Tag: 29/11/21

Smoking During Pregnancy Can Impact a Subsequent Pregnancy

Source: Pawel Czerwinski on Unsplash

University of Southampton researchers have found that the link between smoking at the start of pregnancy and having a smaller baby may extend to future pregnancies.

The research team studied data between 2003 and 2018 for nearly 17 000 mothers who received antenatal care for their first two pregnancies. 

The findings, published in PLOS One, showed that, compared to non-smokers, women who smoked at the start of their first pregnancy were more likely to have a baby born smaller than expected in their second pregnancy. This held true even where they quit by the start of their second pregnancy.

The link between smoking during a pregnancy and that baby’s birth weight is well established. However, until now there has been limited evidence on the impact of maternal smoking on following pregnancies.

This study found that for women who smoked but did not smoke at the start of either pregnancy, there was no extra risk of a small for gestational age (SGA) baby in the second pregnancy compared to non-smokers. A mother who smoked ten or more cigarettes a day at the start of both of her first two pregnancies had the highest odds of SGA birth.

Study leader Dr Nisreen Alwan, Associate Professor at the University of Southampton, said: “It is important to encourage women to quit smoking before pregnancy and to not resume smoking after the baby is born. Resources that support mothers to quit and maintain smoking cessation are needed.”

First author Elizabeth Taylor said: “Women who smoke between pregnancies can reduce the risk of having a SGA baby by stopping smoking before the start of their next pregnancy. The period between pregnancies is when most mothers have close contact with health and care professionals and may require support to stop smoking.”

It is hoped that these findings and future research will encourage healthcare professionals and commissioners to provide better support to women before and between pregnancies, helping them to quit smoking, leading to better health for both mothers and children.

Source: University of Southampton

Kids’ Spit Could be a Great COVID Test

Photo by CDC

Saliva samples are easy to obtain and useful for measuring antibodies to SARS-CoV-2 in children, which could improve epidemiological surveillance in school settings. The study followed over 1500 children who went to summer schools in Barcelona last year. The results were published in BMC Medicine.

One of the pressing questions during this pandemic has been to understand children’s susceptibility to SARS-CoV-2 infection and how they infect others. An obstacle to answer this question is that most infections in children are mild or asymptomatic, and are therefore missed. To establish whether an individual has been exposed to SARS-CoV-2 in the past, virus-specific antibodies in blood need to be detected. Measuring antibody prevalence over time in a cohort of children can provide very valuable epidemiological information. However, this requires techniques that are both sensitive and minimally invasive.

In this study, performed through the Kids Corona platform, the team led by Carlota Dobaño, from the Barcelona Institute for Global Health (ISGlobal), and Iolanda Jordan, from Hospital Sant Joan de Déu (HSJD), used saliva instead of blood to measure virus-specific antibodies in over 1500 children who attended different summer schools in Barcelona in 2020, as well as around 400 adult staff. Two saliva samples per participant were analysed, one at the beginning and one at the end of the camp stay, and different antibody types (IgG, IgA and IgM) targeting different viral antigens were measured.

The study found that 3.2% of the participants developed antibodies between the first and second sample, indicating new infections. This is six times higher than the infection rate estimated by weekly PCR screening. “It has been reported that some children can be positive for antibodies despite being negative by PCR, which suggests that they can generate an immune response that prevents the establishment of SARS-CoV-2 infection,” explained Dobaño, first author of the study. It could also be because asymptomatic children have lower viral loads or that their viral clearance is faster.

Furthermore, the analysis shows that the percentage of new infections was higher in adults (2.94%) than in children (1.3%), suggesting differences in infection and transmission dynamics. Finally, contrary to blood tests, asymptomatic people had higher levels of anti-Spike antibodies in saliva, suggesting these antibodies play a protective role in respiratory mucosae. “This means that anti-Spike antibodies in saliva could be used to measure protective immunity upon vaccination, especially in the case of intranasal vaccines,” said senior study co-author Gemma Moncunill.

“We previously demonstrated in other Kids Corona studies that saliva is useful for detecting virus by PCR. With this study, we demonstrate that it’s also an effective and much friendlier way to measure antibodies, making it the ideal sample for children, instead of the more invasive nasal swab,” said Jordan.

Source: EurekAlert!

Older Women Struggle More with Daily Activities

Photo by Bennett Tobias on Unsplash

Older women are more likely to struggle with both regular daily tasks and mobility activities, according to new analysis of longitudinal cohort studies.

However, the researchers say disparities in ability to perform daily tasks have been steadily decreasing as the socioeconomic gap between the sexes has decreased.  

