Dry drains will reduce the numbers of mosquitoes breeding, but now the Aedes aegypti mosquito is going underground to breed underground in available water and flying to feed. Credit: Zadie Neufville/IPS

By Zadie Neufville
KINGSTON, Jamaica, Apr 18 2017 (IPS)

There were surprised gasps when University of the West Indies (UWI) Professor John Agard told journalists at an Intergovernmental Panel on Climate Change (IPCC) meeting in late November 2016 that mosquitoes were not only living longer, but were “breeding in septic tanks underground”.

For many, it explained why months of fogging at the height of Zika and Chikungunya outbreaks had done little to reduce mosquito populations in their various countries. The revelation also made it clear that climate change would force scientists and environmental health professionals to spend more time studying new breeding cycles and finding new control techniques for vector insects.“Globally, we predict that over 2.17 billion people live in areas that are environmentally suitable for ZIKV transmission." --Dr. Moritz Kraemar

Jump to March 31, 2017 when the UWI and the government of Jamaica opened the new Mosquito Control and Research Unit at the Mona Campus in Kingston, to investigate new ways to manage and eradicate mosquitoes. Its existence is an acknowledgement that the region is looking for improved management and control strategies.

Agard was reporting on a study by the late Dave Chadee, a co-author on the IPCC Fifth Assessment Report and UWI professor. The study examined evolutionary changes in the life cycle of the Aedes aegypti mosquito, which spreads the yellow and dengue fevers as well as the chikungunya and Zika viruses.

“We found out that in higher temperatures, the mosquito’s breeding cycle shortens. They go through more cycles during the season and they produce more offspring. The mosquitoes, however, are a little smaller,” Agard told journalists.

Even more worrisome were Chadee’s findings on the longevity of the “evolved” mosquitoes – 100 days instead of the 30 days they were previously thought to survive. The study also found that mosquitoes that survived longer than 90 days could produce eggs and offspring that were born transmitters, raising new concerns.

Alarming as these findings were, they were only the latest on the evolutionary strategies of vector insect populations in the Caribbean. A study published in February 2016 revealed that the triatomino (or vinchuca), the vector insects for Chagas disease, were breeding twice a year instead of only in the rainy season. And before that in 2011, Barbadian Environmental officers found mosquitoes breeding in junction boxes underground.

Sebastian Gourbiere, the researcher who led the Chagas study, pointed to the need for regional governments to re-examine their vector control methods if they are to effectively fight these diseases.

“The practical limitations that the dual threat poses outweigh the capabilities of local vector teams,” he said in response to questions about the control of Chagas disease.

Caribbean scientists and governments had already been warned. The IPCC’s AR 5 (2013) acknowledged the sensitivity of human health to shifts in weather patterns and other aspects of the changing climate.

“Until mid-century climate change will act mainly by exacerbating health problems that already exist. New conditions may emerge under climate change, and existing diseases may extend their range into areas that are presently unaffected,” the report said.

Gourbiere agrees with Agard and other regional researchers that there is need for solutions that are primarily focused on vector controls: eradication and effective controls of the Aedes aegypti could also eliminate the diseases they spread.

The failure of the newest vector control strategies also forced health professionals to revisit the old, but proven techniques developed with the guidance of researchers like Chadee, whose work on dengue and yellow fever, malaria and most recently the Zika virus had helped to guide the development of mosquito control, surveillance and control strategies in the Caribbean.

And while Zika brought with it several other serious complications like microcephaly, which affects babies born to women infected by the virus, and Guillain Barré Syndrome, the threats also exposed more serious concerns. The rapid spread of the viruses opened the eyes of regional governments to the challenges of emerging diseases and of epidemics like ebola and H1N1.

But it was the World Health Organisation (WHO) that raised concerns about the status and possible effects of the Neglected Tropical Diseases (NTDs) – a group of communicable diseases including the Zika virus – which affect more than a billion people in 149 countries each year but for which there are no treatments.

