‘DDT has become harmless to mosquitoes today’

March 29, 2018

From India today, not news to anyone who follows the fight against malaria, and the fight to save a part of the planet to preserve human life.

DDT resistance prompted India to agree to stop production of DDT by 2020 — the last DDT factory remaining. India’s disease fighters tell of frustration trying to control malaria, because abuse of DDT has bred DDT resistant and immune mosquitoes. This is not news.

But India Today has a news hole to fill, and the continuing crises of vector-borne diseases force public health agencies to turn to “fourth generation” pesticides, as insects are now resistant to DDT and malathion.

The story out of New Delhi on March 13 almost adds some poetry to the issue. I repeat the story from India Today in full, partly because I love the lilt of Indian English, and because it tells the story of continuing attempts to get ahead of pesticide resistance in pests, attempts that just don’t seem to be doing the job.

Delhi’s civic agencies asked to use fourth generation pesticides to kill chemical-resistant insects

A small vehicle fogging streets of Delhi, India, with DDT, to fight mosquitoes. File photo from India Today, used to illustrate the story only.

A small vehicle fogging streets of Delhi, India, with DDT, to fight mosquitoes. File photo from India Today, used to illustrate the story only.

Pesticides such as DDT and malathion, which were once super weapons in the fight against mosquitoes, now seem to have become harmless perfume-like sprays for the blood-sucking parasites.

Scientists at the National Vector Borne Disease Control Programme (NVBDCP), Delhi which is the central nodal agency for prevention of diseases like malaria, dengue, filariasis, kala-azar, Japanese encephalitis and chikungunya, etc, in India has now recommended municipalities in the Capital and other parts of the country to shift to the 4th generation of pesticides that is also the last in the row.

These constitute certain bio-larvicides and insect growth regulators that stop the synthesis of critical hormones in mosquito larvae to prevent them from becoming adult. Only after attaining maturity, do the female Anopheles and Aedes Aegypti mosquitoes suck blood to get protein nutrition to lay eggs.

Scientists explain that the first generation of pesticides was DDT, used since World War II on soldiers in 1940s up till now, as its a powerful poison against mosquitoes. Later, its environmental effects, specifically on birds like vultures, reduced its usage globally.

Then came malathion, which had to be applied in huge quantities, paving the way for 3rdgeneration pesticides like synthetic pyrethroids and temephos. But with reports of mosquitoes developing tolerance towards all of these gradually, scientists are now recommending mixed and increased usage of the fourth generation of pesticides that is also the last line of defence in this class.

Experiments are still going on with genetically modified mosquitoes and introducing batches of mosquitoes injected with wolbachia bacteria in the wild to produce sterile eggs. A senior scientist with the NVBDCP, Civil Lines, said, Just like humans develop resistance towards antibiotics, mosquitoes have also evolved over the past 20-30 years to grow natural defence against DDT, malathion, etc. We are still using these two in virgin areas like forests of northeast India, Odisha, etc. successfully. But we have begun getting reports that even temephos and synthetic pyrethroids have stopped receiving the desired results against mosquitoes.

A pesticide is said to be successful when it kills over 90 per cent of the targeted insect or pest population. Over 3,500 species of mosquitoes, which play host to a number of disease-causing vectors such as zika, yellow fever, west Nile virus, etc. are said to be the deadliest animal family in the world. They kill 700 million people annually world over.
In Delhi itself, at least 10 people died of dengue last year and 9,271 people were affected.

The numbers of malaria and chikungunya cases recorded in 2017 stood at 1,142 and 940. In 2016, at least 21 dengue deaths were reported from various city hospitals. And this year, an early onset of the deadly trio dengue, malaria and chikungunya is expected with summer-like weather conditions already.

High temperature and presence of clear water in desert coolers, flower pots, coconut shells, etc, act as excellent breeding sites for the menacing insects.

We have asked municipalities to even use the fourth generation of pesticides pirimiphos-methyl and diflubenzuron in a mix with the previous generation pesticides to delay mosquitoes developing tolerance towards this in the future, the scientist explained. He said, over the years, the pesticides must be rotated in use so that their effectiveness on hardy mosquitoes does not go down.

