Research news in brief

One in four women in relationships with men have experienced domestic violence

According to international research published in The Lancet, 27% of women around the world aged 15 to 49 years old, who have been in a long term relationship with a man have experienced physical and/or sexual violence from a male intimate partner. The researchers estimated the prevalence of domestic violence using data from the World Health Organization’s Global Database on the Prevalence of Violence Against Women to estimate rates of domestic violence, including over 300 eligible surveys and studies conducted between 2000 and 2018. It covers 161 countries and areas, accounting for 2 million women aged 15 years and older, which WHO says is representative of 90% of women worldwide. Among women who have ever been married, lived with a partner or had a long term sexual partner who is male, the researchers say 13% have experienced intimate partner violence in the past year, and 24% have already experienced it between the ages of 15 and 19 years. Regional variations by Global Burden of Disease classifications revealed that the lifetime prevalence of intimate partner violence among women aged 15–49 years was highest in Oceania (49%), and Central Sub-Saharan Africa (44%). The regions with the lowest lifetime intimate partner violence prevalence estimates were Central Asia (18%), and Central Europe (16%).

Bats found to carry viruses genetically similar to SARS-CoV-2

Coronaviruses that are genetically similar to SARS-CoV-2, identified within bat populations in northern Laos, are described in an article published in Nature. The French research suggests that these novel bat coronaviruses may have a potential for infecting humans similar to that of early strains of SARS-CoV-2. The researchers tested 645 bats (belonging to six families and 46 species) living in the limestone caves in northern Laos. They found three viruses that they considered to be closely related to SARS-CoV-2. They found that the genetic sequences encoding the ACE2 binding regions in the novel viruses were similar to that of SARS-CoV-2; ACE2 is a human cell receptor that SARS-CoV-2 uses to gain entry to cells. The bat viruses were able to bind to human ACE2 receptors more efficiently than the original SARS-CoV-2 strain isolated from humans. One of these viruses was also shown to replicate within human cell lines, but was inhibited by antibodies neutralising SARS-CoV-2. The findings support the hypothesis that SARS-CoV-2 could have originated from bats living in the limestone caves of South-East Asia and southern China.

Bacteria in the nose may increase risk of Alzheimer disease

Research from Griffith University, published in Scientific Reports, has shown that Chlamydia pneumoniaea – a bacterium commonly present in the nose – can sneak into the brain via the nerves of the nasal cavity and set off a cascade of events that may lead to Alzheimer disease. While this bacterium often causes respiratory tract infections, it has also been found in the brain, raising the question of whether it causes damage to the central nervous system. The research shows that once the bacteria are in the central nervous system, the cells of the brain react within days by depositing β-amyloid peptide, which is the hallmark plaque of Alzheimer disease. After several weeks, numerous gene pathways that are known to be involved in Alzheimer disease are also dramatically activated. The research also showed that when the bacteria invade the olfactory nerve, peripheral nerve cells become infected and these cells may be how the bacteria can persist within the nervous system. While the studies were conducted in mice, humans have the same nerves and can be infected by the same bacteria, so the researchers believe the results are translatable to humans.

Molecular “culprit” caught driving cell death and inflammation

A Walter and Eliza Hall Institute-led study, published in Immunity, has identified a molecular “culprit” responsible for causing damaging levels of cell death and inflammation in the body. The findings could lead to improved treatment options for a range of conditions driven by inflammatory cell death, including the SARS-CoV-2 virus, the authors write. Cell death is an important part of the body’s immune response to infection. When uncontrolled, it can cause harmful amounts of inflammation in otherwise healthy organs and tissue. The research team uncovered how an overproduction of the molecule nitric oxide, which the protein caspase-8 helps to produce, caused dangerous levels of cell death. Key findings: Nitric oxide and the protein that enables its production, caspase-8, have been shown to cause a unique form of cell death that can drive excessive levels of inflammation in the body; the researchers showed that blocking the activity of caspase-8 and nitric oxide in a preclinical SARS-CoV-2 model reduced the severity of inflammation and infection; the findings suggest targeting this novel cell death pathway could create new therapeutics for a range of diseases where damaging levels of nitric oxide, cell death and inflammation occur, including asthma, inflammatory bowel disease, and COVID-19.