvariants include XBB.1, BQ.1.1.17, BQ.1.1, BQ.1.2, and BQ.1.8. Both BA.5.2 and BF.7 are derivatives of BA.5.)
Meanwhile, as of January 29, the U.S. Centers for Disease Control and Prevention has reported that XBB 1.5 is the leading source of U.S. infections, accounting for about 61.3% of infections, followed by BQ.1.1 at 21.8% .
The XBB. 1.5 originated from BA.2, XBB and XBB.1 recombined by two BA.2 sublineages. Both BA.5 and XBB originate from BA.2. The Centers for Disease Control and Prevention has a chart that clearly illustrates how each lineage is related to the others.
None of the abovementioned variants are new variants, since they were previously identified in other countries. In particular, BF.7 and XBB (the predecessor of XBB 1.5) shows surprising infectivity, with a reproductive rate as high as 10 to 18 (In comparison, the Delta variant has a reproductive rate of about 4 or 5). Also, they very efficiently escape the host humoral antibody-based immune response. Fortunately, thus far, they do not show increased severity in disease, and the vaccination still offers protection against severe infections.
Will there be a new COVID-19 variant?
The current surge of variants and significant wave of infections in China and the U.S has clearly established that the COVID-19 pandemic is not over. However, we are still determining what will happen in the future and the emergence of new, more serious variants cannot be ruled out. This is especially important in China, because the number of infections is so high that it could lead to a new generation of mutations. Since vaccination began more than a year ago, China’s domestic vaccine has been less effective than the mRNA-based vaccine; The booster rate is also very low, resulting in decreased immunity. Thus, in the hundreds of millions of cases that have occurred in China, viral mutations, or genetic drift, are possible and has the potential to spill over globally. Given the current situation, we need to focus on preparedness and surveillance.
The Importance of Surveillance, Preparedness, and International Collaborations
According to an article published in Nature, sequencing around 0.5% of the cases, with a turnaround time of less than 21 days, could provide a benchmark for SARS-CoV-2 genomic surveillance. The study noted that of the 189 countries that shared sequences through GISAID in the first two years of the pandemic, 78% of high-income countries sequenced 0.5% of their COVID-19 cases, while 42% of low- and middle-income countries achieved this level. About 25 percent of the genomes from high-income countries were submitted within 21 days, as were 5 percent of the genomes from low – and middle-income countries. However, surveillance has changed dramatically since the beginning of 2022, with an increasing number of people using at-home rapid COVID-19 test kits or not testing at all.
In this context, genomics-based surveillance and effective detection of the virus at borders, as well as in clinical and wastewater samples, will be key in the coming months. COVID-19 is a global challenge, and independent, science-based international collaborations is essential. USF Health and Global Virus Network scientists will continue to strengthen their collaboration and work with international partners to contribute to the surveillance and monitoring of novel variants and the understanding of their transmissibility.
Christian Brèchot, MD, PhD
Senior Associate Dean for Research in Global Affairs, USF Health Morsani College of Medicine
Associate Vice President for International Partnerships and Innovation, USF
Professor, Department of Internal Medicine
President, Global Virus Network
Linman Li, MBA, MPH, PMP, CPH
Director, USF- GVN Center
USF Health Morsani College of Medicine
Vice President, Global Virus Network
December 7, 2022
New Insights on long COVID
It has been nearly three years since the first COVID-19 case was reported. Unfortunately, now it is clear that this infection can cause the long-term complications that we refer to as “long COVID” or “post-COVID conditions (PCC)”. So, what is long COVID? People infected with SARS-COV-2 may experience, in addition to the frequent loss of taste and/or smell, symptoms such as fatigue, brain fog, shortness of breath and cardiovascular problems for as long as a few weeks, months, or even a year or more. Please visit U.S. Centers for Disease Control and Prevention for a complete list of long COVID symptoms. Also, it is important to understand that we are just getting now the results of the first prospective studies, based on many COVID19-infected individuals over the past two years. We are just starting to see the full picture of this novel disease emerge.
Long COVID prevalence and potential impact of vaccines
According to a long COVID cohort study in south Africa, one-third of infected patients are likely to have persistent symptoms following COVID-19. Indeed, this study has shown that 46.7% of hospitalized and 18.5% of non-hospitalized participants had more than one symptom 6 months after infection with SARS-COV-2. Many risk factors play an important role in the severity of the symptoms. For example, the patient’s age, race, gender (women are more susceptible to long COVID) and preexisting diseases (cardiovascular disease, diabetes, obesity and so on) are involved. The frequency of long-COVID also depends on the variant which has induced the disease. In fact, it is now clear that Omicron and Omicron-related variants (such as the BQ1.1, which is leading the race in the USA) induce long COVID much less frequently (around 60 % for Beta and Delta variants, but only around 19% for Omicron-related variants) While this is good news, given the huge number of infected patients, 19 % still means that many people may suffer from persistent symptoms.
The impact of COVID-19 vaccination on the frequency of long COVID is debated. The study in South Africa reported no correlation between self-reported vaccination status before and after SARS-CoV-2 infection and persistent symptoms. However, in another cross-sectional U.S. study published in JAMA Network, of 16,000 US adults who had previously tested positive for COVID-19, 15% reported current prolonged COVID symptoms, but those who were vaccinated experienced less frequently prolonged symptoms. Another study, published in The Lancet Discovery Science, also suggested that vaccination before the SARS-COV-2 infection might reduce the prevalence of long COVID. All these studies have their limitations. Vaccination may reduce the risk of developing long COVID, but further studies are needed to draw any solid conclusion.
The Importance of international collaborations
Scientists around the world should work together to address the mechanism of long COVID-19 by sharing clinical samples and data. There are many mechanisms which need to be explored to really understand the disease and to offer treatments in the future. Even though many people suffer from persistent symptoms after recovering from COVID-19, the diversity of symptoms can make it difficult to define a syndrome. To promote a global and coordinated response to the threat of long COVID, the Global Virus Network (GVN) hosted a first of its kind, two-day on-line conference in July 2022 called GVN Science of Long Covid Conference to bring together a global network of experts to exchange scientific ideas, distill the most important scientific advances in our understanding of long COVID, and help chart a comprehensive and collaborative scientific program of research on long COVID. You can watch the Day 1 and Day 2 recordings here. The chairs of the conference and GVN Long-COVID Task Force members Dr. Rubeshan Perumal from Centre for the AIDS Programme of Research in South Africa (CAPRISA) and Dr. Janko Nikolich-Žugich from University of Arizona have identified a framework of mechanisms underlying the persistence of symptoms that affect a significant portion of the individuals that were infected with SARS-CoV-2, resulting in high human and health care costs.
What to do if you have long COVID?
If you are experiencing any long-COVID symptoms, please make sure seek professional help. Make an appointment with your health care providers. USF Tampa General Physicians Group is here to help you. Always remember that vaccination is the best option. We wish everyone to have a safe and healthy holiday season.
Christian Brèchot, MD, PhD
Senior Associate Dean for Research in Global Affairs, USF Health Morsani College of Medicine
Associate Vice President for International Partnerships and Innovation, USF
Professor, Department of Internal Medicine
President, Global Virus Network
Linman Li, MBA, MPH, PMP, CPH
Director, USF- GVN Center
USF Health Morsani College of Medicine
Vice President, Global Virus Network