Dr Himmat Singh, senior scientist at the National Institute of Malaria Research (NIMR), Dwarka, said, The benefit with these two latest pesticides is that they are only hormone-inhibitors, not poisons, and specific to mosquitoes. So they wouldnt have any effect on other insects, birds, mammals, fishes, etc. They are categorised as non-hazardous by WHO. However, their cost has been prohibitive so far, he said.

Delhi municipalities have begun their use after a meeting of scientists and bureaucrats of NVBDCP, NIMR, ministry of health and family welfare and the Central Insecticide Board (CIB) authorised their application in January, sources said.

Dr NR Das, head of the department of Public Health in east MCD said, We have already procured diflubenzuron on NVBDCP directions and been using it for one month satisfactorily. However, we will be able to ascertain its degree of effectiveness only after two to three months.

For at least a decade, India has been the world’s largest producer of DDT, and the largest user, spraying more DDT than the rest of the world together. China and North Korea were the only two other nations making DDT at the end of the 20th century, but both cut off production. Counter to popular conceptions, India has struggled to control malaria, often being the only nation in the world to account increases in the disease from year to year, since 2001. Malaria increased despite increasing DDT application.

To fight malaria effectively DDT spraying should be limited to Indoor Residual Spraying (IRS), which leaves a fine coat of DDT on the walls of sleeping rooms, where malaria-carrying mosquitoes bite humans, then pause on the walls to squeeze water out of the blood they’ve fed on, to reduce weight to fly. Broadscale spraying of DDT only speeds development of resistance in all mosquito species, and many other pests.

India is catching up with the rest of the world on DDT.

Tip of the old scrub brush to India Today’s Twitter feed.

 

 

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Mozambique uses 4 million mosquito nets in turn from pesticide, in war on malaria

June 20, 2017

Mozambique’s National Malaria Control Programme distributed 4 million LLIN, insecticide-impregnated nets, to protect children and others from malaria as they sleep, the time most malaria-infecting mosquito bites occur. Malaria Consortium photo

Mozambique’s National Malaria Control Programme distributed 4 million LLIN, insecticide-impregnated nets, to protect children and others from malaria as they sleep, the time most malaria-infecting mosquito bites occur. Malaria Consortium photo

Mozambique is one of only ten nations still using DDT for Indoor Residual Spraying (IRS) to fight malaria.

But DDT’s effectiveness diminishes rapidly, as does the effectiveness of the other eleven insecticides generally used for IRS against malaria or other vector-borne diseases. Insecticides are sprayed indoors, and not outdoors, to provide protection where humans are most often bitten, and to prevent non-target mosquitoes and other creatures from being exposed to the insecticides. This prevents harmful pests from developing resistance to the insecticides, and diminishes damage to beneficial species, like food fish.

Instead of spraying, malaria fighters turn increasingly to bednets impregnated with insecticide, known as Long-Lasting Insecticide-impregnated Nets (LLIN). A net provides closer to 100% protection from bites than IRS. A net immediately protects anyone sleeping under it, while IRS must treat at least 80% of nearby homes to achieve more than 50 percent prevention.

While still using IRS, Mozambique stakes its future malaria fighting on nets.

The Malaria Consortium aided in the recent distribution of nets.

Malaria Consortium has successfully completed a mass distribution campaign of over four million long-lasting insecticidal nets (LLINs) across Nampula and Niassa provinces in Mozambique. The nets were distributed almost simultaneously across all districts of each province – 23 districts in Nampula in November 2016, and 16 districts in Niassa in May 2017 – using a new operational model aimed at optimising resources.

Throughout the campaigns, Mozambique’s National Malaria Control Programme was responsible for the LLIN acquisition and led overall planning and implementation through the decentralised structures of the health system. Malaria Consortium’s role consisted of operational support, which included financial management, transport, procurement, logistics, training, management of service providers, efficient use of resources and effective coordination at provincial, district and field levels.

Sonia Gwesela, Malaria Consortium Mozambique Country Director said, “In Nampula Province, a major achievement was that 99 percent of households collected their nets. We successfully delivered 98 percent of the nets in both provinces, coming well above the 90 percent target set by the National Malaria Control Programme.

“With the successful completion of the distribution, we can now focus on a post-distribution communications campaign about the correct use of LLINs,” she concluded.

