Malaria congénita por Plasmodium falciparum / Congenital malaria by Plasmodium falciparum

INTRODUCCIÓN: La malaria congénita (MC) es la infección por Plasmodium spp adquirida in útero o durante el parto y sus manifestaciones clínicas son inespecíficas. Puede causar enfermedad grave en la embaraza da y en el recién nacido. OBJETIVO: describir dos casos de MC causados por Plasmodium falciparum, diagnóstico diferencial de sepsis en recién nacidos de gestantes que hayan visitado o residan en áreas endémicas para malaria. CASOS CLÍNICOS: Neonatos de sexo femenino, nacidos en área no endémica para malaria, diagnosticados con sepsis neonatal y tratados con antibióticos sin respuesta clínica. Después de la primera semana de vida la gota gruesa identificó trofozoítos de Plasmodium falciparum y los neonatos recibieron tratamiento con quinina intravenosa con mejoría. Las madres de las recién nacidas tuvieron malaria en el embarazo, una de ellas recibió tratamiento y estaba asintomática y otra tenía malaria complicada al momento del parto. CONCLUSIONES: La MC puede causar enfermedad neonatal grave con manifestaciones clínicas inespecíficas y similares a la sepsis, el tratamiento oportuno disminuye el riesgo de malaria complicada. Es un diagnóstico diferencial en recién nacidos de mujeres con malaria durante el embarazo o gestantes que visiten o residan en áreas endémicas.

INTRODUCTION: Congenital malaria (CM) is a Plasmodium spp infection acquired in utero or during delivery with nonspecific clinical manifestations. Plasmodium falciparum can cause severe illness in pregnant wo men and newborns. OBJECTIVE: to describe two cases of CM caused by Plasmodium falciparum, di fferential diagnosis of sepsis in newborns of pregnant women who live in or have visited endemic malaria zones. CLINICAL CASES: Female neonates born in a non-endemic malaria area, diagnosed with neonatal sepsis and treated with antibiotics without clinical response. After the first week of life, the peripheral blood smear identified trophozoites of Plasmodium falciparum thus the newborns were treated with intravenous quinine, improving their condition. The mothers of the two newborns who had malaria in pregnancy, one of them received treatment and she was asymptomatic, and the other one had severe malaria at the time of delivery. CONCLUSIONS: CM can cause severe neonatal disease with non-specific, sepsis-like clinical manifestations in which early treatment decreases the risk of complicated malaria. It is a differential diagnosis in newborns of women with a history of malaria during pregnancy or pregnant women visiting or living in endemic malaria areas.

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.

High malaria transmission in a forested malaria focus in French Guiana: How can exophagic Anopheles darlingi thwart vector control and prevention measures?

In French Guiana, malaria vector control and prevention relies on indoor residual spraying and distribution of long lasting insecticidal nets. These measures are based on solid epidemiological evidence but reveal a poor understanding of the vector. The current study investigated the behaviour of both vectors and humans in relation to the ongoing prevention strategies. In 2012 and 2013, Anopheles mosquitoes were sampled outdoors at different seasons and in various time slots. The collected mosquitoes were identified and screened for Plasmodium infection. Data on human behaviour and malaria episodes were obtained from an interview. A total of 3,135 Anopheles mosquitoes were collected, of which Anopheles darlingi was the predominant species (96.2%). For the December 2012-February 2013 period, the Plasmodium vivax infection rate for An. darlingi was 7.8%, and the entomological inoculation rate was 35.7 infective bites per person per three-month span. In spite of high bednet usage (95.7%) in 2012 and 2013, 52.2% and 37.0% of the participants, respectively, had at least one malaria episode. An. darlingi displayed heterogeneous biting behaviour that peaked between 20:30 and 22:30; however, 27.6% of the inhabitants were not yet protected by bednets by 21:30. The use of additional individual and collective protective measures is required to limit exposure to infective mosquito bites and reduce vector densities.

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.

