Quanrantine of Dengue patients
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Instead of weekly foggings that is hardly effective, the MOH shd consider taking more drastic measures like quanrantine of patients to stop the spread of the virus.
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hallo. this is dengue. not SARS. if u want to quarantine the aedes aegypti mosquitoes, den i will back u up lah. quarantine patients for wad???????????Originally posted by crazy monkey:Instead of weekly foggings that is hardly effective, the MOH shd consider taking more drastic measures like quanrantine of patients to stop the spread of the virus. -
the disease is spread when mosquitoe bite an infected person.Originally posted by sinicker:hallo. this is dengue. not SARS. if u want to quarantine the aedes aegypti mosquitoes, den i will back u up lah. quarantine patients for wad??????????? -
http://www.tpub.com/content/medical/10669-c/css/10669-c_358.htm
Dengue Fever (Breakbone fever)
Dengue fever is characterized by a sudden onset of fever (occasionally lasting 7 days or more), intense headache, pain behind the eyes, joint and muscle pain, and a rash. There is early redness of the skin in some patients; usually for 3 to 4 days after the beginning of fever, a rash presents with small discolored raised spots or closely aggregated bright red points. Minute hemorrhagic or purpuric spots may appear on the feet, legs, axillae, or palate at about the same time the temperature returns to normal. Patients with dark skin often have no visible rash.
The infectious agents are the viruses of dengue fever (types 1, 2, 3, and 4). These viruses also cause dengue hemorrhagic fever (discussed later).
The reservoir is either man-mosquito or monkey- mosquito, depending on the geographic area. Dengue is endemic to tropical Asia, West Africa, parts of the Caribbean, and several countries in Central and South America.
The virus is transmitted to man by the bite of mosquitoes belonging to the genus Aedes. Mos- quitoes acquire the virus by biting man and, in some areas, monkeys. The incubation period is usually 5 to 6 days.
Patients are normally infec- tive to mosquitoes 24 hours before the onset until the fifth day of the disease. -
Treatment is suppor- tive; there are no specific antibiotics. Preventive measures require
(1) implementing mosquito surveys in affected communities to determine the density of vector mosquitoes, iden- tifying breeding places, and eliminating the vec- tors where practical; and
(2) making information available to the public concerning methods for protection from the vector mosquito bites such as the use of repellents, screening, and bed nets.
Management of patients, contacts, and the nearby environment includes (1) precautions with patient blood by denying mosquitoes access to the patient for at least 5 days after attack by using screens, an approved residual insecticide, or by the use of bed nets; and
(2) investigation of a case including the place of residence at the time of in- fection (3 to 15 days prior to the onset) and search for unreported or undiagnosed cases. There is no requirement for quarantine or immunization.
Epidemic measures, when necessary, include
(1) surveying, locating, and eliminating all manmade Aedes mosquito breeding places;
(2) en- couraging all persons who are occupationally exposed to the vectors to use repellents; and
(3) air dispersal of approved insecticides to stop epidemics. International measures require strict enforce- ment of all existing international agreements designated to prevent the spread of this disease by man, monkey, and mosquitoes via ships, airplanes, and land transportation from endemic areas. -
I think I know why there is a rise in dengue cases...
It is proven that cigarette smoke helps chase away mosquitoes right? At least it is proven when I was in SAF and deep in the jungle. Well, with an increase in cigarette prices and the prohibition of smoking in so many places, this is the reason why we are having a dengue problem...
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Originally posted by crazy monkey:
yes, i do agree wiv u on that. but think abt it, all this while, dengue fever has always been there.
the disease is spread when [b]mosquitoe bite an infected person. [/b]
the increase in the population of mosquitoes is the main cause of the increase of dengue fever cases in singapore, not the increase in the number of dengue patients. so the root of the increase in the population of mosquitoes is the fact that they have more breeding grounds. stagnant water in construction sites etc. quarantine of dengue patients is no use until we can lessen the number of aedes aegypti mosquitoes. -
Make sense.Originally posted by sinicker:yes, i do agree wiv u on that. but think abt it, all this while, dengue fever has always been there.
the increase in the population of mosquitoes is the main cause of the increase of dengue fever cases in singapore, not the increase in the number of dengue patients. so the root of the increase in the population of mosquitoes is the fact that they have more breeding grounds. stagnant water in construction sites etc. quarantine of dengue patients is no use until we can lessen the number of aedes aegypti mosquitoes. -
like this also can har?Originally posted by ndsef:I think I know why there is a rise in dengue cases...