The Malaria Prevention and Control Project is funded by the Global Fund to Fight AIDS, TB and Malaria and supports the efforts of the Mozambican government to reduce malaria throughout the country through scale up of prevention and control efforts with community involvement. Malaria Consortium is working in partnership with World Vision, Fundacao para o Desenvolvimento da Comunidadeo, International Relief and Development, and the Mozambique Ministry of Health.

Bednets can be twice as effective as IRS in preventing the spread of malaria. Beating malaria also requires upgrading health care for quick diagnoses and quick, complete treatment of malaria in humans, and prevention projects to drain mosquito-breeding places within 50 yards of homes; more prevention of bites means less medical treatment is required.

WHO estimated 5 million people died of malaria in the 1950s into the 1960s. WHO’s Malaria Report 2016 reported malaria deaths fell to less than 430,000 world wide, a more than 90 percent reduction since 1963, mostly accomplished without DDT.

Malaria Consortium on Twitter, @FightingMalaria.

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Quick shot: What if it were your kid who had cancer? How would you pay?

June 11, 2017

Incredibly sad photo.

Cullen Crawford posted this on Twitter:

Cullen Crawford posted this on Twitter: “We dip our toes into depressing images on this site but nothing no approaches these torn up lotto ticket on floor of emergency room triage.”

If America is a just and true nation, the Affordable Care Act will be strengthened, not repealed to redistribute wealth to rich guys.

This is not a cartoon. It’s real life.


No, Rachel Carson didn’t cause an increase in malaria; bonus film to WGBH American Experience “Rachel Carson”

February 7, 2017

Rachel Carson at a microscope, American Experience/RetroReport image. Did Carson's work cause an increase in malaria? Is she to blame for continued malaria deaths? No, answers a short film bonus to "Rachel Carson," the 2017 PBS film.

Rachel Carson at a microscope, American Experience/RetroReport image. Did Carson’s work cause an increase in malaria? Is she to blame for continued malaria deaths? No, answers a short film bonus to “Rachel Carson,” the 2017 PBS film.

A straight up, historic look at the question of Rachel Carson’s fault in stopping malaria.

Anti-environmentalists and corporate hoaxsters argue that Rachel Carson should be blamed for an imaginary increase in malaria deaths, after the U.S. banned DDT use on crops.

In conjunction with WGBH’s American Experience film on Carson released early in 2017, this short film focusing on malaria as a continuing plague puts to rest the idea that Carson should be blamed at all.

Soaking in the bathtub, we find the film not strident enough in defense of Carson; but for those strident nuts who claim Carson a murderer, it may have some good effect. And of course, you, intelligent dear reader, will be persuaded more gently.

Where malaria is the question, DDT is not the answer. Where malaria still exists, it’s not Rachel Carson’s fault.

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Fact sheet for World Malaria Report 2016

December 16, 2016

A woman shows the mosquito net that protects her and her family from malaria transmission, in India. India remains the world's top DDT user, but is switching to nets in an effort to bring malaria rates down and set up malaria eradication before the end of DDT in 2020. WHO image.

A woman shows the mosquito net that protects her and her family from malaria transmission, in India. India remains the world’s top DDT user, but is switching to nets in an effort to bring malaria rates down and set up malaria eradication before the end of DDT in 2020. WHO image.

World Health Organization publishes an annual World Malaria Report, with the year appended to the title. It summarizes the state of the fight against malaria worldwide, recording progress and setbacks.

In the tally of progress we get a clear indication of what is needed to continue or increase that progress, with the ultimate goal of controlling malaria to the point it poses no great economic risk, or health risk, to any nation, or better that human malaria is eradicated.

World Malaria Report 2016 is 184 pages, shorter than some previous reports but packed with figures and history, some of which requires greater background to understand completely.

For example, the 2016 publication notes that about 412,000 people died from malaria in 2016. This is a shocking figure. Most of the news coverage of the report mentions this death toll in the first paragraph.

It’s too many deaths. But it’s a more than 50% reduction in deaths from 1990s rates, and it’s a more than 90% reduction from the annual death tolls that shocked the world to concerted action after World War II. Most estimates are that about 5 million people a year died from malaria through the 1950s, and into the 1960s.

