[Seasonal transmission of malaria in the Senegal River Valley: case study of the city of Kaedi-Mauritanie]. / Transmission saisonnière du paludisme au niveau de la vallée du fleuve Sénégal: cas de la ville de Kaédi-Mauritanie.

INTRODUCTION: In the face of environmental and climatic changes both ongoing and planned, the epidemiology of malaria in the city of Kaedi (Mauritania), along the Senegal River Valley, requires special attention. Some cases of malaria have been registered in the health facilities throughout the year, with an average of 150,000 annual suspected cases and climatic and ecological conditions which are now favorable for seasonal transmission. METHODS: We conducted two cross-sectional descriptive surveys in the city of Kaedi in September 2014 (wet season) and in May 2015 (dry season). Our cluster sampling involved 700 households. Microscopic examination was performed in all household members. Furthermore, larval surveys, early morning wildlife spraying and nocturnal traps breaking were performed. RESULTS: During both seasons, 9.313 thick smears were manufactured, 15 were positive, with a plasmodium prevalence rate of 0.16%. Among these, 12 were positive in the dry season and 3 in the rainy season. Plasmodium prevalence rate was 0.26% and 0.06% respectively in the dry season (n = 4642) and in the wet season (n = 4671). In the rainy season, rates were 0.04% (2/4671) and 0.02% (1/4671) respectively for Plasmodium malariae and Plasmodium falciparum. The only species found in the dry season was Plasmodium falciparum. Entomological investigations showed the presence of a single species of Anopheles mosquito, Anopheles gambia (two in the rainy season and six in the dry season). Larval surveys showed that the larval fauna was dominated by Culex larvae (99.6%). Anopheles larvae (0.4%) were collected only during the dry season. CONCLUSION: Despite low malaria transmission in the city of Kaedi, in a context of lack of rainfall, health authorities should implement a strategy for malaria elimination in the wilayas of the Senegal River.

Malaria prevalence, anemia and baseline intervention coverage prior to mass net distributions in Abia and Plateau States, Nigeria.

BACKGROUND: Nigeria suffers the world's largest malaria burden, with approximately 51 million cases and 207,000 deaths annually. As part of the country's aim to reduce by 50% malaria-related morbidity and mortality by 2013, it embarked on mass distribution of free long-lasting insecticidal nets (LLINs). METHODS: Prior to net distribution campaigns in Abia and Plateau States, Nigeria, a modified malaria indicator survey was conducted in September 2010 to determine baseline state-level estimates of Plasmodium prevalence, childhood anemia, indoor residual spraying (IRS) coverage and bednet ownership and utilization. RESULTS: Overall age-adjusted prevalence of Plasmodium infection by microscopy was similar between Abia (36.1%, 95% CI: 32.3%-40.1%; n = 2,936) and Plateau (36.6%, 95% CI: 31.3%-42.3%; n = 4,209), with prevalence highest among children 5-9 years. P. malariae accounted for 32.0% of infections in Abia, but only 1.4% of infections in Plateau. More than half of children ≤10 years were anemic, with anemia significantly higher in Abia (76.9%, 95% CI: 72.1%-81.0%) versus Plateau (57.1%, 95% CI: 50.6%-63.4%). Less than 1% of households in Abia (n = 1,305) or Plateau (n = 1,335) received IRS in the 12 months prior to survey. Household ownership of at least one bednet of any type was 10.1% (95% CI: 7.5%-13.4%) in Abia and 35.1% (95% CI: 29.2%-41.5%) in Plateau. Ownership of two or more bednets was 2.1% (95% CI: 1.2%-3.7%) in Abia and 14.5% (95% CI: 10.2%-20.3%) in Plateau. Overall reported net use the night before the survey among all individuals, children <5 years, and pregnant women was 3.4%, 6.0% and 5.7%, respectively in Abia and 14.7%, 19.1% and 21.0%, respectively in Plateau. Among households owning nets, 34.4% of children <5 years and 31.6% of pregnant women in Abia used a net, compared to 52.6% of children and 62.7% of pregnant women in Plateau. CONCLUSIONS: These results reveal high Plasmodium prevalence and childhood anemia in both states, low baseline coverage of IRS and LLINs, and sub-optimal net use-especially among age groups with highest observed malaria burden.

