PLATFORM ON AFLATOXIN MANAGEMENT IN GHANA

transcript

Kwame Nkrumah University of Science and Technology

STAKEHOLDER MEETING ON INNOVATION PLATFORM ON AFLATOXIN MANAGEMENT IN GHANA: 17TH JUNE, 2015

SITUATIONAL ANALYSIS OF THE

AFLATOXIN PROBLEM IN GHANA

RICHARD .T. AWUAH

Outline of presentation

Basic information on Afs and effects

Af challenge and some studies in Ghana

The way forward

EU’s Threat to ban cereals from Ghana ‘Ghana is to face a ban from exporting

commodities like groundnuts, peanut butter and cereals products to the European markets if it is unable to reduce the level of aflatoxin contamination in such commodities’

Ghanaian Times, 14th May 2015 Edition

STAKEHOLDER MEETING ON INNOVATION PLATFORM ON AFLATOXIN MANAGEMENT IN GHANA: 17TH JUNE 2015

What are Aflatoxins (Afs)?• Toxic secondary metabolites of fungal origin

(Mycotoxin)

• 25% of world food crops are affected

• Countries that are situated between the 40 ºN and 40 ºS are most at risk

• Aspergillus section Flavi group A. flavus Link ex Fries A. parasiticus Speare A. nomius Kurtzman• Aflatoxin- A. flavus toxin

A. flavus

Types of AfsB1 - A. flavus, A. parasiticus

and A. nomius

B2 - A. flavus, A. parasiticus and A. nomius

G1 - A. parasiticus and A. nomius

G2 - A. parasiticus and A. nomius

Most potent - AF B1

Other AFs

M1, B2a, M2, Q1, G2a

Factors affecting Af ContaminationN

Pre harvest Post harvest

Improper dryingStorage in poorly ventilated

warm environmentsDamage during shellingStorage in polyethylene bagsStorage insects (Caryedon

serratus; Sitophilus zea mays)

Stress (Warm, dry periods; soil moisture stress)

Mechanical damage (Cultivation, damage by arthropods, birds, rodents nematodes etc)

Delayed harvestingPlanting time (Early vs. Late)

Some common AF substrates • Groundnut • Maize • Beans• Smoked fish• Kenkey• Groundnut paste• Tiger nut• Tree nuts

• Breast milk (human, cattle)• Smoked fish/fresh pond-raised

fish• Meats• Sorghum• Copra• Cheese• Black pepper• Donkwa

Other substrates

• Faeces• Urine• Human semen• Human blood• Maternal plasma samples

Af permissible levels in foods

Kenya 10 µg/kg

Nigeria 4 µg/kg

Ghana 20 µg/kg (raw groundnut)

4 µg/kg (groundnut butter)

Zambia 10 µg/kg (cereals, g’nut, nuts)

Malawi 5 µg/kg (cereals, g’nut, nuts)

Zimbabwe 5 µg/kg (cereals, g’nut, nuts)

Egypt 10 µg/kg (cereals, g’nut, nuts)

FAO and WHO 30 µg/kg

EU countries 4 µg/kg (total AF)

2 µg/kg (AF B1)

USA 20 µg/kg (all foods except milk)

USA 4 µg/kg (milk)

Codex Standard 10 µg/kg (all processed foods)

Af and healthImpaired biochemical

processes • Lipid metabolism

(cholesterols)• Glucose metabolism

(hyperglycaemia)• Mineral absorption

Afs also impair:• Growth rate• Female reproductive

efficiency• Male reproductive

efficiency• Immune system

efficiency

Some human studies

• Correlation between serum AF levels and liver cancers• Correlation between AF intake

and Hepatitis B in liver cancer incidence• Aflatoxicoses in humans

• Aflatoxins and kwashiokor• Aflatoxin and human male

sterility problems

Implications for food security It is an agricultural issue in the

sense that:

• Contaminated foods should not be eaten nor fed to livestock.

• Presence of aflatoxigenic fungi in staple foods contributes to decay and dry matter loss

• Impacts negatively on food security by affecting all four food security pillars i.e. availability, access, utilization and quality.

