Fatal sleeping sickness can spread through skin

December 19, 2016

London, Dec 19: Skin plays a significant role in harbouring and transmitting a parasite that causes African sleeping sickness - a condition which is often fatal if left untreated, a new study has found.flly

The study by researchers from the University of Glasgow in Scotland and the Institut Pasteur in France, may have a major impact on the way the disease is diagnosed, treated and potentially eradicated.

The disease, which kills thousands in Sub-Saharan African every year, is primarily transmitted to humans via the bite of an infected tsetse fly as it takes a blood meal, with diagnosis then confirmed through the presence of parasites in the blood.

The new study definitively shows that substantial quantities of trypanosomes that cause the disease exist within the skin and can be transmitted back to the tsetse fly vector, even in the absence of detectable signs of infection in the animal or detectable parasites in the blood.

The researchers were also able to observe the presence of parasites in human skin biopsies from individuals who displayed no symptoms.

The study's findings suggest skin-dwelling parasites may be sufficiently abundant in the skin to be ingested, transmitted and so able to spread the disease further.

"Our results have important implications with regard to the eradication of sleeping sickness," said Annette MacLeod from University of Glasgow.

"Firstly, our findings indicate that current diagnostic methods, which rely on observing parasites in the blood, should be re-evaluated and should include examining the skin for parasites," said MacLeod.

"In terms of treatment, it may also be necessary to develop novel therapeutics capable of targeting sources of infection outside the blood circulation and in the reservoirs underneath the skin," she said.

The findings also suggest the need for a re-evaluation of disease control policies.

The current policy of the World Health Organisation (WHO) is to avoid treating people who do not show any symptoms of sleeping sickness, unless parasites are detected in their blood, due to the long duration and high toxicity of the treatment, MacLeod said.

"This policy should be reconsidered in light of our compelling evidence that these patients represent a carrier population," she said.

"This is because their lack of treatment may help maintain disease outbreaks and explain previously thwarted efforts to eliminate this major pathogen," she added.

The study appears in the journal eLife.

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Agencies
February 10,2020

Washington D.C, Feb 10: Children's vulnerability towards depression, anxiety, impulsive behaviour, and poor cognitive performance could be determined by considering the hours of sleep they manage to get.

Sleep states are active processes that support the reorganisation of brain circuitry. This makes sleep especially important for children, whose brains are developing and reorganising rapidly.

In a study by researchers from the University of Warwick -- recently published in the journal Molecular Psychiatry -- cases of 11,000 children aged between 9 and 11 years from the Adolescent Brain Cognitive Development dataset were analyzed to find out the relationship between sleep duration and brain structure.

The study was carried out by researchers Professor Jianfeng Feng, Professor Edmund Rolls, Dr. Wei Cheng and colleagues from the University of Warwick's Department of Computer Science and Fudan University.

Measures of depression, anxiety, impulsive behaviour and poor cognitive performance in the children were associated with shorter sleep duration. Moreover, the depressive problems were associated with short sleep duration one year later.

The reduced brain volume of areas such as orbitofrontal cortex, prefrontal, and temporal cortex, precuneus, and supramarginal gyrus was found to be associated with the shorter sleep duration.

Professor Jianfeng Feng, from the University of Warwick's Department of Computer Science, comments: "The recommended amount of sleep for children 6 to 12 years of age is 9-12 hours. However, sleep disturbances are common among children and adolescents around the world due to the increasing demand on their time from school, increased screen time use, and sports and social activities."

A previous study showed that about 60 per cent of adolescents in the United States receive less than eight hours of sleep on school nights.

Professor Jianfeng Feng further added: "Our findings showed that the total score for behavior problems in children with less than 7 hours sleep was 53 per cent higher on average and the cognitive total score was 7.8 per cent lower on average than for children with 9-11 hours of sleep. It highlights the importance of enough sleep in both cognition and mental health in children."

Professor Edmund Rolls from the University of Warwick's Department of Computer Science also commented: "These are important associations that have been identified between sleep duration in children, brain structure, and cognitive and mental health measures, but further research is needed to discover the underlying reasons for these relationships."

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Agencies
June 19,2020

While coughing, fever and difficulty in breathing are common symptoms of COVID-19, a new case study has found that pink eye is also a reason to be tested for the disease.

The study, published in the Canadian Journal of Ophthalmology, determined that conjunctivitis and keratoconjunctivitis can also be primary symptoms of COVID-19.

