Latest news with #epidemiologist
CBC
13 hours ago
- Health
- CBC
Obesity rates in Canada jumped during COVID-19, says new study
About one-third of Canadians have become obese — with more weight gain happening during the pandemic, according to a new study published in the Canadian Medical Association Journal on Monday. Dr. Christopher Labos, an epidemiologist and cardiologist, explains.
Yahoo
a day ago
- Health
- Yahoo
Cannabis Use Is Linked to Epigenetic Changes, Scientists Discover
Cannabis use may leave lasting fingerprints on the human body, a study of over 1,000 adults suggests – not in our DNA code itself, but in how that code is expressed. US researchers found it may cause changes in the epigenome, which acts like a set of switches that activate or deactivate genes involved in how our bodies function. "We observed associations between cumulative marijuana use and multiple epigenetic markers across time," explained epidemiologist Lifang Hou from Northwestern University when the research was published in 2023. Cannabis is a commonly used substance in the US, with nearly half of Americans having tried it at least once, Hou and team report in their published paper. Related: Some US states and other countries have made cannabis use legal, but we still don't fully understand its effects on our health. To investigate this, the researchers analyzed data from a long-running health study that had tracked around 1,000 adults over two decades. Participants, who were between 18 and 30 years old when the study began, were surveyed about their cannabis use over the years and gave blood samples at the 15- and 20-year marks. Using these blood samples from five years apart, Hou and her team looked at the epigenetic changes, specifically DNA methylation levels, of people who had used cannabis recently or for a long time. The addition or removal of methyl groups from DNA is one of the most studied epigenetic modifications. Without changing the genomic sequence, DNA methylation affects how easily cells 'read' and interpret genes, much like someone covering up key lines in your set of instructions. Environmental and lifestyle factors can trigger these methylation changes, which can be passed to future generations, and blood biomarkers can provide information about both recent and historical exposures. "We previously identified associations between marijuana use and the aging process as captured through DNA methylation," Hou said. "We wanted to further explore whether specific epigenetic factors were associated with marijuana and whether these factors are related to health outcomes." The comprehensive data on the participants' cannabis use allowed the researchers to estimate cumulative use over time as well as recent use and compare it with DNA methylation markers in their blood for analysis. They found numerous DNA methylation markers in the 15-year blood samples, 22 that were associated with recent use, and 31 associated with cumulative cannabis use. In the samples taken at the 20-year point, they identified 132 markers linked to recent use and 16 linked to cumulative use. "Interestingly, we consistently identified one marker that has previously been associated with tobacco use," Hou explained, "suggesting a potential shared epigenetic regulation between tobacco and marijuana use." Multiple epigenetic changes associated with cannabis use had previously been linked to things like cellular proliferation, hormone signaling, infections, neurological disorders like schizophrenia and bipolar disorder, and substance use disorders. It's important to note that this study doesn't prove that cannabis directly causes these changes or causes health problems. "This research has provided novel insights into the association between marijuana use and epigenetic factors," said epidemiologist Drew Nannini from Northwestern University. "Additional studies are needed to determine whether these associations are consistently observed in different populations. Moreover, studies examining the effect of marijuana on age-related health outcomes may provide further insight into the long-term effect of marijuana on health." The study has been published in Molecular Psychiatry. An earlier version of this article was published in July 2023. To Tackle Our Obesity Crisis, Experts Say Everything We Do Must Change Big City Lights Could Be Damaging Your Heart Health Ice Bath Trend Raises Health Concerns. Here Are 6 Tips For Staying Safe.
Medscape
7 days ago
- Health
- Medscape
Can Long COVID Be Decoded?
For Ziyad Al-Aly, MD, senior clinical epidemiologist at Washington University in St. Louis, this is a critical time for long COVID research in the United States. Even as funding cuts imperil progress, there is a hope that potential new treatments, as well as a better understanding of the causes of the condition, can help researchers like himself make real progress in uncovering effective treatments for patients. In a recent interview, Al-Aly explains how the research he and others are conducting could affect patients in the near future.
RNZ News
07-07-2025
- Health
- RNZ News
Epidemiologist on teen who died from flu complications
health national 19 minutes ago A 15-year-old died from complications of influenza B on Saturday. Otago University epidemiologist, Professor Michael Baker spoke to Ingrid Hipkiss.
Yahoo
10-05-2025
- Health
- Yahoo
Whooping cough is surging. Here's what you can do to protect yourself.