NTDs include Dengue, Chic-V and Chagas Disease and until the last outbreak in 2014 that killed more than 6,000 people, Ebola was among them. In the previous 26 outbreaks between 1976 and 2013, only 1,716 people in sub-Saharan African nations were infected, WHO data showed.

Now the Caribbean is changing its approach to the study and control of vector insects. So while there are no widespread infections of Chagas disease, UWI is preparing to begin its own studies on the triatomino and the disease it transmits.

An addition to UWI’s Task Force formed just over a year ago to “aggressively eliminate” breeding sites for the Aedes aegypti mosquito, the Mosquito Unit is expected to build on Professor Chadee’s groundbreaking research.

“From dealing with the consequences of Chikungunya, Dengue and Zika on our population to managing the potentially harmful effects of newly discovered viruses, the benefits of establishing a unit like this will produce significant rewards in the protection of national and regional health,” UWI Mona Professor Archibald McDonald said at the launch.

Zika had been infecting thousands of people in Asia and Africa for decades before it made its devastating appearance in Brazil and other parts of Latin America and the Caribbean. Zika also made its way to the US and several European nations in 2016, before being confirmed in Thailand on Sept 30.

Not surprising, as in its 3rd AR, and most recently in the 5th AR the IPCC projected increases in threats to human health, particularly in lower income populations of mainly tropical and sub-tropical countries. Those findings are also supported by more recent independent studies including Mapping global environmental suitability for Zika virus, published by the University of Oxford (UK) in February 2016.

By combining climate data, mosquito prevalence and the socio-economic makeup of each region, researchers found the likelihood of the Zika virus gaining a foothold worldwide to be “extremely high”. The team led by Moritz Kraemer also concluded that Zika alone could infect more than a third of the world’s population.

The findings noted that shifts in the breeding patterns of the Aedes family of mosquitos allowed it to take advantage of newly ‘favourable conditions’ resulting from climate change. The environmentally suitable areas now stretch from the Caribbean to areas of South America; large portions of the United States to sizeable areas of sub-Saharan Africa; more than two million square miles of India “from its northwest regions through to Bangladesh and Myanmar”; the Indochina region, southeast China and Indonesia and includes roughly 250,000 square miles of Australia.

“Globally, we predict that over 2.17 billion people live in areas that are environmentally suitable for ZIKV transmission,” Dr. Kraemar said.

The Aedes aegypti mosquitoes’ efficiency at spreading diseases in urban areas and population densities are believed to be the main factors driving the rapid spread of the Zika virus. Other studies have found the Zika virus in 19 species of the Aedes family, with the Asian Tiger Mosquito (Aedes albopictus) – which has now spread its range to Europe –  likely another efficient vector.

Back in the Caribbean, Chadee’s findings on the adaptation of the Aedes aegypti mosquito from clean water breeders to breeding in available waters is expected to drive the development of regional strategies that are better suited to the evolving environment of a changing climate.

HIV-positive children in Muhanga, a village in Rwanda. Credit: Aimable Twahirwa/IPS

By Carey L. Biron
WASHINGTON, Apr 4 2013 (IPS)

A first-time ranking of 54 top research universities in the United States and Canada has found that a miniscule percentage of funding goes to neglected diseases, despite the outsized influence that public universities play in developing medicines for illnesses often ignored by the private sector.

According to the University Global Health Impact Report Card, released Thursday, less than three percent of research funding at these 54 universities went to neglected diseases in 2010. This includes not only the tropical illnesses, such as Chagas disease and sleeping sickness, but also paediatric HIV/AIDS, malaria and multi-drug-resistant tuberculosis.Universities have a big role in making sure their research is translated into affordable medications for people in developing countries.

Altogether, more than a billion people globally suffer from these diseases, primarily in poor communities, according to data provided by the Universities Allied for Essential Medicines (UAEM), an international student coalition that carried out the research for the report card. Further, around 10 million people a year are said to die because they are unable to access required medicines, many of which are simply too expensive for them to purchase.

