Molecular Epidemiology of Plasmodium species in Conflicted Federally Administered Tribal Area (FATA) Pakistan / Epidemiologia molecular de espécies de plasmódio em área tribal sob administração federal em conflito do Paquistão

Military conflicts have been significant obstacles in detecting and treating infectious disease diseases due to the diminished public health infrastructure, resulting in malaria endemicity. A variety of violent and destructive incidents were experienced by FATA (Federally Administered Tribal Areas). It was a struggle to pursue an epidemiological analysis due to continuing conflict and Talibanization. Clinical isolates were collected from Bajaur, Mohmand, Khyber, Orakzai agencies from May 2017 to May 2018. For Giemsa staining, full blood EDTA blood samples have been collected from symptomatic participants. Malaria-positive microscopy isolates were spotted on filter papers for future Plasmodial molecular detection by nested polymerase chain reaction (nPCR) of small subunit ribosomal ribonucleic acid (ssrRNA) genes specific primers. Since reconfirming the nPCR, a malariometric study of 762 patients found 679 positive malaria cases. Plasmodium vivax was 523 (77%), Plasmodium falciparum 121 (18%), 35 (5%) were with mixed-species infection (P. vivax plus P. falciparum), and 83 were declared negative by PCR. Among the five agencies of FATA, Khyber agency has the highest malaria incidence (19%) with followed by P. vivax (19%) and P. falciparum (4.1%). In contrast, Kurram has about (14%), including (10.8%) P. vivax and (2.7%) P. falciparum cases, the lowest malaria epidemiology. Surprisingly, no significant differences in the distribution of mixed-species infection among all five agencies. P. falciparum and P. vivax were two prevalent FATA malaria species in Pakistan's war-torn area. To overcome this rising incidence of malaria, this study recommends that initiating malaria awareness campaigns in school should be supported by public health agencies and malaria related education locally, targeting children and parents alike.

Os conflitos militares têm sido obstáculos significativos na detecção e tratamento de doenças infecciosas devido à diminuição da infraestrutura de saúde pública, resultando na endemicidade da malária. Uma variedade de incidentes violentos e destrutivos foi vivida pelas FATA (áreas tribais administradas pelo governo federal). Foi uma luta busca ruma análise epidemiológica devido ao conflito contínuo e à talibanização. Isolados clínicos foram coletados de agências Bajaur, Mohmand, Khyber e Orakzai, de maio de 2017 a maio de 2018. Para a coloração de Giemsa, amostras de sangue completo com EDTA foram coletadas de participantes sintomáticos. Isolados de microscopia positivos para malária foram colocados em papéis de filtro para futura detecção molecular plasmódica por reação em cadeia da polimerase aninhada (nPCR) de primers específicos de genes de subunidade ribossômica de ácido ribonucleico (ssrRNA). Desde a reconfirmação do nPCR, um estudo malariométrico de 762 pacientes encontrou 679 casos positivos de malária. Plasmodium vivax foi 523 (77%), Plasmodium falciparum 121 (18%), 35 (5%) eram com infecção de espécies mistas (P. vivax mais P. falciparum) e 83 foram declarados negativos por PCR. Entre as cinco agências da FATA, a agência Khyber tem a maior incidência de malária (19%), seguida por P. vivax (19%) e P. falciparum (4,1%). Em contraste, Kurram tem cerca de 14%, incluindo 10,8% casos de P. vivax e 2,7% P. falciparum, a epidemiologia de malária mais baixa. Surpreendentemente, não há diferenças significativas na distribuição da infecção de espécies mistas entre todas as cinco agências. P. falciparum e P. vivax foram duas espécies prevalentes de malária FATA na área devastada pela guerra no Paquistão. Para superar essa incidência crescente de malária, este estudo recomenda que o início de campanhas de conscientização sobre a malária na escola deve ser apoiado por agências de saúde pública e educação relacionada com a malária localmente, visando crianças e pais.