When you buy through links on our articles, Future and its syndication partners may earn a commission. Whooping cough, a bacterial infection that can be especially dangerous for babies and young children, is on the rise. Already in 2025 the U.S. has recorded 8,485 cases. That's compared with 4,266 cases during the same period in 2024. Like measles, which is also spreading at unprecedented levels, whooping cough, more formally known as pertussis, can be prevented by a safe and effective vaccine. But with anti-vaccine sentiment increasing and cuts to immunization services, vaccination rates for whooping cough over the past two years have declined in children. The Conversation asked epidemiologist Annette Regan to explain why pertussis has become so prevalent and how families can protect themselves from the disease. Pertussis is a vaccine-preventable disease caused by the bacterium Bordetella pertussis. Researchers in France first identified the B. pertussis bacterium in 1906. The first recorded epidemic of pertussis is thought to have occurred in Paris in 1578. Infection can cause an acute respiratory illness characterized by severe and spasmodic coughing spells. The classic symptom of pertussis is a "whoop" sound caused by someone trying to breath during a bad cough. Severe complications of pertussis include slowed or stopped breathing, pneumonia and seizures. The disease is most severe in young babies, although severe cases and deaths can also occur in older children and adults. Some doctors call pertussis "the 100-day cough" because symptoms can linger for weeks or even months. Related: Whooping cough outbreaks: Why is pertussis on the rise in several countries? The World Health Organization estimates that 24.1 million pertussis cases and 160,700 deaths occur worldwide in children under 5 each year. Pertussis is highly contagious. Upon exposure, 80% of people who have not been previously exposed to the bacterium or vaccinated against the disease will develop an infection. Fortunately, the disease is largely preventable with a safe and effective vaccine, which was first licensed in the U.S. in 1914. During the COVID-19 pandemic between 2020 and 2022, pertussis cases were lower than usual. This may have been a result of limited social contact due to social distancing, masking, school closures and lockdown measures, which reduced the spread of disease overall. In the past two years, however, pertussis cases have surpassed figures from before the pandemic. In 2024, local and state public health agencies reported 35,435 pertussis cases to the Centers for Disease Control and Prevention — a rate five times higher than the 7,063 cases reported in 2023 and nearly double the 18,617 cases reported in 2019 prior to the pandemic. Between October 2024 and April 2025, at least four people in the U.S. have died of pertussis: two infants, one school-age child and one adult. Although vaccines have resulted in a dramatic decline in pertussis infections in the U.S., incidence of the disease has been rising since the 1990s, except for a brief dip during the COVID-19 pandemic. Before the start of routine childhood vaccination for pertussis in 1947, its rates hovered between 100,000 and 200,000 cases per year. With vaccines, rates plunged under 50,000 annually by the late 1950s and under 10,000 per year in the late 1960s. They reached a low of 1,010 cases in 1976. Starting in the 1980s and 1990s, however, the U.S. and several other countries have been seeing a steady resurgence of pertussis cases, which have exceeded 10,000 cases in the U.S. every year from 2003 to 2019. They dropped again during the pandemic until last year's resurgence. There is no single explanation for why cases have been rising recently, but several factors probably contribute. First, pertussis naturally occurs in cyclic epidemics, peaking every two to five years. It is possible that the U.S. is headed into one of these peaks after a period of low activity between 2020 and 2022. However, some scientists have noted that the increase in cases is larger than what would be expected during a usual peak. Some scientists have noted that this apparent resurgence correlates with a change in the type of vaccine used in children. Until the 1990s, the pertussis vaccine contained whole, killed B. pertussis bacteria cells. Whole-cell vaccine can stimulate a long-lasting immune response, but it is also more likely to cause fever and other vaccine reactions in children. In the 1990s, national vaccine programs began to transition to a vaccine that contains purified components of the bacterial cell but not the whole cell. Some scientists now believe that although this partial-cell vaccine is less likely to cause high fevers in children, it provides protection for a shorter time. Immunity after whole-cell vaccination is thought to last 10-12 years compared with three to five years after the partial-cell vaccine. This means people may become susceptible to infection more quickly after vaccination. Vaccination rates are also not as high as they should be and have started falling in children since 2020. In the U.S., the percent of kindergartners who are up to date with recommended pertussis vaccines has declined from 95% during the 2019-20 school year to 92% in the 2023-24 school year. Even fewer adolescents receive a booster dose. Routine vaccination for children starting in infancy followed by booster doses in adolescents and adults can help keep immunity high. Public health experts recommend that children receive five doses of the pertussis vaccine. According to the recommendations, they should receive the first three doses at 2, 4 and 6 months of age, then two additional doses at 15 months and 4 years of age, with the aim of providing protection through early adolescence. Infants younger than 6 weeks are not old enough to get a pertussis vaccine but are at the greatest risk of severe illness from pertussis. Vaccination during pregnancy can offer protection from birth due to antibodies that pass from the mother to the developing fetus. Many countries, including the U.S., now recommend that women receive one dose of pertussis vaccine between the 27th and 36th week of every pregnancy to protect their babies. To maintain protection against pertussis after childhood, a booster dose of pertussis vaccine is recommended for adolescents at 11 to 12 years of age. The CDC recommends that all adults receive at least one booster dose. Because immunity declines over time, people who are in contact with infants and other high-risk groups, such as caregivers, parents and grandparents, may benefit from additional booster doses. When feasible, the CDC also recommends a booster dose for adults 65 years and older. Vaccine safety studies over the past 80 years have proven the pertussis vaccine to be safe. Around 20% to 40% of vaccinated infants experience local reactions, such as pain, redness and swelling at the vaccination site, and 3% to 5% of vaccinated infants experience a low-grade fever. More severe reactions are much less common and occur in fewer than 1% of vaccinated infants. RELATED STORIES —Measles has long-term health consequences for kids. Vaccines can prevent all of them. —Shingles vaccine may directly guard against dementia, study hints —'We're already on the precipice of disaster': Deadly measles outbreaks could explode across the US in the next 25 years if vaccinations fall, model predicts The vaccine is also highly effective: For the first year after receiving all five doses of the pertussis vaccine, 98% of children are protected from pertussis. Five years after the fifth dose, 65% of vaccinated children remain protected. Booster vaccination during adolescence protects 74% of teens against pertussis, and booster vaccination during pregnancy protects 91% to 94% of immunized babies against hospitalization due to pertussis. Families can talk to their regular health care providers about whether a pertussis vaccine is needed for their child, themselves or other family members. This edited article is republished from The Conversation under a Creative Commons license. Read the original article.