It is proven that cigarette smoke helps chase away mosquitoes right? At least it is proven when I was in SAF and deep in the jungle. Well, with an increase in cigarette prices and the prohibition of smoking in so many places, this is the reason why we are having a dengue problem... 
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$10 per person per day to bring down the number of mosquitoes?!Originally posted by ndsef:I think I know why there is a rise in dengue cases...
It is proven that cigarette smoke helps chase away mosquitoes right? At least it is proven when I was in SAF and deep in the jungle. Well, with an increase in cigarette prices and the prohibition of smoking in so many places, this is the reason why we are having a dengue problem... -
Sept 15, 2005
Soldiers told to soak uniforms in insect repellent
THE Singapore Armed Forces (SAF) has asked all servicemen to soak their uniforms in insect repellent before heading out for field training.
Adopting a practice used by the Australian and United States forces, soldiers here will dip their uniforms in permethrin, which on drying leaves a protective coating against insect bites for up to six weeks, even after repeated washings.
Troops were also told to roll down their sleeves and regularly apply mosquito repellent when in the field.
These measures were taken following a sharp rise in dengue cases islandwide. Within the SAF, 85 servicemen have come down with dengue since the start of the year, the Defence Ministry told The Straits Times yesterday.
To keep dengue in check, soldiers stricken with it must inform their medical officers they have the disease. -
Current fogging practices ineffective in killing the Aedes mosquitoes
SINGAPORE : In the war against dengue, current fogging practices may be ineffective in killing the Aedes mosquitoes.
The World Health Organization (WHO) has advised that fogging at dawn is most effective.
But according to the Singapore Pest Management Association, most fogging here is carried out after 10am or in the afternoons when most Singaporeans are at work and away from their homes.
Mosquitoes may be killed when they come into contact with the fogging fumes but fogging done during these times is not very effective for several reasons.
One, ambient temperature is higher in the day and hot air causes the fumes to dissipate faster.
Two, more air drafts in the day carry the fumes away from intended target areas.
"You can actually fog anytime during the day because the Aedes mosquitoes are active during the day time and they bite throughout the day. But of course, peak biting is during dawn and dusk. So, it is more beneficial to fog during these periods because you have a bigger abundance of mosquitoes around," explained Christina Liew, a medical entomologist at the National Environment Agency (NEA).
So is fogging as it is currently done just a smokescreen?
"The end user insists that fogging be done because he is being harassed by mosquitoes. So when he sees that there is lots of smoke going on, he is happy that something is being done.
The pest company knows it is ineffective doing it. I have heard stories. Some just add kerosene to water so that when you fog, you still get white smoke coming out. In fact, it's all for show, " said G. Surajan, president of Singapore Pest Management Association.
Responding to Channel NewsAsia's query, NEA says it does not know of any pest control companies which have been adding kerosene to water. And it will take action against any who has done so.
So why don't pest companies carry out fogging at dawn or dusk?
They say cost is an issue. Pest companies have to pay their workers one and a half times more in overtime pay if fogging is done outside the standard nine to five work day.
And most town councils, private condominiums and construction companies will only award fogging contracts to the lowest bidder.
There is another reason why fogging is done when the sun is high - pest management companies say Singaporeans complain of noise pollution from fogging at dawn.
Biologists have also warned that fogging, if conducted at sub-lethal dosages, will cause mosquitoes to develop resistance to the pesticides used.
But it is not known if all fogging carried out here is at the appropriate lethal dosages.
- CNA /ls
http://www.channelnewsasia.com/stor.../164775/1/.html -
the patient dun spread the virus, it is the bunny...oops, i mean mosquitosOriginally posted by crazy monkey:Instead of weekly foggings that is hardly effective, the MOH shd consider taking more drastic measures like quanrantine of patients to stop the spread of the virus. 
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We should quarantine the mosquitoes, not the patients.
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u mean exterminate? *ps: mi o level nia...copy tat word from somewhere*Originally posted by ditzy:We should quarantine the mosquitoes, not the patients. -
See what happens when you eat too much frog legs?
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what has this got to do with frog legs?Originally posted by charlize:See what happens when you eat too much frog legs? -
Your inference skills need touching up.Originally posted by shinta:what has this got to do with frog legs? -
you suggesting introducing frogs to control the mosquito population?
