Overview of artemisinin effectiveness during outset years of its implementation in the western Brazilian Amazon

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.

Performance of an immuno-rapid malaria Pf/Pv rapid diagnostic test for malaria diagnosis in the Western Brazilian Amazon

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.

Current vector control challenges in the fight against malaria in Brazil

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.

Acute disseminated encephalomyelitis following inactivated influenza vaccination in the Brazilian Amazon: a case report

Here, 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.

Malaria in the State of Amazonas: a typical Brazilian tropical disease influenced by waves of economic development

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.

In vitro and in vivo antimalarial activity and cytotoxicity of extracts, fractions and a substance isolated from the Amazonian plant Tachia grandiflora (Gentianaceae)

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.

In vitro susceptibility of Plasmodium falciparum Welch field isolates to infusions prepared from Artemisia annua L. cultivated in the Brazilian Amazon

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.

Infecção pelo HIV-1 após acidente ocupacional, no Estado do Amazonas: primeiro caso documentado / HIV-1 infection after occupational accidents in the State of Amazonas: first reported case

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.

Genotyping of two Neisseria gonorrhoeae fluroquinolone-resistant strains in the Brazilian Amazon Region

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.

Vantagens do diagnóstico molecular para malária em comparação à microscopia / Advantages of malaria molecular diagnosis in comparison to microscopy

A malária é um problema de saúde pública na região Amazônica, onde mais de 200 mil casos ocorrem anualmente somente no estado do Amazonas. A principal técnica para o diagnóstico da malária é a gota espessa; entretanto, outros métodos vêm sendo avaliados e os testes moleculares têm se mostrado mais sensíveis e específicos para detectar e diferenciar as espécies em baixas parasitemias. Neste estudo foram analisadas 300 amostras, sendo que 200 eram referentes ao D0 (diagnóstico inicial da infecção) e 100 coletadas no sétimo dia (D7) de tratamento e comparadas as técnicas de microscopia, PCR em tempo real e nested-PCR. Nodiagnóstico microscópico inicial pela gota espessa, não foi detectada nenhuma amostra com infecção mista, sendo 9% por P. falciparum e 91% por P. vivax. No diagnóstico molecular por nested-PCR foram observadas infecções mistas, coinfecção de P. falciparum e P. vivax, em 19% destas amostras. A sensibilidade dos testes para P. vivax foi em média 71%, e a especificidade 92%,e para P. falciparum foi 91% e 79%, respectivamente. As 100 amostras restantes do dia D7 de tratamento eram negativas pela microscopia, porém, o diagnóstico molecular demonstrou 21% de positividade. Este estudo mostrou que muitas infecções mistas vêmsendo subestimadas e que testes moleculares devem ser indicados como um diagnóstico alternativo e complementar à gota espessa,principalmente nos casos de pacientes com baixas parasitemias, estudo de infecções criptônicas, na avaliação da negativação da parasitemia para monitoramento terapêutico e em estudos que visem a diminuição da transmissão pela existência de prováveisgametócitos persistentes após o tratamento.

Malaria is a problem of public health in the Amazonian area where more than 200,000 cases happen annually only in the state of Amazon. The main technique for diagnosis of the malaria is the drop thickens, however, other methods are being appraised, and the molecular tests have shown more sensitive and specific to detect and to differentiate the species in low parasitaemias. In this study 300 samples were analyzed, and 200 were regarding D0 (initial diagnosis of the infection) and 100 collected in the seventh day (D7) of treatment and compared the microscopy techniques, PCR in real time and nested-PCR. In the initial microscopic diagnosis for the drop thickens, any sample was not detected with mixed infection, being 9% for P. falciparum and 91% for P. vivax. In themolecular diagnosis for nested-PCR mixed infections, co-infection of P. falciparum and P. vivax were observed, in 19% of these samples. The sensibility of the tests for P. vivax was 71%, and the specificity 92% on average, and for P. falciparum it was 91% and 79%, respectively. The 100 remaining samples of the day treatment D7 were negative for the microscopy, however, the molecular diagnosis demonstrated 21% of assertiveness. This study showed that many mixed infections have been underestimated and thatmolecular tests should be suitable as complemental diagnosis in patients with low parasitemias, study of cryptonic infections, in the evaluation of the clareance of the parasitaemia for monitoring therapeutic, and in studies that seek the decrease of the transmission for the existence of probable persistent gametocities after the treatment.

Prevalência de Staphylococcus aureus meticilina resistente (MRSA) em pacientes atendidos em Ambulatório de Dermatologia Geral em Manaus-Amazonas / Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in patients attended at a General Dermatology Ambulatory in Manaus, Amazon State, Brazil

O Staphylococcus aureus meticilina resistente (MRSA), de origem hospitalar ou comunitária, tem sido relatado como um dos principais problemas graves de saúde por apresentar resistência aos antibióticos beta lactâmicos e a outros como macrolídeos, lincosaminas, clindamicina, aminoglicosídeos, tetracilinas e sulfas. Diante desse problema, buscou-se identificar a prevalência de MRSA nos casos registrados pela Fundação de Dermatologia Tropical e Venereologia Alfredo da Matta em Manaus, Amazonas, Brasil. Os dados foram obtidos do livro de registro de resultados de exames de cultura geral e antibiograma do laboratório de bacteriologia clínica, no período de setembro de 1998 a outubro de 2007. Foram realizados 1.494 exames em 1.500 amostras , das quais 783 (52,2por cento) eram de pacientes do gênero feminino e 717 (47,8por cento) do masculino. Das 239 amostras de S. aureus isoladas, 232 foram submetidas ao testes de suscetibilidade; dessas 44,0por cento (102/232) apresentaram resistência à oxalina, portanto a taxa de prevalência de MRSA foi de 15,5por cento nas amostras estudadas. O fato de a resistência à oxalina/meticilina inviabilizar a utilização de vários antibióticos justifica a preocupação com as taxas de prevalência ou incidência de infeccções causadas por estafilococos MRSA, ante as possíveis consequências para a terapia dos processos infecciosos, muitas vezes complicados e de elevado potencial de morbidade e mortalidade tanto em adultos quanto em crianças. Ações de vigilância e controle são necessárias para minimizar os riscos de infecção ou colonização dos profissionais de saúde ou pacientes e assegurar a continuidade das pesquisas. Desse modo, será possível caracterizar genotipicamente a origem hospitalar ou comunitária dessas cepas.

