Artemisinin-based combination therapy does not measurably reduce human infectiousness to vectors in a setting of intense malaria transmission

• Published in: Malaria journal 2012-04, Vol.11 (1), p.118-118, Article 118
• Main Authors: Huho, Bernadette J, Killeen, Gerard F, Ferguson, Heather M, Tami, Adriana, Lengeler, Christian, Charlwood, J Derek, Kihonda, Aniset, Kihonda, Japhet, Kachur, S Patrick, Smith, Thomas A, Abdulla, Salim Mk
• Format: Article
• Language: English
• Subjects: Animals; Antigens, Protozoan - analysis; Antimalarials; Antimalarials - administration & dosage; Artemisinin-based combination therapy; Artemisinins - administration & dosage; Asymptomatic Diseases - epidemiology; Biomedical research; Busta Rhymes; Case management; Child, Preschool; Colleges & universities; Control; Culicidae - parasitology; Disease control; Disease prevention; Disease transmission; Disease Vectors; Distribution; Drug Combinations; Drug therapy; Enzyme-Linked Immunosorbent Assay; Female; Health aspects; Health sciences; Humans; Infant; Infant, Newborn; Infection; Intervention; Malaria; Malaria, Falciparum - drug therapy; Malaria, Falciparum - epidemiology; Malaria, Falciparum - transmission; Mortality; Mosquitoes; Parasites; Parasitic diseases; Plasmodium falciparum; Plasmodium falciparum - isolation & purification; Pregnancy; Prevalence; Pyrimethamine - administration & dosage; Risk factors; Sulfadoxine - administration & dosage; Tanzania - epidemiology; Transmission reduction
• ISSN: 1475-2875; 1475-2875
• DOI: 10.1186/1475-2875-11-118

Artemisinin-based combination therapy (ACT) for treating malaria has activity against immature gametocytes. In theory, this property may complement the effect of terminating otherwise lengthy malaria infections and reducing the parasite reservoir in the human population that can infect vector mosquitoes. However, this has never been verified at a population level in a setting with intense transmission, where chronically infectious asymptomatic carriers are common and cured patients are rapidly and repeatedly re-infected. From 2001 to 2004, malaria vector densities were monitored using light traps in three Tanzanian districts. Mosquitoes were dissected to determine parous and oocyst rates. Plasmodium falciparum sporozoite rates were determined by ELISA. Sulphadoxine-pyrimethamine (SP) monotherapy was used for treatment of uncomplicated malaria in the contiguous districts of Kilombero and Ulanga throughout this period. In Rufiji district, the standard drug was changed to artesunate co-administered with SP (AS + SP) in March 2003. The effects of this change in case management on malaria parasite infection in the vectors were analysed. Plasmodium falciparum entomological inoculation rates exceeded 300 infective bites per person per year at both sites over the whole period. The introduction of AS + SP in Rufiji was associated with increased oocyst prevalence (OR [95%CI] = 3.9 [2.9-5.3], p