Fight dengue with a clean environment

By Carol Aloysius

A relentless surge in the number of dengue cases underscores the dengue menace is still very real and in fact escalating by the day. This year alone over 285 suspected cases have been reported countrywide - over 80 percent positive. Last Saturday, two more persons died from dengue in Katthankudi bringing the total to nearly 15 since January, the victims being mostly children.

The dengue mosquito (Aedes egypti) survives by feeding on the blood of several humans. This very active small black mosquito which bites mainly in the mornings and evenings, lays between 100-200 eggs at a time, in its short life span.

With the Health Ministry continuing to battle against the rising toll of lives, and the grave complications that dengue can bring with it, their call for clean environments free of dengue breeding grounds is now loud and clear. The Health of the Epidemiology Unit, Dr Paba Palihawadana, MOH’s and Public Health Inspectors doing house to house inspections while continuing their on going anti dengue activities, have reiterated their frequent appeals to the public: “For God’s sake, keep your environments clean. Don’t litter your gardens with discarded plastic containers and lunch sheets. Don’t throw your coconut shells where even the tiniest collection of rainwater can cause the larvae of the mosquito to hatch. Clean your gutters. If you can’t do this at least every week, get rid of them. Mend your broken drains. And make sure that not just your premises, but those of your immediate neighbours are clean since the dengue mosquito is basically a neighbourhood creature which can fly about 150 metres.”

Since the Western Province has the highest incidence of Dengue the Sunday Observer spoke to the Chief Medical Officer in charge of three municipal areas - Dehiwela, Mt Lavinia and Ratmalana, to tell us more about the disease, how to detect it, treat it and most importantly prevent it.

Following are excerpts of the interview with Dr INDIKA ELLAWELA.

Q. What is dengue?

A. It is an infection caused a virus. The virus is transmitted by Aedes aegypti and Aedes albopictus.

Q. When a patient gets an attack of dengue is he resistant to the disease thereafter?

A. There are four subtypes of the virus: DEN 1, DEN 2, DEN 3, DEN4. Therefore a human can contract dengue fever four times during the life time.

Q. What do you know about Dengue Mosquito?

A. It’s a very active small black mosquito. Female Aedes mosquito is the vector of dengue. It bites several people to get one blood meal. It bites mainly the mornings and evenings. The life span of an adult Aedes mosquito is around 2-4 weeks. It lays eggs around four times during the life span. It lays around 100 - 200 eggs at a time, The eggs are sticky, therefore difficult to remove. It takes 7-11 days to emerge an adult mosquito from the egg. The eggs can remain live up to 1 year in dry conditions and hatch on contact with water.

Q. Who are those most at risk?

A. The risk groups are:

??Children - As the Aedes mosquitoes are day bitters, school going children are more vulnerable to get infected with dengue virus

*Elders

*Obese people

*Persons with chronic diseases (eg: Bronchial asthma, diabetes)

*Persons with immunodeficiency.

Q. What happens when someone is infected with Dengue virus?

A. Around 90 percent of people infected with dengue virus for the first time do not show symptoms and signs. But they too have Dengue virus in their blood for 5-7 days. During this period if they are bitten by mosquitoes, the virus can enter into these mosquitoes with the blood meal and multiply within the mosquitoes. These infected mosquitoes can transmit virus to healthy people. Accordingly you may have already contracted Dengue fever for the first time with or without your knowledge. Once the virus enters your body it will take about 7-10 days to develop symptoms and signs.

If a person infected with one subtype of Dengue virus, antibodies are formed against that subtype and he/she will be protected for that particular virus subtype in the future, but not protected for remaining three subtypes. Therefore they can contract Dengue fever again by any of other three subtypes of virus.

When a person contracted Dengue fever for the 2nd, 3rd, or 4th time disease is more severe than first episode and possibility of developing Dengue Haemorrhagic fever is high.

Q. What are the different types of dengue commonly found in Sri Lanka?

A. Many patients infected with dengue virus remain asymptomatic. Others can develop a febrile illness one of the following types:

Undifferentiated fever

Dengue Fever (DF)

Dengue Haemorragic Fever (DHF) - most serious.

In Dengue Haemorrhagic Fever, the patient goes through different phases.

1. Fever phase

2. Critical (Leakage) phase

3. Convalescent (Recovery) phase

Q. How long does the fever phase last?

A. The fever phase usually lasts for 2-7 days’ during which patient can have body aches and pain, muscle pain, severe headache, pain behind the eyes, vomiting and rash (Red colour).

Sometimes there can be sore throat and congestion of eyes (red eyes). These symptoms are similar in both dengue fever and dengue haemorrhagic fever.

Sometimes the fever can be subside abruptly, but the patient’s condition deteriorates and develops into complications of dengue fever.

