Prospective study of malaria in pregnancy, placental and congenital malaria in Northwest Colombia.

BACKGROUND: Pregnancy Associated Malaria (PAM) include malaria in pregnancy (MiP), placental malaria (PM), and congenital malaria (CM). The evidence available in Colombia on PAM focuses on one of the presentations (MiP, PM or CM), and no study longitudinally analyses the infection from the pregnant woman, passing through the placenta, until culminating in the newborn. This study determined the frequency of MiP, PM, and CM caused by Plasmodium vivax, Plasmodium falciparum, or mixed infections, according to Thick Blood Smear (TBS) and quantitative Polymerase Chain Reaction (qPCR). Identifying associated factors of PAM and clinical-epidemiological outcomes in northwestern Colombia. METHODS: Prospective study of 431 pregnant women, their placenta, and newborns registered in the data bank of the research Group "Salud y Comunidad César Uribe Piedrahíta" which collected information between 2014 and 2020 in endemic municipalities of the departments of Córdoba and Antioquia. The frequency of infection was determined with 95% confidence intervals. Comparisons were made with the Chi-square test, Student t-test, prevalence ratios, and control for confounding variables by log-binomial regression. RESULTS: The frequency of MiP was 22.3% (4.6% using TBS), PM 24.8% (1.4% using TBS), and CM 11.8% (0% using TBS). Using TBS predominated P. vivax. Using qPCR the proportions of P. vivax and P. falciparum were similar for MiP and PM, but P. falciparum predominated in CM. The frequency was higher in nulliparous, and women with previous malaria. The main clinical effects of PAM were anaemia, low birth weight, and abnormal APGAR score. CONCLUSIONS: The magnitude of infections was not detected with TBS because most cases were submicroscopic (TBS-negative, qPCR-positive). This confirmed the importance of improving the molecular detection of cases. PAM continue being underestimated in the country due to that in Colombia the control programme is based on TBS, despite its outcomes on maternal, and congenital health.

Social determination of malaria in pregnancy in Colombia: a critical ethnographic study.

BACKGROUND: The meanings and experiences related to malaria in pregnancy (MiP) and its processes of social determination of health (PSDH) have not been reported in the world scientific literature. The objective was to understand the meanings and experiences of MiP, and to explain their PSDH in an endemic area from Colombia, 2022. METHODS: Critical ethnography with 46 pregnant women and 31 healthcare workers. In-depth and semi-structured interviews, focus group discussions, participant and non-participant observations, and field diaries were applied. A phenomenological-hermeneutic analysis, saturation and triangulation was carried out. The methodological rigor criteria were reflexivity, credibility, auditability, and transferability. RESULTS: At the singular level, participants indicated different problems in antenatal care and malaria control programmes, pregnant women were lacking knowledge about MiP, and malaria care was restricted to cases with high obstetric risk. Three additional levels that explain the PSDH of MiP were identified: (i) limitations of malaria control policies, and health-system, geographic, cultural and economic barriers by MiP diagnosis and treatment; (ii) problems of public health programmes and antenatal care; (iii) structural problems such as monetary poverty, scarcity of resources for public health and inefficiency in their use, lacking community commitment to preventive actions, and breach of institutional responsibilities of health promoter entity, municipalities and health services provider institutions. CONCLUSION: Initiatives for MiP control are concentrated at the singular level, PDSH identified in this research show the need to broaden the field of action, increase health resources, and improve public health programmes and antenatal care. It is also necessary to impact the reciprocal relationships of MiP with economic and cultural dimensions, although these aspects are increasingly diminished with the predominance and naturalization of neoliberal logic in health.

A systematic review of mixed studies on malaria in Colombia 1980-2022: what the "bifocal vision" discovers.

