Brotes emergentes de leptospirosis del Amazonas colombiano / Emerging leptospirosis outbreaks in the Colombian Department of Amazonas

Se describe por primera vez una serie de nueve casos con clínica indicativa de leptospirosis en el municipio Puerto Nariño en el departamento Amazonas, Colombia. Se muestran evidencias serológicas de exposición con Rickettsia del grupo de las fiebres manchadas. Los casos fueron clínicamente considerados como síndrome febril de origen desconocido. Se descartó infección por dengue y malaria. El diagnóstico de Leptospira se realizó mediante el método de reacción en cadena de la polimerasa en tiempo real. Igualmente, se detectó la presencia de anticuerpos contra rickettsias del grupo de las fiebres manchadas por inmunofluorescencia Indirecta. Finalmente, se realiza revisión del tema(AU)

A description is provided for the first time of a series of nine cases with a clinical examination suggestive of leptospirosis in the municipality of Puerto Nariño, Department of Amazonas, Colombia. Serological evidence is presented of exposure to Rickettsia, spotted fever group. The cases were clinically considered as febrile syndrome of unknown origin. Infection with dengue or malaria was ruled out. Diagnosis of leptospirosis was achieved by real-time polymerase chain reaction. Additionally, indirect immunofluorescence detected the presence of antibodies against rickettsia, spotted fever group. Finally, a review was conducted about the topic(AU)

Behavioral fever response in Rhodnius prolixus (Reduviidae: Triatominae) to intracoelomic inoculation of Trypanosoma cruzi

Abstract: INTRODUCTION: Behavioral fever is a response to infections with microorganisms observed in some poikilothermic animals. Rhodnius prolixus is involved in the transmission of two parasites: Trypanosoma cruzi (pathogenic for humans and transmitted in feces) and Trypanosoma rangeli (non-pathogenic for humans, pathogenic for Rhodnius and transmitted by the bite of an infected individual). Only T. rangeli is found in the hemolymph of Rhodnius as it travels to the salivary glands. METHODS: To study vector-parasite interactions, we evaluated possible behavioral fever responses of R. prolixus to intracoelomic inoculation with T. cruzi or T. rangeli. Temperature preferences of fifth-instar nymphs of R. prolixus were evaluated after inoculation with T. rangeli KP1(+), KP1(-), T. cruzi I, or the Trypanosome culture medium. Four different fixed temperatures (25, 30, 35, and 40°C) in two simultaneous experiments (enclosed and free-moving insects) were evaluated. Free-moving insects were marked daily according to their temperature preferences on each of the 15 days after inoculation. Numbers of insects in each temperature shelter and daily mortality were compared with those enclosed shelters of different temperatures. RESULTS: Rhodnius prolixus inoculated with both strains of T. rangeli and with the trypanosome culture medium showed preferences for the lowest temperatures (25°C). However, R. prolixus inoculated with T. cruzi I showed significant preferences for temperatures around 35°C. CONCLUSIONS: This is the first known investigation to demonstrate a behavioral fever response in R. prolixus injected intracoelomically with T. cruzi I.

The proportion of fevers attributable to malaria varies significantly between sites in Papua New Guinea

@#Malaria is endemic across lowland Papua New Guinea (PNG) and case management has been based on symptomatic diagnosis and presumptive treatment of fever cases with an antimalarial. This study aimed to investigate the prevalence of malaria infection among fever cases presenting to 5 purposely selected sentinel health facilities in order to estimate the proportion of patients requiring antimalarial drugs. A total of 1807 fever patients were screened. Overall, 45% of fever patients had a positive malaria blood slide; 35% were infected with Plasmodium falciparum, 9% with P. vivax and 2% with P. malariae. Slide positivity was highest in Dreikikir (75%) and lowest in Wipim (2%). Among patients aged 1-4 years, 22% had moderate to severe anaemia (Hb < 8 g/dI) and 21% of children 2-9 years of age showed signs of splenomegaly (Hackett score 1-5). Comorbidity differed significantly between study sites and was not closely correlated with malaria infection. Clinical diagnosis by health facility staff was malaria for 67% of all fever cases, including 89% of slide-positive and 48% of slide-negative patients. 70% of rapid diagnostic test-negative cases were treated with an antimalarial. It is estimated that due to the lack of parasitological diagnosis the selected health facilities reported an excess of 18% (Dreikikir) to 98% (Wipim) malaria patients on average each month. In consideration of the significant differences in malaria-attributable fevers between study sites, the implementation of parasitological diagnosis in health facilities and administration of antimalarials only to test-positive patients has the potential to significantly improve the management of fever cases and reporting of malaria. A better tailoring to different settings may increase the effectiveness of malaria control interventions.