“We often hear from students in university labs who really want to focus on these issues but find that the same resources aren’t available to them as in more traditional areas of study,” Bryan Collinsworth, UAEM executive director, told IPS.

“This is not just about bringing in more grant funding – though that’s huge – but also about universities taking more concrete steps to say they’ll support this area of focus. For instance, hiring more faculty in these areas, making sure students have more fellowships in both the field and lab on these issues, and perhaps officially establishing a centre to ensure a specific focus.”

Indeed, 15 of the universities studied had created such a centre, and 10 of those succeeded in offering higher funding for neglected diseases, Alex Lankowski, a BostonUniversity student that participated in the UAEM research, told IPS.

Over the past three decades, some 1,556 new drugs were created, UAEM reports, but only 21 – less than two percent – were for neglected diseases.

“Universities are non-profit institutions operating in the public interest, heavily funded by government grants – meaning taxpayer-funded sources – so students know this means they have a special responsibility to serve the public good,” Rachel Kiddell-Monroe, president of the UAEM board, said Thursday at the report card’s unveiling.

“Universities regularly position themselves as places of learning, operating for the good of the world. Unfortunately, leading research institutions are not living up to their missions … So, students are demanding that these schools start taking concrete steps.”

The UAEM ranking does not focus solely on neglected diseases. Rather, it uses some 14 metrics to look more broadly at whether academic institutions are investing in research that addresses the health of poor communities worldwide.

This includes how those schools are licensing any research discoveries for commercial development, particularly whether they are doing so in socially responsible ways that ensure that related products will be affordable in developing countries. It also includes looking at university programming aimed at creating a subsequent generation of global health practitioners, as well as analysing the extent to which those attempts include a focus on low-income countries and quality of health worldwide.

Under these parametres – the data for which comes only from self-reported, publicly available sources – some of the world’s highest-profile universities fare poorly. Out of 54 schools listed, for instance, 15 are given “D” ratings, including the Massachusetts Institute of Technology (at 39th), New YorkUniversity (40) and ColumbiaUniversity (45).

By deadline, none of these schools had responded to request for comment for this story.

Clear challenge

Kiddell-Monroe notes that global health is no longer the sole prerogative of the United Nations or private foundations. Rather, universities are “increasingly a site of key research and development in medicine – a role that is only set to increase,” she says. “For this reason, we need to examine the impact they’re having and hold them to account.”

Researchers have estimated that up to a third of new medicines are developed within the university system, including at least a quarter of current HIV/AIDS treatments.

“Universities play a huge role, yet we really need to consider this role a bit more carefully,” Dr. Unni Karunakara, international president of Medecins Sans Frontieres (MSF), a humanitarian group, told reporters Thursday.

“It is a problem not only when universities are failing to conduct research on diseases that afflict the developing world. But further, when a university discovers a lifesaving new medicine and licenses it to a drug company in such a way that developing world patients can’t afford – that impedes global health.”

Karunakara notes that Glivec, the anti-cancer drug whose renewed patent was recently denied by the Supreme Court of India, was developed largely through research done in universities. It was subsequently priced out of the market in developing countries, however, when the drug was licensed to the Swiss pharmaceutical company Novartis.

“If universities make commitments to prioritise low-income communities, we can go a long way towards improving global public health,” Karunakara says. “Universities have a big role in making sure their research is translated into affordable medications for people in developing countries.”

The study does turn up some mixed data in this regard. For instance, 21 of the universities reported having come up with standards for socially responsible licensing, while more than half of research licenses are “non-exclusive” – though that figure drops to around a third for medical technologies.

Further, “Self-reporting universities rarely seek to patent their technologies in developing countries, at least within the first year of disclosure, meaning that generic drug manufacturers could develop affordable developing-world medical products from these discoveries without fear of patent restrictions,” a report accompanying the report card states.

“Even in the emerging BRICS economies (Brazil, Russia, India, China, South Africa), universities sought patents on new technologies less than 9% of the time, and less than 2% for all other low- and middle-income countries.”