Therefore, monitoring of patient’s general condition, adequate rest and fluid intake is essential to prevent complications.

Critical phase

The critical phase is usually evident after the third day of fever and the symptoms and signs are due to plasma (liquid part of the blood) leakage through blood vessels due to the adverse effects of the virus on walls of blood vessels.

This will cause thickening of blood and circulatory failure leading to shock.

Due to the same reason, there is reduction of blood supply to essential organs in the body causing failure of vital organs.

The patient can die of either of these complications or by both. Early detection and prompt treatments can prevent death’. Reduction of platelets however is usually not a reason for death in dengue patients.

Convalescent (Recovery) phase

During the recovery phase, plasma which leaked out of the blood vessels will re-enter to the blood stream and patient’s condition improves gradually. Regaining appetite and improvement of urine output are some indicators of recovery. During this phase too it is necessary to take adequate rest and food.

Q. When or how does one suspect dengue illness?

A. Presence of the following clinical features with acute onset of fever.

Headache and retro-orbital pain

Nausea and vomiting

Joint pain (Arthralgia) and muscle pain (myalgia)

Rash

Laboratory findings

Low white cell counts (Leucopenia - WBC <5000/mm3)

Low platelet count (?150,000/ mm3)

Rising Haematocrit (HCT- 5-10%)

Q. How is the fever managed? Can it be managed at home?

A. If the patient is treated at home, make sure he/she is given adequate oral fluid intake (oral rehydration fluid, king coconut water, other fruit juices, kanji, soup) - Avoid giving red and brown drinks. Make sure he gets adequate physical rest

* Sponge him with tepid water to bring down the fever.

* If drugs are to be taken, take only paracetamol (10-15mg/kg/dose- Do not exceed 60mg/kg/24 hours)

* Anti-emetics if necessary

*Avoid other analgesics in any form and steroids

* Review daily with Full Blood Count (FBC)

First FBC should be done on the third day of fever and daily thereafter if the platelet count is >150,000/mm3; twice daily if <150,000/mm3)

However, a FBC is recommended on the first day of fever during infancy and in patients with major medical problems

Q. What are the warning signs of the onset of DHF?

A. Inability to tolerate oral fluids

*Refuse to eat or drink

*Feeling extremely thirsty

*Severe abdominal pain/ vomiting

*Cold and clammy extremities

*Bleeding manifestations

*Not passing urine for more than six hours

*Behavioural changes eg: Confusion, restlessness, lethargy, irritability

Q. When should a patient be taken to hospital?

A. All patients with a platelet count of ?100,000/ mm3

*?All patients with above mentioned warning signs

*?Infants, obese patients, patients with major medical problems, patients with adverse social circumstances (living alone, living far from health care facility without reliable transport, unreliable patients also should be admitted.

Q. Treatment given at the hospital?

A. Mortality from dengue can be reduced by timely management. Appropriate clinical management, which involves early clinical and laboratory diagnosis, intravenous rehydration and staff training.

Q. How can dengue be prevented?

A. A vaccine against dengue fever is in the process of being developed.

Chemical control is also effective in controlling mosquito population. Insecticides can be used to kill mosquito larvae or adult mosquitoes. The use of insecticides is recommended in emergency situations during dengue epidemics. However, on a regular basis use of chemical methods can make mosquitoes to develop resistance to insecticides. In addition, insecticides are expensive and harmful to human when using high doses.

Mosquito repellants which contain DEET, Picaridin or oil of lemon/eucalyptus

Precautions to avoid being bitten by mosquitoes

-Keep unscreened windows closed

One practical and recommended environmental management strategy

Is to eliminate unnecessary breeding habitats that collect water (plastic jars, bottles, cans, tires) in which Aedes aegypti mosquito can lay the eggs. This strategy is called ‘source reduction’.

Q. Your message to the public?

A. Community based approaches must go hand in hand with educational initiatives that teach people about mosquito vectors and the risk of having mosquito breeding habitats near their houses. Educational initiatives can encourage people to take an active role in participating in source reduction. Communities must understand that behavioural changes are the most effective way to control dengue.

As all of us at risk to dengue virus infection, pay attention to roof gutters because 20 percent of breeding places are found in those sites.

If you have fever…

* Suspect it as dengue fever

*Take adequate rest

*Avoid sending children to schools, adults should not to go work

*Exempt from strenuous exercise/work

*Take only Paracetamol in recommended doses for fever

* Avoid other fever reducing drugs in any form (tablets, syrups, suppositories etc) such as Diclofenac Sodium, Mefenemic Acid, Aspirin and Ibuprofen

*If fever continues for more than two days, consult a qualified doctor.

*?Drink adequate amount of liquids (oral rehydration fluid-Jeewani, king coconut water, other fruit juices, kanji, soup)

*Avoid taking red/brown colour foods or drinks which can change the colour of stools/urine.