The researchers noted that in March, a 29-year-old woman arrived at the Royal Alexandra Hospital's Eye Institute of Alberta with a severe case of conjunctivitis and minimal respiratory symptoms.

After the patient had undergone several days of treatment with little improvement -- and after it had been determined that the woman had recently returned home from Asia -- a resident ordered a COVID-19 test.

The test came back positive, according to the researchers.

"What is interesting in this case, and perhaps very different to how it had been recognised at that specific time, was that the main presentation of the illness was not a respiratory symptom. It was the eye," said Carlos Solarte, an assistant professor at the University of Alberta in Canada.

"There was no fever and no cough, so we weren't led to suspect COVID-19 at the beginning. We didn't know it could present primarily with the eye and not with the lungs," Solarte said.

Academic studies at the outset of the pandemic identified conjunctivitis as a secondary symptoms in about 10 to 15 per cent of COVID-19 cases, he said.

Since then, scientists have gained greater knowledge of how the virus can transmit through and affect the body's mucous membrane system, of which the conjunctiva -- the clear, thin membrane that covers the front surface of the eye -- is an extension.

While the finding provides important new health information for the public, it also makes eye exams more complicated for ophthalmologists and staff, the researchers noted.

"The patient in this case eventually recovered well without any issues. But several of the residents and staff who were in close contact with the patient had to be under quarantine," said Solarte.

"Fortunately, none who were involved in her care also tested positive," he said.

Patients coming into an eye clinic with conjunctivitis and keratoconjunctivitis are now treated as potential cases of COVID-19 and extra precautions are taken by staff, according to the researchers.

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Agencies
January 11,2020

Europe, Jan 11: Researchers have revealed the people who drink tea at least three times a week have healthy years of life and longer life expectancy.

The research was published in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).

Dr Xinyan Wang, who is the author of the study, said: "Habitual tea consumption is associated with lower risks of cardiovascular disease and all-cause death. The favourable health effects are the most robust for green tea and for long-term habitual tea drinkers."
The analysis that was conducted included about 100,902 participants of the China-PAR project2 with no history of heart attack, stroke, or cancer.

Participants were classified into two groups: Habitual tea drinkers and never or non-habitual tea drinkers and followed-up for a median of 7.3 years.

The analyses estimated that 50-year-old habitual tea drinkers would develop coronary heart disease and stroke 1.41 years later and live 1.26 years longer than those who never or seldom drank tea. Compared with never or non-habitual tea drinkers, the habitual tea consumers had a 20 per cent lower risk of incident heart disease and stroke, 22 per cent lower risk of fatal heart disease and stroke, and 15 per cent decreased risk of all-cause death.

The potential influence of changes in tea drinking behaviour was suspected in a subset of 14,081 participants with assessments at two-time points. The average duration between the two surveys was 8.2 years, and the median follow-up after the second survey was 5.3 years.

Habitual tea drinkers who maintained their habit in both surveys had a 39 per cent lower risk of incident heart disease and stroke, 56 per cent lower risk of fatal heart disease and stroke, and 29 per cent decreased risk of all-cause death compared to consistent never or non-habitual tea drinkers.

Senior author Dr Dongfeng Gu said: "The protective effects of tea were most pronounced among the consistent habitual tea drinking group. Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term. Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect."

In a subanalysis by type of tea, drinking green tea was linked with approximately 25 per cent lower risks for incident heart disease and stroke, fatal heart disease and stroke, and all-cause death. However, no significant associations were observed for black tea.
Dr Gu noted that a preference for green tea is unique to East Asia.

Two factors may be at play. First, green tea is a rich source of polyphenols which protect against cardiovascular disease and its risk factors including high blood pressure and dyslipidaemia. Black tea is fully fermented and during this process, polyphenols are oxidised into pigments and may lose their antioxidant effects. Second, black tea is often served with milk, which previous research has shown may counteract the favourable health effects of tea on vascular function.

Gender-specific analyses showed that the protective effects of habitual tea consumption were pronounced and robust across different outcomes for men, but only modest for women. Dr Wang said: "One reason might be that 48 per cent of men were habitual tea consumers compared to just 20 per cent of women. Secondly, women had a much lower incidence of, and mortality from, heart disease and stroke. These differences made it more likely to find statistically significant results among men."

She said: "The China-PAR project is ongoing, and with more person-years of follow-up among women the associations may become more pronounced."

In conclusion, the authors have found that randomised trials are required to validate the results and to illustrate nutritional guidelines and advice for lifestyle.

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