Malaria in the paediatric wards of a rural Mozambican hospital and the clinical development of new antimalarial drugs

Despite a renewed impetus on bringing together efforts to wipe malaria from the globe, the truth is that this ancient disease remains one of the principal threats to child survival in vast areas of the world. The existing control measures are largely insufficient to reduce globally the malaria burden, and as of today, malaria remains endemic in more than 100 countries, where at least half of the world's population live exposed to the risk of being infected. Indeed, the burden of malaria morbidity and mortality continues to be unacceptably high, with more than 250 million clinical episodes and at least one million deaths per year. While morbidity due to malaria affects all age groups and is scattered throughout the world, Sub-Saharan Africa concentrates the brunt of the malaria deaths, which overwhelmingly occur in children under five years of age infected with P. falciparum. The exciting and almost palpable perspective of an effective malaria vaccine, added to the promotion of innovative control strategies such as intermittent preventive treatment for infants or pregnant women, have in the recent years centred the scientific discussions regarding the approach to malaria control. However, in contrast to these innovative perspectives, malaria control has remained in the last two decades essentially dependent on the early identification and prompt treatment of clinical malaria cases and the reduction of man-vector contact. Unless there is a major renewal, optimisation and scale-up of the antimalarial arsenal and strategies, malaria will continue to dictate the health status of the world, and eradication will not be achievable in a realistic timeframe. As malaria is a life-threatening infection, a fundamental requirement for its adequate control is the availability of effective antimalarial drugs. The first paper in this thesis describes a large randomised clinical trial (around 1500 children) performed in five different African countries to assess the non-inferiority of a novel combination, dihydroartemisinin-piperaquine, produced under strict good manufacturing practices, when compared to the standard combination therapy AL, for the treatment of uncomplicated malaria in African children under the age of five years. In the second paper, we describe the results of another large (around 900 patients) randomised clinical trial in which we assessed in 5 different African countries the non-inferiority of a new, paediatric-suited cherry-flavoured, dispersible formulation of AL, when compared to standard crushed AL tablets, for the treatment of uncomplicated malaria in children younger than 12 years of age. The results of these two trials, reflected in paper 1 and paper 2 of this thesis, bring to the malaria community public-health relevant data on alternatives to the currently limited antimalarial drug arsenal. The third paper in this thesis describes the clinical presentation of severe malaria in a rural Mozambican Hospital, and the associated risk factors for a negative outcome. It also presents minimum community based incidence rates, a useful indicator of the malaria burden in the area. Finally, the fourth paper addresses the relationship between severe malaria and bacterial invasive disease in children younger than 5 years admitted to a Manhica's rural hospital, Mozambique. Malaria is an ancient disease of terrible consequences for mankind. All efforts devised to diminish the burden that malaria imposes in endemic areas need to be embraced and brought together on a coordinated manner to fight this infection from all possible fronts. Understanding the clinical determinants of the infection and its relation with other coexistent infectious diseases will give an insight to the basic pathophysiology of malaria, and thus guide appropriate management strategies. New highly effective drugs, and their paediatric-orientated formulations, need to be developed and made available to those most at need.