scholarly journals Cohort profile: the Mâncio Lima cohort study of urban malaria in Amazonian Brazil

BMJ Open ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. e048073
Author(s):  
Igor C Johansen ◽  
Priscila T Rodrigues ◽  
Juliana Tonini ◽  
Joseph Vinetz ◽  
Marcia C Castro ◽  
...  
Keyword(s):  
Cohort Study ◽  
Malaria Transmission ◽  
Housing Quality ◽  
Effective Control ◽  
Asymptomatic Malaria ◽  
Adult Males ◽  
Cross Sectional ◽  
Study Protocols ◽  
Phenotypic Characterisation ◽  
Amazonian Brazil

PurposeThis population-based open cohort study aims to investigate biological and sociodemographic drivers of malaria transmission in the main urban hotspot of Amazonian Brazil.ParticipantsNearly 20% of the households in the northwestern town of Mâncio Lima were randomly selected and 2690 participants were enrolled since April 2018. Sociodemographic, housing quality, occupational, behavioural and morbidity information and travel histories were collected during consecutive study visits. Blood samples from participants>3 months old were used for malaria diagnosis and human genetic studies; samples from participants with laboratory-confirmed malaria have been cryopreserved for genetic and phenotypic characterisation of parasites. Serology was introduced in 2020 to measure the prevalence and longevity of SARS-CoV-2 IgG antibodies.Findings to dateMalaria prevalence rates were low (up to 1.0% for Plasmodium vivax and 0.6% for P. falciparum) during five consecutive cross-sectional surveys between April–May 2018 and October–November 2020; 63% of infections diagnosed by microscopy were asymptomatic. Malaria risk is heterogeneously distributed, with 20% study participants contributing 86% of the overall burden of P. vivax infection. Adult males are at greatest risk of infection and human mobility across the urban–rural interface may contribute to sustained malaria transmission. Local P. vivax parasites are genetically diverse and fragmented into discrete inbred lineages that remain stable across space and time.Future plansTwo follow-up visits, with similar study protocols, are planned in 2021. We aim to identify high-risk individuals that fuel onwards malaria transmission and represent a priority target for more intensive and effective control interventions.Trial registration numberNCT03689036.

scholarly journals Asymptomatic malaria and anaemia among pregnant women during high and low malaria transmission seasons in Burkina Faso: household-based cross-sectional surveys in Burkina Faso, 2013 and 2017

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Toussaint Rouamba ◽  
Sékou Samadoulougou ◽  
Mady Ouédraogo ◽  
Hervé Hien ◽  
Halidou Tinto ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Pregnant Women ◽  
Malaria Transmission ◽  
Asymptomatic Malaria ◽  
Cross Sectional ◽  
Transmission Season ◽  
Low Transmission ◽  
High Transmission ◽  
Asymptomatic Carriage ◽  
Low Malaria Transmission

Abstract Background Malaria in endemic countries is often asymptomatic during pregnancy, but it has substantial consequences for both the mother and her unborn baby. During pregnancy, anaemia is an important consequence of malaria infection. In Burkina Faso, the intensity of malaria varies according to the season, albeit the prevalence of malaria and anaemia as well as their risk factors, during high and low malaria transmission seasons is underexplored at the household level. Methods Data of 1751 pregnant women from October 2013 to March 2014 and 1931 pregnant women from April 2017 to June 2017 were drawn from two cross-sectional household surveys conducted in 24 health districts of Burkina Faso. Pregnant women were tested for malaria in their household after consenting. Asymptomatic carriage was defined as a positive result from malaria rapid diagnostic tests in the absence of clinical symptoms of malaria. Anaemia was defined as haemoglobin level less than 11 g/dL in the first and third trimester and less than 10.5 g/dL in the second trimester of pregnancy. Results Prevalence of asymptomatic malaria in pregnancy was estimated at 23.9% (95% CI 20.2–28.0) during the high transmission season (October–November) in 2013. During the low transmission season, it was 12.7% (95% CI 10.9–14.7) between December and March in 2013–2014 and halved (6.4%; 95% CI 5.3–7.6) between April and June 2017. Anaemia prevalence was estimated at 59.4% (95% CI 54.8–63.8) during the high transmission season in 2013. During the low transmission season, it was 50.6% (95% CI 47.7–53.4) between December and March 2013–2014 and 65.0% (95% CI 62.8–67.2) between April and June, 2017. Conclusion This study revealed that the prevalence of malaria asymptomatic carriage and anaemia among pregnant women at the community level remain high throughout the year. Thus, more efforts are needed to increase prevention measures such as IPTp–SP coverage in order to reduce anaemia and contribute to preventing low birth weight and poor pregnancy outcomes.