Malaria grave en mujeres gestantes hospitalizadas entre el 2010 y el 2014 en el departamento de Antioquia, Colombia / Severe malaria in pregnant women hospitalized between 2010 and 2014 in the Department of Antioquia (Colombia)

Resumen Introducción. La malaria (o paludismo) durante la gestación impacta negativamente la salud de la madre y del neonato, con alto riesgo de complicaciones clínicas y mortalidad. En las regiones de alta endemia se han caracterizado, especialmente, la anemia materna y el bajo peso al nacer, pero es poco conocido el espectro clínico en las zonas de baja endemia. Objetivo. Caracterizar clínica y epidemiológicamente los episodios de malaria en mujeres gestantes hospitalizadas en el departamento de Antioquia entre el 2010 y el 2014. Materiales y métodos. Se hizo un estudio descriptivo, transversal y retrospectivo, con historias clínicas de mujeres gestantes con malaria por Plasmodium falciparum y P. vivax. Se utilizaron los criterios diagnósticos de malaria complicada de la Organización Mundial de la Salud (OMS) y de la Guía para la atención clínica integral del paciente con malaria vigente en Colombia. Resultados. Se analizaron 111 casos; el 13,5 % se clasificó como complicación grave según los criterios de la OMS, porcentaje que ascendió a 23,4 % según los criterios de la guía colombiana. Las complicaciones detectadas fueron disfunción hepática, anemia, acidosis y trombocitopenia grave. No se observó diferencia en la frecuencia de las complicaciones según la especie de plasmodio. El 39,4 % de los casos presentó signos generales de peligro; la palidez y la ictericia fueron los más frecuentes. El 40,5 % presentó signos de peligro para la gestación como la cefalea persistente, el dolor abdominal y el sangrado vaginal. Conclusiones. La malaria grave se presenta con gran frecuencia en las mujeres gestantes, sin diferencia según la especie de plasmodio, y se manifiesta con signos de peligro precozmente reconocibles. Se encontró un subregistro hospitalario del 88 % de los casos graves y falta de exámenes de laboratorio para un diagnóstico más completo. Se requiere un protocolo para el diagnóstico clínico de las mujeres gestantes con malaria.

Abstract Introduction: Malaria during pregnancy has a negative impact on maternal-neonatal health, with a high risk of clinic complications and mortality. High endemic areas are specially characterized by maternal anaemia and low birth weight. The clinical spectrum is little known in low endemic areas. Objective: To clinically and epidemiologically characterize malaria episodes in hospitalized pregnant women in the Department of Antioquia (Colombia) in the period 2010-2014. Materials and methods: Retrospective, cross-sectional, descriptive study with medical records of pregnant women with P. falciparum and P. vivax malaria. The WHO severe malaria diagnostic criteria and the Colombian Guía para la atención clínica integral del paciente con malaria (guidelines for comprehensive malaria treatment) were used. Results: We analyzed 111 cases, out of which 13.5% were classified as severe malaria according to the WHO criteria. Following the Colombian Guidelines, the proportion increased to 23.4%. Identified complications included hepatic dysfunction, anaemia, acidosis, and severe thrombocytopenia. No difference in the frequency of complications by Plasmodium species was observed; 39.4% of the cases presented general danger signs, pallor and jaundice being the most frequent; 40.5% showed danger signs for pregnancy, such as persistent headache, abdominal pain, and vaginal bleeding. Conclusions: Severe malaria is a highly frequent event in pregnant women, without differences by Plasmodium species. It shows early recognizable dangers signs. Hospital under-reporting was identified in 88% of severe cases as well as a lack of laboratory tests for a more comprehensive diagnosis. A protocol for the clinical diagnosis of pregnant women with malaria is required.

Asymptomatic plasmodium infection in a residual malaria transmission area in the atlantic forest region: implications for elimination

Abstract INTRODUCTION: Elimination of malaria in areas of interrupted transmission warrants careful case assessment to avoid the reintroduction of this disease. Occasional malaria cases are reported among visitors of the Atlantic Forest area of Brazil, while data on residents of this area are scarce. METHODS: A sectional study was carried out to examine 324 individuals living in a municipality where autochthonous cases were detected. RESULTS: Asymptomatic Plasmodium infections were detected in 2.8% of the individuals by polymerase chain reaction (PCR), with one case of P. falciparum (0.3%), two cases of P. vivax (0.6%), and six cases of P. malariae (1.9%). The thick blood smears were negative in all individuals. Serological tests performed in 314 subjects were reactive in 11.1%, with 3.5% for P. falciparum and 7.7% for P. vivax. A subsample of 42 reactive individuals for any Plasmodium species showed P. malariae in 30.9% of specimens. Individuals who entered the Atlantic Forest region were 2.7 times more likely to exhibit reactive serology for P. vivax compared with individuals who did not enter this region (p<0.05). Children <15 years had a higher chance of reactive serology for P. falciparum and P. vivax than individuals ≥15 years of age (p<0.05). Individuals living in the Paraiso district had a higher chance of reactive serology for P. vivax compared to other districts (p<0.05). No associations were found between sex, past exposure to malaria, or serological response to antibodies of any Plasmodium species. CONCLUSIONS: The implications of these results for the elimination of malaria were discussed.

