New study quantifies aflatoxin exposure in Kenya

Aflatoxin infected maize
Aflatoxin infected maize. Findings of a new research study suggest that aflatoxin exposure is a public health problem throughout Kenya.  (Photo: IITA)

In the past few weeks, I’ve been doing some reading on aflatoxins to keep myself updated with recent research on this subject, with a particular focus on Kenya.

I came across a recent study on human aflatoxin exposure in Kenya carried out by the Centers for Disease Control and Prevention (CDC) and the Kenya Ministry of Public Health and Sanitation.

The study aimed at assessing aflatoxin exposure throughout the entire country. Most of the previous outbreaks of aflatoxicosis in Kenya occurred in Kenya’s Eastern Province, but since there is no national aflatoxin surveillance, it was not known if aflatoxicosis outbreaks were limited to that region or if they occur in other regions of the country. The study also sought to find out if aflatoxin exposure varied by demographic, socioeconomic and ecological factors.

From analysis of aflatoxin levels in serum specimens from the 2007 Kenya AIDS Indicator survey — a nationally representative, cross-sectional survey — aflatoxin B1 was detected in 78% of the specimens.

Aflatoxin exposure did not vary by sex, age group, religion, marital status or socioeconomic characteristics. However, exposure to aflatoxin varied by province, with the highest levels recorded in Eastern and Coast provinces and the lowest in Nyanza and Rift Valley provinces.

The bottom line is that human exposure to aflatoxin across Kenya can be considered to be a public health problem, in light of the widespread exposure levels that cut across the spectrum of age, sex and socioeconomic status. All the more reason for increased education and awareness on this public health risk and the practical steps that can be taken to control it.

In this Business Daily article on the persistent problem of aflatoxin contamination in maize in Kenya (published 27 Oct 2013),  I found out that some researchers at the Kenya Agricultural Research Institute (KARI) are carrying out studies on the susceptibility of maize varieties to aflatoxin so that they can breed aflatoxin-resistant varieties. I think that would be a great leap forward in the fight against aflatoxin contamination in the country.

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Discussions on research and innovation in biotechnology for Africa’s development

Calestous Juma delivers his lecture at KICC, Nairobi
Calestous Juma delivers his lecture at KICC, Nairobi

Earlier this week on Tuesday afternoon, I was down at the Kenyatta International Conference Centre for a public lecture by Prof Calestous Juma on the topic, Rebooting African Economies:Innovation for Economic Development. Prof Juma is a professor of the Practice of International Development at the Harvard Kennedy School. The lecture was sponsored by the Jomo Kenyatta University of Agriculture and Technology (JKUAT) and the US government.

Rebooting African Economies

Below is the abstract of the lecture:

“The role of modern biotechnology in the economic transformation of developing countries has become the subject of intense academic inquiry and public policy discourse. There is increasing debate about the potential contribution of biotechnology not only in Kenya, but also globally. This debate has taken two divergent perspectives. Proponents of biotechnology see it as the only viable solution to Africa’s socio-economic problems. On the other hand, critics of biotechnology application treat it with caution and suspicion. This public lecture provides a platform to interrogate this issue and chart the way forward on biotechnology for the East African region in terms of policy and research.”

A section of the audience at Calestous Juma's lecture
A section of the audience at the lecture

During his introduction, Prof Juma talked about a series of “waves of innovation” each of which was associated with an expansion of economic space. He sees the next innovation wave as focusing on issues such as the green economy, renewable energy, biotechnology and sustainability, and Africa stands to benefit from this new innovation wave.

Key to taking advantage of this will be investment in the life sciences to help Africa leap-frog ahead of the front-runner countries that benefited from the previous waves. The rapid decline in the cost of generating research knowledge (e.g. cost of DNA sequencing has drastically reduced in the past 4 years), the spread of high-speed internet connectivity and the mobile economy boom are among the drivers of Africa’s development in science, technology and innovation.

The main focus of the talk was on the economic, environmental and health impacts of biotechnology supported by examples of peer-reviewed research findings.

Here are some of the key points I noted [I’ve added the hyperlinks to the source material for those interested in reading further]:

  • There’s a high rate of adoption of biotech crops globally with the highest rate in Asia. Though the actual hectarage may be disputed by some, there is agreement that there is a general trend towards increased adoption of GM crops globally.
  • The European Union has documented 10 years of EU-funded research on GMOs, a report that builds on a previous 15-year study. This covers over 130 research projects, providing a rich base of research evidence on risk assessment of GMOs (Link to the PDF report: A decade of EU-funded GMO research, 2001-2010)
  • In the USA, unintended consequences of GM crops were found to be beneficial. A study by Hutchison et al. (2010) published in the journal Science reports that Bt corn had a beneficial effect on neighbouring non-Bt corn farms whereby pesticide use was reduced. This was replicated in China where Bt cotton suppressed the pink bollworm on non-Bt cotton (Wan et al., 2010).
  • A review by Snell et al. (2012) published in the journal Food and Chemical Toxicology examined the health impacts of GM crops and found that existing GM crops and non-GM crops have similar risk profiles. In other words, GM crops and their non-GM counterparts are nutritionally equivalent and can be safely used as food.