Bad things happen when MAN tries to play GOD.
They should stick to curing the disease on all fronts. So far the health ministry's approach is prudent. To quarantine patients will lead to protests by the family members and relatives.
It's like caging a sick dog. -
PERMETHRIN
The insecticide permethrin (in the synthetic pyrethroid family) is widely used on cotton, wheat, corn, alfalfa, and other crops. In addition, over 100 million applications are made annually in and around U.S. homes.
Permethrin, like all synthetic pyrethroids, is a neurotoxin. Symptoms include tremors, incoordination, elevated body temperature, increased aggressive behavior, and disruption of learning. Laboratory tests suggest that permethrin is more acutely toxic to children than to adults.
The U.S. Environmental Protection Agency has classified permethrin as a carcinogen because it causes lung tumors in female mice and liver tumors in mice of both sexes. Permethrin inhibits the activity of the immune system in laboratory tests, and also binds to the receptors for a male sex hormone. It causes chromosome aberrations in human and hamster cells.
Permethrin is toxic to honey bees and other beneficial insects, fish, aquatic insects, crayfish, and shrimp. For many species, concentrations of less than one part per billion are lethal. Permethrin causes deformities and other developmental problems in tadpoles, and reduces the number of oxygen-carrying cells in the blood of birds.
Permethrin has been found in streams and rivers throughout the United States. It is also routinely found on produce, particularly spinach, tomatoes, celery, lettuce, and peaches.
A wide variety of insects have developed resistance to permethrin. High levels of resistance have been documented in cockroaches, head lice, and tobacco budworm.
BY CAROLINE COX
Caroline Cox is JPRÂ’s editor. -
Permethrin is used to kill pest in-sects in agriculture, home pest control, forestry, and in public health programs, including head lice control. It was first marketed in 1973. Worldwide, the dominant use of permethrin is on cotton, accounting for about 60 percent (by weight) of the permethrin used.1 In the U.S., al-most 70 percent of the permethrin used in agriculture is used on corn, wheat, and alfalfa.2 Over 100 million applications of permethrin are made each year in U.S. homes, and over 18 million applications are made in yards and gardens.3
Permethrin is a synthetic pyrethroid. Like most members of this family of insecticides, it has four isomers, molecules made up of the same atoms with different three-dimensional structures. (See Figure 1)
Mode of Action
Permethrin, like all synthetic pyrethroids, kills insects by strongly exciting their nervous systems. Permethrin makes the nervous system hypersensitive to stimuli from sense organs. Rather than sending a single impulse in response to a stimulus, permethrin-exposed nerves send a train of impulses. This excitation occurs because permethrin blocks the movement of sodium ions from outside to inside of the nerve cells. PermethrinÂ’s mode of action is similar to that of the organochlorine insecticide DDT.5
Acute Lethal Dose
PermethrinÂ’s LD50 (the amount of permethrin that kills 50 percent of a population of test animals) is variable. In a summary of nine oral LD50 tests using rats, the LD50 varied from 430 milligrams per kilogram of body weight (mg/kg) to over 4,000 mg/kg. Some of this variability occurs because the proportions of isomers in the test materials vary. The cis isomers are about ten times more toxic than the transisomers.6
Neurotoxicity
In mammals, permethrin has complex effects on the nervous system. As in insects, it causes repetitive nerve impulses. It also inhibits a variety of nervous system enzymes: ATPase, whose inhibition results in increased release of the neurotransmitter acetylcholine 7; monoamine oxidase-A, the enzyme which maintains normal levels of three other neurotransmitters 8; and acetylcholinesterase, the enzyme that breaks down acetylcholine.9 (Two large families of insecticides, the organophosphates and the carbamates, are acetylcholinesterase inhibitors.) In addition, permethrin inhibits a nervous system receptor, the GABAA receptor, producing excitability and convulsions.10 Finally, permethrin inhibits respiration (the process by which cells use sugars as an energy source) in a manner similar to other neurotoxic drugs.11 It is therefore not surprising that permethrin causes a wide variety of neurotoxic symptoms.