Urban malaria transmission in a non-endemic area in the Andean region of Colombia

BACKGROUND Rapid urbanisation in difficult socio-economic conditions such as inadequate housing infrastructure, lack of public services, improper sanitation, and poor water drainage systems in vegetation-rich areas lead to ecological conditions that are conducive to the breeding of mosquitoes and transmission of malaria, in semi-urban and urban settings. OBJECTIVES This study aimed to describe the cases of malaria that were reported in the peri-urban areas of Pereira (Colombia), between 2008 and 2015. METHODS A retrospective study was conducted using data from the Malaria Surveillance System 2009-2015 and an outbreak study (between December 2008 and March 2009). Frequency distributions and summary measures, as well as univariate analysis were performed for all the variables in consideration. The annual parasite index (API) was calculated. FINDINGS Data on 214 cases were obtained from the surveillance system. A majority of the cases were reported in men (63.1%), followed by in children < 15 years (23.8%), and were caused predominantly by Plasmodium vivax (86.0%), with most of the infection occurring in the urban areas (52.8%) of Pereira. The API, by sex and age group, was higher among men ≥ 80 years. The outbreak study reported 14 cases of malaria in rural/peri-urban neighborhoods, and it was observed that the anopheline breeding sites were in close proximity to the houses in these areas. This population did not use protective measures against mosquitoes and chemical control was conducted through residual and spatial insecticide spraying. MAIN CONCLUSIONS This study suggested the presence of autochthonous malaria transmission, in Pereira, between 2008 and 2015, most of which were cases of P. vivax. A greater intensity was observed between 2008 and 2009 when malaria was possibly reintroduced to the region. During the years of the study, a gradual decrease in the number of reported cases of malaria was observed in Pereira, except for the time period between 2008 and 2009 when a spike was noted (estimated using the API); this was most likely caused by an outbreak. Interventions that are more aggressive in nature are required to prevent further malarial transmission and dissemination.

Indicadores epidemiológicos de malaria en el área Ixil, Guatemala. 2012-2015 / Epidemiological indicators of malaria in the Ixil area, Guatemala. 2012-2015

Se realizó un estudio observacional descriptivo para determinar algunas variables epidemiológicas de malaria en el área Ixil de los años 2012-2015, de una muestra, de 171 pacientes que representaron el 100% de la ocurrencia; para el análisis y procesamiento se incluyó el cálculo de medidas descriptivas, para la estratificación del riesgo se hicieron cálculos matemáticos, ponderados con los objetivos de estratificar el riesgo de Malaria, determinar tendencia histórica de la enfermedad, distribuir los casos según variables socio demográficas, identificar tiempo transcurrido de los primeros síntomas al diagnóstico y precisar antecedentes de la enfermedad en los pacientes (AU)

Plasmodium vivax: causa de malária grave / Plasmodium vivax: a cause of severe malaria

O presente estudo é um relato de caso de malária por Plasmodium vivax em paciente internado no Hospital Universitário de Mato Grosso do Sul. O objetivo do trabalho foi ressaltar a existência de casos de malária grave provocada por esta espécie do protozoário, visto que a epidemiologia envolvendo P. vivax e suas complicações clínicas severas não é grande, e os relatos não são frequentes na literatura. A doença foi caracterizada por febre contínua, icterícia, hemorragia alveolar e insuficiência renal aguda, sendo que o paciente evoluiu com insuficiência renal, pneumonia associada à ventilação mecânica e meningite bacteriana durante período de internação, com boa resposta ao tratamento.A importância do caso relatado reside na constatação de que a intervenção rápida, mesmo na forma grave da doença, promove a recuperação satisfatória do indivíduo acometido por essa patologia.