Especies de Anopheles presentes en el departamento del Putumayo y su infección natural con Plasmodium / Anopheles species present in the department of Putumayo and their natural infectivity with Plasmodium

Introducción. El departamento del Putumayo es una región endémica para malaria, o paludismo, causada principalmente por Plasmodium vivax . Los vectores en esta región incluyen Anopheles darlingi , el cual se ha encontrado solamente en el municipio de Puerto Leguízamo, y recientemente se incriminaron como vectores en Puerto Asís a las especies An. rangeli y An. oswaldoi . Objetivo. El propósito del trabajo fue determinar el papel de An. benarrochi B en la transmisión de malaria en este departamento, ya que se reporta como la especie más abundante que pica a los humanos. Materiales y métodos. Se recolectaron larvas y adultos de Anopheles spp. entre el 2006 y el 2008 en los municipios Puerto Leguízamo y Puerto Asís, y se obtuvieron secuencias del gen ITS-2 y del gen mitocondrial COI para confirmar las determinaciones taxonómicas por morfología. Se practicó la prueba ELISA para establecer la infección por P. vivax y P. falciparum. Resultados. Se identificaron 6.238 individuos correspondientes a 11 especies: An. albitarsis s.l. (1,83 %), An. benarrochi B (72,35 %), An. braziliensis (0,05 %), An. costai (0,06 %), An. darlingi (19,37 %), An. mattogrossensis (0,08 %), An. neomaculipalpus (0,13 %), An. oswaldoi s.l. (0,64 %), An. punctimacula (0,03 %), An. rangeli (5,12 %) y An. triannulatus s.l. (0,34 %). Se evaluaron 5.038 adultos por ELISA y 5 se encontraron positivos para P. vivax 210 y VK 247, todos pertenecientes a la especie An. benarrochi B. Conclusión. Los resultados sugieren que An. benarrochi B juega un papel en la transmisión de P. vivax en el departamento de Putumayo, dada su alta atracción por los humanos y su infección natural con Plasmodium spp.

Introduction: Putumayo is considered an endemic region for malaria transmission, mainly due to Plasmodium vivax. The vectors in this region are Anopheles darlingi , which has been found only in the municipality of Puerto Leguízamo, and An. rangeli and An. oswaldoi s.l. , which were recently incriminated as vectors in Puerto Asís. Objective: The purpose of this study was to determine the role of An. benarrochi B in malaria transmission in Putumayo, given that it is the most abundant species biting humans. Materials and methods: Collections of immature and adult stages of Anopheles spp. were made between 2006 and 2008 in the municipalities of Puerto Leguízamo and Puerto Asís in Putumayo, and sequences of internal transcribed spacer 2 ( ITS-2 ) of ribosomal DNA and the mitochondrial gene COI were obtained to confirm the morphological determinations. ELISA was carried out for P. vivax and P. falciparum infectivity. Results: A total of 6,238 specimens were identified, distributed in 11 species: An. albitarsis s.l. (1.83%), An. benarrochi B (72.35%), An. braziliensis (0.05%), An. costai (0.06%), An. darlingi (19.37%), An. mattogrossensis (0.08%), An. neomaculipalpus (0.13%), An. oswaldoi s.l. (0.64%), An. punctimacula (0.03%), An. rangeli (5.12%), and An. triannulatus s.l. (0.34%). A total of 5,038 adults were assessed by ELISA and 5 were found positive for P. vivax 210 and VK 247, all belonging to An. benarrochi B. Conclusion: The results suggest that An. benarrochi B plays a role in the transmission of P. vivax in Putumayo due to its high human contact and natural infection with Plasmodium sp.

Biomarkers for susceptibility to infection and disease severity in human malaria

Malaria remains a major infectious disease that affects millions of people. Once infected with Plasmodium parasites, a host can develop a broad range of clinical presentations, which result from complex interactions between factors derived from the host, the parasite and the environment. Intense research has focused on the identification of reliable predictors for exposure, susceptibility to infection and the development of severe complications during malaria. Although most promising markers are based on the current understanding of malaria immunopathogenesis, some are also focused more broadly on mechanisms of tissue damage and inflammation. Taken together, these markers can help optimise therapeutic strategies and reduce disease burden. Here, we review the recent advances in the identification of malarial biomarkers, focusing on those related to parasite exposure and disease susceptibility. We also discuss priorities for research in biomarkers for severe malaria.

Seasonal prevalence & resting behaviour of Anopheles minimus Theobald & An. fluviatilis James (Diptera: Culicidae) in east-central India.

