Proportion of fever attributable to malaria in Colombia: potential indicators for monitoring progress towards malaria elimination / Proporción de fiebre atribuible a malaria en Colombia: indicadores potenciales para el seguimiento hacia la eliminación

ABSTRACT Objective Identify and characterize indicators to assess progress in terms of control and monitoring of malaria in endemic areas of Colombia and compare malaria elimination findings with those of countries in the same region. Methods Cross-sectional surveys were carried out in 2011 and 2014 in malaria endemic areas in Colombia, Pacific and Caribbean regions. A socio-demographic and a clinical questionnaire were applied to each participant; likewise, written and informed consents were obtained. Capillary blood samples were taken and examined through microscopic tests and rapid diagnostic test. A narrative systematic review was conducted to correlate malaria elimination in Colombia and in countries of the Amazon Region. Results The sample consisted of 548 participants from the departments of Córdoba and Nariño, Colombia. The proportion of positive malaria cases was 3 % (17/548), in which the prevalence of malaria mixed infections was 47 % (8/17). Regarding fever, temperature over 38.0o C, its prevalence was 2.7 % (15/548). Only two febrile patients tested positive for the disease. Prevalence of asymptomatic malaria cases among all positive cases was 88 %. Conclusion Asymptomatic malaria cases, mixed infections and self-medication are the challenges that malaria control and elimination programs face. It is important to note that studies on subclinical malaria in the region are scarce. Endemic areas with dense populations and experiencing an increase in immigration levels are more vulnerable to malaria reemergence. Imported malaria cases impact the basic reproduction rate (Ro). Funding resources availability has impact on the sustainability of public health actions and the elimination of malaria in South America.(AU)

RESUMEN Objetivo Identificar y caracterizar indicadores de evaluación del progreso en el control de la malaria en regiones endémicas de Colombia y contrastar los hallazgos de eliminación con países de la misma región. Métodos Se realizaron cortes transversal en 2011 y 2014, en regiones endémicas para malaria de la Costa Pacífica y del Caribe de Colombia. Se obtuvo consentimiento informado y se aplicó una encuesta socio-demográfica y clínica a cada voluntario. La punción capilar se utilizó para examen microscópico y pruebas de diagnóstico rápido. La revisión narrativa y sistemática permitió comparar el estado de eliminación de malaria en Colombia y los países de la Amazonía. Resultados Un total de 548 voluntarios fueron estudiados en Córdoba y Nariño. La proporción de casos positivos de malaria fue 3 % (17/548). Las infecciones mixtas de malaria se presentaron en un 47 % (8/17). La prevalencia de fiebre, temperatura mayor o igual a 38oC, fue 2.7 % (15/548). Dos pacientes febriles fueron positivos para malaria. La prevalencia de casos asintomáticos se presentó en 88 %. Conclusión Los casos de malaria asintomática, infecciones mixtas y la automedicación constituyen un reto para los programas de control y eliminación. Estudios sobre malaria subclínica y eliminación son limitados en la región. Regiones endémicas con alta densidad poblacional y aumento en los niveles de migración incrementan la vulnerabilidad. Los casos importados afectan la reducción de la tasa reproductiva básica (Ro) por debajo de 1. El recurso financiero insuficiente afecta la sostenibilidad de las acciones de salud pública y la eliminación de malaria en las Américas.(AU)

Clean Home-delivery in Rural Southern Tanzania: Barriers, Influencers, and Facilitators.