Mixed methods are essential in public health research and malaria control, because they allow grasping part of the complexity and diversity of the factors that determine health-disease. This study analyzes the mixed studies on malaria in Colombia, 1980-2022, through a systematic review in 15 databases and institutional repositories. The methodological quality was assessed with Mixed Methods Appraisal Tool (MMAT), STrengthening the Reporting of OBservational studies in Epidemiology (STROBE), and Standards for Reporting Qualitative Research (SRQR). The qualitative and quantitative findings were grouped into a four-level hierarchical matrix. The epidemiological profile of malaria morbidity, from traditional epidemiology, has been sustained by environmental problems, armed conflict, individual risk behaviors, and low adherence to recommendations from health institutions. However, the qualitative component reveals deeper causes that are less studied, of greater theoretical complexity, and that reflect challenges to design and implement health interventions, such as socioeconomic and political crises, poverty, and the neoliberal orientation in the malaria control policy; the latter reflected in the change in the role of the State, the fragmentation of control actions, the predominance of insurance over social assistance, the privatization of the provision of health services, the individualistic and economistic predominance of health, and low connection with popular tradition and community initiatives. The above confirms the importance of expanding mixed studies as a source of evidence to improve malaria research and control models in Colombia, and to identify the underlying causes of the epidemiological profile.

Interaction of histological events and physiological mediators in healthy placentas from malaria-endemic area in Colombia: An approach with a factorial model.

The biological study of the placenta is fragmented and focused on morbid events. The interaction of histological events and mediators of physiological processes in healthy placentas in malaria-endemic areas is unknown. This study aimed to build a factorial model for the convergence of events and mediators in healthy placentas of women living in northwestern Colombia through a study of 44 placentas. Linear correlations and exploratory factor analysis were carried out with histological events and expression of genes related to mediators. The factor analysis allowed us the identification of three components. The first compound by the following histological variables: number of capillaries and villus, immune cells in villus, atherosis, and CD8+ lymphocytes. The second with articulation of histological variables (syncytyal nodes, fibrinoid deposits, thrombi and immune cells) and physiological mediators of apoptosis and regulation. The thirth included physiological mediators of hypoxia, angiogenesis, pro-inflammation and anti-inflammation. All components presented excellent predictive and construct validity, and excellent goodness of fit parameters. In healthy placentas, the factorial structure of histological events and physiological mediators in three underlying components that support their interactions was demonstrated. These findings are significant because they help improve the study of healthy placental biology in malaria endemic areas and evaluate mechanisms that alter its morphology and function, with their subsequent risk for pregnancy and maternal-fetal health.

Cost-effectiveness of rapid diagnostic tests, compared to microscopic tests, for the diagnosis and treatment of gestational malaria in Colombia from an institutional perspective.

BACKGROUND: Gestational malaria is associated with negative outcomes in maternal and gestational health; timely diagnosis is crucial to avoid complications. However, the limited infrastructure, equipment, test reagents, and trained staff make it difficult to use thick blood smear tests in rural areas, where rapid testing could be a viable alternative. The purpose of this study was to estimate the cost-effectiveness of rapid tests type III (Plasmodium falciparum/Plasmodium spp P.f/pan) versus microscopic tests for the diagnosis and treatment of gestational malaria in Colombia. METHODS: Cost-effectiveness analyses of gestational malaria diagnosis from an institutional perspective using a decision tree. Standard costing was performed for the identification, measurement and assessment phases, with data from Colombian tariff manuals. The data was collected from Health Situation Analysis, SIVIGILA and meta-analysis. Average and incremental cost-effectiveness ratio were estimated. The uncertainty was assessed through probabilistic sensitivity analysis. RESULTS: The cost of rapid diagnostic tests in 3,000 pregnant women with malaria was US$66,936 and 1,182 disability adjusted life years (DALYs) were estimated. The cost using thick blood smear tests was US$50,838 and 1,023 DALYs, for an incremental cost-effectiveness of US$ 101.2. The probabilistic sensitivity analysis of rapid diagnostic tests determined that they are highly cost-effective in 70% of the cases, even below the US$1,200 threshold; also, they showed an incremental net monetary benefit of $150,000 when payer's willingness is US$1,000. CONCLUSION: The use of rapid diagnostic tests for timely diagnosis and treatment of gestational malaria is a highly cost-effective strategy in Colombia, with uncertainty analyses supporting the robustness of this conclusion and the increased net monetary benefit that the health system would obtain. This strategy may help in preventing the negative effects on maternal health and the neonate at a low cost.