This study is a case report of Plasmodium vivax malaria in a patient admitted to the University Hospital of Mato Grosso do Sul. The aim of the work was to highlight the existence of cases of severe malaria caused by this species of the parasite, as the epidemiology involving P. vivax and severe clinical complications is not wide, and the reports are not frequent in the literature. The disease was characterized by continuous fever, jaundice,alveolar hemorrhage and acute renal failure, with the patient developing renal failure, ventilator-associated pneumonia, and bacterial meningitis during hospital stay, with good response to treatment. The importance of the case lies in the realization that rapid intervention, even in the severe form of the disease, promotes safe recovery of the individual affected by this disease

Malaria in gold-mining areas in Colombia

Gold-mining may play an important role in the maintenance of malaria worldwide. Gold-mining, mostly illegal, has significantly expanded in Colombia during the last decade in areas with limited health care and disease prevention. We report a descriptive study that was carried out to determine the malaria prevalence in gold-mining areas of Colombia, using data from the public health surveillance system (National Health Institute) during the period 2010-2013. Gold-mining was more prevalent in the departments of Antioquia, Córdoba, Bolívar, Chocó, Nariño, Cauca, and Valle, which contributed 89.3% (270,753 cases) of the national malaria incidence from 2010-2013 and 31.6% of malaria cases were from mining areas. Mining regions, such as El Bagre, Zaragoza, and Segovia, in Antioquia, Puerto Libertador and Montelíbano, in Córdoba, and Buenaventura, in Valle del Cauca, were the most endemic areas. The annual parasite index (API) correlated with gold production (R2 0.82, p < 0.0001); for every 100 kg of gold produced, the API increased by 0.54 cases per 1,000 inhabitants. Lack of malaria control activities, together with high migration and proliferation of mosquito breeding sites, contribute to malaria in gold-mining regions. Specific control activities must be introduced to control this significant source of malaria in Colombia.

Basic sanitation, socioeconomic conditions, and degree of risk for the presence and maintenance of malaria in a low-transmission area in the Brazilian Amazon

ABSTRACTINTRODUCTION:This study aimed to evaluate basic sanitation and socioeconomic indicators, reported cases of malaria, and risk of contracting malaria in the Ananindeua municipality, State of Pará.METHODS:Data on basic sanitation and socioeconomic dimensions were taken from the Brazilian Institute of Geography and Statistics [ Instituto Brasileiro de Geografia e Estatística (IBGE)] 2010 census. Epidemiological malaria information was taken from the Epidemiological Malaria Surveillance Information System [ Sistema de Informação de Vigilância Epidemiológica de Malária (SIVEP/Malaria)], between 2003 and 2013 of the Ministry of Health and from the SIVEP/Malaria forms of the municipality's Endemic Diseases Unit for 2,013 cases.RESULTS:Our data do not confirm the correlation among indicators of basic sanitation, socioeconomic conditions, and water supply with malaria cases. Of the 1,557 cases evaluated, most were caused by Plasmodium vivax , with rare cases of Plasmodium falciparum and mixed infections. There were 756 notifications in 2003. The number of reported cases was sharply reduced between 2006 and 2012, but a 142-case outbreak occurred in 2013. Ananindeua municipality's Annual Parasite Index indicated low risk in 2003 and no risk in other years, and the 2,013 cases were predominantly male individuals aged ≥40 years.CONCLUSIONS:Our data confirm the non-endemicity of malaria in the Ananindeua municipality, as the Annual Parasite Indices described for the years 2004-2013 classify it as a risk-free area. However, the 2013 outbreak indicates the need to strengthen prevention, surveillance, and control activities to reduce the risk of new outbreaks and consequent economic and social impacts on the population.

Malaria in pregnant women living in areas of low transmission on the southeast Brazilian Coast: molecular diagnosis and humoural immunity profile

Studies on autochthonous malaria in low-transmission areas in Brazil have acquired epidemiological relevance because they suggest continued transmission in what remains of the Atlantic Forest. In the southeastern portion of the state of São Paulo, outbreaks in the municipality of Juquitiba have been the focus of studies on the prevalence of Plasmodium, including asymptomatic cases. Data on the occurrence of the disease or the presence of antiplasmodial antibodies in pregnant women from this region have not previously been described. Although Plasmodium falciparum in pregnant women has been widely addressed in the literature, the interaction of Plasmodium vivax and Plasmodium malariae with this cohort has been poorly explored to date. We monitored the circulation of Plasmodium in pregnant women in health facilities located in Juquitiba using thick blood film and molecular protocols, as well as immunological assays, to evaluate humoural immune parameters. Through real-time and nested polymerase chain reaction, P. vivax and P. malariae were detected for the first time in pregnant women, with a positivity of 5.6%. Immunoassays revealed the presence of IgG antibodies: 44% for ELISA-Pv, 38.4% for SD-Bioline-Pv and 18.4% for indirect immunofluorescence assay-Pm. The high prevalence of antibodies showed significant exposure of this population to Plasmodium. In regions with similar profiles, testing for a malaria diagnosis might be indicated in prenatal care.

