Konzo associated with war in Mozambique

Abstract

SummaryWe report an epidemic of konzo, symmetric spastic paraparesis associated with cassava consumption and cyanide exposure: 384 patients were treated in rehabilitation centres; the prevalence rate in a badly affected area was 30/1000. Most patients were children over 3 and women. Owing to war, communities turned to bitter cassava as their staple and took shortcuts in its processing. When the war ended, they continued to depend on inadequately processed bitter cassava. The epidemic lasted 2 years (the last year of war and the first of peace) with peaks each year during the cassava harvest. Although most cases were reported from rural inland areas, patients also came from small towns and the coast. School children had raised urinary thiocyanate and linamarin and low inorganic sulphate concentrations. Urinary thiocyanate values were lower than those previously reported in konzo epidemics, probably because we collected specimens before the cassava harvest and epidemic peak. The necessary conditions for konzo were present: intensive cultivation of bitter cassava, insufficient processing, a probable high cyanide intake, and a low intake of protein-rich foods.

Production, consumption and nutritional value of cassava (Manihot esculenta, Crantz) in Mozambique: An overview

“…This has been reported in countries where cassava is used as staple food, including Mozambique (Dufour, 1988;Mckey and Beckerman, 1993;Ministry of Health Mozambique, 1984;Cliff at al., 1997;Cliff at al., 2011). Chronic intoxication from cassava manifests as tropical neuropathy (Osuntokun, 1994), glucose intolerance and konzo , Cliff at al., 1997Cliff at al., 2011), goitre and cretinism (Delange et al, 1994).…”

“…Population groups found to be most vulnerable are women of child bearing age and children up to two years of age (Cliff et al, 2011). All cases reported in the country have been found to be related to consumption of bitter cassava which was poorly processed, collected during a famine period, during the civil war, or to a diet deficient in sulfur amino acids (Ministry of Health Mozambique, 1984;Essers at al., 1992;Tylleskar er al., 1993;Cliff at al., 1997;Ernesto et al, 2002;Cliff at al., 2011 1984;Ernesto et al, 2002;Cliff at al., 2011). Thiocyanate remains in the body as a result of the detoxification of cyanide.…”

“…It is a multiple year crop and roots can be kept in the ground until needed, thus increasing food security (El-Sharkawy, 2004;Donovan et al, 2011;Gbadegesin et al, 2013). Cyanogenic glycosides and other anti-nutritional factors are a threat to human health that is well recognized in Mozambique (Ministry of Health Mozambique, 1984;Essers et al, 1992;Cliff, 1994;Cliff et al, 1997;Nhassico et al, 2008;Cliff et al, 2011). However, a less recognized threat is the poor nutrient quality, which because of the high level of consumption of this staple carbohydrate, threatens a large proportion of the population with malnutrition and poor quality of life.…”

Reducing neurodevelopmental disorders and disability through research and interventions

“…Epidemiological studies have documented konzo outbreaks -mostly in women and children -in periods of food insecurity that have been brought about by drought, displacement by war or conflict, or other factors that have led to the insufficient processing of cassava tubers. The insufficient breakdown of linamarin compounds that contain cyanide result in neurological damage and seem to lead to outbreaks of konzo, which has been documented mostly in the Congo, Central African Republic, Mozambique and Tanzania [51][52][53] with a prevalence of between 0.1% and 17% in affected villages 54 . Studies have recently documented neurocognitive impairments in children with konzo.…”

Health factors associated with persistent konzo in four villages in the Democratic Republic of Congo (DRC)

“…Konzo epidemics also result from war when local village people are forced from their homes and gardens and forced to eat unprocessed high cyanide cassava from the bush (Cliff et al, 1997;Nhassico et al, 2008;Chabwine et al, 2011). Konzo outbreaks also occur in Central Africa when peeled cassava roots are not immersed in water for the 3 to 4 days necessary to allow the enzyme linamarase to break down fully the cyanogenic glucoside, but are short soaked for only 1 to 2 days.…”