[Quantitative detection and species identificaton of human Plasmodium spp. by using SYBR Green I based real-time PCR].

OBJECTIVE: To develop a real-time PCR method for human Plasmodium spp. qantitative detection and species identificaton. METHODS: According to the sequence of Plasmodium 18S rRNA, the primer set was designed based on the genus-specific region around the species-specfic region. The PCR products were amplified and cloned into pGEM-T vector to produce standard plasmids of real-time PCR, and melting curve analysis was conducted following real-time PCR for Plasmodium species indentification. RESULTS: By using the primer set, specific PCR products were produced from all of 4 human malaria parasites. The correlation of real-time PCR standard curve was good enough (r = -1.00) for quantitation. According to the melting curve analysis, the melting temperatures (Tm) of Plasmodium malariae, falciparum, ovale and vivax were significantly different, being 71.3, 72.8, 74.6 degrees C and 75.8 degrees C, respectively. CONCLUSION: The SYBR Green I based real-time PCR method developed in this study can be used for human Plasmodium spp. quantitative detection and species identificaton.

Space-time clustering of childhood malaria at the household level: a dynamic cohort in a Mali village.

BACKGROUND: Spatial and temporal heterogeneities in the risk of malaria have led the WHO to recommend fine-scale stratification of the epidemiological situation, making it possible to set up actions and clinical or basic researches targeting high-risk zones. Before initiating such studies it is necessary to define local patterns of malaria transmission and infection (in time and in space) in order to facilitate selection of the appropriate study population and the intervention allocation. The aim of this study was to identify, spatially and temporally, high-risk zones of malaria, at the household level (resolution of 1 to 3 m). METHODS: This study took place in a Malian village with hyperendemic seasonal transmission as part of Mali-Tulane Tropical Medicine Research Center (NIAID/NIH). The study design was a dynamic cohort (22 surveys, from June 1996 to June 2001) on about 1300 children (<12 years) distributed between 173 households localized by GPS. We used the computed parasitological data to analyzed levels of Plasmodium falciparum, P. malariae and P. ovale infection and P. falciparum gametocyte carriage by means of time series and Kulldorff's scan statistic for space-time cluster detection. RESULTS: The time series analysis determined that malaria parasitemia (primarily P. falciparum) was persistently present throughout the population with the expected seasonal variability pattern and a downward temporal trend. We identified six high-risk clusters of P. falciparum infection, some of which persisted despite an overall tendency towards a decrease in risk. The first high-risk cluster of P. falciparum infection (rate ratio = 14.161) was detected from September 1996 to October 1996, in the north of the village. CONCLUSION: This study showed that, although infection proportions tended to decrease, high-risk zones persisted in the village particularly near temporal backwaters. Analysis of this heterogeneity at the household scale by GIS methods lead to target preventive actions more accurately on the high-risk zones identified. This mapping of malaria risk makes it possible to orient control programs, treating the high-risk zones identified as a matter of priority, and to improve the planning of intervention trials or research studies on malaria.

Short communication: concomitant malaria and filariasis infections in Georgetown, Guyana

Lymphatic filariasis and malaria are endemic in Guyana, South America. To determine the prevalence of concomitant infections, we conducted a 1-year survey of febrile patients attending the malaria (day) and filariasis (night) clinics in Georgetown. In all, 1278 thick blood smears were collected; 769 for filariasis, of which 103 were positive for Wucheria bancrofti, and three for both W. bancrofti and malaria parasites; and 509 for malaria, 21 of which tested positive for malaria and 17 for both malaria and filariasis. The age groups and sex of the infected persons with malaria and W. bancrofti are descibed. These results suggest that the incidence of concomitant infections in Guyana may be quite low but efforts should be made to reduce the disease burden in Georgetown, Guyana (AU)