[Social determination and determinants of malaria: a systematic review, 1980-2018Determinação social e determinantes sociais da malária: revisão sistemática, 1980-2018]. / Determinación y determinantes sociales de la malaria: revisión sistemática, 1980-2018.

OBJECTIVE: Describe how the 'social determination of health' approach has been applied in malaria studies around the world. METHODS: Systematic review of original studies published from 1980 to 2018. Six search strategies were used in ten multidisciplinary databases, and in libraries and repositories of seven universities in Brazil, Colombia, Ecuador, and Peru. PRISMA guidelines were followed, methodological quality was evaluated according to STROBE criteria, and a qualitative summary of the results was conducted. RESULTS: Ten studies published from 1984 to 2017 met pre-established inclusion and exclusion criteria; 33 social determinants of malaria were identified. Of individual determinants, greater malaria risk was found in adults, people who are often outdoors at night, and people who do not take preventive measures; intermediate determinants were dwellings with poor physical and sanitary infrastructure, overcrowded, located in forested areas, and containing animals. Regarding socioeconomic determinants, the people at greatest risk were involved in agro-forestry activities, migrants, and those with low income and a low educational level. Malaria caused high economic losses and led to poverty and educational delay. CONCLUSION: No studies were found that used Latin American social medicine approaches or that applied the World Health Organization's hierarchical and multilevel analysis for individual, intermediate, and structural determinants. No progress has been made in the analysis of social categories-territory, social class, gender, ethnic group, macroeconomic policies-or other socioeconomic characteristics that determine risk of illness or death from malaria.

OBJETIVO: Descrever como foi aplicado o enfoque da determinação social da saúde nos estudos de malária no mundo. MÉTODOS: Uma revisão sistemática de estudos originais publicados entre 1980 e 2018 foi conduzida com o uso de seis estratégias de busca em 10 bases de dados multidisciplinares e em bibliotecas e repositórios de sete universidades do Brasil, Colômbia, Equador e Peru. O estudo se baseou nos critérios da recomendação PRISMA e a qualidade metodológica foi avaliada segundo os critérios da iniciativa STROBE. Foi realizada uma síntese qualitativa dos resultados. RESULTADOS: Dez estudos publicados entre 1984 e 2017 preencheram os critérios de inclusão e exclusão predefinidos. Foram identificados 33 determinantes sociais da malária. Com relação aos determinantes individuais, foi observado maior risco da malária em adultos, pessoas com hábitos noturnos e que não aderem a práticas preventivas. Os determinantes intermediários foram moradias com infraestruturas física e sanitária precárias, com aglomeração de pessoas, localizadas em áreas de mata e com a presença de animais. E, quanto aos determinantes socioeconômicos, houve maior risco da doença entre os indivíduos que se dedicam a atividades agroflorestais, migrantes e pessoas com baixa escolaridade e baixa renda. A malária causou grande prejuízo econômico, gerando pobreza e atraso educacional. CONCLUSÃO: Não foram encontrados estudos com enfoques da medicina social latino-americana nem estudos contendo análises com modelo hierárquico e multinível para os determinantes individuais, intermediários e estruturais de acordo com a definição da Organização Mundial da Saúde. Não foi possível aprofundar a análise das categorias sociais (território, classe social, gênero, etnia e políticas macroeconômicas) ou outras características socioeconômicas que determinam o risco de ter a doença ou morrer de malária.

Clinical Outcomes of Submicroscopic Infections and Correlates of Protection of VAR2CSA Antibodies in a Longitudinal Study of Pregnant Women in Colombia.