Malária álgida: um diagnóstico sindrômico / Algid malaria: a syndromic diagnosis

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).

Diagnóstico molecular da malária em uma unidade de atenção terciária na Amazônia Brasileira / Molecular diagnosing of malaria in a tertiary care center in the Brazilian Amazon region

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 por cento, co-negatividade de 62,2 por cento e coeficiente kappa de 0,44 entre PCR e gota espessa para Plasmodium falciparum. Para Plasmodium vivax, co-positividade de 100 por cento, co-negatividade de 78,1 por cento e coeficiente kappa de 0,56. Na detecção da malária mista, co-positividade de 100 por cento, co-negatividade de 84,9 por cento 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 percent, co-negativity of 62.2 percent and kappa coefficient of 0.44 were observed between PCR and thick blood smear for Plasmodium falciparum. For Plasmodium vivax, co-positivity of 100 percent, co-negativity of 78.1 percent and kappa coefficient of 0.56 were observed. For mixed infection, co-positivity of 100 percent, co-negativity of 84.9 percent 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.

Associação de metemoglobinemia e deficiência de glicose-6-fosfato desidrogenase em pacientes com malária tratados com primaquina / Association of methemoglobinemia and glucose-6-phosphate dehydrogenase deficiency in malaria patients treated with primaquine

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 por cento (38) e 8,7 por cento (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 percent (38) and 8.7 percent (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.

Avaliação dos testes rápidos Optimal-IT® e ICT P.f./P.v.® para o diagnóstico da malária, na Atenção Básica de Saúde, no município de Manaus, Amazonas / Evaluation of the Optimal-IT® and ICT Pf/Pv® rapid dipstick tests for diagnosing malaria within primary healthcare in the municipality of Manaus, Amazonas

O diagnóstico da malária é realizado rotineiramente pelo exame da gota espessa, entretanto, esta técnica requer o treinamento de microscopistas e pode consumir muito tempo. Foi realizado um estudo de concordância de dois testes rápidos (Optimal-IT® e ICT P.f./P.v.®) com a gota espessa, na atenção básica de saúde, em Manaus.

Malaria is routinely diagnosed using the thick blood smear test. However, this technique requires the training of microscopists and may be time-consuming. A concordance study was conducted on two dipstick tests (Optimal-IT® and ICT P.f./P.v.®) and the thick blood smear test, within primary healthcare in Manaus.

Tratamento de crianças com malária pelo Plasmodium falciparum com derivados da artemisinina / Treatment of children with malaria Plasmodium falciparum with derivatives artemisinin

No período compreendido entre janeiro de 1996 e dezembro de 1998, administramos derivados da artemisinina em 108 crianças com malária por Plasmodium falciparum, para avaliar a resposta clínica e terapêutica. Foram incluídas apenas crianças com clínica de malária moderada ou grave. No Grupo I, incluímos 62 pacientes e administramos artesunate por via endovenosa. Clinicamente, 50,8 por cento tinham malária moderada e 49,2 por cento malária grave; a parasitemia foi baixa em 53,2 por cento, média em 22,6 por cento e alta em 24,2 por cento; no D2 a parasitemia estava negativa em 58,1 por cento. No Grupo II,incluímos 46 pacientes que receberam artemeter (Paluter®) intramuscular. Clinicamente, 67,4 por cento apresentavam malária moderada e 32,6 por cento malária grave; a parasitemia foi baixa em 52,2 por cento, média em 36,2 por cento e alta em 15,2 por cento; em D2, 56,5 por cento apresentaram negativaçäo da parasitemia. Nos dois grupos, a melhora clínica e evoluçäo da parasitemia näo mostraram diferença estatística; no D7 havia clareada a parasitemia em todos os pacientes. Para evitar recrudescência usamos mefloquina ou clindamicina

Tratamento da malária com artesunate (retocaps©) em crianças da Amazônia brasileira / Malaria treatment with artesunate (retocaps©) in children of the Brazilian Amazon

Avaliamos a resposta clínica e parasitológica à terapêutica com o artesunate retocaps© em 32 crianças internadas na Fundaçäo de Medicina Tropical do Amazonas, que apresentavam malária com quadro clínico moderado e grave. Destas, 29 tinham a doença por P. falciparum e três, P. vivax. A melhora clínica foi observada após 24 horas do início da terapêutica, com 33,3 por cento de pacientes afebris e, 48 horas após o tratamento, 77,2 por cento das crianças näo apresentavam febre. O acompanhamento da parasitemia assexuada, mostrou que no D2 58,6 por cento das crianças com malária falciparum estavam negativas; em D4 todas haviam negativado, tanto na malária pelo P. falciparum como pelo P. vivax. No seguimento prolongado, na malária P. falciparum, encontramos 66,6 por cento de recrudescências. Os resultados nos permitem concluir pela eficácia e praticidade no uso do artesunate retocaps© com rápida reduçäo da parasitemia e melhora clínica. Entretanto, na malária P. falciparum a taxa de recrudescência foi elevada. Näo foi observado para-efeito que possa ser imputado ao uso da droga