The study explored the childbirth-related hygiene and newborn care practices in home-deliveries in Southern Tanzania and barriers to and facilitators of behaviour change. Eleven home-birth narratives and six focus group discussions were conducted with recently-delivering women; two focus group discussions were conducted with birth attendants. The use of clean cloth for delivery was reported as common in the birth narratives; however, respondents did not link its use to newborn’s health. Handwashing and wearing of gloves by birth attendants varied and were not discussed in terms of being important for newborn’s health, with few women giving reasons for this behaviour. The lack of handwashing and wearing of gloves was most commonly linked to the lack of water, gloves, and awareness. A common practice was the insertion of any family member’s hands into the vagina of delivering woman to check labour progress before calling the birth attendant. The use of a new razor blade to cut the cord was near-universal; however, the cord was usually tied with a used thread due to the lack of knowledge and the low availability of clean thread. Applying something to the cord was near-universal and was considered essential for newborn’s health. Three hygiene practices were identified as needing improvement: family members inserting a hand into the vagina of delivering woman before calling the birth attendant, the use of unclean thread, and putting substances on the cord. Little is known about families conducting internal checks of women in labour, and more research is needed before this behaviour is targeted in interventions. The use of clean thread as cord-tie appears acceptable and can be addressed, using the same channels and methods that were used for successfully encouraging the use of new razor blade.

Globalización y salud: el caso de las enfermedades tropicales y olvidadas / Globalization and health: the case of tropical and neglected diseases

Se presenta una revisión del impacto de la globalización sobre los determinantes del operativo salud-enfermedad y del bienestar y ofrece una mirada de las posibles acciones mitigantes. Se realizó una revisión sistemática, con énfasis para América Latina y Colombia de los determinantes de la salud y bienestar enfocada en aspectos económicos, culturales, tecnológicos, ambientales-climáticos y demográficos. Se describen procesos interrelacionados de la globalización. Los análisis de modelos predictivos documentan la interacción de factores sociales, culturales y económicos sobre la salud-enfermedad y el bienestar y son determinantes de la equidad. Los indicadores de salud globales disminuyen con el aumento de diferenciales socio-económicos dentro de un país dado. Los procesos de globalización han impactado la dinámica social y económica afectando directamente el estado de salud. Las migraciones y procesos de urbanización influyen en los modelos de riesgos sociales, medioambientales y biológicos. Se observa un deterioro del estado sanitario y un aumento en la precariedad social. Esta situación combinada con los cambios climáticos globales y de los ecosistemas favorecen la transmisión de enfermedades (malaria, dengue). La perspectiva prometedora para alcanzar las Metas de Desarrollo de Milenio se ve en países con fortalecimiento coherente de los sistemas de salud y la reducción de la pobreza. Es urgente el desarrollo de nuevas herramientas para el control de las enfermedades (medicamentos y/o vacunas), pero además se deben robustecer los sistemas de salud, las redes sociales con aproximaciones desde la salud pública y los ecosistemas en un contexto social, político, cultural y económico particular.

Ultrastructural Alterations of Adult Schistosoma haematobium Harbored in Mice Following Artemether Administration / 中国寄生虫学与寄生虫病杂志

Objective To perform a temporal examination of ultrastructural alterations in adult Schistosoma haematobium due to artemether Methods Eight mice infected with 100-120 S. haematobium cercariae for 81 days were treated intragastrically with 400 mg/kg artemether. At 24 hours, 3, 7 and 14 days post-treatment, groups of 2 mice were sacrificed and schistosomes collected by the perfusion technique. Worm samples were fixed and examined by transmission electron microscopy. Schistosomes were also obtained from 2 untreated mice that served as control.Results Typical ultrastructural alterations included swelling, lysis and vacuolization of the tegumental matrix, and disappearance of basal membrane. In sensory organelles and tubercles, there was extensive or local lysis of internal structure. In the musculature, parenchymal tissues, syncytium and gut epithelial cells, focal or extensive lysis, decrease in granular endoplasmic reticulum, vacuolization and degeneration of mitochondria were observed. These alterations became apparent both in male and female worms 24 hours post-treatment. In female worms, severe damage to the vitelline cells was also observed, resulting in the emergence of vacuoles, a decrease in granular endoplasmic reticulum,fusion of vitelline balls or even collapse of damaged vitelline cells. The most extensive tegumental alterations were observed 3-7 days post-treatment. Whilst 14 days post-treatment ultrastructural damage was still apparent, the tegument of some worms showed similar features to those recovered from untreated control mice. Conclusion Administration of artemether to mice infected with adult S. haematobium results in extensive damage to the ultrastructure in the tegument and subtegument tissues of the worms, confirming previous results with other schistosome species.