The international study, published in The Lancet Healthy Longevity, uses data from more than 27 000 men and 34 000 women aged 50 to 100, born between 1895 and 1960, to examine sex differences in daily activity and mobility limitations. Researchers at UCL and the National Institute of Health and Medical Research (INSERM) in France drew on four large longitudinal studies, covering 14 countries*.

Women were more found to be more likely than men to be limited in their ‘functional capacity’ (both tasks and mobility) as they get older. From age 75, women were also more likely to have three or more mobility issues (such as going up a flight of stairs) or limitations with more complex daily tasks (eg managing money) compared to men who were more likely to have just one or two. At age 85 years, the prevalence of three or more mobility limitations was 10% higher in women than in men.

Lead author, Mikaela Bloomberg, UCL PhD candidate, explained: “Our study of over 60,000 participants born between 1895 and 1960 provides new insights on functional limitations and sex differences.

“We found that women are more likely to be limited than men in carrying out daily tasks from age 70, while we observed women were more likely to be limited in mobility activities from age 50 onward.

“This is an important observation because mobility limitations can precede other more severe limitations and targeting these gaps at middle age could be one way to reduce sex differences in limitations at older ages.”

Historical socioeconomic differences between men and women in areas such as education and entrance to the labour force may partly explain these differences, as women are disproportionately exposed to associated health risks that can lead to disability.

“It appears that gender inequalities in the ability to carry out daily tasks at older age are decreasing over time and this could be explained by the fact that women have better access to education and are more likely to enter the paid labour force in recent generations,” said Bloomberg.

“And although reductions in socioeconomic inequalities may be associated with smaller disparities in simple daily tasks, we did not see the same reductions in sex disparities for mobility after accounting for socioeconomic factors. This might be partly due to sex differences in body composition such as body mass and skeletal muscle index but more research is needed to identify other factors.”

Co-author Dr Séverine Sabia added: “Developing targeted prevention policies to preserve independent living and quality of life for older adults requires an understanding of drivers of sex differences in functional limitations.

“Our study indicates improvements in socioeconomic conditions for women could play an important role in reducing these sex differences. Findings also highlight the importance of early prevention to tackle sex differences in mobility that may trigger sex differences in disability at older age.”

Source: University College London

Differences in Drug Onset Explain Development of Resistance

HIV invading a human cell
HIV invading a human cell: Credit NIH

Researchers examining the development of resistance to HIV drugs have uncovered a mechanism of drug resistance development in combination therapy, where ‘windows’ open up for resistance to develop.

In the late 1980s, when HIV treatments were first introduced, patients would often develop resistance to those treatments within six months. The introduction of triple-drug treatment regimens in the 1990s was intended to rectify that. Even if the virus developed resistance to one drug, two others would still knock it out – in theory. Unfortunately, some patients still develop resistance, leaving scientists with a critical question to answer: Why?

“There’s all these things that we still don’t understand, like why do we even get resistance when treating with three drugs,” said San Francisco State University Associate Professor of Biology Pleuni Pennings. “We understand why it is becoming less common, but it should have been zero all along.”

Prof Pennings and her colleagues offer explanations for this phenomenon in a study published in eLife.

Several interesting observations were noted from analysis of HIV patient records. Drug resistance can evolve years after successful therapy, often the result of sequential mutations that occur in a predictable order. Current models could not explain these observations, and while some studies identify mutations that confer drug resistance, they don’t address how and where they arise.

Drawing on two computational models, the researchers suggest that these observations may result from drug heterogeneity over time and throughout the body. While patients receive three HIV therapies simultaneously, drugs have different half-lives and patients do not always adhere to therapy regimens. This could create opportunities for drug resistance evolution, during a window when only one drug is active. Drugs also don’t uniformly penetrate the entire body, meaning that in some locations in a patient’s body, only one of the drugs might be active, creating another evolution and escape opportunity.

“I think one main reason why we should care is actually not because of HIV but because of drug resistance in other situations,” Prof Pennings explained.

Although drug resistance among patients with HIV is fairly low, drug resistance to multidrug therapies is a big problem for diseases such as malaria and tuberculosis. In addition, the COVID pandemic and the rise of variants show how our understanding of evolving pathogens is still lacking.

“In a way, HIV is the poster child of how we solved drug resistance. … [But] if we don’t understand how we did it, then it’s really hard to take these lessons to other situations,” Prof Pennings said.

Source: San Francisco State University

About 1% of Hospitalised COVID Patients Develop Neurological Complications

49-year-old female with past medical history of mitral valve disease and tricuspid valve regurgitation who developed headache followed by cough and fever presented to the ER with right upper eyelid ptosis (drooping). Credit: Radiological Society of North America and Scott H. Faro, M.D.