Q. Any other comments?

A. We have noticed that more than 75 percent Dengue cases, the source of infection is inside their premises and people still believe that this source reduction exercise has to be carried out by health officials. People have to realise that regular cleaning of their premises both inside and outside is their own responsibility.

Researchers determine how the brain controls robotic grasping tools

Findings could lead to assistive technologies benefitting the disabled

Grasping an object involves a complex network of brain functions. First, visual cues are processed in specialized areas of the brain. Then, other areas of the brain use these signals to control the hands to reach for and manipulate the desired object.

New findings from researchers at the University of Missouri suggest that the cerebellum, a region of the brain that has changed very little over time, may play a critical role. Findings could lead to advancements in assistive technologies benefiting the disabled.

“We live in a world of advanced technology in which a button can move a crane or open a door,” said Scott Frey, professor of psychological sciences in the College of Arts and Science and director of the Brain Imaging Center at MU.

“For those with disabilities, assistive technologies, such as robotic arms or sensors inserted in the brain, make it possible to accomplish actions like grasping with the press of a button or directly through brain activity; however, little is known about how the human brain adapts to these technologies.

We found that the brain didn't necessarily evolve to control modern robotic arms, but rather the cerebellum, an ancient portion of our brain that has remained relatively unchanged, plays a vital role in helping us reach and grasp with these tools - often with only minimal training.”

Tasks

In the study, participants completed a series of ordinary reaching and grasping tasks involving colored wooden blocks. Regions of the brain were monitored by functional magnetic resonance imaging (fMRI). Then, in a training session, participants were introduced to a robotic arm that performed the same reaching and grasping tasks when they pressed specific buttons. Participants were told that the next day's tasks would involve their controlling the robot remotely by video feed from within an MRI scanner.

“We found evidence that the brain is very flexible and can be rapidly conditioned to associate new consequences with a variety of movements,”

Frey said. “Pressing a button is a very simple act that does not naturally result in grasping.

Nevertheless, after subjects learned that pressing one button would result in grasping objects with a robotic arm, this same movement resulted in a dramatically different pattern of brain activity than pressing an identical button known by them to have no effect on the robot's behavior. Localized activity within the cauliflower-shaped cerebellum, or ‘small brain’ sitting toward the back of the head, increased dramatically.

These findings suggests that we might look to the cerebellum when seeking potential targets for brain-controlled interfaces.”

MNT

One in two people ‘will be diagnosed with cancer’ at some point in their lives

One in two people will develop a cancer at some point in their lives, experts now estimate.

Previous calculations that indicated cancer will affect just over one in three people were underestimating the scale of the disease, according to a new analysis by Cancer Research UK.

However, because of advances in treatment and early detection, more people are now surviving cancer.

Two-thirds of the increase in risk can be attributed to the fact we are now living longer, and cancer is a disease that becomes more likely the older we get. The additional third is down to changes in lifestyle, CRUK said.

The study calculates the lifetime risk of cancer for men born in the UK in 1960 is 53.5 per cent and for women 47.55 per cent, averaging at 50.5 per cent. The risk is likely to increase for people born after 1960, and CRUK said it was confident in predicting that this meant at least half the population can now expect to get cancer.

“Cancer is primarily a disease of old age, with more than 60 per cent of all cases diagnosed in people aged over 65,” said cancer specialist Prof Peter Sasieni, who led the new study. “If people live long enough then most will get cancer at some point.

“But there’s a lot we can do to make it less likely – like giving up smoking, being more active, drinking less alcohol and maintaining a healthy weight.” The new calculation does not mean that each individual in the UK has 50/50 chance of getting cancer, as risk varies significantly according to age, weight, diet, as well as a range of lifestyle, genetic and environmental factors.

Recent estimates suggest that half of people who get cancer now survive the disease for 10 years or more - so it is projected that despite more cases, the number of deaths attributable to cancer will remain stable at around one in four.

Changes in lifestyle that have contributed to the increase in cancer risk include an increase in obesity, which is linked to a number of cancers and is projected to continue rising. Higher consumption of red and processed meats is also linked to a rise in bowel cancer. Other factors include an increase in the culture of using sunbeds and sunbathing, which has increased incidence of skin cancer, while women having babies later and breastfeeding less is also raising their chance of developing breast cancer. As well as this, more cancers are being detected by screening programs.

CRUK’s chief executive Harpal Kumar, said that the NHS faced a challenge to ensure it was “fit to cope” with the increase in cases. “If the NHS doesn’t act and invest now, we will face a crisis in the future - with outcomes from cancer going backwards,” he said. Cancer services are already coming under increased strain, with the NHS in England having missed key waiting time targets for cancer patients for the first time last year.

- The Independent