Asymptomatic malaria and anemia among pregnant women during high and low malaria transmission seasons in Burkina Faso: household-based cross-sectional surveys in Burkina Faso, 2013–2017

2020 ◽  
Author(s):  
Toussaint Rouamba ◽  
Sékou Samadoulougou ◽  
Mady Ouédraogo ◽  
Hervé Hien ◽  
Halidou Tinto ◽  
...  
Keyword(s):  
Burkina Faso ◽  
Pregnant Women ◽  
Malaria Transmission ◽  
Malaria In Pregnancy ◽  
Asymptomatic Malaria ◽  
Cross Sectional ◽  
Transmission Season ◽  
Asymptomatic Carriage ◽  
Low Malaria Transmission ◽  
In Pregnancy

Abstract Background: Malaria in endemic countries is often asymptomatic during pregnancy, but it has substantial consequences for both the mother and her unborn baby. In Burkina Faso, the prevalence and risk factors of asymptomatic malaria in pregnancy and its main consequence, anemia, during high and low malaria transmission seasons is underexplored at the household level.Methods: Data of 1751 pregnant women from October 2013 to March 2014 and 1931 pregnant women from April 2017 to June 2017 were drawn from two cross-sectional household surveys conducted in 24 health districts of Burkina Faso. Pregnant women were tested for malaria in their household after consenting. Asymptomatic carriage was defined as a positive result from malaria rapid diagnostic tests in the absence of malaria symptoms. Anemia was defined as hemoglobin level less than 11 g/dL.Results: Prevalence of asymptomatic malaria in pregnancy was estimated at 23.9% (95%CI: 20.2–28.0) during the high transmission season (October–November) in 2013. During the low transmission season, it was 12.7% (95%CI: 10.9–14.7) between December and March in 2013–2014 and halved (6.4%; 95%CI: 5.3–7.6) between April and June 2017. Anemia prevalence was estimated at 43.7% (95%CI: 39.3–48.3) during the high transmission season in 2013. During the low transmission season, it was 32.7% (95%CI: 30.1–35.5) between December and March 2013–2014 and 46.6% (95%CI: 44.3–48.9) between April and June, 2017.Conclusion: Prevalence of asymptomatic malaria in pregnancy was significantly higher during the high malaria transmission season while anemia prevalence was lower. Our study provides an opportunity to assess the prevalence of asymptomatic carriage and one of its main consequences, anemia, among pregnant women at the community level throughout the year. In order to mitigate the harmful effects of asymptomatic carriage for both the mother and fetus, health programs aimed at increasing the number of women coming into contact with health workers are necessary.

scholarly journals Asymptomatic malaria remains high among seasonal migrant workers depart to home from malarious areas and may cause a resurgence of malaria transmission at high lands of northwest Ethiopia: a cross-sectional study

2021 ◽  
Author(s):  
Tesfaye Tilaye Tilaye ◽  
Belay Tessema Tessema ◽  
Keshaun Alemu Gelaye
Keyword(s):  
Malaria Transmission ◽  
Migrant Workers ◽  
Study Participant ◽  
Malaria Prevention ◽  
Cross Sectional Study ◽  
Northwest Ethiopia ◽  
Asymptomatic Malaria ◽  
Sectional Study ◽  
Cross Sectional ◽  
Land Preparation