Af contamination : An export trade issuei. Affects the potential of countries to engage in the

export trade

ii. AF levels in cereals and legumes and their products and other food items in Ghana are far above the EU and USA permissible standards of 4 and 20ug/kg, respectively. This means that many food and food items from Ghana will not be allowed into the EU and USA and perhaps many other foreign markets

AF and groundnut trade

The Ghanaian situation

Groundnut samples in Accra – 69% highly contaminated with AF (Beardwood 1964)

Northern groundnut Volta groundnut

Local market

Average of five samples(μg/kg)

Range of five samples(μg/kg)

Average of five samples(μg/kg)

Range of five samples(μg/kg)

Makola 13 3 - 27 42 14 - 100

Kaneshie 12 4 - 22 50 13 - 99

Salaga 28 3 - 88 78 15 - 141

Adabraka 33 5 - 71 59 10 - 116

Teshie 26 5 - 58 69 10 - 187

Nungua 27 10 - 47 67 27 - 145

Madina 41 5 - 133 86 10 - 216

Aflatoxin levels (μg/kg) in Northern and Volta types of groundnut sold in various markets in Accra.

Source: Mintah & Hunter (1978)

Location of market % Damaged kernels

Total aflatoxin levels (μg/kg)

Damaged kernels Undamaged kernelsAccra 5.3 75.6 NDAshaiman 9.25 12.2 NDMankessim 2.87 17.7 0.2Cape Coast 3.87 860.6 1.4Koforidua 2.37 5.7 0.1Takoradi 4.3 13144.3 NDKumasi 3.2 105.0 0.4Ho 5.92 22168.0 NDSunyani 2.33 54.2 NDTekyiman 3.31 5530.1 NDTamale 1.5 71.4 0.5Wa 2.92 14.5 NDNavrongo 2.0 3505.2 154.2Bolgatanga 1.67 301.8 12.2

Av. 3.6 Av. 3276 Av. 12.1

Aflatoxin levels in damaged/mouldy and undamaged/wholesome groundnut kernels from markets in the ten regions in Ghana

Source: Awuah & Kpodo (1996)

Maize samples in Ghana – 80% with AF > 30 µg/kg (Kpodo and Halm, 1990)

31 of 32 fermented dough samples – up to 310 µg/kg AF (Kpodo et al.,1996)

15 of 16 Ga Kenkey samples – up to 200 µg/kg AF (Kpodo et al.,1996)

Relatively lower levels detected in Rice - < 2µg/kg

Cocoa cake - < 8µg/kg

Agushie - < 15µg/kg (Kpodo, 2005)

Afs in Ghanaians

Af detected in human breast milk and maternal blood samples (Lamplugh and Hendrickse, 1988)

Afs in Ghanaians (Cont’d)

AFB1measured in 140 blood samples

High AFB1– 0.12 - 3 pmol/mg (Median – 0.80 pmol/mg)

AFM1measured in 91 urine samples ND – 11,562.36 pg/mg (Median – 472.7pg/mg)(Jolly et al., 2006)

Significantly higher levels of AFB1 were from participants with symptoms of acute aflatoxicosis, history of yellow mouth and history of sore swollen stomach.

30-40% of the study group had abnormal liver function and also HBV and HBC infections

Poor liver function was positively correlated with AFB1 levelsHBV was positively associated with high AFB1 levels whereas HCV

was marginally associated with AFB1 levels andApproximately 20% of participants were positive for malaria

Conclusion from the study High AFB1 levels in the blood of participants, high

expression of symptoms of acute aflatoxicosis, high levels HBV/HCV infections and abnormal liver functions puts the study participants at risk of developing hepatocellular carcinoma

Sensational report on Af in Ghana

Sensational reports on Af in Ghana (Cont’d)

‘Scientific studies from major producing sites and

markets in Accra have concluded comprehensively that there is a widespread occurrence of the strain that causes cancer, particularly liver cancer, in Ga kenkey.’

Kofi Koomson, Ghanaian Chronicle Vol. 6, No.133

August 17- August 18, 1998

ARE GHANAIANS AWARE OF THE AFLATOXIN MENACE?

