Johannesburg, South Africa

A tiny, rapidly breeding cyanide-munching insect, dubbed a "super-fly" by scientists, is threatening the food security of millions of Africans.

The Bemisia tabaci - one of several whitefly species - carries lethal viruses that cause cassava brown streak disease (CBSD) and cassava mosaic disease (CMD), which have decimated the hardy cassava plant.

Cassava, a tropical root crop, is the third most important source of calories in the tropics, after rice and maize. According to the UN's Food and Agriculture Organization (FAO), it is the staple food for nearly a billion people in 105 countries, where it comprises as much as a third of daily calories consumed. The cheapest known source of starch, cassava is grown by poor farmers - many of them women - often on marginal land; for these people, the crop is vital for both food security and income generation.

The threat to cassava is particularly alarming as the plant is often called the "Rambo" root for its ability to withstand high temperatures and drought. With climate change expected to take a major toll on maize in the coming decades, many hope cassava will offer an alternative route to food security in Africa. Cassava may also prove to be an important source of biofuel .

Experts plan to take aim at the whitefly this week, at a conference of the Global Cassava Partnership for the 21st Century (GCP21), at the Rockefeller Foundation Bellagio Center in Italy. The conference is dedicated to "declaring war on cassava viruses in Africa."

Pandemics

From the'80s to the mid-2000s, CMD ravaged more than 4 million square km in Africa's cassava-growing heartland, stretching from Kenya and Tanzania in the East to Cameroon and the Central African Republic in the West. But in recent years, the scientific community developed cassava varieties resistant to CMD.

James Legg, a leading cassava expert at the International Institute of Tropical Agriculture (IITA), who works out of Tanzania, told IRIN, "The premature celebrations for this apparent victory were very soon squashed, however, as sinister new reports were received of the occurrence and apparent spread of CBSD in southern Uganda."

Until then, scientists had assumed that the viruses causing CBSD could not spread at medium-to-high altitudes; the disease had previously only been reported in coastal areas of East Africa and the low-altitude areas around Lake Malawi. "The spread recorded from Uganda instantly cast doubt of the validity of that earlier theory," said Legg. "Worse still, the disease spread out from Uganda over following years, and into the neighbouring countries of Kenya, Tanzania, Burundi and Rwanda."

CBSD is now a pandemic, threatening Nigeria, the world's largest producer and consumer of cassava. The cassava starch industry in Nigeria generates US$5 billion per year and employs millions of smallholder farmers and numerous small-scale processors.

Only in 2005 were scientists able to confirm that the whitefly responsible for spreading CMD was also responsible for spreading CBSD.

"With this realization, it became clear that the spread of these two disease pandemics was really only a consequence of the fact that East and Central Africa was experiencing a devastating outbreak of the whitefly that transmits both of them," explained Legg.

He told IRIN that in the'80s, researchers recorded an average of less than one fly per plant, but by the mid-1990s, the number of whiteflies had increased a hundredfold.

Arms race

It seems Bemisia tabaci has been assisted by climate change: The warmer temperatures occurring in higher altitudes have created optimal conditions for the insect to breed rapidly, speeding its adaptation and evolution. More importantly, said Legg, is the fact that these flies seem to have worked out how to do better on cassava plants, whose cyanide production deters all but a very small group of insects. As the whitefly population has exploded, rapid spread of the viral diseases - CMD and CBSD - was an inevitable consequence.

What makes a bad situation even worse, however, is that these diseases, in turn, may promote the whitefly. "These insects also seem to have a close relationship with the viruses that they transmit, and some evidence has shown that the insects do better on virus-diseased plants, leading to an 'I scratch your back, you scratch my back' type of mutually beneficial relationship," Legg said.

Scientists are working towards solutions. A member of Legg's team is examining the impact of climate change on the whitefly in search of ways to deal with the pest. Other planned projects are working to control whiteflies directly, either through introducing other beneficial insects that kill whiteflies, or through producing varieties that combine whitefly and disease resistance.

Efforts to breed high-yielding, disease-resistant plants suitable for Africa's various growing regions will involve going to South America, where cassava originated, and working with scientists at the cassava gene bank of the International Center for Tropical Agriculture (CIAT), IITA's sister organization, in Colombia. CIAT is the biggest repository of cassava cultivars in the world.

Experts at the conference in Italy will also discuss a more ambitious plan to eradicate cassava viruses altogether. The aim will be to develop a regional strategy that gradually replaces farmers' infested cassava plants with virus-free planting material of the best and most disease-resistant cultivars. Approaches to developing these cultivars will include new molecular breeding and genetic engineering technologies to speed up selection. The hope of the team is that by joining forces, and employing the whole range of technologies available, a lasting impact will be made in tackling a crop crisis that poses the single greatest challenge to the future of Africa's cassava crop.