Infeccao do Anopheles (Kerteszia) cruzi por Plasmodium vivax e Plasmodium vivax variante VK247 nos Municipios de Sao Vicente e Juquitiba, Sao Paulo / Infection of Anopheles (Kerteszia) cruzi with Plasmodium vivax and Plasmodium vivax variant VK247 in the municipalities of Sao Vicente and Juquitiva, Sao Paulo

O Estado de São Paulo, situado na região Sudeste do Brasil, apresenta esporadicamente casos autóctones de malária que se caracterizam pela presença de quadro clínico benigno com parasitemias baixas e sintomatologia branda, identificados como malária vivax. Pouco se sabe a respeito da sintomatologia e resposta imune desenvolvidas pelo ser humano para as variantes Plasmodium vivax VK247 e Plasmodium vivax-like humano. Estas variantes são transmitidas pelo mosquito Anopheles (Kerteszia) cruzii, uma das espécies mais abundantes no Sudeste brasileiro. O objetivo deste trabalho foi verificar a infecção em anofelinos desta região, através do teste imunoenzimático ELISA com utilização de anticorpos monoclonais específicos dirigidos contra as regiões repetitivas da proteína circunsporozoíta de P. vivax clássico, P. brasilianum/P. malariae e P. vivax VK247. Coletas entomológicas foram realizadas no período de 1991 a 1993 em São Vicente e Juquitiba, municípios localizados em área remanescente da Mata Atlântica do Estado de São Paulo. A Mata Atlântica é rica em plantas da família Bromeliaceae, criadouros de formas imaturas de anofelinos do subgênero Kerteszia. De um total de 1 117 espécimes de An. (Ker.) cruzii capturados no Município de São Vicente, 0,179% foram positivos para P. vivax clássico. Em Juquitiba, dentre 1 161 An. (Ker.) cruzii pesquisados, 0,086% foram positivos para o P. vivax VK247, o que demonstra a presença da variante na região. Embora o índice de infecção encontrado seja baixo, a alta densidade destes mosquitos e sua voracidade (picam durante as 24 h do dia) poderiam compensar a baixa porcentagem de espécimes infectados

Sporadic cases of autochthonous malaria have been recorded in São Paulo State, located in the Southeast region of Brazil. These cases are characterized by their benign course, low parasitemia, and mild symptomatology and have been identified as vivax malaria. Little is known about the symptoms and immune response elicited in humans by the variants Plasmodium vivax VK247 and P. vivax-like human malaria parasites. These variants are transmitted by Anopheles (Kerteszia) cruzii, one of the most common species of mosquitoes in the Southeast of Brazil. The objective of the study described in this paper was to investigate infection in anophelines using ELISA immunoenzymatic assay with specific monoclonal antibodies directed against the repetitive regions of the circumsporozoite protein in classic P. vivax, P. brasilianum/P. malariae, and P. vivax VK247. Between 1991 and 1993, mosquitoes were collected in São Vicente and Juquitiba, municipalites located in a remnant of the Brazilian Atlantic forest in São Paulo State, an ecosystem rich in plants of the Bromeliaceae family. These plants function as nurseries for immature forms of anophelines of the subgenus Kerteszia. Of 1 117 An. (Ker.) cruzii captured in São Vicente, 0.179% were positive for classic P. vivax. In Juquitiba, of 1 161 An. (Ker.) cruzii, 0.086% were positive for P. vivax VK247, confirming the presence of this variant in the region. Although the infection rate is low, the high density of these mosquitoes and their voracity (they exhibit 24-h biting activity) could compensate for the low percentage of infected specimens

Orientaciones técnicas de prevención, tratamiento y control de la malaria / Technical otientations for the prevention, treatment and control of malaria

Aborda la transmisión de la malaria al hombre sano a través del mosquito infestado, definiendo como reservorio fundamental el hombre infestado por malaria. Además, describe los agentes causales de infección en cuatro especies del género Plasmodium: Plasmodium vivax, Plasmodium falciparun, Plasmodium malariae y plasmodium ovale, señalando a los dos últimos como causantes de las formas graves de malaria. Describe también los aspectos clínicos de la infección malárica