Abstract INTRODUCTION: Rapid diagnostic tests (RDTs) for detecting Plasmodium antigens have become increasingly common worldwide. We aimed to evaluate the accuracy of the Immuno-Rapid Malaria Pf/Pv RDT in detecting Plasmodium vivax infection compared to standard thick blood smear (TBS) under microscopy. METHODS: Hundred and eighty-one febrile patients from the hospital’s regular admissions were assessed using TBS and RDT in a blinded experiment. RESULTS: RDT showed a sensitivity of 98.9%, specificity of 100%, and accuracy of 99.5% for P. vivax infection when compared to TBS. CONCLUSIONS: The RDT is highly accurate, making it a valuable diagnostic tool for P. vivax infection.

Abstract In Brazil, malaria is an important public health problem first reported in 1560. Historically, fluctuations in malaria cases in Brazil are attributed to waves of economic development; construction of railroads, highways, and hydroelectric dams; and population displacement and land occupation policies. Vector control measures have been widely used with an important role in reducing malaria cases. In this review article, we reviewed the vector control measures established in the Brazilian territory and aspects associated with such measures for malaria. Although some vector control measures are routinely used in Brazil, many entomological and effectiveness information still need better evidence in endemic areas where Plasmodium vivax predominates. Herein, we outlined some of the needs and priorities for future research: a) update of the cartography of malaria vectors in Brazil, adding molecular techniques for the correct identification of species and complexes of species; b) evaluation of vector competence of anophelines in Brazil; c) strengthening of local entomology teams to perform vector control measures and interpret results; d) evaluation of vector control measures, especially use of insecticide-treated nets and long-lasting insecticidal nets, estimating their effectiveness, cost-benefit, and population acceptance; e) establishment of colonies of malaria vectors in Brazil, i.e., Anopheles darlingi, to understand parasite-vector interactions better; f) study of new vector control strategies with impacts on non-endophilic vectors; g) estimation of the impact of insecticide resistance in different geographical areas; and h) identification of the relative contribution of natural and artificial breeding sites in different epidemiological contexts for transmission.

BACKGROUND The elimination of malaria depends on the blocking of transmission and of an effective treatment. In Brazil, artemisinin therapy was introduced in 1991, and here we present a performance overview during implementation outset years. METHODS It is a retrospective cohort (1991 to 2002) of patients treated in a tertiary centre of Manaus, with positive microscopic diagnosis of Plasmodium falciparum malaria, under treatment with using injectable or rectal artemisinin derivatives, and followed over 35-days to evaluate parasite clearance, death and recurrence. FINDINGS This cohort outcome resulted 97.6% (1554/1593) of patients who completed the 35-day follow-up, 0.6% (10/1593) of death and 1.8% (29/1593) of follow-up loss. All patients that died and those that presented parasitaemia recurrence had pure P. falciparum infections and received monotherapy. Considering patients who completed 35-day treatment, 98.2% (1527/1554) presented asexual parasitaemia clearance until D4 and 1.8% (27/1554) between D5-D10. It is important to highlight that had no correlation between the five treatment schemes and the sexual parasite clearance. Finally, it is noteworthy that we were able to observe also gametocytes carriage during all follow-up (D0-D35). MAIN CONCLUSIONS Artemisinin derivatives remained effective in the treatment of falciparum malaria during first 12-years of use in north area of Brazil.

AbstractHere, we describe a case of acute disseminated encephalomyelitis (ADEM) that occurred during a plausible risk interval following inactivated influenza vaccination in a previously healthy 27-year-old man from Manaus, Brazil. He was treated with intravenous methylprednisolone and immunoglobulin. One-month follow-up revealed resolution of the brain lesions, but not of the spinal cord lesions. No recurrence or progression of the main neurological symptoms was observed. After two years of monitoring, the patient continues to experience weak lower limbs and urinary retention. Thus, we recommend that ADEM should be considered in a patient presenting with neurological symptoms after influenza vaccination.