Background & objectives: Anopheles minimus has recently been reported to have re-appeared in Keonjhar district of Orissa after a period of about 45 years of launching the malaria eradication programme. An. minimus and An. fluviatilis were the incriminated major malaria vectors in the district, endemic for falciparum malaria. The information on seasonal prevalence and resting behaviour of the vectors is crucial for implementing appropriate malaria control measures. Therefore, a study was undertaken on seasonal prevalence and resting behaviour of An. minimus and An. fluviatilis in this district. Methods: Seven randomly selected villages of Keonjhar district, Orissa, were studied during August 2005 to November 2007. Daytime resting collections indoors and outdoors were made covering three seasons of the year. The Anopheles mosquitoes obtained from different habitats were identified. Collections were maintained separately according to different sites as well as heights of the walls in human dwellings. Results: Among the indoor collections, the densities of An. minimus and An. fluviatilis were higher in human dwellings than cattle sheds. An. fluviatilis was the predominant (41.5%) species followed by An. minimus (26.3%) in human dwellings. The density of both the vector species in human dwellings peaked during rainy and winter seasons followed by summer. Walls were the most preferred site by these vectors for resting and the maximum number was collected at a height of 3 to 4 ft. Interpretation & conclusions: The resting behaviour of the vector species increases their contact with the sprayed walls and therefore, a quality residual spraying of human dwellings focusing indoor walls could interrupt the malaria transmission in this area.

Expansão urbana e distribuição espacial da malária no município de Manaus, Estado do Amazonas / Urban expansion and spatial distribution of malaria in the municipality of Manaus, State of Amazonas

No município de Manaus, a intensificação do processo migratório, aliada a precária vigilância epidemiológica e entomológica, resultou na reintrodução da transmissão de malária no perímetro urbano, zona Leste, em julho de 1988, após 13 anos sem registro de autoctonia. Este estudo descreve sobre a situação epidemiológica da malária e áreas que sofreram ações antrópicas (desmatamento, assentamentos humanos, atividades de piscicultura, etc.) em Manaus, no período entre 1986 e 2005. Nesse Município, o incremento populacional em 2005 atingiu 105,2 por cento, em relação a 1986, resultado de ocupação dos espaços (invasões e conjuntos habitacionais). A partir de 2003, a doença teve incremento acima 2.000 por cento em relação a 1986. Nessas áreas ocorreu aumento da incidência da doença. O índice parasitário anual no Município oscilou de baixo a médio risco, e entre as zonas urbanas, variou de sem risco a alto risco. As zonas Leste, Oeste e Norte onde ainda existem áreas com características rurais apresentaram maior receptividade e vulnerabilidade de transmissão.

In the municipality of Manaus, intensification of the migratory process, along with precarious epidemiological and entomological surveillance, resulted in reintroduction of malaria transmission on the urban perimeter (in the eastern zone), in July 1988, after 13 years without any records of autochthonous disease. This study reports on the epidemiological situation relating to malaria and to the areas that were subjected to human actions (deforestation, human settlement, fish-rearing activity, etc) in Manaus, between 1986 and 2005. In this municipality, the population increase from 1986 to 2005 was 105.2 percent. This resulted from occupation of space, in the form of invasions and housing projects. From 2003, the increase in relation to 1986 was more than 2,000 percent. In these areas, there were increases in disease incidence. The annual parasitic index in the municipality ranged from low to medium risk and, between urban zones, it ranged from no risk to high risk. In the eastern, western and northern zones, which still contain areas with agricultural characteristics, there was greater receptivity and vulnerability to transmission.

Plasmodium falciparum gametocytaemia with chloroquine chemotherapy in persistent malaria in an endemic area of India.