WHO concentrates on the malaria fight, and plays down the political aspects to encourage international cooperation to help fight the disease. But there are political statements made, if one has the background to understand them. There remains controversy over the use of DDT, with many people yelling far and wide that if ‘bans on DDT were removed’ then malaria would quickly become an eradicated disease. This position ignores the facts, that there were still 5 million people dying each year during peak DDT use; that death tolls plunged after the U.S. banned DDT use on crops; that the U.S. ban covered only crop use, and that DDT use against disease has never been banned anywhere in the world; and that DDT use continued long after the U.S. banned DDT, around the world. DDT use never stopped.

Taken together, we would understand that the 90% reduction in malaria deaths from peak DDT use years, was accomplished mostly without DDT, and that therefore DDT is not a panacea.

World Malaria Report 2016 also tallies the slow demise of DDT. Mosquito resistance to pesticides, especially DDT, is a major problem in the fight against the disease. But more DDT can’t fix that problem now that every mosquito on Earth carries alleles that make them resistant and wholly immune to the stuff. DDT will probably never be a panacea, even were its manufacture not scheduled to stop very soon.

History, and a complete assessment of the science and current conditions in the frontlines of the malaria fight, can help us put these things in perspective.

So far, only the Los Angeles Times in the U.S. provided any in-depth reporting on World Malaria Report 2016. We hope other media will take up the challenge to inform. They will find WHO’s Fact Sheet useful.

With that warning in mind, it’s good to look at the broad outlines of the report, which WHO has packaged into a fact sheet for our convenience.

Fact Sheet: World Malaria Report 2016

13 December 2016

The World Malaria Report, published annually by WHO, tracks progress and trends in malaria control and elimination across the globe. It is developed by WHO in collaboration with ministries of health and a broad range of partners. The 2016 report draws on data from 91 countries and areas with ongoing malaria transmission.

Global progress and disease burden (2010–2015)

According to the report, there were 212 million new cases of malaria worldwide in 2015 (range 148–304 million). The WHO African Region accounted for most global cases of malaria (90%), followed by the South-East Asia Region (7%) and the Eastern Mediterranean Region (2%).

In 2015, there were an estimated 429 000 malaria deaths (range 235 000–639 000) worldwide. Most of these deaths occurred in the African Region (92%), followed by the South-East Asia Region (6%) and the Eastern Mediterranean Region (2%).

Between 2010 and 2015, malaria incidence rates (new malaria cases) fell by 21% globally and in the African Region. During this same period, malaria mortality rates fell by an estimated 29% globally and by 31% in the African Region.

Between 2010 and 2015, malaria incidence rates (new malaria cases) fell by 21% globally and in the African Region. During this same period, malaria mortality rates fell by an estimated 29% globally and by 31% in the African Region.

Other regions have achieved impressive reductions in their malaria burden. Since 2010, the malaria mortality rate declined by 58% in the Western Pacific Region, by 46% in the South-East Asia Region, by 37% in the Region of the Americas and by 6% in the Eastern Mediterranean Region. In 2015, the European Region was malaria-free: all 53 countries in the region reported at least 1 year of zero locally-acquired cases of malaria.

Children under 5 are particularly susceptible to malaria illness, infection and death. In 2015, malaria killed an estimated 303 000 under-fives globally, including 292 000 in the African Region. Between 2010 and 2015, the malaria mortality rate among children under 5 fell by an estimated 35%. Nevertheless, malaria remains a major killer of under-fives, claiming the life of 1 child every 2 minutes.

Trends in the scale-up of malaria interventions

Vector control is the main way to prevent and reduce malaria transmission. Two forms of vector control are effective in a wide range of circumstances: insecticide-treated mosquito nets (ITNs) and indoor residual spraying (IRS).

ITNs are the cornerstone of malaria prevention efforts, particularly in sub-Saharan Africa. Over the last 5 years, the use of treated nets in the region has increased significantly: in 2015, an estimated 53% of the population at risk slept under a treated net compared to 30% in 2010.

Indoor residual spraying of insecticides (IRS) is used by national malaria programmes in targeted areas. In 2015, 106 million people globally were protected by IRS, including 49 million people in Africa. The proportion of the population at risk of malaria protected by IRS declined from a peak of 5.7% globally in 2010 to 3.1% in 2015.