In Brazil, more than 99% of malaria cases are reported in the Amazon, and the State of Amazonas accounts for 40% of this total. However, the accumulated experience and challenges in controlling malaria in this region in recent decades have not been reported. Throughout the first economic cycle during the rubber boom (1879 to 1912), malaria was recorded in the entire state, with the highest incidence in the villages near the Madeira River in the Southern part of the State of Amazonas. In the 1970s, during the second economic development cycle, the economy turned to the industrial sector and demanded a large labor force, resulting in a large migratory influx to the capital Manaus. Over time, a gradual increase in malaria transmission was observed in peri-urban areas. In the 1990s, the stimulation of agroforestry, particularly fish farming, led to the formation of permanent Anopheline breeding sites and increased malaria in settlements. The estimation of environmental impacts and the planning of measures to mitigate them, as seen in the construction of the Coari-Manaus gas pipeline, proved effective. Considering the changes occurred since the Amsterdam Conference in 1992, disease control has been based on early diagnosis and treatment, but the development of parasites that are resistant to major antimalarial drugs in Brazilian Amazon has posed a new challenge. Despite the decreased lethality and the gradual decrease in the number of malaria cases, disease elimination, which should be associated with government programs for economic development in the region, continues to be a challenge.

Tachia sp. are used as antimalarials in the Amazon Region and in vivo antimalarial activity of a Tachia sp. has been previously reported. Tachia grandiflora Maguire and Weaver is an Amazonian antimalarial plant and herein its cytotoxicity and antimalarial activity were investigated. Spectral analysis of the tetraoxygenated xanthone decussatin and the iridoid aglyone amplexine isolated, respectively, from the chloroform fractions of root methanol and leaf ethanol extracts was performed. In vitro inhibition of the growth of Plasmodium falciparum Welch was evaluated using optical microscopy on blood smears. Crude extracts of leaves and roots were inactive in vitro. However, chloroform fractions of the root and leaf extracts [half-maximal inhibitory concentration (IC50) = 10.5 and 35.8 µg/mL, respectively] and amplexine (IC50= 7.1 µg/mL) were active in vitro. Extracts and fractions were not toxic to type MRC-5 human fibroblasts (IC50> 50 µg/mL). Water extracts of the roots of T. grandiflora administered by mouth were the most active extracts in the Peters 4-day suppression test in Plasmodium berghei-infected mice. At 500 mg/kg/day, these extracts exhibited 45-59% inhibition five to seven days after infection. T. grandiflora infusions, fractions and isolated substance have potential as antimalarials.

OBJECTIVES: Describing rates of seroconversion and its associated factors in a series of Brazilian infants following the final dose of the vaccine at 6 months of age. METHODS: Peripheral blood samples were collected after the third dose of the vaccine for the detection of anti-hepatitis B surface antibodies among infants of 7-12 months of age. We measured the association between seroconversion and birthweight, gestational age, time since administration of the vaccine in the maternity hospital and whether or not testing for hepatitis B surface antigen had been performed during pregnancy. RESULTS: We examined 40 infants. The mean birthweight was 2787 g (standard deviation = 853 g) and mean gestational age was 37.5 (standard deviation = 3.08) weeks. The proportion that seroconverted was non-significantly higher in infants who weighed >2000 g at birth (96.7%) than in those with birthweights <2000 g (80%, p = 0.149). There was no difference between the infants who were born at <37 weeks of gestational age and those born at >37 weeks (p < 0.178) neither between seroconversion and the time of application of the first dose of the vaccine after delivery (p = 0.202). CONCLUSION: The proportion of infants who seroconverted was similar to that found in other Brazilian studies. There were no differences in the proportion seroconverting by age at first immunization.

