Mâncio Lima malaria cohort study 2018–2021: Prevalence surveys
Data files
Nov 27, 2024 version files 610.10 KB
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Data_Rodrigues_2024_EID_v3.xlsx
604.50 KB
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README.md
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Abstract
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.
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”.