Abstract Background In Ethiopia, thousands of seasonal migrant workers used to travel from non-malaria or mild malaria transmission areas to malaria endemic areas for the purposes of seasonal farm activities. Most of these migrants are staying in the farm areas for land preparation, ploughing, planting, weeding and harvesting for specific period of time and back to their living areas. However, there is limited evidence how the seasonal migrant workers contribute in the transmission of malaria to new or less malaria transmission areas. Methods A cross sectional study was conducted at departure phase of seasonal migrant workers in Metema district from September 2018 to October 2019. A total of 1208 seasonal migrant workers were interviewed during their departure to home. Interviewed face to face interview was done using a pretested structured questionnaire. Moreover, blood samples were collected from each study participant for microscopic malaria parasite examination. The data was fitted with the logistic regression model to estimate the predictors’ of malaria transmissions. Results At the departure to home, the prevalence of malaria among seasonal migrant workers was 17.5% (15.6-19.45%). About 71.80 % (177/212) of the cases were Plasmodium falciparum, and 28.20% (35/212) Plasmodium vivax. The majority of seasonal migrant workers (77.4%) were from rural residence and highlanders (55%). Most (55.4%) of the migrants were visited two and more farm sites during their stay at development corridors for harvesting activities. About 116 (54.7%) asymptomatic malaria cases were returning to Dembiya(21.7%), Chilaga(19.8%) and Metema(13.2%) districts. Conclusion This study focuses on the prevalence of asymptomatic malaria among seasonal migrant workers during the departure phase to home. The role of seasonal migrant workers in carrying and spreading malaria parasites, as well as challenging the country's malaria prevention and elimination efforts, could be enormous. Age, occupation, origin, the number of farm sites visited, and the frequency with which LLINs used were all associated with an increased asymptomatic malaria prevalence in the study area. Tailored interventions for seasonal migrant workers could be in place by programers, partners and implementers to enhance malaria control and elimination.

scholarly journals PO 8419 SPATIO-TEMPORAL MAPPING OF ASYMPTOMATIC AND CLINICAL MALARIA INFECTIONS REVEALS FOCI OF MALARIA TRANSMISSION FOR TARGETED CONTROL INTERVENTIONS

2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A35.2-A35
Author(s):  
Makhtar Niang ◽  
Cheikh Talla ◽  
Nafissatou Diagne ◽  
Fatoutama Diene-Sarr ◽  
Cheikh Sokhna
Keyword(s):  
Malaria Transmission ◽  
Malaria Incidence ◽  
Clinical Malaria ◽  
Asymptomatic Malaria ◽  
Design Strategies ◽  
Cross Sectional ◽  
Asymptomatic Infections ◽  
Spatio Temporal ◽  
Malaria Episodes

BackgroundThe global decline of malaria incidence over the past decade has led to the thought that elimination could be achieved. This has resulted in an increased interest to design strategies to target the hidden reservoir of asymptomatic infections among populations and interrupt on-going residual local malaria transmission. This study explored the reservoir of asymptomatic Plasmodium infections and its relationship with subsequent clinical malaria infections in low-transmission areas in Senegal.MethodsCross-sectional surveys were carried out in 2013, 2014, 2015, and 2016 and combined with longitudinal follow-up to determine and geolocalise both asymptomatic and clinical malaria episodes in Dielmo and Ndiop, Senegal. The prevalence of asymptomatic Plasmodium carriage in the community was investigated by real-time PCR while clinical malaria attacks were identified at health facilities during the transmission season. All households were georeferenced to spatially map asymptomatic and clinical infections.ResultsThe study revealed substantial asymptomatic infections with average parasite carriage of 8.11% and 7% in Dielmo and Ndiop, respectively. P. falciparum accounted for most asymptomatic infections (more than 90%). In Dielmo, 95% of asymptomatic infections clustered within the same geographical areas while infections were disparate in Ndiop. Preliminary fine-scale mapping of asymptomatic and clinical malaria infections identified clusters of higher malaria incidence interpreted as foci of transmission across the four-year study period with 95%–98% of clinical infections occurring in households where an asymptomatic malaria infection existed.ConclusionThis study revealed substantial asymptomatic Plasmodium infections in both settings throughout the four-year study period and spatial clusters of malaria infections at the microepidemiological level. Together, these findings could offer a feasible approach for a rational targeting of malaria control interventions to achieve elimination.

scholarly journals Asymptomatic malaria remains high among seasonal migrant workers depart to home from malarious areas and may cause a resurgence of malaria transmission at high lands of northwest Ethiopia: a cross-sectional study

2021 ◽  
Author(s):  
Tesfaye Tilaye ◽  
Belay Tessema ◽  
Kassahun Alemu
Keyword(s):  
Malaria Transmission ◽  
Migrant Workers ◽  
Study Participant ◽  
Malaria Prevention ◽  
Cross Sectional Study ◽  
Northwest Ethiopia ◽  
Asymptomatic Malaria ◽  
Sectional Study ◽  
Cross Sectional ◽  
Land Preparation