Artemisinin is the active antimalarial compound obtained from the leaves of Artemisia annua L. Artemisinin, and its semi-synthetic derivatives, are the main drugs used to treat multi-drug-resistant Plasmodium falciparum (one of the human malaria parasite species). The in vitro susceptibility of P. falciparum K1 and 3d7 strains and field isolates from the state of Amazonas, Brazil, to A. annua infusions (5 g dry leaves in 1 L of boiling water) and the drug standards chloroquine, quinine and artemisinin were evaluated. The A. annua used was cultivated in three Amazon ecosystems (várzea, terra preta de índio and terra firme) and in the city of Paulínia, state of São Paulo, Brazil. Artemisinin levels in the A. annua leaves used were 0.90-1.13% (m/m). The concentration of artemisinin in the infusions was 40-46 mg/L. Field P. falciparum isolates were resistant to chloroquine and sensitive to quinine and artemisinin. The average 50% inhibition concentration values for A. annua infusions against field isolates were 0.11-0.14 μL/mL (these infusions exhibited artemisinin concentrations of 4.7-5.6 ng/mL) and were active in vitro against P. falciparum due to their artemisinin concentration. No synergistic effect was observed for artemisinin in the infusions.

O atendimento de acidentes ocupacionais na Fundação de Medicina Tropical Dr. Heitor Dourado (FMT- HVD), envolvendo sangue e fluídos corpóreos, iniciou-se de forma rotineira em 1999. O objetivo deste relato é enfatizar a importância da utilização de medidas para o controle dos acidentes com material biológico. Após investigação epidemiológica detalhada, confirmamos um caso de soroconversão ao vírus da imunodeficiência humana (HIV) após acidente ocupacional, envolvendo fluído corpóreo e perfurocortante.

The medical care of occupational accidents in Tropical Medicine Foundation Dr. Heitor Dourado (FMT-HVD), involving blood and body fluids, started routinely in 1999. The objective of this report is to emphasize the importance of the measures used for the control of accidents with biological material. This study is carried out after a detailed epidemiological investigation confirmed one case of human immunodeficiency virus (HIV) seroconversion after an occupational accident involving bodily fluids and sharp instruments.

We report two ciprofloxacin and ofloxacin-resistant Neisseria gonorrhoeae strains that were isolated from the urethral discharge of male patients at the sexually transmitted diseases outpatient clinic of the Alfredo da Matta Foundation (Manaus, state of Amazonas, Brazil). The gonococci displayed minimal inhibitory concentrations (> 32.00 µg/mL) and three mutations in the quinolone resistance-determining region (S91F and D95G in GyrA and S87R in ParC). Both isolates were genotyped using N. gonorrhoeae multi-antigen sequence typing and the analysis showed that the ST225 which represented an emerging widespread multi-resistant clone that has also been associated with reduced susceptibility to ceftriaxone. We recommend continued surveillance of this pathogen to assess the efficacy of anti-gonococcal antibiotics in Brazil.

São relatados dois casos de pacientes com malária por Plasmodium falciparum, evoluindo com síndrome do choque. Receberam suporte hemodinâmico em unidade de terapia intensiva, sem uso de antibióticos, evoluindo com melhora. Malária álgida deve ser um diagnóstico sindrômico, de etiologia diversa (desidratação, infecção bacteriana, sangramento e/ou insuficiência adrenal).

Two patients with malaria due to Plasmodium falciparum who progressed to shock syndrome are reported. They received hemodynamic support in an intensive care unit without using antibiotics and presented improvements. Algid malaria should be a syndromic diagnosis of varying etiology (dehydration, bacterial infection, bleeding and/or adrenal insufficiency).

