Preventing malaria and anaemia in infants in Ghana

In poor African communities malaria is the leading cause of death and disease among infants and is also one of the main causes of anaemia and anaemia-related deaths in infants. What effect will treating infants, whether they do or do not have the disease, have in preventing malaria and anaemia in an area with intense, seasonal transmission of the disease?

An estimated 515million cases of falciparum malaria occurred in 2002 and about 70 percent ofthese were in Africa. Malaria is a leading cause of anaemia in children insub-Saharan Africa and malaria associated anaemia causes an estimated 190,000to almost a million deaths a year. The most significant burden of malaria andmalaria associated anaemia in areas with high intensity transmission is amonginfants. Control of these conditions mostly depends on assessing children whenthey are brought to health facilities, but as many children show no symptomsthey have a high risk of developing severe anaemia.

Research inTanzania has shown that treatment with appropriate drugs in the first year of achild’s life significantly reduced the rate of malaria and anaemia. Aftertreatment was stopped the risk of these conditions increased in the second yearof life, however, suggesting that the treatment had impaired the development ofimmunity.

The strategy knowas the intermittent preventive treatment for malaria in infants (IPTi) treats infants without malaria symptoms, regardlessof their malaria infection status, with regularly spaced doses of anti-malarialdrugs. A study by the London School of Hygiene and Tropical Medicine, UK, setout to evaluate whether running IPTi for up to 24months in combination with a child immunisation programme would offer protectionagainst malaria and malaria-related anaemia in areas with intense, seasonaltransmission in Ghana.

The researchers reportthat:

• Treating 12 months old infants with sulfadoxine-pyrimethamine as well as diphtheria-pertussis-tetanus vaccines (DPT-2 andDPT-3) and measles vaccine reduced the incidence of malaria by 25 percentand anaemia by 35 percent.
• The highest protection occurred when IPTi with sulfadoxine-pyrimethaminewas given with DPT-2 and DPT-3 in the wet season.
• When treatment stopped, however, theincidence of severe malaria increased by 20percent.
• IPTi had no protective effect againstmalaria or anaemia between 16 and 24 months old. In fact, the incidence ofsevere malaria was higher in this group than in the placebo group. 
• 10 infants died in the first monthafter IPTi was given, compared with no deaths inthe placebo group. Physicians investigating the deaths found no link with theIPTi drugs.

The study found asubstantially lower protection rate against malaria and anaemia in infants whentreating with IPTi in combination with sulfadoxine-pyrimethamine than that reported by research inTanzania. This may be due to differences between the two sites.

The report makes anumber of recommendations:

• More data are needed to determine the appropriatedosing schedules for IPTi in high seasonaltransmission areas, as well as the interaction of IPTiwith insecticide-treated bed nets.
• There appears to be a potentialrebound effect – a significant number of malaria attacks – between 16 and24 months. This must be monitored carefully if IPTiis given on a large scale.
• The apparent trend of a number ofdeaths occurring in the first month after giving IPTineeds to be monitored carefully in all IPTiprogrammes.