Genetic diversity of chloroquine-resistant Plasmodium vivax parasites from the western Brazilian Amazon

The molecular basis of Plasmodium vivax chloroquine (CQ) resistance is still unknown. Elucidating the molecular background of parasites that are sensitive or resistant to CQ will help to identify and monitor the spread of resistance. By genotyping a panel of molecular markers, we demonstrate a similar genetic variability between in vitro CQ-resistant and sensitive phenotypes of P. vivax parasites. However, our studies identified two loci (MS8 and MSP1-B10) that could be used to discriminate between both CQ-susceptible phenotypes among P. vivax isolates in vitro. These preliminary data suggest that microsatellites may be used to identify and to monitor the spread of P. vivax-resistance around the world.

Malaria in Brazil: what happens outside the Amazonian endemic region

Brazil, a country of continental proportions, presents three profiles of malaria transmission. The first and most important numerically, occurs inside the Amazon. The Amazon accounts for approximately 60% of the nation’s territory and approximately 13% of the Brazilian population. This region hosts 99.5% of the nation’s malaria cases, which are predominantly caused by Plasmodium vivax (i.e., 82% of cases in 2013). The second involves imported malaria, which corresponds to malaria cases acquired outside the region where the individuals live or the diagnosis was made. These cases are imported from endemic regions of Brazil (i.e., the Amazon) or from other countries in South and Central America, Africa and Asia. Imported malaria comprised 89% of the cases found outside the area of active transmission in Brazil in 2013. These cases highlight an important question with respect to both therapeutic and epidemiological issues because patients, especially those with falciparum malaria, arriving in a region where the health professionals may not have experience with the clinical manifestations of malaria and its diagnosis could suffer dramatic consequences associated with a potential delay in treatment. Additionally, because the Anopheles vectors exist in most of the country, even a single case of malaria, if not diagnosed and treated immediately, may result in introduced cases, causing outbreaks and even introducing or reintroducing the disease to a non-endemic, receptive region. Cases introduced outside the Amazon usually occur in areas in which malaria was formerly endemic and are transmitted by competent vectors belonging to the subgenus Nyssorhynchus (i.e., Anopheles darlingi, Anopheles aquasalis and species of the Albitarsis complex). The third type of transmission accounts for only 0.05% of all cases and is caused by autochthonous malaria in the Atlantic Forest, located primarily along the southeastern Atlantic Coast. They are caused by parasites that seem to be (or to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon.

Influence of age on the haemoglobin concentration of malaria-infected patients in a reference centre in the Brazilian Amazon

Anaemia is amongst the major complications of malaria, a major public health problem in the Amazon Region in Latin America. We examined the haemoglobin (Hb) concentrations of malaria-infected patients and compared it to that of malaria-negative febrile patients and afebrile controls. The haematological parameters of febrile patients who had a thick-blood-smear performed at an infectious diseases reference centre of the Brazilian Amazon between December 2009-January 2012 were retrieved together with clinical data. An afebrile community control group was composed from a survey performed in a malaria-endemic area. Hb concentrations and anaemia prevalence were analysed according to clinical-epidemiological status and demographic characteristics. In total, 7,831 observations were included. Patients with Plasmodium falciparum infection had lower mean Hb concentrations (10.5 g/dL) followed by P. vivax-infected individuals (12.4 g/dL), community controls (12.8 g/dL) and malaria-negative febrile patients (13.1 g/dL) (p < 0.001). Age, gender and clinical-epidemiological status were strong independent predictors for both outcomes. Amongst malaria-infected individuals, women in the reproductive age had considerably lower Hb concentrations. In this moderate transmission intensity setting, both vivax and falciparum malaria are associated with reduced Hb concentrations and risk of anaemia throughout a wide age range.

G6PD deficiency in Latin America: systematic review on prevalence and variants

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available.