O exame de rotina para o diagnóstico da malária continua sendo a gota espessa, apesar da comprovada diminuição da sensibilidade e especificidade em situações de densidade parasitária baixa e infecções mistas. A reação em cadeia da polimerase vem sendo cada vez mais utilizada para a detecção molecular e identificação das espécies de plasmódio, por apresentar maior sensibilidade e especificidade. Foi realizada a nested-PCR em amostras de sangue total de 344 pacientes com síndrome febril aguda que se apresentaram para o diagnóstico de malária, em uma unidade terciária de saúde, em Manaus (Amazonas). Nenhum caso de malária por Plasmodium malariae foi diagnosticado à gota espessa ou PCR. Observou-se co-positividade de 96,7%, co-negatividade de 62,2% e coeficiente kappa de 0,44 entre PCR e gota espessa para Plasmodium falciparum. Para Plasmodium vivax, co-positividade de 100%, co-negatividade de 78,1% e coeficiente kappa de 0,56. Na detecção da malária mista, co-positividade de 100%, co-negatividade de 84,9% e coeficiente kappa de 0,26. A reação em cadeia da polimerase detectou alto número de infecções mistas nas amostras analisadas, mas seu uso rotineiro no diagnóstico da malária merece ainda ampla discussão.

The routine test for diagnosing malaria is still the thick blood smear, despite its known decreased sensitivity and specificity in situations of low parasite density and mixed infections. The polymerase chain reaction is increasingly being used for molecular detection and identification of Plasmodium species, due to its higher sensitivity and specificity. Nested PCR was performed on whole-blood samples from 344 patients with acute febrile syndrome who came to a tertiary healthcare center in Manaus (State of Amazonas) for diagnostic confirmation of malaria. No malaria cases caused by Plasmodium malariae were detected through the blood smear or PCR. Co-positivity of 96.7%, co-negativity of 62.2% and kappa coefficient of 0.44 were observed between PCR and thick blood smear for Plasmodium falciparum. For Plasmodium vivax, co-positivity of 100%, co-negativity of 78.1% and kappa coefficient of 0.56 were observed. For mixed infection, co-positivity of 100%, co-negativity of 84.9% and kappa coefficient of 0.26 were observed. Polymerase chain reaction detected a high number of mixed infections in the samples analyzed, but its routine use for diagnosing malaria still deserves further discussion.

Este estudo teve como objetivo verificar a ocorrência de metemoglobinemia em indivíduos deficientes da glicose-6-fosfato desidrogenase durante o tratamento da infecção malárica com primaquina. Foram selecionados pacientes com diagnóstico para malária por Plasmodium vivax ou mista V+F (Plasmodium vivax + Plasmodium falciparum), Grupo 1: com 74 indivíduos com diagnóstico clínico de metemoglobinemia e Grupo 2: 161 indivíduos sem diagnóstico clínico de metemoglobinemia. Quanto à deficiência da G6PD, nos Grupos 1 e 2, houveram 51,3% (38) e 8,7% (14) de indivíduos enzimopênicos, respectivamente, demonstrando através de tais dados, significância estatística na associação com a metemoglobinemia somente nos indivíduos do Grupo 1 (p<0,05). A comparação da relação da metemoglobinemia à deficiência da G6PD mostrou haver uma possível associação de indivíduos enzimopênicos desenvolverem metemoglobinemia com maior freqüência.

This study had the aim of investigating occurrences of methemoglobinemia among individuals with glucose-6-phosphate dehydrogenase deficiency during treatment for malaria infection using primaquine. Patients with a diagnosis of malaria caused by Plasmodium vivax or the V+F mixture (Plasmodium vivax + Plasmodium falciparum) were selected. Group 1 consisted of 74 individuals with a clinical diagnosis of methemoglobinemia and Group 2 consisted of 161 individuals without a clinical diagnosis of methemoglobinemia. The glucose-6-phosphate dehydrogenase deficiency rates (numbers of enzymopenic individuals) in Groups 1 and 2 were 51.3% (38) and 8.7% (14) respectively. These data demonstrated a statistically significant association with methemoglobinemia only among the individuals in Group 1 (p<0.05). Investigation of the relationship between methemoglobinemia and glucose-6-phosphate dehydrogenase deficiency showed that there was a possible association such that enzymopenic individuals may develop methemoglobinemia more frequently.