Af awareness study

Zone Farmers Consumers Retailers Processors Feed millers

Poultryfarmers

Northern 186 149 139 106 0 0

Middle 75 159 71 76 7 25

South 70 419 162 218 11 110

Total 331 727 372 400 18 135

Total number of respondents -1984

Knowledge of Afs

Knowledge of Afs X education

RESPONDENT STAKEHOLDERS CHI SQUARE PROBABILITY

Farmer 6.003 0.20

Livestock 27.06 0.00069

Feed Millers 21.02 0.0071

Retailers 21.02 0.0071

Processors 32.29 0.00008

Consumers 37.46 0.00001

Af awareness study - professionals

Health personnel-Medical Doctors, Nurses, Pharmacists

Agriculturist-Agricultural Extension Agents (AEAs), Regional Directors of Agriculture (RDAs), District Directors of Agriculture (DDAs), District Agriculture Development Officers (DADOs), Regional Agricultural Development Officers (RADOs), Research Scientist, University teachers

Awareness of the terms ‘mycotoxin’ and ‘aflatoxin’

Mycotoxin

Aflatoxin

Profession No (%) Yes (%) No (%) Yes (%)

Agriculturists 37.7 62.3 17.1 82.9

Doctors 0 100 0 100

Nurses 47.5 52.5 45.8 54.2

Pharmacists 12.5 87.5 3.1 96.9

Biologists 35.3 64.7 29.4 70.6

Others 56.5 43.5 31.9 68.1

Average 31.6 68.4 21.2 78.8

Awareness of Af accumulation in animal products Profession % Yes

Agriculturists 27.2

Medical doctors 50.0

Pharmacists 18.2

Nurses 25.4

Biological Scientists 52.9

Others 14.5

Average 31.36

Formal training on aflatoxin and attendance of Af workshop

Formal training (%) Workshop attendance (%)

Yes (%) No (%) Yes (%) No (%)Agriculturists 15.6 84.4 7.3 92.7

Doctors 33.3 66.7 16.7 83.3

Nurses 11.9 88.1 7.3 92.7

Pharmacists 12.5 87.5 23.1 76.9

Biol. Sci. 11.9 88.1 17.6 82.4

Others 13.0 87.0 10.1 89.9

Average 16.4 83.6 13.7 86.3

Tests of dependencies

Factor Chi square Probability

Profession X awareness of AF 103.041 0.000

Profession X awareness of effects 60.76 0.019

Qualifications X awareness 107.000 0.000

Rank of Agriculturists X awareness 103.011 0.000

Profession X what produces mycotoxin 36.991 0.008

Sex X awareness 4.504 0.342

Sex X Awareness of harmful effects humans 3.799 0.434

Profession X indication of mycotoxin 0.262 0.500

Profession X diffusion of info to colleagues 74.496 0.014

Profession X diffusion of info to subordinates 112.317 0.500

Conclusions 2003

Though awareness of AF among some health, agricultural and other professionals in Ghana is good, the same cannot be said of the general population

This, together with the inability of most responding professionals to accurately indicate the harmful effects of Af suggests that the menace of the toxin is not well appreciated in Ghana

Management of Af contamination

Pre harvest interventions• Planting date• Control soil insects (groundnut)• Minimize mechanical damage

during cultivation• Early harvesting• Varieties with tight fitting husks

(maize)• Resistant varieties?• Bio control (Aflasafe Ghana)

Post harvest interventions• Inverted windrow vs

random wind row drying• Drying to < 8% moisture

(g’nut); Maize (<12%)• Sorting of nuts• Preservation of shelled nuts

with plant based products

POSTHARVEST INTERVENTIONS (Cont’d)

Storage in interlaced polypropylene and jute bags (placed on wooden platform)

Spit out off-taste kernelsAvoid market groundnut butter (homemade butter

preferable)Preservation of kernels with plant products, chemicals

Proper drying of in-shell nuts

Proper drying of dehusked maize

Improper drying of shelled maize

Improper holding of maize in transit

Improper post harvest handling of maize

Postharvest interventions (Cont’d)

Storage in interlaced polypropylene and jute bags (placed on wooden platform)

Spit out off-taste kernelsAvoid market groundnut butter (homemade butter

preferable)Preservation of kernels with plant products, chemicals

Shelled market groundnut

Shelled nuts in a supermarket

Packaged nuts in a supermarket

Packaged mouldy /weeviled nuts

Kwame Nkrumah University of Science and TechnologyR.T. AWUAH, DEPARTMENT OF CROP AND SOIL SCIENCES, KNUST

GHANAIAN MEDICINAL/CULINARY PLANTS

SYZIGIUM -TREATED AND UNTREATED GROUNDNUT

Treated and untreated nuts

Kwame Nkrumah University of Science and TechnologyAssays were made at 3 and 6mn.(6 mn values are in parenthesis);IPPB= interlaced polypropylene bag: PB= polythene bag. AF before storage = 0 µg/K g