Effect of Artemether on the Tegument of Adult Schistosoma haematobium Recovered from Mice / 中国寄生虫学与寄生虫病杂志

Objective To assess the effect of artemether on the tegument of adult Schistosoma haematobium harbored in mice. Methods Ten mice were infected subcutaneously with 100-120 S. haematobium cercariae each. At day 81 post-infection, 8 mice were treated orally with 400 mg/kg artemether. Mice were sacrificed at 1, 3, 7 and 14 days post-treatment, and schistosomes were collected by the perfusion technique, fixed and examined under a scanning electron microscope. Schistosomes obtained from the 2 untreated mice served as a control. Results Twenty-four hours post-treatment, tubercles on the tegument of male worms showed lesions, characterized by enlargement, collapse and partial peeling off from the border with the tegument. In both male and female worms, the tegument showed focal or extensive swelling, fusion, vacuolization, erosion, peeling, and destruction of sensory structures. Three days post-treatment,tegumental alterations further aggravated; particularly severe damage was the swelling or collapse of the oral sucker observed in both sexes. In addition, extensive swelling, erosion and peeling of tegumental ridges and destruction of discoidlike sensory structures were seen in female worms. Seven to 14 days post-treatment, moderate-to-severe damage was still evident in some worms, whereas other worms surviving the treatment showed apparent recovery in most parts of their tegument. Conclusion Artemether causes extensive and severe tegumental damage in adult S. haematobium.

Cost-effectiveness analysis of the impacts on infection and morbidity attributable to three chemotherapy schemes against Schistosoma japonicum in hyperendemic areas of the Dongting Lake region, China.

A study was carried out in 8 villages endemic with S. japonicum in Hunan Province, China from 1998 to 2000 to evaluate the cost-effectiveness in preventing schistosome infection and related morbidity under three chemotherapy schemes: (1) 'clue' chemotherapy, consisting of treatment to those with contact with infected water and/or symptoms of infection; (2) 'mass' chemotherapy-treatment to all the villagers except those not able to take praziquantel; and (3) 'screen' chemotherapy-treatment prescribed to the stool egg positive cases after Kato-Katz examination. An itemized cost menu was used to estimate the cost incurred to each scheme, from the perspective of the health care provider. The numbers of cases prevented by chemotherapy schemes were estimated through standardized attributable fractions of the outcomes to absence of chemotherapy before intervention. The cost-effectiveness ratios were calculated using weighted ranks of unit costs of the four outcome measurements: the costs per case with infection, liver and spleen abnormality (as determined by ultrasonography) prevented and 1% reduction in intensity of infection (as estimated by egg per gram feces, EPG) after the two years of intervention. Sensitivity of total cost to changes in the costs of personnel, praziquantel and other key factors were analyzed. It is demonstrated that all the three schemes had a significant impacts on the prevalence and intensity of infection, but the overall effects on liver and spleen morbidity of the residents varied between schemes. Mass chemotherapy achieved the best cost-effectiveness ratio, with unit costs of preventing cases of infection, liver and spleen abnormality and 1% reduction of EPG being RMB yuan 161.2, 99.8, 219.3 and 176.3, respectively. However, clue and screen chemotherapy schemes did not show significant prevention of liver damages in the villagers. The unit costs per case prevented for the outcomes were RMB yuan 140.2, 602.7 and 169.3, respectively for clue chemotherapy, while RMB yuan 190.0, 448.4 and 145.0 respectively for screen chemotherapy. The study concluded that mass chemotherapy should still be the choice of preference in areas where prevalence of infection and frequencies of contact with infested water by residents are high, particularly if the drug cost could be further reduced. Clue chemotherapy could be an alternative to mass chemotherapy, especially when the frequency of water contact is not as high as 80% recorded in our study. Screen chemotherapy is the least favored option in the hyperendemic area of Hunan Province.