At relatively high doses, these neuro-toxic symptoms of permethrin include tremors, incoordination, hyperactivity, paralysis, and an increase in body temperature. These symptoms can persist up to three days.12 Other behavioral effects have been observed at lower doses. For example, sublethal exposure of mice to the permethrin-containing insecticide Ambush increased activities like chewing 13 ; sublethal exposure of rats to permethrin increased aggressive behavior, agitation, and resistance to being captured 14 ; and permethrin disrupted a learned feeding behavior in rats at doses of about 20 percent of the LD50. 15
Eye and Skin Irritation
Permethrin-containing products can be irritating to both eyes and skin. For example, the agricultural insecticide Pounce 3.2 EC “causes moderate eye irritation.”16 Ortho Total Flea Control 2 and Solaris Flea-B-Gon Total Flea Killer Indoor Fogger both cause “tearing, swelling, and blurred vision.”17,18 They also cause “redness, swelling, and possibly blistering” of the skin.17,18 Adams 14 Day Flea Dip “causes eye injury”19 and “may cause al-allergic reactions”19 on skin.
Effects on the Immune System
Experiments with laboratory animals indicate that the immune system (used by living things to defend themselves from disease) “appears to be a sensitive target for permethrin activity.” Ingestion of permethrin reduces the ability of immune system cells called T-lymphocytes to recognize and respond to foreign proteins. Doses equivalent to 1/100 of the LD50 , inhibited T-lymphocytes over 40 percent. Permethrin ingestion also reduced the activity of a second type of immune system cell, natural killer cells, by about 40 percent.20(See Figure 2.) In tests using mouse cell cultures, permethrin had similar effects on the immune system, inhibition of two kinds of lymphocytes.21 Researchers concluded that “the immune system is exquisitely sensitive … at exposure levels that cause no overt toxicity.”20
Effects on Reproduction
Permethrin affects both male and female reproductive systems. It binds to receptors for androgen, a male sex hormone, in skin cells from human males, causing researchers to “advise protection from any form of contact or ingestion of the pyrethroids.” 22 Permethrin also binds to a different receptor, called the peripheral benzodiazepine receptor, that stimulates production of the male sex hormone testosterone.23 In addition, permethrin caused reduced testes weights in a long-term feeding study of mice.24 In females, permethrin exposure has caused embryo loss in pregnant rabbits24 and in pregnant rats.25
Mutagenicity
Permethrin was mutagenic (damaging to genetic material) in three tests with human cell cultures, one with hamster cells, and one with fruit fly larvae. In cultures of human lymphocytes (white blood cells), permethrin exposure caused an increase in chromosome aberrations, chromosome fragments,26 and DNA lesions.27 In hamster ovary cell cultures, permethrin exposure caused chromosome aberrations.28 Exposure to Ambush (a permethrin-containing insecticide) during larval development increased sex-linked lethal mutations in fruit flies.29
Carcinogenicity
According to the U.S. Environmental Protection Agency (EPA), permethrin is a possible human carcinogen (chemical that causes cancer).30 EPA found that permethrin increased the frequency of lung tumors in female mice, and increased the frequency of liver tumors in male and female mice.24 The World Health Organization reports that permethrin increased the frequency of lung tumors in females in two out of the three mouse studies it reviewed. (See Figure 3.) Lung tumors increased with increasing permethrin exposure in the third study, but the increase was not statistically significant.31
There are no publicly available studies of the carcinogenicity of permethrin-containing insecticide products.
There are two molecular mechanisms which could explain permethrin’s carcinogenicity. First, permethrin reduces the activity of an enzyme involved in the breakdown of the amino acid tryptophan. This can lead to the buildup of carcinogenic tryptophan breakdown products.32 Second, permethrin inhibits what is called “gap junctional intercellular communication” (GJIC), chemical communication between cells. GJIC plays an important role in the growth of cells, and some cancer promoting chemicals inhibit GJIC.33
Other Chronic Effects
The liver is a sensitive target for permethrin effects. When EPA summarized 17 medium- and long-term laboratory studies that exposed rats, mice, and dogs to permethrin, effects on the liver were noted at the “lowest effect level” in all of them.24 Other chronic effects in laboratory tests include enlarged adrenal glands at all doses tested in a rabbit feeding study, and increased kidney weights at all doses tested in a rat feeding study.24 -
Hmm.... I don't suppose they want to un-ban DDT just for this?
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If the relevant authorities had taken intensive actions earlier, would this outbreak been better contained?
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SINGAPORE : The number of dengue cases has almost tripled overnight.
A total of 144 new cases were confirmed between 3pm on Friday and 3pm on Saturday, compared to Friday's figure of 54.
A total of 90 confirmed, or suspected dengue patients were admitted to hospital on Friday. - CNA/de