Diagnostics

WHO recommends diagnostic testing for all people with suspected malaria before treatment is administered. Rapid diagnostic testing (RDTs), introduced widely over the past decade, has made it easier to swiftly distinguish between malarial and non-malarial fevers, enabling timely and appropriate treatment.

New data presented in the report show that, in 2015, approximately half (51%) of children with a fever who sought care at a public health facility in 22 African countries received a malaria diagnostic test compared to 29% in 2010. Sales of RDTs reported by manufacturers rose from 88 million globally in 2010 to 320 million in 2013, but fell to 270 million in 2015.

Treatment

Artemisinin-based combination therapies (ACTs) are highly effective against P. falciparum, the most prevalent and lethal malaria parasite affecting humans. Globally, the number of ACT treatment courses procured from manufacturers increased from 187 million in 2010 to a peak of 393 million in 2013, but subsequently fell to 311 million in 2015.

Prevention in pregnancy

Malaria infection in pregnancy carries substantial risks for the mother, her fetus and the newborn child. In Africa, the proportion of women who receive intermittent preventive treatment in pregnancy (IPTp) for malaria has been increasing over time, but coverage levels remain below national targets.

IPTp is given to pregnant women at scheduled antenatal care visits after the first trimester. It can prevent maternal death, anaemia and low birth weight, a major cause of infant mortality. Between 2010 and 2015, there was a five-fold increase in the delivery of 3 or more doses of IPTp in 20 of the 36 countries that have adopted WHO’s IPTp policy – from 6% coverage in 2010 to 31% coverage in 2015.

Insecticide and drug resistance

In many countries, progress in malaria control is threatened by the rapid development and spread of antimalarial drug resistance. To date, parasite resistance to artemisinin – the core compound of the best available antimalarial medicines – has been detected in 5 countries of the Greater Mekong subregion.

Mosquito resistance to insecticides is another growing concern. Since 2010, 60 of the 73 countries that monitor insecticide resistance have reported mosquito resistance to at least 1 insecticide class used in nets and indoor spraying; of these, 50 reported resistance to 2 or more insecticide classes.

Progress towards global targets

To address remaining challenges, WHO has developed the Global Technical Strategy for Malaria 2016-2030 (GTS). The Strategy was adopted by the World Health Assembly in May 2015. It provides a technical framework for all endemic countries as they work towards malaria control and elimination.

This Strategy sets ambitious but attainable goals for 2030, with milestones along the way to track progress. The milestones for 2020 include:

  • Reducing malaria case incidence by at least 40%;
  • Reducing malaria mortality rates by at least 40%;
  • Eliminating malaria in at least 10 countries;
  • Preventing a resurgence of malaria in all countries that are malaria-free.

Progress towards the GTS country elimination milestone is on track: In 2015, 10 countries and areas reported fewer than 150 locally-acquired cases of malaria. A further 9 countries reported between 150 and 1000 cases.

However, progress towards other GTS targets must be accelerated. Less than half (40) of the 91 malaria-endemic countries are on track to meet the GTS milestone of a 40% reduction in malaria case incidence by 2020. Progress has been particularly slow in countries with a high malaria burden.

Forty-nine countries are on track to achieve the milestone of a 40% reduction in malaria mortality; this figure includes 10 countries that reported zero malaria deaths in 2015.

Funding trends

In 2015, malaria funding totalled US$ 2.9 billion, representing only 45% of the GTS funding milestone for 2020. Governments of malaria-endemic countries provided 32% of total funding. The United States of America and the United Kingdom are the largest international funders of malaria control and elimination programmes, contributing 35% and 16% of total funding, respectively. If the 2020 targets of the GTS are to be achieved, total funding must increase substantially.

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Why we need war on the mosquito, the deadliest animal – Bill Gates

October 16, 2016

World's Deadliest Animals, Gates Foundation

World’s Deadliest Animals, Gates Foundation

One could quibble, and point out that it’s the malaria parasite that does the dirty work, more than the mosquito; but it’s only a quibble.

Short film from Bill Gates explaining why he helps wage war on the lowly mosquito. Use of science to find ways to defeat mosquito-borne disease transmission is especially important in the post-DDT world, since DDT resistance now aids every mosquito on Earth.