Infección experimental de aislados humanos de Blastocystis sp. en ratones inmunosuprimidos con dexamentasona / Experimental infection using human isolates of Blastocystis sp. in dexamethasone immunosurpressed mice

Blastocystis sp. es un protozoario controversial en cuanto a su papel patogénico, asociado a enfermedad gastrointestinal, con alta prevalencia. A fin de evaluar signos, síntomas y hallazgos de laboratorio producidos por Blastocystis sp., ratones inmunosuprimidos con dexametasona fueron infectados con morfologías del parásito obtenidos de pacientes sintomáticos y asintomáticos. Los parásitos se aislaron empleando gradiente de densidad con lymphoprep™, se realizó semicuantificación de las morfologías presentes en las muestra de heces, y se inocularon 1,6 × 105 parásitos en ratones Balb/c, vía intragástrica. En heces de pacientes sintomáticos se encontraron seis veces más vacuolares que granulares, mientras que en asintomáticos la relación fue apenas dos veces mayor. Los síntomas más frecuentes en los pacientes fueron: flatulencia (85%), dolor de cabeza(62%), dolor abdominal (55%), fiebre (30%) y estreñimiento (8%). La semicuantificación de parásitos por campo en humanos no encontró relación directa entre carga parasitaria y sintomatología gastrointestinal, mientras que en la cuantificación de parásitos por gramo de heces si existió. Los ratones presentaron signos variables luego de la infección, todos aquellos infectados con muestras de pacientes sintomáticos presentaron signos, mientras que solo algunos de los infectados con muestras de pacientes asintomáticos los desarrollaron. Se demostró que no existe relación estadísticamente significativa (p= 0,8) entre la morfología del parásito y los signos manifestados por el ratón; sin embargo hubo una relación estadísticamente significativa (p=0,02) entre las formas vacuolares del parásito y la aparición de síntomas en los pacientes. Se concluye que Blastocystis sp. tiene capacidad de producir signos sugestivos de patología en ratones.

Blastocystis sp. is a controversial protozoan in terms of its pathogenic role associated with high-prevalence gastrointestinal disease. To evaluate signs, symptoms and laboratory findings produced by Blastocystis sp., dexamethasone immunosuppressed mice were infected with parasite morphologies obtained from symptomatic and asymptomatic patients. The parasites were isolated using density gradient with lymphoprep™, semi-quantification of the morphologies present in the stool sample was performed and 1.6 × 105 parasites were inoculated into Balb/c mice, intragastrically. In the faeces of symptomatic patients, vacuolar morphology was six times greater than granular morphology, whereas the ratio in asymptomatic patients was only two times greater. The most common symptoms in patients were flatulence (85%), headache (62%), abdominal pain (55%), fever (30%) and constipation (8%). The semi-quantification of parasites per field in humans evidenced no direct relationship between parasite burden and gastrointestinal symptoms, while in parasite quantification per gram of feces, a direct relationship was found. The mice showed variable signs after infection; all those infected with samples from symptomatic patients showed signs, while only some of those infected with samples from asymptomatic patients developed them. It was demonstrated that no statistically significant (p = 0.8) relationship exists between the morphology of the parasite and the signs manifested by the mouse; nevertheless, there was a statistically significant (p = 0.02) relationship between the vacuolar forms of the parasite and onset of symptoms in patients. Conclusions are that Blastocystis sp. is capable of producing signs suggestive of pathology in mice.

association of Plasmodium vivax malaria with thrombocytopenia in febrile children

Plasmodium vivax infection has always been considered much less severe than Plasmodium falciparum and usually not associated with complications. Recently it was observed that many patients with malaria due to Plasmodium vivax also develop thrombocytopenia and other complications, once considered to be the exclusively due to Plasmodium falciparum. We carried out this study in order to find out the association of Plasmodium vivax with thrombocytopenia and to determine the presence of malaria in admitted cases of thrombocytopenia with febrile illness. This study was carried out at the pediatric ward of the Dow University of Health Sciences and Civil Hospital Karachi from Aug 2006 to Dec 2006. All patients in the age group of 1 month - 15 years and admitted in the pediatric ward with febrile illness were checked for thrombocytopenia. All study cases were also screened for the presence of malarial parasites in the thick and thin blood films and by immunochromatography [ICT]. Patients with malarial parasitemia and thrombocytopenia were included in the study. The data was then analyzed and conclusions drawn. 18/36 study cases [50%] were found to have malarial parasites in blood. 13/18 cases [72%] of malaria had thrombocytopenia and were infected with P.vivax while 2/18 cases [11%] were infected with Pl. falciparum. Six patients with malarial parasitemia showed normal platelet counts, 4 cases were due to Pl. falciparum. Platelet count was