Still, “provisions to promote global affordability in exclusive licenses” were found to be “exceedingly rare”, being included less than 11 percent of the time.

Together, these statistics present a “clear challenge” to universities, MSF’s Karunakara says: “As institutions dedicated to the public good, now is the time for them to step up and play a major role in improving health worldwide.”

Luz Maldonado contracted Chagas disease from contaminated fruit juice in her urban upper-middle class Caracas neighbourhood. Credit: Estrella Gutiérrez/IPS

By Estrella Gutiérrez
CARACAS, Dec 21 2012 (IPS)

Chagas disease, the third most serious infectious disease in Latin America, is developing a “new face” and moving into urban areas, while a new treatment may offer hope for millions of sufferers.

The new face of the disease is exemplified by Luz Maldonado, a 47-year-old teacher from Venezuela. Maldonado contracted Chagas disease by drinking contaminated fruit juice, in an outbreak that infected 103 people at a school in Chacao, an upper-middle-class neighborhood in Caracas. One child died, and the lives of the other people infected have been changed forever.

Micro-epidemics caused by contaminated food are a new phenomenon. And, according to the scientific sources consulted for this story, the disease is even more virulent when it is contracted this way, because thousands of parasites enter the bloodstream all at once. The largest of these incidents were reported in 2005 in Brazil, in December 2007 in Caracas, and in 2010 in the nearby town of Chichiriviche de la Costa.

Maldonado now lives with headaches, rashes, joint problems, memory loss, tachycardia, insomnia and depression, largely due to the side effects of the drugs she must take to fight the parasites.

Chagas disease is caused by Trypanosoma cruzi, a protozoan (single-celled) parasite that is transmitted by blood-sucking insects. According to the World Health Organization (WHO), it affects between 17 and 20 million people in Latin America.

In addition, almost 25 percent of the region’s population is at risk of contracting the disease, which kills at least 50,000 people a year.

According to WHO, Chagas disease is one of the world’s 13 most neglected tropical diseases, the third most serious infectious disease in Latin America, after HIV/AIDS and tuberculosis, and the parasitic infection with the highest morbidity and greatest socioeconomic impact in the region. The only country in Latin America to be declared free of the insect that spreads the disease, in mid-2012, is Uruguay.

However, all statistics on the disease are approximate, because “many cases are never diagnosed,” Belkisyolé Alarcón de Nola, the director of immunology at Venezuela’s Institute of Tropical Medicine (IMT), told Tierramérica*.

People whose infection goes undiagnosed either do not develop symptoms, or the symptoms are attributed to other illnesses. They may die decades later of heart failure or a stroke that is never linked to Chagas disease, explained Nola, a medical doctor and researcher who coordinates the follow-up of Chagas patients in Venezuela.

Today, “the image of Chagas disease as a rural disease of the poor has been dispelled,” she said. “We can have cases at any altitude, latitude or stratum, and we need to change the way we confront its vectors.”

Urban sprawl has invaded the natural habitat of the disease’s vectors, said Nola. Caracas, located in a valley at an altitude of 1,000 meters, “has these sort of green fingers that extend into it, and these are the areas that are most accessible for the vectors to reach people’s homes,” she explained.

Logging and the clearing of forests by the slash-and-burn technique have left little food for the “chipos”, as Triatoma infestans, the insect that spreads the disease, is commonly known in Venezuela. It goes by various names in different countries of the region, including vinchuca, chirimacha and chichi, and is referred to as the “kissing bug” in English.

“We have vectors everywhere and even more so with climate change, because the warmer the earth becomes, the greater the reproduction of the insects,” said Nola.

Transmission most commonly occurs when insects infected with the parasites bite humans, ingest their blood, and then immediately defecate. Chagas disease is contracted if the parasites in the insect feces enter the organism through a break in the skin, such as when people scratch the bites, or through other openings, such as the eyes, when people rub them.

In Caracas, there is also a secondary, “poor” vector, Panstrongyilus geniculatus, “which is clumsy and takes longer to defecate,” said Nola.