Malaria in pregnancy can cause serious adverse outcomes for the mother and the fetus. However, little is known about the effects of submicroscopic infections (SMIs) in pregnancy, particularly in areas where Plasmodium falciparum and Plasmodium vivax cocirculate. A cohort of 187 pregnant women living in Puerto Libertador in northwest Colombia was followed longitudinally from recruitment to delivery. Malaria was diagnosed by microscopy, reverse transcription-quantitative PCR (RT-qPCR), and placental histopathology. Gestational age, hemoglobin concentration, VAR2CSA-specific IgG levels, and adhesion-blocking antibodies were measured during pregnancy. Statistical analyses were performed to evaluate the impact of SMIs on birth weight and other delivery outcomes. Twenty-five percent of women (45/180) were positive for SMIs during pregnancy. Forty-seven percent of infections (21/45) were caused by P. falciparum, 33% were caused by P. vivax, and 20% were caused by mixed Plasmodium spp. Mixed infections of P. falciparum and P. vivax were associated with lower gestational age at delivery (P = 0.0033), while other outcomes were normal. Over 60% of women had antibodies to VAR2CSA, and there was no difference in antibody levels between those with and without SMIs. The anti-adhesion function of these antibodies was associated with protection from SMI-related anemia at delivery (P = 0.0086). SMIs occur frequently during pregnancy, and while mixed infections of both P. falciparum and P. vivax were not associated with a decrease in birth weight, they were associated with significant risk of preterm birth. We propose that the lack of adverse delivery outcomes is due to functional VAR2CSA antibodies that can protect pregnant women from SMI-related anemia.

Asymptomatic plasmodial infection in pregnant women: A global scenario.

Though asymptomatic plasmodial infection (API) is well known phenomenon and play an important role in different populations and malaria transmission settings, it has received less attention in malaria intervention strategies. This review was aimed to estimate the prevalence of API in pregnant women across the world. The bibliography records relevant to the study were searched on PubMed and Lilacs, till August 15, 2016, without restriction of language. A total of 78 references were identified, of which 29 met the inclusion criteria. The study of the identified reports revealed that the mean prevalence of API in pregnant women was 10.8% (3382/31186), with wide variation among countries and transmission settings. The reports showed that APIs are very common even in low malaria transmission areas, and most of the APIs are due to submicroscopic plasmodial infection (SPI). More sensitive diagnostic tools are required to address API and SPI in such areas. Every malaria endemic region/country should carry out systematic studies for accurate estimation of frequency for both these events (API and SPI) in different populations for planning appropriate intervention measures.

Submicroscopic infection of placenta by Plasmodium produces Th1/Th2 cytokine imbalance, inflammation and hypoxia in women from north-west Colombia.

BACKGROUND: A large-scale study was set up in order to study the epidemiology, clinical aspects, and immunopathology of gestational and placental malaria in north-west Colombia. In this region, recent reports using a qPCR technique, confirmed frequencies of infection, by Plasmodium falciparum or Plasmodium vivax, up to 45%. Given the high rates of infection observed both in mother and placenta, a first exploratory study was proposed in order to characterize the effect on the inflammation status, tissue damage and hypoxia in Plasmodium spp. infected placentas. METHODS: A descriptive, prospective, cross-sectional design was applied to pregnant women with (PM+) and without (PM-) placental malaria. Messenger RNA expression of Fas, FasL; COX-1, COX-2, HIF, VEGF, and the cytokines IL-2, IL-4, IL-10, IFN-γ and TNF, were measured in peripheral and placental blood using a quantitative PCR. The percentage of apoptotic cells was determined with a TUNEL assay. RESULTS: In total 50 placentas were studied: 25 were positive for submicroscopic infection and 25 were negative for Plasmodium infection. Expression of IL-4 and IL-10 was observed high in placental tissue of PM+, while IL-2 was high in peripheral blood of the same group. Expression of TNF and IFNγ in peripheral blood of the PM + group was high. Similarly, the apoptotic index and Fas expression were significantly high in PM+. However, FasL expression was observed low in PM + compared to PM-. Inflammation markers (HIF, VEGF) and hypoxia markers (COX-1, COX-2) were high in the PM + group. CONCLUSION: During placental malaria expression of some pro-inflammatory cytokines is up-regulated and markers of hypoxia and tissue damage are increased in cases of submicroscopic infection.

Prevalence of gestational, placental and congenital malaria in north-west Colombia.