Malaria in the state of Rio de Janeiro, Brazil, an Atlantic Forest area: an assessment using the health surveillance service

The lethality of malaria in the extra-Amazonian region is more than 70 times higher than in Amazonia itself. Recently, several studies have shown that autochthonous malaria is not a rare event in the Brazilian southeastern states in the Atlantic Forest biome. Information about autochthonous malaria in the state of Rio de Janeiro (RJ) is scarce. This study aims to assess malaria cases reported to the Health Surveillance System of the State of Rio de Janeiro between 2000-2010. An average of 90 cases per year had parasitological malaria confirmation by thick smear. The number of malaria notifications due to Plasmodium falciparum increased over time. Imported cases reported during the period studied were spread among 51% of the municipalities (counties) of the state. Only 35 cases (4.3%) were autochthonous, which represents an average of 3.8 new cases per year. Eleven municipalities reported autochthonous cases; within these, six could be characterised as areas of residual or new foci of malaria from the Atlantic Forest system. The other 28 municipalities could become receptive for transmission reintroduction. Cases occurred during all periods of the year, but 62.9% of cases were in the first semester of each year. Assessing vulnerability and receptivity conditions and vector ecology is imperative to establish the real risk of malaria reintroduction in RJ.

Emerging Plasmodium vivax resistance to chloroquine in South America: an overview

The global emergence of Plasmodium vivax strains resistant to chloroquine (CQ) since the late 1980s is complicating the current international efforts for malaria control and elimination. Furthermore, CQ-resistant vivax malaria has already reached an alarming prevalence in Indonesia, East Timor and Papua New Guinea. More recently, in vivo studies have documented CQ-resistant P. vivax infections in Guyana, Peru and Brazil. Here, we summarise the available data on CQ resistance across P. vivax-endemic areas of Latin America by combining published in vivo and in vitro studies. We also review the current knowledge regarding the molecular mechanisms of CQ resistance in P. vivax and the prospects for developing and standardising reliable molecular markers of drug resistance. Finally, we discuss how the Worldwide Antimalarial Resistance Network, an international collaborative effort involving malaria experts from all continents, might contribute to the current regional efforts to map CQ-resistant vivax malaria in South America.

Factors associated with recurrent Plasmodium vivax malaria in Porto Velho, Rondônia State, Brazil, 2009 / Fatores associados às recidivas de malária causada por Plasmodium vivax no Município de Porto Velho, Rondônia, Brasil, 2009 / Fatores associados às recidivas de malária causada por Plasmodium vivax no Município de Porto Velho, Rondônia, Brasil, 2009 / Factores asociados a las recidivas de malaria, causada por Plasmodium vivax, en el municipio de Porto Velho, Rondônia, Brasil, 2009

This open retrospective cohort study aimed to describe the incidence of recurrent Plasmodium vivax malaria and associated factors in Porto Velho, Rondônia State, Brazil, in 2009. Data were collected from the National Information System for Malaria Epidemiological Surveillance. There were 23,365 reported P. vivax malaria cases in 2009, 23% of which were classified as relapses. Incidence density of P. vivax recurrence was 45.1/100 patient-years, mostly occurring between the 4th and 13th week after initiating treatment. Male gender, shorter time since onset of symptoms, and higher parasitemia in the initial infection increased the risk of relapse during the year, with a 10% reduction in relative risk for longer symptoms and 11% and 15% increases in relative risk for males and higher initial parasitemia, respectively. However, the results show low clinical relevance for these associations, thereby limiting their applicability to decision-making at the public health level.

Estudo de coorte histórica aberta, construída com informações registradas no Sistema de Informação de Vigilância Epidemiológica da Malária, com objetivo de descrever a incidência e os fatores associados à recidiva de malária causada pelo Plasmodium vivax em Porto Velho, Rondônia, Brasil. Foram notificados 23.365 casos de malária por P. vivax no município, sendo que 23% deles apresentaram recidiva no decorrer de 2009. A densidade de incidência de recidivas foi de 45,1/100 pacientes-ano, ocorrendo, principalmente, entre a 4a e a 13a semana após o início do tratamento. Ser homem, ter menos tempo de sintomas e ter maior nível de parasitemia na infecção inicial aumentaram o risco de recidiva no decorrer do ano, com 10% de redução relativa do risco para maior tempo de sintomas e de 11% e 15% de incremento relativo do risco para o sexo masculino e maiores níveis de parasitemia, respectivamente. Contudo, os resultados demonstram baixa relevância clínica das associações encontradas, comprometendo a sua aplicabilidade na tomada de decisão em nível de saúde pública.