- Provided by Integrated Regional Information Networks.

 

Cape Town, South Africa

South Africa will expand its rollout of GeneXpert tuberculosis (TB) testing machines, which can diagnose TB and drug-resistant TB within 90 minutes, but concerns remain about the capacity to back up this commitment with supplies and treatment.

The country is the largest buyer of GeneXpert technology in the world, but the machines have not yet become point-of-care tests and are often deployed at district rather than clinic level. Nonetheless, they have shaved weeks off waiting times for patients because samples no longer have to be transported to and from national referral hospitals kilometres away for diagnosis.

At the opening of the TB Vaccines Third Global Forum in Cape Town on 25 March, [ www.tbvaccines2013.org/ ] Precious Matsoso, director general of the South African Department of Health, announced that an additional 135 machines will be imported by the end of 2013. The GeneXpert was released in 2010 and South Africa already has 150.

Matsoso's announcement was made a day after the health department handed over six machines to the Department of Correctional Services at Cape Town's Pollsmoor Prison. A former inmate at Pollsmoor, Dudley Lee, took the correctional services department to court after he contracted TB during incarceration. Although Lee eventually died of TB, the courts found in his favour.

During the handover, South African Deputy President Kgalema Motlanthe also announced that TB screening for inmates would carried out every six months, and reiterated a commitment that at-risk miners would be annually screened for TB. Of the 735 Pollsmoor inmates screened for TB during Motlanthe's visit, 12 percent had TB, according to Matsoso.

The World Health Organization (WHO) lists South Africa in the top 22 countries with a high TB burden. An estimated 500,000 cases of active TB are diagnosed annually and the disease remains the leading cause of natural death according to the national statistical service, StatSa.

South Africa could become WHO observatory

Matotoso also announced that the health department, the National Department of Science and Technology, and the US-based non-profit TB vaccine developer, Aeras, would continue to fund the recently created South Africa Consortium on TB Vaccines.

"We are at the centre of the TB epidemic, so we have to have our own response… in terms of vaccines being developed. Hopefully, South Africa will become a global player," Willem Hanekom, director of the South Africa TB Vaccine Initiative, told IRIN.

Matsoso, who has worked with WHO on issues of intellectual property, said that through the consortium South Africa would be well-placed to become one of the research observatories envisioned in WHO resolutions aimed at promoting research and development. He noted that these initiatives would have to be accompanied by changes to regulations, for instance to facilitate fast-track review to allow the country earlier access potential new vaccines.

Stand and deliver

South African AIDS lobby the Treatment Action Campaign (TAC) and international medical humanitarian organization Médecins Sans Frontières (MSF) have questioned the government's ability to deliver on these promises as stockouts and slow decentralization persist.

In a joint letter delivered to South African Minister of Health Dr Aaron Motsoaledi on 22 March, the organizations stressed that the success of the GeneXpert rollout hinged on a steady supply of testing cartridges for the machines, the decentralization of drug-resistant TB (DR-TB) care and treatment, and improved supply-chain management to avoid recurring drug stockouts.

The organizations also questioned the continued delay in implementing the health department's 2011 policy decision to move DR-TB care out of designated TB hospitals with a shortage of beds to primary healthcare clinics closer to patients' homes.

"Provincial operational plans for decentralization of multidrug-resistant TB (MDR-TB) care have not been drafted, nor have readiness assessments been conducted of all proposed decentralized MDR-TB (sites)," the letter pointed out.

The organizations urged the health department to implement the 2011 policy, which would allow all of South Africa's nine provinces to begin initiating and managing stable adult and paediatric MDR-TB at local clinics before the end of 2013.

- Provided by Integrated Regional Information Networks.

 

Johannesburg, South Africa

South Africa's gold mines are estimated to have the highest number of new tuberculosis (TB) cases in the world, making the disease a leading export to neighbouring countries. IRIN takes a look at the declaration meant to change this situation.

In August 2012, heads of state from the Southern African Development Community (SADC) agreed to sign the SADC Declaration on TB in the Mining Sector, following endorsements by their national ministers for health, labour and justice.

According to Swaziland's Minister of Health, Benedict Xaba, he and South African Health Minister Dr Aaron Motsoaledi, and Lesotho's former Minister of Health, Dr Mphu Ramatlapeng, began pushing for the declaration in 2010. Xaba, the son of a miner, admitted that he has lost members of his family to TB.