BACKGROUND: The frequency of pregnancy-associated malaria is increasingly being documented in American countries. In Colombia, with higher frequency of Plasmodium vivax over Plasmodium falciparum infection, recent reports confirmed gestational malaria as a serious public health problem. Thick smear examination is the gold standard to diagnose malaria in endemic settings, but in recent years, molecular diagnostic methods have contributed to elucidate the dimension of the problem of gestational malaria. The study was aimed at exploring the prevalence of gestational, placental and congenital malaria in women who delivered at the local hospitals of north-west Colombia, between June 2008 and April 2011. METHODS: A group of 129 parturient women was selected to explore the prevalence of gestational, placental and congenital malaria in a descriptive, prospective and transversal (prevalence) design. Diagnosis was based on the simultaneous application of two independent diagnostic tests: microscopy of thick blood smears and a polymerase chain reaction assay (PCR). RESULTS: The prevalence of gestational malaria (thick smear /PCR) was 9.1%/14.0%; placental malaria was 3.3%/16.5% and congenital malaria was absent. A history of gestational malaria during the current pregnancy was significantly associated with gestational malaria at delivery. Plasmodium vivax caused 65% of cases of gestational malaria, whereas P. falciparum caused most cases of placental malaria. CONCLUSIONS: Gestational and placental malaria are a serious problem in the region, but the risk of congenital malaria is low. A history of malaria during pregnancy may be a practical indicator of infection at delivery.

Diagnostic Accuracy of a Thick Blood Smear Compared to qPCR for Malaria Associated with Pregnancy in Colombia.

This study aimed to evaluate the accuracy of the thick blood smear (TBS) versus quantitative polymerase chain reaction (qPCR) for the diagnosis of malaria associated with pregnancy (MAP) caused by P. falciparum or P. vivax in Colombia in its gestational malaria (GM), placental malaria (PM), and congenital malaria (CM) forms as well as to compare its accuracy in different subgroups of pregnant women according to the presence of fever, anemia and a history of malaria. This was a diagnostic evaluation of 829 pregnant women, 579 placentas, 381 umbilical cord samples, and 221 neonatal peripheral blood samples. Accuracy was evaluated based on the parameters of sensitivity, specificity, predictive values, likelihood ratios, and validity index, with their 95% confidence intervals. The frequency of GM was 36% (n = 297/829), PM 27% (n = 159/579), and CM 16.5% (n = 63/381) in umbilical cord samples and 2% (n = 5/221) in neonatal peripheral blood samples. For GM, the sensitivity was 55%, with higher rates in those infected with P. vivax (68%), with a history of malaria (69%), and with fever (96%). These three subgroups presented the best results in terms of the negative likelihood ratio and validity index. For PM, sensitivity was 8%; in subgroup analyses in terms of species, symptomatology (anemia and fever), and history of malaria, it was 1-18%, and the negative likelihood ratio was >0.80 in all subgroups. No false positives were recorded in any of the subgroups. The TBS did not detect any cases of CM. This study found the TBS yielded satisfactory results in terms of diagnosing GM for P. vivax, pregnant women with previous malaria and febrile. It also showed that the TBS is not useful for diagnosing PM and CM. It is necessary to conduct surveillance of MAP with molecular methods in in groups where TBS is deficient (asymptomatic GM, P. falciparum, and pregnant women without history of malaria) to optimize the timely treatment of PM and CM, avoid the deleterious effects of MAP and achieve the malaria elimination goals in Colombia.

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

This study compared the clinical-parasitological profiles of gestational (GM), placental (PM), and congenital (CM) malaria in northwestern Colombia. A cross-sectional study with 829 pregnant women, 549 placentas, and 547 newborns was conducted. The frequency of GM was 35.8%, PM 20.9%, and CM 8.5%. P. vivax predominated in GM; in PM, the proportion of P. vivax and P. falciparum was similar; in CM, P. falciparum predominated. The main clinical findings were headache (49%), anemia (32%), fever (24%), and musculoskeletal pain (13%). The clinical manifestations were statistically higher in P. vivax infections. In submicroscopic GM (positive with qPCR and negative with thick blood smear), the frequency of anemia, sore throat, and a headache was statistically higher compared with pregnant women without malaria. GM, PM, and CM reduce birth weight and head circumference. In Colombia, this is the first research on the clinical characteristics of GM, PM, and CM; contrary to evidence from other countries, P. vivax and submicroscopic infections are associated with clinical outcomes.