Abstract Background: In Ethiopia, thousands of seasonal migrant workers used to travel from non-malaria or mild malaria transmission areas to malaria-endemic areas for seasonal farm activities. Most of these migrants are staying in the farm areas for land preparation, plowing, planting, weeding, and harvesting for a specific period and back to their living areas. However, there is limited evidence of how the seasonal migrant workers contribute to the transmission of malaria to new or less malaria transmission areas.Methods: A cross-sectional study was conducted at the departure phase of seasonal migrant workers in the Metema district from September 2018 to October 2019. A total of 1208 seasonal migrant workers were interviewed during their departure from farm sites to their homes. Interviewed face to face interview was done using a pretested structured questionnaire. Moreover, blood samples were collected from each study participant for microscopic malaria parasite examination. The data were fitted with the logistic regression model to estimate the predictors’ of malaria transmissions. Results: At the departure to home, the prevalence of malaria among seasonal migrant workers was 17.5% (15.6-19.45%). About 71.80 % (177/212) of the cases were Plasmodium falciparum, and 28.20% (35/212) Plasmodium vivax. The majority of seasonal migrant workers (77.4%) were from rural residences and highlanders (55%). Most (55.4%) of the migrants have visited two and more farm sites during their stay at development corridors for harvesting activities. About 116 (54.7%) asymptomatic malaria cases were returning to Dembiya(21.7%), Chilaga(19.8%) and Metema(13.2%) districts. Conclusion: This study focuses on the prevalence of asymptomatic malaria among seasonal migrant workers during the departure phase to home. The role of seasonal migrant workers in carrying and spreading malaria parasites, as well as challenging the country's malaria prevention and elimination efforts, could be enormous. Age, occupation, origin, the number of farm sites visited, and the frequency with which LLINs were used were all associated with an increased asymptomatic malaria prevalence in the study area. Tailored interventions for seasonal migrant workers could be in place by programmers, partners, and implementers to enhance malaria control and elimination.

scholarly journals Exploring Why Adult Mexican Males Do Not Get Vaccinated: Implications for COVID-19 Preventive Actions

2020 ◽  
Vol 42 (4) ◽  
pp. 515-527
Author(s):  
V. Nelly Salgado de Snyder ◽  
Deliana Garcia ◽  
Roxana Pineda ◽  
Jessica Calderon ◽  
Dania Diaz ◽  
...  
Keyword(s):  
Preventive Medicine ◽  
Age Groups ◽  
Adult Males ◽  
Cross Sectional ◽  
Administrative Services ◽  
Minority Males ◽  
Socially Disadvantaged ◽  
Preventive Actions ◽  
Socially Excluded ◽  
Age Range

Vaccination is the single most important preventive medicine action worldwide. However, there are inequalities in the procurement of vaccines particularly among US ethnic and racial minority males when compared to the rest of the US population. This study explored the reasons given by adult Mexican-origin males residing in Texas, for obtaining or not, immunizations. This was a cross-sectional, exploratory study with a sample of convenience of 401 adult males (age range 18–79) who were invited to participate in the study while waiting their turn to receive administrative services at the Mexican Consulate in Austin Texas. Data was collected in Spanish with a seven-item multiple choice questionnaire, using electronic tablets. The majority of respondents received their last vaccination longer than 5 years earlier. A higher percentage of individuals in the older age groups received a vaccine in the last year, as opposed to their younger counterparts who obtained their last immunization 3 to 5 years earlier. Among the reasons given for not getting vaccinated were lack of time or money, feared injections and side effects, insufficient information, interest or motivation. Others did not get vaccines because they perceived themselves to be healthy and did not feel sick. Findings from this study have important implications for future preventive medicine and vaccination practices that reach socially excluded groups in times of COVID-19. Recommendations are made to facilitate access to vaccines to the target group of this study and other socially disadvantaged populations in the global health context.

scholarly journals Eastern Cape Healthcare Workers Acquisition of SARS-CoV-2 (ECHAS): Cross-Sectional (Nested Cohort) Study Protocol