Diagnóstico de leishmaniasis visceral en el departamento de parasitología: Valencia estado Carabobo / Diagnosis of visceral leishmaniasis in the parasitology departament: Valencia Carabobo state state

La leishmaniasis visceral (LV) es una protozoosis humana caracaterizada clínicamente por síndrome febril prolongado hepatoesplenomegalia, anemia y pérdida progresiva de peso. En América afecta principalmente a niños de 5 años pudiendo causar la muerte, por lo cual es necesario contar con procedimientos confiables para el diagnóstico precoz. Entre 1989 y 2003, el laboratorio de Leishmaniasis del Departamento de Parasitología (FCS-UC) Valencia, ha abordado el diagnóstico de LV, en pacientes sospechosos. El protocolo disgnóstico consideró los criterios: epidemiológico, clínico, serológico (ELISA) y demostración directa del parásito, por extendido de médula ósea (MO) coloreado con Giemsa e inoculación de MO en hámster. Se consideró como caso LV a todo paciente con diagnóstico parasitológico positivo o tener al menos 3 de los otros criterios. De los 118 evaluados, 23 cumplieron los criterios disgnósticos para LV. El método de ELISA detectó 95,7 por ciento, extendido de MO 91,3 por ciento e inoculación en hámster 70 por ciento. El 78,3 por ciento procedieron de áreas endémicas conocidas de LV; 43,5 por ciento en menores de 10 años. El número de casos por año presentó un patrón hipoendémico, no cíclico. El presente estudio ratifica la importancia de la integración de criterios para garantizar un diagnóstico eficaz precoz, con el fin de iniciar tratamiento y evitar complicaciones. Además contribuye a documentar la morbilidad e importancia de LV en el país

Thrombocytopenia: a predictor of malaria among febrile patients in Liberia

The study was conducted to evaluate thrombocytopenia as a predictor for the diagnosis of malaria in febrile patients. Design: Retrospective, descriptive Place and duration of study: The study was conducted at Pakistan Field Level II hospital of United Nations Mission in Liberia during a period extending from March to November 2004. A total of 503 consecutive febrile patients were included in the study. Platelet counts were performed on automated hematology analyzer. Blood smears for malarial parasite were examined by experienced technicians. A total of 145 patients were diagnosed to have Plasmodium falciparum malaria. Out of these 109 [75.18%] had thrombocytopenia. The platelet count was normal in 77.09% of the malarial parasite negative febrile patients. The sensitivity of the platelet count considered as a predictor of malaria was 80.11% while specificity was 81.36%. The positive predictive value was 63.87% and the negative predictive value was 90.86%. Thrombocytopenia is a predictor of falciparum malaria in febrile patients in Liberia. Peripheral blood smears of febrile, thrombocytopenic patients should be carefully examined for the presence of malarial parasites in endemic areas. Key words Thrombocytopenia, Malaria, Plasmodium falciparum

Low-dose quinine for treatment of chloroquine-resistant falciparum malaria in Sudanese pregnant women

Pregnant Sudanese women who presented at a hospital in eastern Sudan with chloroquine-resistant falciparum malaria were randomly allocated to one of two quinine regimens: low-dose [10 mg/kg 2 times/day] [18 patients] or st and ard [10 mg/kg 3 times/day] [24 patients]. Treatment was for 7 days and follow-up for 28 days. Significantly fewer patients in the low-dose group reported vomiting and abdominal pain than the st and ard regimen group. Hypoglycaemia, preterm labour and recrudescence were slightly but not significantly higher in patients in the st and ard group than low-dose group. There were no significant differences between the groups in the mean time from admission to remission of fever and parasite clearance. We tentatively advocate the use of quinine 2 times/day to reduce side-effects and improve compliance

Determinants of malaria mortality among displaced people in Khartoum state, Sudan

