Seroprevalence of malaria in inhabitants of the urban zone of Antananarivo, Madagascar

Olivier Domarle¹ , Romy Razakandrainibe¹ , Emma Rakotomalala¹ , Laurence Jolivet² , Rindra Vatosoa Randremanana¹ , Fanjasoa Rakotomanana¹ , Charles Emile Ramarokoto¹ , Jean-Louis Soares¹ and Frédéric Ariey³

¹Institut Pasteur de Madagascar, Antananarivo, Madagascar

²Ecole Nationale des Sciences Géographiques, Marne la Vallée, France

³Institut Pasteur du Cambodge, Phnom Penh, Cambodia

author email corresponding author email

Malaria Journal 2006, 5:106doi:10.1186/1475-2875-5-106


Published:	10 November 2006

Abstract

Background

Antananarivo, the capital of Madagascar, is located at an altitude of over 1,200 m. The environment at this altitude is not particularly favourable to malaria transmission, but malaria nonetheless remains a major public health problem. The aim of this study was to evaluate exposure to malaria in the urban population of Antananarivo, by measuring the specific seroprevalence of Plasmodium falciparum.

Methods

Serological studies specific for P. falciparum were carried out with an indirect fluorescent antibody test (IFAT). In a representative population of Antananarivo, 1,059 healthy volunteers were interviewed and serum samples were taken.

Results

The seroprevalence of IgG+IgA+IgM was 56.1% and that of IgM was 5.9%. The major risk factor associated with a positive IgG+IgA+IgM IFAT was travel outside Antananarivo, whether in the central highlands or on the coast. The abundance of rice fields in certain urban districts was not associated with a higher seroprevalence.

Conclusion

Malaria transmission levels are low in Antananarivo, but seroprevalence is high. Humans come into contact with the parasite primarily when travelling outside the city. Further studies are required to identify indigenous risk factors and intra-city variations more clearly.