2021 ◽  
Vol 18 (1) ◽  
pp. 323
Author(s):  
Oladele Vincent Adeniyi ◽  
David Stead ◽  
Mandisa Singata-Madliki ◽  
Joanne Batting ◽  
Leo Hyera ◽  
...  
Keyword(s):  
Cohort Study ◽  
Infection Rate ◽  
Healthcare Workers ◽  
Health Facilities ◽  
Control Measures ◽  
Infection Prevention And Control ◽  
Eastern Cape ◽  
Rt Pcr ◽  
Cross Sectional ◽  
Increased Risk

Healthcare workers (HCWs) are at increased risk of infection by the virulent severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Though data exist on the positivity rate of the SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) test as well as COVID-19-related deaths amongst HCWs in South Africa, the overall infection rate remains underestimated by these indicators. It is also unclear whether the humoral immune response after SARS-CoV-2 infection offers durable protection against reinfection. This study will assess the SARS-CoV-2 seroprevalence amongst HCWs in the Eastern Cape (EC) and examine the longitudinal changes (rate of decay) in the antibody levels after infection in this cohort. Using a multi-stage cluster sampling of healthcare workers in selected health facilities in the EC, a cross-sectional study of 2250 participants will be recruited. In order to assess the community infection rate, 750 antenatal women in the same settings will be recruited. Relevant demographic and clinical characteristics will be obtained by a self-administered questionnaire. A chemiluminescent microparticle immunoassay (CMIA) will be used for the qualitative detection of IgG antibodies against SARS-CoV-2 nucleocapsid protein. A nested cohort study will be conducted by performing eight-weekly antibody assays (X2) from 201 participants who tested positive for both SARS-CoV-2 RT-PCR and serology. Logistic regression models will be fitted to identify the independent risk factors for SARS-CoV-2 infection. The cumulative SARS-CoV-2 infection rate and infection fatality rate among the frontline HCWs will be estimated. In addition, the study will highlight the overall effectiveness of infection prevention and control measures (IPC) per exposure sites/wards at the selected health facilities. Findings will inform the South African Department of Health’s policies on how to protect HCWs better as the country prepares for the second wave of the SARS-CoV pandemic.

scholarly journals Diet quality in relation to the risk of hypertension among Iranian adults: cross-sectional analysis of Fasa PERSIAN cohort study

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Amir Motamedi ◽  
Maryam Ekramzadeh ◽  
Ehsan Bahramali ◽  
Mojtaba Farjam ◽  
Reza Homayounfar
Keyword(s):  
Blood Pressure ◽  
Cohort Study ◽  
Diet Quality ◽  
Dietary Diversity ◽  
Antihypertensive Drugs ◽  
Healthy Eating Index ◽  
Cross Sectional ◽  
Common Chronic Disease ◽  
History Of ◽  
Prevention Of Hypertension

Abstract Background Hypertension is a common chronic disease with various complications and is a main contributing factor to cardiovascular disease (CVD). This study aimed to assess the association of diet quality, assessed by dietary diversity score (DDS), Mediterranean dietary score (MDS), diet quality index-international (DQI-I), and healthy eating index-2015 (HEI-2015) with the risk of hypertension. Methods This study recruited a total of 10,111 individuals (45.14% male) with mean age of 48.63 ± 9.57 years from the Fasa Cohort Study, Iran. Indices of diet quality, including MDS, HEI-2015, DQI-I, and DDS were computed by a 125-item Food Frequency Questionnaire. Participants were diagnosed as hypertensive if they had a diastolic blood pressure (DBP) ≥90 mmHg, systolic blood pressure (SBP) ≥140 mmHg,, or used antihypertensive drugs. Results Hypertension was prevalent in 28.3% of the population (21.59% in males and 33.74% in females). In the whole population, after adjustment for potential covariates, including daily energy intake, age, gender, physical activity, smoking, family history of hypertension, body mass index, and the level of education, higher adherence to the MDS (OR: 0.86, 95%CI = 0.75–0.99) and HEI-2015 (OR: 0.79, 95%CI = 0.68–0.90) was significantly associated with decreased risk of hypertension. The protective effect of HEI-2015 against hypertension remained significant for both males (OR: 0.80, 95%CI = 0.64–0.99) and females (OR: 0.78, 95%CI = 0.66–0.94), while, for MDS, this relationship disappeared in the subgroup analysis by gender. DQI-I and DDS were not related to the odds of hypertension. Conclusions Adhering to MDS and HEI-2015 diets could contribute to the prevention of hypertension.

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