scholarly journals Short-Time Recurrences of Plasmodium vivax Malaria as a Public Health Proxy for Chloroquine-Resistance Surveillance: A Spatio-Temporal Study in the Brazilian Amazon

Author(s):  
Antonio A. S. Balieiro ◽  
Andre M. Siqueira ◽  
Gisely C. Melo ◽  
Wuelton M. Monteiro ◽  
Vanderson S. Sampaio ◽  
...  

In Brazil, malaria caused by Plasmodium vivax presents control challenges due to several reasons, among them the increasing possibility of failure of P. vivax treatment due to chloroquine-resistance (CQR). Despite limited reports of CQR, more extensive studies on the actual magnitude of resistance are still needed. Short-time recurrences of malaria cases were analyzed in different transmission scenarios over three years (2005, 2010, and 2015), selected according to malaria incidence. Multilevel models (binomial) were used to evaluate association of short-time recurrences with variables such as age. The zero-inflated Poisson scan model (scanZIP) was used to detect spatial clusters of recurrences up to 28 days. Recurrences compose less than 5% of overall infection, being more frequent in the age group under four years. Recurrences slightly increased incidence. No fixed clusters were detected throughout the period, although there are clustering sites, spatially varying over the years. This is the most extensive analysis of short-time recurrences worldwide which addresses the occurrence of P. vivax CQR. As an important step forward in malaria elimination, policymakers should focus their efforts on young children, with an eventual shift in the first line of malaria treatment to P. vivax.

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ghulam R Awab ◽  
Fahima Aaram ◽  
Natsuda Jamornthanyawat ◽  
Kanokon Suwannasin ◽  
Watcharee Pagornrat ◽  
...  

X-linked glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzymopathy. The severe Mediterranean variant (G6PD Med) found across Europe and Asia is thought to confer protection against malaria, but its effect is unclear. We fitted a Bayesian statistical model to observed G6PD Med allele frequencies in 999 Pashtun patients presenting with acute Plasmodium vivax malaria and 1408 population controls. G6PD Med was associated with reductions in symptomatic P. vivax malaria incidence of 76% (95% credible interval [CI], 58–88) in hemizygous males and homozygous females combined and 55% (95% CI, 38–68) in heterozygous females. Unless there is very large population stratification within the Pashtun (confounding these results), the G6PD Med genotype confers a very large and gene-dose proportional protective effect against acute vivax malaria. The proportion of patients with vivax malaria at risk of haemolysis following 8-aminoquinoline radical cure is substantially overestimated by studies measuring G6PD deficiency prevalence in healthy subjects.


PLoS ONE ◽  
2014 ◽  
Vol 9 (8) ◽  
pp. e105922 ◽  
Author(s):  
Gisely C. Melo ◽  
Wuelton M. Monteiro ◽  
André M. Siqueira ◽  
Siuhelem R. Silva ◽  
Belisa M. L. Magalhães ◽  
...  

2018 ◽  
Vol 17 (1) ◽  
Author(s):  
Siuhelem Rocha Silva ◽  
Anne Cristine Gomes Almeida ◽  
George Allan Villarouco da Silva ◽  
Rajendranath Ramasawmy ◽  
Stefanie Costa Pinto Lopes ◽  
...  

2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Dinberu Seyoum ◽  
Delenasaw Yewhalaw ◽  
Luc Duchateau ◽  
Patrick Brandt ◽  
Angel Rosas-Aguirre ◽  
...  

2021 ◽  
Author(s):  
Mario JC Ayala ◽  
Leonardo S Bastos ◽  
Daniel A.M. Villela

Background: Malaria incidence in Brazil reversed its decreasing trend when cases from recent years, as recent as 2015, exhibited an increase in the Brazilian Amazon basin, the area with highest transmission of Plasmodium vivax and Plasmodium falciparum. In fact, an increase of more than 20% in the years 2016 and 2017 revealed possible vulnerabilities in the national malaria-control program. Methods: We studied factors that are potentially associated with this reversal, including migration, economical activities, and deforestation, and weakening of investment in control programs. We analyze past incidences of malaria cases due to Plasmodium vivax and Plasmodium falciparum with a spatio-temporal Bayesian model using more than 5 million individual records of malaria cases from January of 2003 to December of 2018 in the Brazilian Amazon to establish the municipalities with unexpected increases in cases. Results: We observe an increase in imported cases from border countries in Roraima state and found small effects due to deforestation and change of occupations. Also, an overall funding reduction from 2013 to 2016 happened before an increase in malaria cases in five regions in Amazon basin, markedly for P. vivax incidence and especially, in Pará and Roraima States. Conclusion: Urban developments, discontinued funding for control programs, migration from border areas, deforestation activities, and different economic activities such as mining and agriculture appear linked to the rebound on malaria incidence. These multifactorial drivers show that malaria control programs require permanent attention towards elimination.


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