Approximately one in 100 patients hospitalised with COVID will likely develop complications of the central nervous system, according to a large international study. These can include stroke, haemorrhage, and other potentially fatal complications. The study was presented at the annual meeting of the Radiological Society of North America (RSNA).

“Much has been written about the overall pulmonary problems related to COVID, but we do not often talk about the other organs that can be affected,” said study lead author Scott H. Faro, MD, FASFNR, professor of radiology and neurology at Thomas Jefferson University. “Our study shows that central nervous system complications represent a significant cause of morbidity and mortality in this devastating pandemic.”

Dr Faro initiated the study after finding that only a small number of cases informed existing literature on central nervous system complications in hospitalised COVID patients.

To build a more complete picture, he and his colleagues analysed nearly 40 000 cases of hospitalised COVID patients, admitted between September 2019 and June 2020. Their average age was 66 years old, and two thirds were men.

Confusion and altered mental status were the most common causes of admission followed by fever. Comorbidities such as hypertension, cardiac disease and diabetes were common.

There were 442 acute neuroimaging findings most likely associated with the viral infection, with central nervous system complications in 1.2% of this large patient group.

“Of all the inpatients who had imaging such as MRI or a CT scan of the brain, the exam was positive approximately 10% of the time,” Dr Faro said. “The incidence of 1.2% means that a little more than one in 100 patients admitted to the hospital with COVID are going to have a brain problem of some sort.”

Ischaemic stroke, with an incidence of 6.2%, was the most common complication, followed by intracranial haemorrhage (3.72%) and encephalitis (0.47%).

A small percentage of unusual findings was uncovered, such as acute disseminating encephalomyelitis, an inflammation of the brain and spinal cord, and posterior reversible encephalopathy syndrome, a syndrome that mimics many of the symptoms of a stroke.

“It is important to know an accurate incidence of all the major central nervous system complications,” Dr Faro said. “There should probably be a low threshold to order brain imaging for patients with COVID.”

Source: EurekAlert!

WHO Criticises Omicron Travel Bans as SA Stays at Level 1

Image by Quicknews

The emergence of the Omicron SARS-CoV-2 variant which has resulted in renewed lockdowns and travel bans around the world, which have been criticised by the WHO. In contrast, South Africa will stick to an adjusted Level 1 lockdown for the time being, though pushing for mandatory vaccinations. Business and civil society groups had warned that increasing restrictions would have provoked backlash as recent election campaign events had effectively ignored them.

Many nations around the world have reacted quickly to the new variant, which has a large number of mutations compared to the Delta variant. The UK’s decision to suspend flights from South Africa as well as nine other African countries has provoked criticism from a number of quarters, including President Cyril Ramaphosa. The sudden move has caught many travellers by surprise, including a Welsh rugby team which had two members test positive, one of which was for Omicron. They will have to self-isolate before they are able to return, depending on flight availability.

Japan and Israel have taken the more extreme steps of closing their borders to foreigners. The first cases of Omicron that were recorded in Botswana were revealed to be in visiting diplomats, although which country they came from has not been revealed. 

The World Health Organization criticised the imposition of travel restrictions, acknowledging that although they may play a role in slightly reducing the spread of COVID, they still place a heavy burden on lives and livelihoods. It pointed out that if restrictions are implemented, they should not be unnecessarily invasive or intrusive, and should be scientifically based, under international law, the International Health Regulations. It notes South Africa followed International Health Regulations, and informed WHO as soon as its national laboratory identified the Omicron variant. 

“The speed and transparency of the South African and Botswana governments in informing the world of the new variant is to be commended. WHO stands with African countries which had the courage to boldly share life-saving public health information, helping protect the world against the spread of COVID,” said Dr Matshidiso Moeti, WHO Regional Director for Africa. “On the eve of a special session on pandemic preparedness I urge all countries to respect their legal obligations and implement scientifically based public health actions. It is critical that countries which are open with their data are supported as this is the only way to ensure we receive important data in a timely manner.”

Although a full picture of the new variant’s severity is still two or three weeks away, Angelique Coetzee, chair of the South African Medical Association, told the AFP she had recently seen around 30 patients at her Pretoria practice who tested positive for COVID but had unfamiliar symptoms.

“What brought them to the surgery was this extreme tiredness,” she said, something she said was unusual for younger patients. Most were men under 40, and just under half were vaccinated. Other symptoms included mild muscle aches, a “scratchy throat” and dry cough, she said. Just a few had a slightly high temperature. These very mild symptoms stand in contrast to other variants, which typically result in more severe symptoms.