Treatment (%) Mouldy kernels AF at 3 mn (µg/Kg)

9.0% with Syzygium 3.71 (8.26) 25.1

9.0% without Syzygium 6.73 (20.53) 36.2

6.0 with Syzygium 1.03 (4.83) ND

6.0% without Syzygium 3.24 (19.83) 27.5

9.0% without Syzygium 3.39 (100) 29.3

9.0% without Syzygium 45.76 (100) 64.0

6.0 with Syzygium 1.55 (4.96) 1.6

6.0 without Syzygium 24.01 (32.63) 84.0

LSD 0.63 (0.068)

CV 2.26 (1.08)

NovaSil clay enteropsorption studies in Ghana

• Afriyie-Gyawu E, Ankrah NA, Huebner HJ, Ofosuhene M, Kumi J, Johnson NM, Tang L, Xu L, Jolly PE, Ellis WO, Ofori-Adjei D, Williams JH, Wang JS, Phillips TD.• College of Veterinary Medicine and Biomedical

Sciences, Texas A&M University, College Station, TX, USA.• Noguchi

NovaSil clay enteropsorption studies in Ghana (

NovaSil clay Processed calcium montmorillonite clay Has great affinity for Afs Binds with AFs in the GIT and decreases Af uptake in farm animals Administered at 3.0, 1.5 and 0 g/day in capsules Reduced blood and urine Afs No negative effects on vitamin A and E iron and zinc No negative effects on haematology, liver function, kidney function

and electrolytes

NovaSil clay enteropsorption studies (Cont’d)

Side effectsNauseaDiarrheaHeartburndizziness

Ghana Aflasafe research

Update on aflatoxin bio-control research in Ghana GHANA

2012- Visit to Ghana by a team from IITAP. Cotty; R. Bandyopadhyay; D. AgbetiamehUse of atoxigenic strains of A. flavusMechanism : Competitive exclusion

From February to March - Sampling of farmers stores for maize and groundnut in major production areas Eastern, Ashanti, Brong Ahafo, Northern, Upper West, Upper East and Volta regions Purpose –i) Prevalence of aflatoxin contamination in maize and groundnut ii) Identify native atoxigenic strains of Aspergillus flavus that could be used for bio-control

2013 research

Survey areas

2013 research (Cont’d)

5083 isolates obtained

843 were atoxigenic strains of Aspergillus flavus

174 isolates- competition studies for potential to reduce aflatoxin production, in vitro, by a toxigenic A. flavus isolate

Major findings of 2013 research

• 12 atoxigenic strains - selected for field evaluation in in 2014

• Aflatoxin inhibition - 87% – 98%

2014 research

Preparation of preliminary aflasafe Ghana product for field testing

• Isolates (strains) were mixed to broaden efficacy • Each strain mixture was composed of 4 atoxigenic isolates; so

3 products to be tested

• So 3 aflasafe Ghana products to be evaluated in the field

2014 research (cont’d)

• They were evaluated for their ability to reduce aflatoxin in maize and groundnut

• Determine relative efficacy of the 12 isolates to persist in soil and displace toxigenic strains of Aspergillus flavus

• Identify four best atoxigenic strains among the twelve

initial strains to prepare the final aflasafe Ghana product

Locations of farms in 2014

Aflasafe application in a groundnut farm in Ghana

Aflasafe application in a maize farm in Ghana

2015 research

Evaluate the final aflasafe Ghana product as before

Initiate ‘carry over’ studies (frequency of application)

2016 and 2017 activities

Continue with ‘carry over’ studies Register aflasafe Ghana Product?

Some workshops

R.T. AWUAH, DEPARTMENT OF CROP AND SOIL SCIENCES, KNUST

Workshops (cont’d)

R.T. AWUAH, DEPARTMENT OF CROP AND SOIL SCIENCES, KNUST

Workshops (cont’d) Ejura; 2014

International meetings on Afs

Paca.pdf

The way forward

Formation of Af Platform Scoping study to identify

needsAwareness creation

(Workshops, print media, electronic media, fliers, posters, handbooks etc)

Process of change studies

Monitoring of contamination (Who is to do this? PPRSD, FDC, AEA , Farmers )

Workshop on SPSS

Sensitization on Ghana Aflasafe programme (Private sector led initiative; Gov’t to provide enabling environment )

APPRECIATIONFARAGFAPAUDIENCE

PLATFORM ON AFLATOXIN MANAGEMENT IN GHANA

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