Frequency of placental malaria and its associated factors in northwestern Colombia, pooled analysis 2009–2020

Abstract

Knowledge about placental malaria (PM) is insufficient in the world, and incipient in Colombia where studies are few and recent. In this country, PM has been reported by Plasmodium vivax, Plasmodium falciparum, and mixed infection. The objective was to determine the frequency of PM and its associated clinical-epidemiological factors in mothers and neonates in northwestern Colombia, 2009–2020. A Retrospective pooled analysis with 602 placentas captured in five investigations. The diagnosis of PM was made with thick blood smear (TBS) and qPCR. The groups with and without PM were compared using the Chi-square test, Mann-Whitney test, and crude and adjusted prevalence ratios in a log-binomial model. The prevalence of PM was 27.7% with 92% (155/167) of submicroscopic cases; 41.3% by P. vivax, 44,3% by P. falciparum, and 14.4% by mixed infections. In the multivariate adjustment, PM was associated with the diagnosis of congenital malaria, low neonatal weight, gestational malaria, maternal anemia, previous malaria during pregnancy, and age between 25–43 years. This research is the investigation with the largest number of subjects for studying PM in Colombia, in the ecoepidemiological zone that produces more cases of malaria per year, finding a high prevalence of submicroscopic PM that caused serious maternal (anemia) and neonatal (congenital malaria and low neonatal weight) effects. The results show limitations in the timely diagnosis and treatment, given that the epidemiological surveillance program in Colombia is based on thick blood smear, which generates a substantial underestimation of the magnitude of PM, with serious effects and clinical risks. It is urgent to demand that the health authorities adopt measures such as prenatal control visits as soon as the pregnancy begins, monthly implementation of TBS, and active search for infected pregnant women in their homes and workplaces.

Clinical and Parasitological Profiles of Gestational, Placental and Congenital Malaria in Northwestern Colombia

“…In PM, the frequency of anemia was higher in P. vivax . Although higher pathogenicity has been reported for P. falciparum [ 22 ], the evidence provided by this research is added to reviews that described the pathophysiology of P. vivax with serious effects such as anemia and other hematological complications, severe malaria, acute respiratory distress, and multiple organ failure [ 28 ], as well as Colombian studies that reported the pathological effects of P. vivax in PAM [ 8 , 9 , 10 ]. It is important to highlight that the frequency of GM, parasitemia density, and the infection trimester are the main risk factors for PM; therefore, intermittent preventive treatment, screening, and treatment of GM from the first trimester must be provided [ 29 , 30 ].…”

“…In Colombia, there are few clinical studies on PAM. Some epidemiological antecedents reported a high frequency of GM (35.8%), PM (27.7%), and CM (12.2%), associated with a higher risk of maternal anemia and lower birth weight [ 8 , 9 , 10 ]. In clinical practice guidelines for malaria, the clinical aspects of PAM are cited from WHO and CDC reports [ 11 ].…”