DOI: 10.5061/dryad.69p8cz9cb
title: Mâncio Lima malaria cohort study 2018–2021: Prevalence surveys

description: Malaria is increasingly diagnosed in urban centers across the
 Amazon Basin. In this study, we combined repeated prevalence
 surveys over a 4-year period of a household-based random sample of 2,774
 persons with parasite genotyping to investigate the epidemiology
 of malaria in Mâncio Lima, the main urban transmission hotspot
 in Amazonian Brazil. We found that most malarial
 infections were asymptomatic and undetected by point-of-care
 microscopy. Our findings indicate that as malaria transmission decreases,
 the detection threshold of microscopy rises, resulting in more
 missed infections despite similar parasite densities estimated by
 molecular methods. We identified genetically highly diverse
 populations of Plasmodium vivax and P. falciparum in the region;
 occasional shared lineages between urban and rural residents suggest
 cross-boundary propagation. The prevalence of low-density and asymptomatic
 infections poses a significant challenge to routine surveillance and the
 effectiveness of malaria control and elimination strategies in urbanized
 areas with readily accessible laboratory facilities.
description: # Mâncio Lima malaria cohort study 2018–2021: Prevalence surveys
 [https://doi.org/10.5061/dryad.69p8cz9cb](https://doi.org/10.5061/dryad.69p8cz9cb) ## Description of the data and file structure This dataset contains the data of repeated prevalence surveys over a 4-year period of a household-based random sample of 2,774 persons to investigate the epidemiology of malaria in Mâncio Lima, the main urban transmission hotspot in Amazonian Brazil. ### Variables | Variable | Description | Field Attributes | | :------------------------------- | :---------------------------------------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------- | | visit | Study wave number. | Apr 2018; Sep 2018; May 2019; Sep 2019; Oct 2020; Apr 2021; Oct 2021. | | age\_category | Age category of patient. | 0-4; 5-9; 10-14; 15-19; 20-24; 25-29; 30-34; 35-39; 40-44; 45-49; 50-54; 55-59; 60-64; 65-69; 70-74; 75-79; 80-84; 85-89; 90-94; 95-99; 100-104. | | specie | *Plasmodium* species determined by qPCR. | Negative; *P. vivax*; *P. falciparum*; Mix infection. | | ct\_vivax | cycle threshold of *P. vivax*. | (numeric); empty cells represent individuals without detected *P. vivax* parasitemia. | | ct\_falciparum | cycle threshold of *P. falciparum*. | (numeric); empty cells represent individuals without detected *P. falciparum* parasitemia. | | copies\_ul\_vivax\_rev | Revised number of *P. vivax* amplicon copies per microliter. | (numeric); empty cells represent individuals without detected *P. vivax* parasitemia. | | copies\_ul\_falciparum\_rev | Revised number of *P. falciparum* amplicon copies per microliter. | (numeric); empty cells represent individuals without detected *P. falciparum* parasitemia. | | thick\_smear\_result | Thick smear result. | 0 - Negative; 1 - Positive. | | thick\_smear\_test | Thick smear test. | 0 - Not available; 1 - Available. | | sex | Sex of patients. | 0 - Female; 1 - Male. | | previous\_malaria | Report of any past malaria. | 0 - No; 1 - Yes; 9 - No answer. | | bed\_net\_use\_past\_night | Patient report of bed net use past night. | 0 - No; 1 - Yes - no insecticide; 2 - Yes - insecticide; 9 - No answer. | | wealth\_idx | Wealth index associated with each patient. | 1 - poorest; 2; 3; 4 - wealthiest. | | eave\_gaps | Presence of eave gaps in the household. | 0 - No; 1 - Yes; 9 - No answer. | | cohort\_individuals | Individuals from the cohort. | 0 - No; 1 - Yes. | | thick\_smear\_result\_vivax | Thick smear result for *P. vivax.* | 0 - No; 1 - Yes. | | thick\_smear\_result\_falciparum | Thick smear result for *P. falciparum.* | 0 - No; 1 - Yes. | | symptoms | Any signs or symptoms in the last 7 days. | 0 - No; 1 - Yes. | ### Missing values Missing values not collected during the surveys are indicated as "n/a".