GatesNotes said:

There are about a dozen different diseases that are spread to humans by mosquito bites including dengue, yellow fever, Zika, chikungunya, and malaria. This little mosquito actually kills more humans than any other thing.

Learn more at: http://b-gat.es/2cUd9Ff


How USA spends so much money to fight malaria in other nations

January 2, 2016

Fighting malaria is difficult, and complex, and expensive. No magic bullet can slow or stop malaria.

Reasonable people understand the stakes, not only for Africa, where $12 billion is lost every year to malaria illness and death, according to WHO records; but also for all nations who trade with Africa and other malaria endemic nations in the world.

What should we do about malaria?

Before we leap to solutions, let us look to see what the United States is already doing, according to USAID, the agency which has led U.S. malaria-fighting since the 1950s.

USAID explains on their website:

Fighting Malaria

A mother and child sit under the protection of malaria nets

A mother and child sit under the protection of malaria nets. Learn more about PMI’s contributions to the global fight against malaria. Maggie Hallahan Photography

Each year, malaria causes about 214 million cases and an estimated 438,000 deaths worldwide

While malaria mortality rates have dropped by 60 percent over the period 2000–2015, malaria remains a major cause of death among children. Although the disease is preventable and curable, it is estimated that a child dies every minute from malaria. In Asia and the Americas, malaria causes fewer severe illnesses and deaths, but antimalarial drug resistance is a serious and growing problem.

The U.S. Agency for International Development (USAID) has been committed to fighting malaria since the 1950s. Malaria prevention and control remains a major U.S. foreign assistance objective and supports the U.S. Government’s vision of ending preventable child and maternal deaths and ending extreme poverty. USAID works closely with national governments to build their capacity to prevent and treat the disease. USAID also invests in the discovery and development of new antimalarial drugs and malaria vaccines. USAID-supported malaria control activities are based on country-level assessments, and a combination of interventions are implemented to achieve the greatest public health impact – most importantly the reduction of maternal and child mortality. These interventions include:

  • Indoor residual spraying (IRS): IRS is the organized, timely spraying of an insecticide on the inside walls of houses or dwellings. It kills adult mosquitoes before they can transmit malaria parasites to another person.
  • Insecticide-treated mosquito nets (ITNs): An insecticide-treated mosquito net hung over sleeping areas protects those sleeping under it by repelling mosquitoes and killing those that land on it.
  • Intermittent preventive treatment for pregnant women (IPTp): Approximately 125 million pregnant women annually are at risk of contracting malaria. IPTp involves the administration of at least two doses of an antimalarial drug to a pregnant woman, which protects her against maternal anemia and reduces the likelihood of low birth weight and perinatal death.
  • Diagnosis and treatment with lifesaving drugs: Effective case management entails diagnostic testing for malaria to ensure that all patients with malaria are properly identified and receive a quality-assured artemisinin-based combination therapy (ACT).

The President’s Malaria Initiative (PMI) works in 19 focus countries in sub-Saharan Africa and the Greater Mekong Subregion in Asia. PMI is an interagency initiative led by USAID and implemented together with the U.S. Centers for Disease Control and Prevention. In 2015, PMI launched its next 6-year strategy for 2015–2020, which takes into account the progress over the past decade and the new challenges that have arisen. It is also in line with the goals articulated in the Roll Back Malaria (RBM) Partnership’s second generation global malaria action plan, Action and Investment to Defeat Malaria (AIM) 2016–2030: for a Malaria-Free World [PDF, 18.6MB] and The World Health Organization’s (WHO’s) updated Global Technical Strategy: 2016–2030 [PDF, 1.0MB]. The U.S. Government’s goal under the PMI Strategy 2015-2020 [PDF, 8.9MB] is to work with PMI-supported countries and partners to further reduce malaria deaths and substantially decrease malaria morbidity, toward the long-term goal of elimination. USAID also provides support to malaria control efforts in other countries in Africa, including Burkina Faso, Burundi and South Sudan, and one regional program in the Amazon Basin of South America. The latter program focuses primarily on identifying and containing antimalarial drug resistance.

Do you think the U.S. spends too much on foreign aid, even good aid to fight malaria? How much do you think is spent? Put your estimate in comments, please — and by all means, look for sources to see what the actual amount is.


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