Background & objectives: Gametocyte sex-ratio in Plasmodium falciparum malaria is an important determinant of transmission success and basis of disease epidemiology. Information on ratio of male to female gametocytes after an exposure of antimalarial regimens under field conditions is very limited. In this retrospective study we observed high densities of gametocytes along with high sex-ratio in P. falciparum cases, which may be responsible for persistent malaria transmission in this area. Methods: Laksar PHC of Hardwar district, Uttarakhand State, India was selected because it contributed 90 per cent of the total malaria cases. A total of 568 uncomplicated P. falciparum malaria patients were assessed to investigate prevalence of gametocytes while 339 P. falciparum thick smears containing 5620 gametocytes were screened for measuring the gametocyte density for microgametocyte (male) and macrogametocyte (female). Homology of variance (‘F’ test) was checked on days 7 and 14 including the variables and risk factors namely fever, parasitaemia, gametocyte carriage in sensitive and resistant chloroquine treated P. falciparum cases. Results: Slide positivity rate (SPR) increased drastically from 0.23 to 11.4 per cent with the predominance in P. falciparum infection after 1998. All 568 cases showed gametocytes in their peripheral blood, of which 109 (19%) were infected with rings and gametocytes and 459 (81%) had gametocytes stages in their peripheral blood while 422 (74.3%) cases were infected with ring stages only. Of the 339 P. falciparum positive blood smears, 5620 gametocytes were screened for their sex-ratio. The mean sex-ratio was 0.31 (3.22 female per male). Prevalence of gametocytaemia was significantly higher (P<0.05) in chloroquine (CQ)- resistant than in CQ-sensitive patients with days 7 and 14 follow up. The homology of variance with risk factors for gametocytes on days 7 and 14 were highly significant (P<0.001) in the study period but during the post-exposure period of days 3 and 5, these were insignificantly correlated. Interpretation & conclusion: A high density of P. falciparum gametocytes was observed at the time of preparation of blood slide on day 0. Improper chloroquine treatment along with poor patient compliance for radical treatment and the presence of chloroquine resistant P. falciparum malaria may have enhanced the prevalence and density of P. falciparum gametocytes which was instrumental in signaling the persistent malaria in this area.

Age composition of incriminated malaria vector in a rural foothills in West Bengal, India.

Two 1 yr surveys carried out at a gap of 10 yr revealed nine anopheline species from malaria endemic foothills area of Ayodhya - Baghmindi range of West Bengal, India, with 8.4 per cent populations of Anopheles culicifacies. An. culicifacies was incriminated as vector of Plasmodium falciparum with sporozoite rate of 1.23 per cent. Studies on age composition indicated that proportion parous and daily survival rate of An. culicifacies were assessed to be 0.50 and 0.84 respectively. The survival rate per gonotrophic cycle averaged over the two year was 0.61. Rainy season was found to be the favourable period for transmission.

Malaria outbreaks in a non-endemic area of Brazil, 2005 / Surtos de malária em área não endêmica do Brasil, 2005

In March 2005, a resident of the municipality of Monte Alegre de Minas, State of Minas Gerais, without any history of traveling to endemic areas for malaria, was diagnosed with Plasmodium vivax infection and local mosquito-borne transmission was suspected. The epidemiological investigation identified another 10 cases with local transmission and all of them were related to the imported malaria case that was detected in this region. The potential exposure site was the banks of the river Tejuco, an area frequented by mineral prospectors. Some of these prospectors were known to have come from states with malaria transmission. In the autochthonous cases, Plasmodium vivax and Plasmodium falciparum were diagnosed. Entomological investigation identified Anopheles (Nyssorhynchus) darlingi, Anopheles (Nyssorhynchus) albitarsis, Anopheles (Nyssorhynchus) triannulatus and Anopheles (Nyssorhynchus) parvus. After the first outbreak, another three autochthonous cases were notified in municipality of Monte Alegre de Minas, in the same year. The occurrence of these outbreaks highlights the importance of surveillance systems in areas that are nonendemic for malaria.

Em março de 2005, um morador do município de Monte Alegre de Minas, Estado de Minas Gerais, sem histórico de viagem para área endêmica de malária foi diagnosticado com infecção por Plasmodium vivax e a transmissão vetorial no local foi suspeitada. A investigação epidemiológica identificou outros 10 casos com transmissão local e todos relacionados ao caso de malária importada detectado na região. A área de potencial exposição foi às margens do rio Tejuco, local freqüentado por garimpeiros, muitos sabidamente, oriundos de estados com transmissão de malária. Nos casos autóctones, Plasmodium vivax e Plasmodium falciparum foram diagnosticados. A investigação entomológica identificou Anopheles (Nyssorhynchus) darlingi, Anopheles (Nyssorhynchus) albitarsis, Anopheles (Nyssorhynchus) triannulatus e Anopheles (Nyssorhynchus) parvus. Após o primeiro surto, outros três casos autóctones foram notificados no município de Monte Alegre de Minas no mesmo ano. A ocorrência desses surtos alerta sobre a importância de sistemas de vigilância em áreas não endêmicas para a malária.

