Malaria prevalence and incidence in an isolated, meso-endemic area of Mozambique

• Published in: PeerJ preprints
• Main Authors: Charlwood, Jacques Derek D, Erzelia VE Tomás, Bragança, Mauro, Nelson Cuamba, Alifrangis, Michael, Kelly-Hope, Louise, Stanton, Michelle
• Format: Journal Article
• Language: English
• Published: San Diego PeerJ, Inc 22.11.2014
• Subjects: Artemisinin; Fever; Insecticides; Malaria; Nets
• ISSN: 2167-9843
• DOI: 10.7287/peerj.preprints.630v1

If malaria can be eliminated from anywhere it is from isolated areas such as the 2x7 km peninsula of Linga Linga in southern Mozambique. Currently available control strategies include bed nets impregnated with pyrethroid insecticides (long-lasting insecticidal bed nets; LLINs), artemisinin combination therapy (ACT) for treatment and rapid diagnostic tests (RDTs) for diagnosis. When these became available, they were applied and their effects on malaria prevalence measured over the years 2007 – 2011. Following a census of the population and mapping of 500 households, five annual all age prevalence surveys were conducted over the years 2007 – 2011. Information on LLIN use, house construction, and animal ownership was obtained. Mean prevalence varied from 16% (in 2007) to 65% (in 2009) according to the season in which the surveys were performed. The 5 – 9 year old age group had the highest prevalence rate in the first three surveys (2007 – 2009). A spatially structured generalised additive model indicated that malaria risk was greatest towards the northern end of the peninsula. The effect on the incidence of malaria of a clinic providing RDT’s for diagnosis and ACT’s for treatment was also monitored from March 2009 to May 2011. Malaria was diagnosed in 31% of the 4321 visits from residents attending the clinic and 72% of those tested were positive. People with confirmed malaria were younger than the median age of people attending the clinic. People with a fever were more likely to have malaria than people without a fever but bednet use did not affect the likelihood of having malaria. People living further away from the health post were less likely to attend. The number of attendees diagnosed with malaria decreased significantly from 35% (399 of 1144 attendees) in 2009 to 24% (271 of 1150 attendees) in 2011 (Chi sq = 19.1, p> 0.0001). In order to reduce malaria prevalence in an area such as Linga Linga further measures of vector control need to be considered if reductions in malaria prevalence are to be achieved.