Genotype comparison of Plasmodium vivax and Plasmodium falciparum clones from pregnant and non-pregnant populations in North-west Colombia.

BACKGROUND: Placental malaria is the predominant pathology secondary to malaria in pregnancy, causing substantial maternal and infant morbidity and mortality in tropical areas. While it is clear that placental parasites are phenotypically different from those in the peripheral circulation, it is not known whether unique genotypes are associated specifically with placental infection or perhaps more generally with pregnancy. In this study, genetic analysis was performed on Plasmodium vivax and Plasmodium falciparum parasites isolated from peripheral and placental blood in pregnant women living in North-west Colombia, and compared with parasites causing acute malaria in non-pregnant populations. METHODS: A total of 57 pregnant women at delivery with malaria infection confirmed by real-time PCR in peripheral or placental blood were included, as well as 50 pregnant women in antenatal care and 80 men or non-pregnant women with acute malaria confirmed by a positive thick smear for P. vivax or P. falciparum. Five molecular markers per species were genotyped by nested PCR and capillary electrophoresis. Genetic diversity and the fixation index FST per species and study group were calculated and compared. RESULTS: Almost all infections at delivery were asymptomatic with significantly lower levels of infection compared with the groups with acute malaria. Expected heterozygosity for P. vivax molecular markers ranged from 0.765 to 0.928 and for P. falciparum markers ranged from 0.331 to 0.604. For P. vivax infections, the genetic diversity was similar amongst the four study groups and the fixation index from each pairwise comparison failed to show significant genetic differentiation. For P. falciparum, no genetic differentiation was observed between placental and peripheral parasites from the same woman at delivery, but the parasites isolated at delivery showed significant genetic differentiation compared with parasites isolated from subjects with acute malaria. CONCLUSIONS: In North-west Colombia, P. vivax parasites have high genetic diversity that is equivalent in pregnant and non-pregnant populations as well as in symptomatic and asymptomatic infections. For P. falciparum, the overall genetic diversity is lower, with specific genotypes associated with asymptomatic infections at delivery.

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

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.

Frequency of gestational malaria and maternal-neonatal outcomes, in Northwestern Colombia 2009-2020.

Research on Gestational Malaria (GM) is scarce in America's. In the few available studies in Colombia, the analysis of immunological or parasitological aspects predominates, with few analyzes of epidemiological aspects. The objectives were to determine the frequency of GM and submicroscopic infections (positive with PCR and negative with thick blood smears), to identify obstetric and malaria history associated with GM, and to describe maternal and neonatal outcomes associated with GM, in northwestern Colombia. A retrospective study with records of 825 pregnant women was conducted. qPCR and thick blood smear were performed. Frequencies were determined with 95% confidence intervals. Comparisons were made with the Chi-square test, Mann-Whitney U test, and prevalence ratios adjusted in a log-binomial model. The frequency of GM was 35.8% (95% CI 32.4-39.1) of submicroscopic infection was 16.2% (95% CI 13.7-18.8). According to the multivariable model, the subgroups with the highest frequency of GM were pregnant women without healthcare coverage (32.3%), in the third trimester of pregnancy (30.5%), nulliparous (35.6%), and with a previous diagnosis of malaria in the current pregnancy (64.0%). GM was associated with more frequency of gestational anemia, infection in neonates, and lower birth weight. The results indicate in a precise and direct way that malaria control in this northwestern region of Colombia is far from adequate, which is even more serious considering the affectations for the mother and the neonate.

Congenital malaria: Frequency and epidemiology in Colombia, 2009-2020.