Insecticide treated mosquito nets for malaria control in India-experience from a tribal area on operational feasibility and uptake

The study assessed the operational feasibility and acceptability of insecticide-treated mosquito nets (ITNs) in one Primary Health Centre (PHC) in a falciparum malaria endemic district in the state of Orissa, India, where 74 percent of the people are tribes and DDT indoor residual spraying had been withdrawn and ITNs introduced by the National Vector Borne Disease Control Programme. To a population of 63,920, 24,442 ITNs were distributed free of charge through 101 treatment centers during July-August 2002. Interview of 1,130, 1,012 and 126 respondents showed that the net use rates were 80 percent, 74 percent and 55 percent in the cold, rainy and summer seasons, respectively. Since using ITNs, 74.5-76.6 percent of the respondents observed reduction of mosquito bites and 7.2-32.1 percent reduction of malaria incidence; 37 percent expressed willingness to buy ITNs if the cost was lower and they were affordable. Up to ten months post-treatment, almost 100 percent mortality of vector mosquitoes was recorded on unwashed and washed nets (once or twice). Health workers re-treated the nets at the treatment centers eight months after distribution on a cost-recovery basis. The coverage reported by the PHC was only 4.2 percent, mainly because of unwillingness of the people to pay for re-treatment and to go to the treatment centers from their villages. When the re-treatment was continued at the villages involving personnel from several departments, the coverage improved to about 90 percent.Interview of 126 respondents showed that among those who got their nets re-treated, 81.4 percent paid cash for the re-treatment and the remainder were reluctant to pay. Majority of those who paid said that they did so due to the fear that if they did not do so they would lose benefits from other government welfare schemes. The 2nd re-treatment was therefore carried out free of charge nine months after the 1st re-treatment and thus achieved coverage of 70.4 percent. The study showed community...

Análise espacial e determinação de áreas para o controle da malária no Estado de Rondônia / Spatial analysis and determination of malaria control areas in the State of Rondônia

Este trabalho discute o uso de análise espacial para confecção de mapas de risco para malária no Estado de Rondônia, entre 1994 e 2005. Para análise do padrão espacial, foram utilizados os índices de Moran global e local. Com base nos valores do Índice Parasitário Anual, pode-se afirmar que os municípios que constituem a área de maior risco são os de urbanização mais recente, caracterizados por: maior crescimento populacional, maior número de famílias assentadas e elevado percentual de área desmatada. O Moran Map mostrou que os agregados de municípios com maior risco para malária sofreram processo de espalhamento para a região noroeste e nordeste do estado. Já nos municípios considerados como de menor risco, o processo se deu em direção ao sudeste. As técnicas utilizadas em nosso estudo merecem ser comparadas com a atual metodologia utilizada pela Secretaria de Vigilância Sanitária na determinação de áreas de risco e repasse financeiro para controle da malária.

This paper discusses the use of spatial analysis for mapping the risk of malaria in the State of Rondônia between 1994 and 2005. Moran’s overall and local indices were used for spatial pattern analysis. Based on the Annual Parasitic Index, it can be stated that the municipalities forming the area at greater risk are those in which the urbanization process is more recent. They are characterized by higher population growth, greater number of settled families and high percentages of deforested area. The Moran map showed that the aggregated areas of municipalities at high risk of malaria have undergone a process of spreading into the northwestern and northeastern regions of the State. Among the municipalities considered to be at low risk, this process has taken place towards the southeast. The techniques used in this study deserve to be compared with the current methodology used by the Health Surveillance Department for determining areas at risk and financial transfers for malaria control.

Urban and suburban malaria in Rondônia (Brazilian Western Amazon) II: perennial transmissions with high anopheline densities are associated with human environmental changes

Longitudinal entomological surveys were performed in Vila Candelária and adjacent rural locality of Bate Estaca concomitantly with a clinical epidemiologic malaria survey. Vila Candelária is a riverside periurban neighborhood of Porto Velho, capital of the state of Rondônia in the Brazilian Amazon. High anopheline densities were found accompanying the peak of rainfall, as reported in rural areas of the region. Moreover, several minor peaks of anophelines were recorded between the end of the dry season and the beginning of the next rainy season. These secondary peaks were related to permanent anopheline breeding sites resulting from human activities. Malaria transmission is, therefore, observed all over the year. In Vila Candelária, the risk of malaria infection both indoors and outdoors was calculated as being 2 and 10/infecting bites per year per inhabitant respectively. Urban malaria in riverside areas was associated with two factors: (1) high prevalence of asymptomatic carriers in a stable human population and (2) high anopheline densities related to human environmental changes. This association is probably found in other Amazonian urban and suburban communities. The implementation of control measures should include environmental sanitation and better characterization of the role of asymptomatic carriers in malaria transmission.