Ultrastructural alterations in adult Schistosoma mansoni caused by artemether

Progress has been made over the last decade with the development and clinical use of artemether as an agent against major human schistosome parasites. The tegument has been identified as a key target of artemether, implying detailed studies on ultrastructural damage induced by this compound. We performed a temporal examination, employing a transmission electron microscope to assess the pattern and extent of ultrastructural alterations in adult Schistosoma mansoni harboured in mice treated with a single dose of 400 mg/kg artemether. Eight hours post-treatment, damage to the tegument and subtegumental structures was seen. Tegumental alterations reached a peak 3 days after treatment and were characterized by swelling, fusion of distal cytoplasma, focal lysis of the tegumental matrix and vacuolisation. Tubercles and sensory organelles frequently degenerated or collapsed. Typical features of subtegumental alterations, including muscle fibres, syncytium and parenchyma tissues, were focal or extensive lysis, vacuolisation and degeneration of mitochondria. Severe alterations were also observed in gut epithelial cells and vitelline cells of female worms. Our findings of artemether-induced ultrastructural alterations in adult S. mansoni confirm previous results obtained with juvenile S. mansoni and S. japonicum of different ages

Evaluation of chemical and physical-morphological factors as potencial determinants of Biomphalaria pfeifferi (Krauss, 1848) distribution

This study was carried out in five sites along a small perennial river system in south-central Tanzania, which had been identified as the focus for transmission of intestinal schistosomiasis in the area. Malacological surveys preceding the study showed a focal distribution of Biomphalaria pfeifferi, intermediate host snail of Schistosoma mansoni, the snail being present in three sites but absent from the other two sites. The objective of this study was to evaluate to what extent chemical and/or physical-morphological factors determine the distribution of B. pfeifferi between these five sites. It was found that none of the chemical constituents in the waters examined were outside the tolerance range of B. pfeifferi snails. Moreover, the composition of water from B. pfeifferi-free sites was not different from that in those sites where snails occurred. Furthermore, none of the physical-morphological constituents seemed likely to be determinant for the absence of B. pfeifferi. In view of these findings, and those of previous studies, it is concluded that the focal distribuition of B. pfeifferi cannot be associated with a single environmental factor and is rather the result of more complex interactions of habitat factors.

Therapeutic effect of artemether and artesunate in mice infected with Schistosoma mansoni / 中国血吸虫病防治杂志

Objective To explore the therapeutic effect of artemether and artesunate on adult Schistosoma mansoni in experimental mice.Methods The mice were administered intragastrically with artemether or artesunate 46 days after being infected with cercariae of S.mansoni subcutaneously. On Day 1,a dose of 400, 300, 200 mg/kg of artemether or artesunate was administered to the mice. From Day 2 to Day 7, a half above dose was administered. On Day 7, the single-dose groups were administered with artemether or artesunate at the dose of 1600, 1200, 800 mg/kg, meanwhile, an infected group of mice was served as control, untreated. Results With 7-day therapy of artemether at the dosage of 1600, 1200, 800 mg/kg, the worm reduction rates were 53%, 49% and 53%, respectively, and female worm reduction rates were from 78%-82%, compared with the control group.The therapeutic effects of artemether on single-dose groups were similar. The worm reduction rates, with 7-day therapy of artemether at the dosage of 1600, 1200, 800 mg/kg , were 16%,37% and 49%, respectively, compared with the control group. Conclusion The efficacy of therapy with artemether and artesunate on S.mansoni infection mice were relatively well. Concerning the therapeutic effect and toxicity, artemether is slightly better than artesunate.