Congenital Malaria (CM) is an underestimated and under-researched problem in Colombia, despite its severe clinical, epidemiological, economic, and public health consequences. The objective was to determine the general frequency of CM, the specific frequency of CM by diagnostic test and plasmodial species, and identify its associated factors. A retrospective study was carried out using the records of 567 newborns. qPCR and Thick Blood Smear (TBS) were performed. The frequency of infection was determined with a 95% confidence interval. Associated factors were identified by non-parametric tests and odds ratios; the confusion was controlled with a logistic regression model. All cases corresponded to submicroscopic CM (negative with TBS and positive with PCR), and the frequency was 12.2% (95%CI = 9.4-14.9). The detection was statistically higher in the umbilical cord with 16,2% (95%CI = 12.4-19.9) versus peripheral blood of the newborn with 2.2% (95%CI = 0.7-4.9). CM was statistically higher in newborn whose mothers had malaria in the last year, gestational and placental malaria. The median birth weight in newborn infected with CM was lower compared to the one of healthy neonates. Because the control program in Colombia is based on TBS, it must be improved with the inclusion of other tests that allow the detection of submicroscopic CM. In addition, the program has other limitations such as do not have specific actions for pregnant women and have a passive surveillance system. These difficulties do not allow to show the magnitude of CM, its consequences on neonatal and infant health, constituting a serious problem of health injustice.

Placental malaria caused by Plasmodium vivax or P. falciparum in Colombia: Histopathology and mediators in placental processes.

Knowledge about the relation of histopathological characteristics and mediators of physiological processes in the placenta malaria (PM) is poor, and that PM caused by Plasmodium vivax is almost null. The objective was to compare histopathological characteristics, cytokines and mediators of physiological processes in PM depending on the parasitic species, through a cross-sectional study in three groups: negative-PM, vivax-PM, falciparum-PM from Northwestern Colombia. The diagnosis of PM was made with thick blood smear, qPCR, and histopathology. Immuno-histochemical was made with EnVision system (Dako) and Zeiss Axio Imager M2 with light microscope. Cells in apoptosis were studied with the TUNEL technique. To measure the expression level of cytokines and mediators qRT-PCR was used. We included 179 placentas without PM and 87 with PM (53% P. vivax and 47% P. falciparum). At delivery, anemia was 25% in negative-PM, 60% in vivax-PM, and 44% in falciparum-PM group. The neonatal weight had an intense difference between groups with 3292±394g in negative-PM, 2,841±239 in vivax-PM, and 2,957±352 in falciparum-PM. The histopathological characteristics and CD+ cells in placenta with statistical differences (Dunn´s test) between negative-PM vs vivax-PM (P. falciparum was similar to P. vivax) were infarction, fibrinoid deposits, calcification, cells in apoptosis, immune infiltrates in decidua and intervillous space, CD4+, CD8+, CD14+, CD56+, CD68+. The expression levels of mediators in the placenta with statistical differences (Dunn´s test) between negative-PM vs vivax-PM (P. falciparum was similar to P. vivax) were Fas, FasL, HIF1α, Cox1, Cox2, VEGF, IL4, IL10, IFNγ, TNF, TGFß, FOXP3, and CTLA4. PM with P. falciparum and P. vivax, damages this organ and causes significant alteration of various physiological processes, which cause maternal anemia and a reduction in neonatal weight in degrees that are statistically and clinically significant. It is necessary that the search for plasmodial infection in pregnant and placenta goes from passive to active surveillance with adequate diagnostic capacity.

A Retrospective Review on Severe Malaria in Colombia, 2007-2020.

BACKGROUND: Knowledge of severe malaria (SM) or complicated malaria is insufficient in all its components. The least known type is the one associated with Plasmodium vivax, compared to that caused by P. falciparum. The aim of this study was to provide a general overview of epidemiological information about the burden of SM, obtained from the National Public Health Surveillance System (SIVIGILA) for the period 2007-2020 in Colombia. METHODS: A descriptive, retrospective, and cross-sectional study of secondary information was performed via SIVIGILA. RESULTS: There were 9881 SM cases among 1,060,950 total malaria cases in Colombia in 2007-2020: 9.31 SM cases per 1000 malaria cases. During this period, there were 7145 SM cases due to the following species: Plasmodium vivax, 57.6%; P. falciparum, 38.6%; severe mixed malaria, 3.2%; and P. malariae, 0.6%. The most compromised organ systems are the hematological system (54.9%), the liver (9.1%), the kidneys (4.2%), the lungs (1.9%) and the brain (1.6%). CONCLUSIONS: There has been a reduction in malaria incidence in Colombia in the last 10-15 years, but there has also been a strong increase in SM incidence. We suggest emphasizing the prevention of the onset of severe malaria, with the early and accurate diagnosis of plasmodial infection.