Climatic variables and transmission of falciparum malaria in New Halfa, eastern Sudan

The study investigated the role of climatic variables and irrigated agricultural on the seasonality of malaria transmission in New Halfa, eastern Sudan. A time-series analysis was performed using monthly climatic variables, monthly water available for irrigation of crops and monthly slide positive rate of malaria during the period 1986-2002. Cases of malaria were reported every month of the year with a mean of 13.0/100 persons/month [95% CI: 11.9-14.2], and bimodal annual pattern in autumn and winter seasons. Rainfall was the significant climatic variable in the transmission of the disease, whereas heavy rainfall was found to initiate epidemics. Temperature, relative humidity and irrigation water were not significant factors

Malaria por Plasmodium falciparum en el servicio de medicina del Hospital San Camilo de San Felipe / Malaria by Plasmodium falciparum in the medicine service of San Camilo Hospital of San Felipe

Paciente de 36 años (camionero), sin antecedentes mórbidos de importancia, que luego de un viaje por Brasil, inicia cuadro de malestar general, poliartralgia y gran decaimiento. Consultando a la semana por sensación febril e ictericia en el Hospital de los Andes. Se constata fiebre, compromiso del estado general, ictericia, destacando en los exámenes de laboratorio: elevación de las transaminasas, fosfatasas alcalinas, hiperbilirrubinemia y disminución de hematocrito y plaquetas. Se lo hospitaliza con el diagnóstico de Síndrome Febril Ictérico Obs: Hepatitis viral, malaria o fiebre amarilla. Evoluciona con caída de su hematocrito y plaquetas, manteniéndose las pruebas hepáticas alteradas. Se realizan exámenes directos e indirectos para diagnóstico de Malaria, confirmándose con la visualización de trofozoítos de Plasmodium falciparum e indirectamente por detección en sangre de pLDH mediante optiMAL IT kit. Se inicia terapia con Cloroquina, con buena respuesta sintomática, con recuperación de plaquetas, mantención del Hematocrito y normalización de las pruebas hepáticas. La malaria por P. falciparum se describe como aquella que ocasiona las formas más graves y con compromiso hepático. Se destaca que ante la facilidad de transporte de personas de áreas endémicas, se hace más factible la aparición de casos en áreas no endémicas como en este servicio. Debido al riesgo, se debe estar preparado para la toma de muestras adecuadas que permitan la certificación en centros que como en éste, llegan pacientes extranjeros. El diagnóstico del paciente se hizo de forma expedita debido a una buena anamnesis, la que orientó claramente al diagnóstico de certeza.

Malaria: revisión retrospectiva de 12 casos no autóctonos en Chile / Malaria: Report of 12 non autochthonous cases

Malaria is a protozoan infection caused by four Plasmodia species transmitted by female Anopheles mosquito. Nearly 40% of the world population is at risk of acquiring the disease because of increasing resistance to treatment, climate changes and travels to endemic zones. We report twelve patients with diagnosis of malaria, supported by the identification of parasites on blood smear. All cases had traveled to endemic zones (Peru, Ecuador, Central America, Africa), but only three used chemoprophylaxis. Seven cases were infected with Plasmodium vivax and five cases with P. falciparum. Three of latter required intensive care. All patients were treated with standard drugs according to the severity and Plasmodium specie, with excellent results and no mortality.

[About two cases of highly probable transfusion induced malaria]

Indigeneous malaria has not been seen in Tunisia since 1979. However blood transfusion has remained a cause of malaria transmission in our country. The last Tunisian transfusion induced malaria was diagnosed in 1985 We report two cases of malaria in two transfused patients documented in our laboratory in November 2003. The first case [patient 1] consisted of a Plasmodium falciparum malaria in a bone marrow transplanted patient; the second case [patient 2] was a Plasmodium malaria malaria, following blood transfusion for stomach surgery. Favourable outcome was obtained under intravenous quinine in patient 1, and oral chloroquine in patient 2. In both cases the relation between transfusion and malaria was not obvious. However, anamnesis showed a donor at risk [African origin] in patient 1, whereas the donor could not be identified at all in patient 2. We concluded that systematic screening of donors at risk would be the best way to prevent transfusion induced malaria in Tunisia