After the talk, there was a vibrant question & answer session that saw contributions from a lawyer, an MP, university lecturers, a student and an NGO representative, among others.

The main eye-opener for me was in relation to the potential applications of polymer science and technology and nanotechnology. Prof Juma gave an example of how nanotechnology can be used to develop a material that absorbs water that is available only to a growing plant… imagine the potential this holds for boosting dryland farming!

Admittedly, nanotechnology is still a new area for me but one well worth reading more about! In fact, a representative from the National Council for Science and Technology mentioned that they are on track towards developing a nanotechnology policy for Kenya so much so that they’ve incorporated it into their performance contracts for the coming year. Looks like nanotech is the next big thing in science, technology and innovation!

Another key take-home message was that a lot of biotechnology research in Kenya is financed by public funds from the National Council of Science and Technology and is being done in our public universities (Kenyatta University, for example, has a Biosafety Level 2 lab)  by Kenyan scientists for the benefit of the Kenyan people. This effectively debunks the oft-cited line that the agri-biotechnology research agenda in Kenya is largely in the hands of foreign multinational companies (read Monsanto).

I had a brief chat with a researcher from Kenyatta University who is working on genetic modification of sweetpotato and cassava to make them pest resistant and thus reduce the levels of post-harvest losses. Both these staple crops are important energy sources in Kenya and much of Africa and boosting their productivity would go a long way in improving not just nutrition and food security but also the incomes of the smallholder farmers who grow these crops.

Calestous Juma talks to journalists after the lecture
Calestous Juma talks to journalists after the lecture

All in all, it was an afternoon well spent. I learned a lot of new stuff and also got a lot of links to reading material. Prof was in a rush to head off to another meeting but the press wouldn’t let him go and kept asking him endless questions so I barely managed to say a quick ‘Hello’ and shake his hand before his JKUAT hosts whisked him away! Thankfully, he is quite accessible on Twitter (@Calestous) so the conversations continued on that platform!

The final word from Prof: “There are more risks if Africa does nothing than if it does something… and that something is adoption of biotechnology”.

New study finds aflatoxin in Kenyan maize more widespread than previously thought

Came across a press release on the IFPRI website that tells of a recent study in Kenya that sought to document the levels of aflatoxin contamination in maize value chains.

The findings are pretty worrying… a significant proportion of samples had aflatoxin levels that were above the legal limit of 10 parts per billion.

Read the press release here.

Super bugs in local milk

The Daily Nation’s Horizon magazine of 1 November 2007 carried an article titled Super bugs in local milk. The article cited a study by researchers from Jomo Kenyatta University of Agriculture and Technology (JKUAT) which revealed that raw milk hawked in Nairobi’s Kahawa West area contained harmful bacteria with high levels of resistance to commonly used antibiotics.

I was drawn to this article largely because of my professional interest in microbial food safety in general and the safety of milk and dairy products in particular.

While the article is an eye-opener to potential milk-borne public health risks, I felt that there were a couple of issues that were not very clear.

First, one of the researchers argued that the high levels of drug-resistant pathogens in milk poses a major health risk because 90 per cent of milk sold in Kenya is raw. While it is true that the sale of raw milk is predominant in Kenya, almost all consumers who buy raw milk boil it first before they drink it, often together with tea leaves.

And boiling of milk effectively kills all pathogens, whether drug-resistant or not. Thus the question of consumption of contaminated milk being a likely cause of emerging multi-drug-resistant pathogens, as reported by the study, does not arise.

The same is true when milk is pasteurized (heated to 72 degrees centigrade for 15 seconds). Indeed, as would be expected, the JKUAT team did not find drug-resistant pathogens in the pasteurized milk samples.

Still, that is not to say that high levels of pathogens in raw milk are acceptable because the milk will be boiled anyway. On the contrary, good quality raw milk is necessary in order to prevent it from getting spoilt quickly. Training of milk handlers and traders on milk hygiene is therefore imperative in order to improve the quality of marketed milk in the country.

Another issue is that the article didn’t say whether the raw milk samples were tested to see if they actually contained antibiotic residues. This is a more likely cause of the emergence of drug-resistant bacteria, especially because neither pasteurization nor boiling will get rid of antibiotic residues in milk.

Drug residues can end up in raw milk if a dairy cow is on antibiotic treatment. After such treatment, there is a specified milk withdrawal period when the milk should not be sold in order to protect consumers from being exposed to the high levels of antibiotic residues.

It would be useful to know more about the prevalence of antibiotic residues in marketed milk (both raw and pasteurized) in Kenya, as this poses a worrying prospect of consumers unknowingly ingesting small amounts of drug residues as they drink their daily chai ya maziwa. Such a scenario can only worsen the existing problem of antibiotic-resistant super bugs.