To find the determinants of malaria mortality among displaced people, across-sectional descriptive study using verbal autopsy was carried out in 2 camps in Khartoum state, Sudan. The heads of 856 households were interviewed about household characteristics, and malaria knowledge, attitudes and behaviour. They reported 81 malaria deaths during the previous year, 3.5% of all household members; 70 [86.4%] were children. Fever, diarrhoea, vomiting and headache were the most prevalent symptoms before death. Having a malaria death in the household was significantly associated with poor knowledge about malaria and, surprisingly, with better education. Poor treatment-seeking behaviour and poor attitudes towards malaria were not associated with higher mortality. However, mortality was significantly higher among households obtaining water by cart than from a well

Seroepidemiological study of visceral leishmaniasis among humans and animal reservoirs in Bushehr province, Islamic Republic of Iran

Using direct agglutination tests, a survey of visceral leishmaniasis was carried out among children and adults from 13 villages and from nomadic tribes in Bushehr province during 1998-99. Of the 1496 plasma samples, the overall seropositive rate [titres > or = 1:3200] was 3.4%. Almost all cases [94.1%] were in children under 10 years old. Eighteen patients were diagnosed with kala azar; fever and splenomegaly were the predominant signs and symptoms. Parasitology and serology examinations of local animals identified dogs and jackals infected with Leishmania infantum. Suggestions for control of visceral leishmaniasis in this area are to eliminate stray dogs, identify cases among humans and suspected leashed dogs, and treat infected individuals

Transfusion-Induced Malaria in a Child after Open Heart Surgery in Korea

We had an opportunity to evaluate a child who developed fever approximately two to three weeks after the open heart surgery for tetralogy of Fallot. His peripheral blood smear showed rings and various stages of Plasmodium vivax. The patient had received packed red blood cells during the surgery and postoperative care, one unit of which was later proved sero-positive for malaria. The possibility of malaria should be included in the differential diagnosis of the patients with unexplained fever after multiple blood product transfusions for the open heart surgery.

Efficacy and effectiveness of five day treatment of uncomplicated falciparum with artemisinin or artesunate in Vietnam.

A study on efficacy and effectiveness of artemisinin (total dose of 60 mg/kg) and artesunate (total dose of 12 mg/kg over five days) in treatment of uncomplicated malaria was conducted in highly malaria transmitted areas in Vietnam. 126 uncomplicated malaria cases finished 14 day follow-up. 100% cure rate achieved at day 14 in patients of the efficacy groups received either artemisinin or artesunate, while it was 83% and 93% in patients treated respectively with artemisinin and artesunate of the effectiveness groups. Compliance of the treatment regimens was discussed.

Dose findings of dihydroartemisinin in treatment of falciparum malaria.

Forty patients with uncomplicated P. falciparum malaria were respectively treated in an open randomized comparative study of dihydroartemisinin tablets given at total doses of 480 mg over 5 days and 640 mg over 7 days in a drug-resistant malaria endemic area in Hainan, China. The result showed that all patients were clinically cured. In 5-day and 7-day groups, the mean fever clearance times (FCT) were 26.1+/-10.2 and 21.1+/-11.8 hours respectively; the mean parasite clearance times (PCT) were 58.7+/-20.9 and 59.4+/-20.9 hours respectively, which showed no significant difference. 28-day follow-ups were accomplished on 39 and 37 cases respectively in two groups, the recrudescence rates were 20.5% (8/39) in 5-day group, while 2.7% (1/37) in 7-day group with significant difference (chi2=4.19, p<0.05). No clinical drug-related side effect was found in two groups during treatment.

Studies on malaria during pregnancy in a tribal area of central India (Madhya Pradesh).

In tribal villages of central India where malaria is highly prevalent (mesoendemic), this preliminary study was undertaken to determine the effects of malaria infection in a group of 456 pregnant women with or without fever. Only 96 women were found infected with malaria, of which Plasmodium falciparum accounted for 64% of the detected parasites, while P. vivax for the remaining 36%. There were no instances of cerebral malaria or death however, one abortion and four still births were recorded among 38 primigravid women. Only one neonate was found infected with P. falciparum on day 21 though parasitemia was not high. Anemia was commonly present in most of the women (80%). Failure to clear P. falciparum parasitemia after a chloroquine regimen (25 mg/kg of body weight) was commonly observed. Persistent P. falciparum parasitemia was recorded in 8% cases. Poor response to chloroquine suggests the need to change the drug policy.