But this “poor vector” is adapting. “Drawn by the lights in homes in urban and peri-urban areas, it enters through kitchen windows, wanders over utensils and food and defecates where it pleases,” she said.

In the transition to oral infection through contaminated food, “there have been many small outbreaks, many of which have gone undiagnosed.” However, there has been no other outbreak like the one in Chacao, given its fully urban location and the large number of people infected, after drinking guava juice contaminated with infected insect feces at the municipal school.

There are two strains of the Trypanosoma cruzi parasite that cause Chagas disease. One is found from Mexico to the north of South America, and the other from Brazil to the southern tip of the continent. The first primarily damages the heart, while the second also damages the esophagus and colon.

The disease has three stages. In the first, acute stage, symptoms can be very marked or very mild and easily confused with other diseases. The second, known as the intermediate or latent stage, lasts a variable period of time – sometimes many years or even decades – and is asymptomatic.

In the final, chronic stage, “the myocardial tissue is destroyed and does not regenerate, and is replaced with fibrous tissue. The heart increases in size and no longer contracts effectively; it pumps less blood into the lungs, and cardiac insufficiency gradually sets in,” explained Nola.

There are only two drugs indicated by WHO to eradicate the parasites: nifurtimox, introduced in 1960, and benznidazole, developed in 1974.

But eradication is only partial when the parasites have lodged into deep tissue and in the chronic stage of the disease.

Moreover, the side effects of these drugs cause collateral damage. “The ones that are most feared are the neurotoxic effects, because they cause peripheral neuropathy symptoms, such as sensations of extreme cold or heat, extreme sensitivity of the feet, and severe headaches,” said Nola.

But the promising findings of two Venezuelan researchers, Julio Urbina and Gustavo Benaim, have led Argentina and Bolivia to conduct clinical trials based on their experiments, while in Venezuela, “we hope to conduct a pilot study as well,” she reported.

Benaim, head of the cell signaling and parasite biochemistry laboratory at the state-run Institute of Advanced Studies, told Tierramérica that the goal is “to attack the parasite without affecting the human being, like current treatment methods do,” as well as “to develop drugs for the chronic stage, which are currently non-existent.”

The study is based on a specific property of Trypanosoma cruzi: its membranes do not contain cholesterol, but rather ergosterol, another sterol. “If you eliminate the ergosterol, which is indispensible for it, you eliminate the parasite,” he explained.

There are drugs that block the synthesis of ergosterol, such as posaconazole, which is approved by the United States Food and Drug Administration, although only for the treatment of fungal infections.

The researchers linked this fact with another clinical observation: Chagas patients whose arrhythmia (irregular heartbeat) was treated with amiodarone showed substantial improvement. “When it is applied to the parasites it is lethal for them,” Benaim enthusiastically reported in his laboratory.

Amiodarone is already used to treat arrhythmia, and 30 percent of Chagas sufferers in the United States receive it. It is not completely harmless, since it contains iodine, but its side effects are much milder than those of current treatments, said Benaim.

“We studied the mechanism of action of posaconazole and amiodarone; both of them were already known to be sterol inhibitors, but we demonstrated that amiodarone also alters the calcium regulation of the parasites,” he reported.

“Combining them boosts their effect, makes it possible to lower dosages, and cuts down on side effects,” he added.

Another new antiarrhythmic drug, dronedarone, which contains less iodine and is more easily eliminated, was also tested in their laboratory and “proved to be very successful. It is more powerful and acts more rapidly” in destroying the parasite, said Benaim.

An article on the new treatment was published in October in Nature Reviews Cardiology. In addition to Chagas disease, it can also be effective against other diseases caused by parasites, such as leishmaniasis.

“A good sterol inhibitor can bring an end to these parasitic diseases, which are viewed as diseases of the poor, and are therefore neglected,” stressed the Venezuelan researcher. In the case of diseases like these, “it isn’t profitable to conduct research into treatments for them. That is the sad reality.”
* This story was originally published by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme, United Nations Environment Programme and the World Bank.