South Africa is supporting the declaration and related initiatives, including a 1,000-day campaign to meet TB and HIV targets in the region, but the country has not yet officially signed the declaration, according to Lynette Mabote, regional HIV, TB and human rights advocacy team leader at the AIDS Rights Alliance of Southern Africa (ARASA), a civil society body that has been heavily involved in the declaration and advocacy around TB in mines.

How big a problem is TB in the mines?

The South African Department of Health estimates the country's gold mining industry has the highest number of new TB cases annually in the world - up to 7,000 cases per 100,000 people per year - according to its TB Strategic Plan for South Africa 2007-2011. [www.info.gov.za/view/DownloadFileAction?id=72544 ]

Data collected from autopsies on formers miners have also shown a prevalence of latent and undiagnosed TB as high as 90 percent, according to a 2009 study.

Why is TB a problem on the mines?

While many people may carry latent TB infection, active TB infection will usually only occur in a small number of them. However, those with compromised immune systems and HIV co-infection are up to 30 times more likely to develop active TB.

In South Africa, where HIV prevalence is about 18 percent, many miners are no doubt living with HIV but face additional occupational risks, according to Rodney Ehrlich from the Centre for Occupational and Environmental Health Research at University of Cape Town. He describes these risks as:

* A high burden of silicosis, a respiratory disease that develops due to inhaling silica dust during the mining process and could be viewed as an immune deficiency illness;

* Silica dust load in the lungs and previous lung damage;

* Poor living conditions, including overcrowding;

* Circular migration between neighbouring countries and South Africa, leading to interrupted TB/HIV treatment and poor access to care.

The mines have also not escaped the growing epidemic of drug-resistant tuberculosis, which in the absence of wide access to molecular testing has not only been harder to diagnose but also to treat. Research released in 2010 estimated that that almost four percent of the national multidrug-resistant TB (MDR-TB) burden, where TB is found to be resistant to both the commonly used first-line drugs isoniazid and rifampicin, may reside on the country's mines.

Falling employment figures indicate that the mines now employ considerably fewer miners than in the late'80s, Ehrlich added. Commodity prices dropped in 2008 and 2009, leading to further lay-offs, which may greatly complicate addressing the needs of affected miners who are no longer employed and will be relying on already stressed health systems in rural areas or home countries for treatment.

What did countries commit to in the declaration?

Countries agree to taking tangible actions like establishing independent mining ombudsmen to handle health-related complaints, harmonising treatment protocols related to addressing HIV, TB and silicosis on the mines, and - controversially for some - classifying TB and silicosis acquired in the mines as such.

At a meeting of SADC health ministers in April 2012, mining companies were reluctant to classify TB and silicosis, a respiratory disease linked to exposure to silica dust produced during gold mining, as occupational diseases. In addition, the responsibility of mining companies to ensure treatment of mine workers with these diseases even after employees have left the company was a sticking point, according to David Mametja, head of South African Department of Health's TB Control and Management Programme.

The document now calls on employers to take full responsibility for the management of all occupational diseases, including TB associated with silicosis post-employment.

However, activists have cautioned that national legal frameworks must be changed to ensure TB is treated as an occupational disease. This would have to include provisions for mine workers who have left employment but later developed active TB.

"The history around the issue of occupational health is littered with companies not taking responsibility," activist Gregg Gonsalves told IRIN at South Africa's 2012 TB conference. "It has to be about regulation - states have to regulate their business practices. Only in jurisdictions where that has happened has that problem been solved. It has to come through statues and regulation."

The declaration also calls for the development of a minimum package of services to facilitate cross-border care.

"Our referral systems do not take into consideration the dynamics that are experienced in the region as far as TB in the mines is concerned," said Stephen Sianga, SADC secretariat director for social and human development and special programmes. "There are challenges regarding standard treatment, both between countries and within countries, where you find that the system used in the mines is different to that used in the public health system."

While TB treatment regimens across the SADC are largely already harmonized, activists have long been calling for the same to be done regarding HIV treatment. This would also facilitate the use of health passports, which would enhance cross-border care, as would the standardization of a minimum package of HIV, TB and silicosis services.

What happens next?

In the run-up to the August 2012 signing of the declaration, civil society groups like ARASA called for a five- or 10-year action plan, with concrete steps to be taken to implement the declaration. Now, SADC will be looking to operationalize the declaration at national level through a code of conduct.

According to Mabote, the draft code was dismissed by ministers of health at a SADC meeting in Angola in July 2012. An SADC technical working group reworked the document in November, but a final version of the document has yet to be released.

- Provided by Integrated Regional Information Networks.