NGOnut discussion summaries - cassava poisoning, and HIV and breastfeeding

The following are edited summaries of e-mail correspondence from the NGO Nutrition Association (NGO Nut) which may be of interest to readers. The NGO Nut was recently set up to act as a discussion group for those who co- ordinate, manage or advise nutrition programmes in developing countries and for those nutritionists who are working in relative isolation.

Cassava poisoning or not?

Working in Maramvya, Burundi, an ACF team recently came across a medical problem which suggested to us possible intoxication from eating raw cassava. We found 40 adults suffering from 'limp paralysis' with inability to walk, painful paresthesia, especially in the calf muscle, absence of knee and babiski reflex, no fever or cardiac or pulmonary problems and no signs of malnutrition. Two of the patients reported that about one month before they had been eating raw cassava roots for 2-3 days after they had been evacuated from their villages for security reasons. Can anyone comment on this diagnosis and about possible treatments if the diagnosis was correct.

Yvonne Grellety
ACF.

From Professor Mike Golden, Aberdeen University:

I read with interest Yvonne Grellety's description of a possible cassava poisoning outbreak. This is not the way that poisoning with cassava usually presents. Symptoms of cassava poisoning - known as "Konzo" have been described in detail. There is a sudden onset of spastic paraparesis affecting mainly women and adolescents. There is no flaccid phase to the illness, the reflexes are exaggerated with clonus, strongly planter-flexed feet and a scissors-gait in those that can stand. The condition is not progressive and there are no sensory signs or symptoms.

I cannot say what condition would present in this way with parasthesia in the lower leg and flaccid paralysis in a sudden epidemic form affecting the non-anthropometrically malnourished although it was most likely to be an intoxication or infection. I wonder if this population which has been hiding in the bush had been taking any unusual plants to eat that were not part of the normal diet. I think that the patients should have a full and comprehensive physical examination to describe the syndrome in detail and a full history of the exact time of onset and the way and order in which the symptoms have evolved in relation to intake of unusual food items.

Yours etc.,
Professor Mike Golden, Aberdeen University

HIV and breastfeeding

I am involved in a study in Zimbabwe on the effects of daily multi-micronutrient supplementation to pregnant and lactating women on mother-to-child HIV-transmission. My work and interest in this subject leaves me in no doubt that breast-feeding is a strong risk factor for vertical transmission of HIV. But, there are insufficient data on the timing of post-natal transmission. This is why I am concerned about the latest interim statement on breastfeeding - where attention is drawn to the fact that breastfeeding may cause HIV. While this is definitely true, it may be a dangerous message for women in developing countries who are rarely aware of their HIV status. The message may determine that women become inclined to stop breastfeeding irrespective of their HIV-status. In which case the following calculation is enlightening.

If one third of pregnant women are HIV positive (34% in our study) and one third of these have an HIV positive child of which one third will be infected post-natally, then if 100 women stopped breastfeeding we would avoid 3.7 (1/27) children getting HIV. This outcome has to be compared with the increased morbidity and mortality of breastfeeding deprivation among the 67 infants of the uninfected mothers, as well as among the 22 children of HIV positive women who would not have become infected and also among the 7.4 infants that had been infected in utero or intrapartum who would be in particular need of breastmilk. Obviously, this is based on the assumption that in an area where there is a one third prevalence of HIV, one third of the women who give up breastfeeding are HIV positive whereas a greater percentage of those who give up may be HIV positive in some situations, e.g. where HIV testing is accessible.

A second point is that we have not identified other risk factors and effect modifiers. One potentially important modifier is maternal nutritional status. There is 'observational' data to suggest that low maternal vitamin A status may increase the risk of having HIV in breast milk. Thus, the risk of post-natal transmission is not absolute, but rather conditional upon maternal nutritional status. If this can be confirmed, then we may have an affordable public health measure, than can be given to all women irrespective of HIV-status so that we maintain the benefits of breast feeding and reduce its risks.

Several studies are in progress that address these issues and I hope that some results will be presented at the forthcoming conference on Global Strategies at NIH in Washington in September this year.

Yours, etc.,
Henrik Friis, MD, PhD
Danish Bilharziasis Laboratory
henrik_friis@online.pol.dk