Estudo de coorte histórica aberta, construída com informações registradas no Sistema de Informação de Vigilância Epidemiológica da Malária, com objetivo de descrever a incidência e os fatores associados à recidiva de malária causada pelo Plasmodium vivax em Porto Velho, Rondônia, Brasil. Foram notificados 23.365 casos de malária por P. vivax no município, sendo que 23% deles apresentaram recidiva no decorrer de 2009. A densidade de incidência de recidivas foi de 45,1/100 pacientes-ano, ocorrendo, principalmente, entre a 4a e a 13a semana após o início do tratamento. Ser homem, ter menos tempo de sintomas e ter maior nível de parasitemia na infecção inicial aumentaram o risco de recidiva no decorrer do ano, com 10% de redução relativa do risco para maior tempo de sintomas e de 11% e 15% de incremento relativo do risco para o sexo masculino e maiores níveis de parasitemia, respectivamente. Contudo, os resultados demonstram baixa relevância clínica das associações encontradas, comprometendo a sua aplicabilidade na tomada de decisão em nível de saúde pública. Recidiva; Plasmodium vivax; Malária.

Estudio de cohorte histórica abierta, construida con información registrada en el Sistema de Información de Vigilancia Epidemiológica de la Malaria, con el objetivo de describir la incidencia y los factores asociados a la reaparición de malaria, causada por el Plasmodium vivax, en Porto Velho, Rondônia, Brasil. Se notificaron 23.365 casos de malaria por P. vivax en el municipio, donde un 23% de ellos presentaron recidiva a lo largo del 2009. La densidad de incidencia de recidivas fue de 45,1/100 pacientes-año, produciéndose, principalmente, entre la 4ª y la 13ª semana tras el inicio del tratamiento. Ser hombre, tener menos tiempo síntomas y tener un mayor nivel de parasitemia en la infección inicial aumentaron el riesgo de recidiva a lo largo del año, con un 10% de reducción relativa del riesgo, para un mayor tiempo de síntomas, y de un 11% y 15% de incremento relativo del riesgo para el sexo masculino y mayores niveles de parasitemia, respectivamente. No obstante, los resultados demostraron baja relevancia clínica de las asociaciones encontradas, comprometiendo su aplicabilidad en la toma de decisiones dentro de la salud pública.

Seroprevalence of Plasmodium vivax in the Republic of Korea (2003-2005) using Indirect Fluorescent Antibody Test

Plasmodium vivax reemerged in the Republic of Korea (ROK) in 1993, and is likely to continue to affect public health. The purpose of this study was to measure levels of anti-P. vivax antibodies using indirect fluorescent antibody test (IFAT) in border areas of ROK, to determine the seroprevalence of malaria (2003-2005) and to plan effective control strategies. Blood samples of the inhabitants in Gimpo-si, Paju-si, and Yeoncheon-gun (Gyeonggi-do), and Cheorwon-gun (Gangwon-do) were collected and kept in Korea Centers for Disease Control and Prevention (KCDC). Out of a total of 1,774 serum samples tested, the overall seropositivity was 0.94% (n=17). The seropositivity was the highest in Paju-si (1.9%, 7/372), followed by Gimpo-si (1.4%, 6/425), Yeoncheon-gun (0.67%, 3/451), and Cheorwon-gun (0.19%, 1/526). The annual parasite incidence (API) in these areas gradually decreased from 2003 to 2005 (1.69, 1.09, and 0.80 in 2003, 2004, and 2005, respectively). The highest API was found in Yeoncheon-gun, followed by Cheorwon-gun, Paju-si, and Gimpo-si. The API ranking in these areas did not change over the 3 years. The seropositivity of Gimpo-si showed a strong linear relationship with the API of 2005 (r=0.9983, P=0.036). Seropositivity data obtained using IFAT may be useful for understanding malaria prevalence of relevant years, predicting future transmission of malaria, and for establishing and evaluating malaria control programs in affected areas.

Genetic Polymorphisms in VIR Genes among Indian Plasmodium vivax Populations

The vir genes are antigenic genes and are considered to be possible vaccine targets. Since India is highly endemic to Plasmodium vivax, we sequenced 5 different vir genes and investigated DNA sequence variations in 93 single-clonal P. vivax isolates. High variability was observed in all the 5 vir genes; the vir 1/9 gene was highly diverged across Indian populations. The patterns of genetic diversity do not follow geographical locations, as geographically distant populations were found to be genetically similar. The results in general present complex genetic diversity patterns in India, requiring further in-depth population genetic and functional studies.

First published record of urban malaria in Puerto Gaitan, Meta, Colombia

Patterns of malaria cases were compared between the department of Meta and the municipality of Puerto Gaitán, Colombia, to examine temporal change in malaria from 2005-2010. During this time frame in Meta the mean ratio was 2.53; in contrast, in Puerto Gaitán it was 1.41, meaning that a surprisingly high proportion of Plasmodium falciparum cases were reported from this municipality. A detailed analysis of data from Puerto Gaitán for 2009 and 2010 detected a significant difference (χ2, p < 0.001) in the distribution of plasmodia, with Plasmodium vivax more prevalent in 2009 and P. falciparum in 2010. Males had the highest number of cases but there was no difference in the distribution of cases between sexes and years. In both years, for both sexes, people 16-40 accounted for the majority of cases (58.9% in 2009; 60.4% in 2010). There were significant differences in the distribution of both P. vivax (χ2, p < 0.01) and P. falciparum cases (χ2, p < 0.05) by geographic setting (urban vs. non-urban) between years. Urban cases of both P. vivax and P. falciparum are recorded in this study for the first time in Puerto Gaitán, possibly the result of area wide displacement and migration due to armed conflict.

Caracterização das epidemias de malária nos municípios da Amazônia Brasileira em 2010 / Characteristics of malaria epidemics in the municipalities of the Brazilian Amazon, 2010 / Caracterización de las epidemias de malaria en los municipios de la Amazonia brasileña en 2010

Malaria epidemics occur annually in various municipalities (counties) in the Brazilian Amazon. However, health services do not systematically adopt tools to detect and promptly control these events. This article aimed to characterize malaria epidemics in the Brazilian Amazon Region based on their duration, the Plasmodium species involved, and the population's degree of vulnerability. An automatic malaria incidence monitoring system based on quartiles was assessed for prompt identification of malaria epidemics. In 2010, epidemics were identified in 338 (41.9%) of the counties in the Brazilian Amazon. P. falciparum and P. vivax epidemics were detected, both singly and in combination. Epidemics lasted from 1 to 4 months in 58.3% of the counties, 5 to 8 months in 34.5%, and 9 to 12 months in 17.4%. Systematic monitoring of malaria incidence could contribute to early detection of epidemics and improve the effectiveness of control measures.

Epidemias de malária ocorrem anualmente nos municípios da Região Amazônica, Brasil, no entanto os serviços de saúde não adotam, de maneira sistemática, instrumentos para detecção e contenção oportunas desses eventos. O objetivo foi caracterizar as epidemias de malária na região segundo duração, espécie de Plasmodium e vulnerabilidade das populações. Foi avaliado um sistema de monitoramento automatizado da incidência da malária, com base no diagrama de controle segundo quartis, para identificar as epidemias da doença. Em 2010, ocorreram epidemias em 338 (41,9%) municípios da região. Houve epidemias por P. falciparum e por P. vivax, separadamente, e também por ambas as espécies. Epidemias com duração de um a quatro meses ocorreram em 58,3% dos municípios epidêmicos; de cinco a oito meses, em 24,3%; e de nove a 12 meses, em 17,4%. O monitoramento automatizado da variação da incidência da malária poderá contribuir para detecção precoce das epidemias e melhorar o seu controle oportuno.

Las epidemias de malaria ocurren anualmente en los municipios de la Región Amazónica, Brasil, no obstante, los servicios de salud no adoptan de manera sistemática instrumentos para la detección y contención oportuna de este tipo de eventos. El objetivo fue caracterizar las epidemias de malaria en la región según su duración, especie de Plasmodium y vulnerabilidad de las poblaciones. Se evalúo un sistema de supervisión automatizado de la incidencia de la malaria, en base al diagrama de control según cuartiles, con el fin de identificar las epidemias de la enfermedad. En 2010, se produjeron epidemias en 338 (41,9%) municipios de la región. Hubo epidemias por P. falciparum y por P. vivax, separadamente, y también por ambas especies. Hubo epidemias con una duración de uno a cuatro meses que se produjeron en un 58,3% de los municipios epidémicos; de cinco a ocho meses, en un 24,3%; y de nueve a 12 meses, en un 17,4%. La supervisión automatizada de la variación de la incidencia de la malaria podrá contribuir a la detección precoz de las epidemias y mejorar su control adecuado.