| 41. |
- Leiva, Byron
(författare)
-
Amoebiasis : diagnosis and prevalence in León Nicaragua
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- About ten yearly cases of liver abscess are presented in University Hospital, León, Nicaragua. Based on serology most of them have been shown to be amoebiasis cases. This raised the question of Entameoba histolytica prevalence in the population. Based on microscopy of stool specimens and serology, about 20% prevalence was found. With the new realization that pathogenic E. histolytica is morphologically indistinguishable from some common apathogenic species such as E. dispar (cysts detected by microscopy are reported as E. histolytica/ E. dispar), the aim was to determine the true prevalence of E. histolytica using various tests designed to differentiate between pathogenic and apathogenic species. In 480 apparently healthy individuals, the prevalence of E. histolytica/ E. dispar was 12% (58/480) as determined by microscopy. Out of these 58 stool samples an E. histolytica specific PCR was positive in 5%; thus the prevalence E. histolytica was 0.6%. In a group of 134 diarrhea patients, the most common finding was E. histolytica/ E. dispar (24%) at the health center laboratory level. In the Microbiology Department E. histolytica/E. dispar was found only in 4.5%. With the Triage Parasite test, only one case of E. histolytica/ E. dispar was found. By PCR, E. dispar was recognized in 10 (7.5%) and E. histolytica in two cases (1.5%). Over diagnosis was also confirmed in a quality control study where León health centers were examining 10 different stool samples. We found that the health center technicians continue to mix up E. histolytica/ E. dispar with other amoebas. The consequences of the apparent widespread over diagnosis of E. histolytica were studied retrospectively in 100 records of patients with intestinal symptoms. We found that all patients received treatment with metronidazole or related drugs. In 41% these treatments were not based on any laboratory findings at all. In 32 % E. histolytica/E. dispar were found. Other parasites (Entamoeba coli, Giardia intestinalis, Endolimax nana, Enterobius. vermicularis, Iodamoeba bütschlii) were seen in 27%. To explain the high seroprevalence of anti-E.histolytica antibodies in sero-epidemiological surveys we considered two possibilities: cross reactivity due to the common intestinal apathogenic E. dispar and antibodies to ubiquitous freeliving environmental amoebas. A study was undertaken to identify environmental amoebas and to determine cross-reactivity using antibodies from amoebiasis patients. Amoebas isolated from environmental water samples were characterized by morphological and immunohistochemical methods. In fresh water Acanthamoeba spp. were found in 21 %. Fifty three percent of tested wells in the geothermal area contained thermotolerant amoeboflagellates. Naegleria spp. was identified in 24 out of 39 (62 %) of isolated amoeboflagellates. Absorption studies did not support the idea that environmental free- living amoebas induce antibodies cross-reacting with E. histolytica. Antigenic cross reactivity between E. dispar and E. histolytica remains a possible explanation for the high seroprevalence in the population. This is supported by the observation that IF antibody titers in sera from healthy individuals are similar with both antigens. Also the ratio of antibody reactivity was similar when measured by a densitometric method. In contrast, sera from patients with invasive amoebiasis reacted preferentially with E. histolytica. We conclude that amoebiasis is not a major problem in the community. Overdiagnosis and overtreatment of diarrhea patients thought to suffer from amoebiasis are serious problems. Thus there is an urgent need for education and quality assessment.
|
|
| 42. |
|
|
| 43. |
|
|
| 44. |
- Rodríguez, Teresa, 1966-, et al.
(författare)
-
Biological Monitoring of Pesticide Exposures among Applicators and Their Children in Nicaragua
- 2006
-
Ingår i: International journal of occupational and environmental health. - : Maney Publishing. - 1077-3525 .- 2049-3967. ; 12, s. 312-320
-
Tidskriftsartikel (refereegranskat)abstract
- Exposures were assessed for seven small-scale farmers using chlorpyrifos on corn and ten banana plantation employees applying diazinon, and for one child of each worker. Metabolites (TCPYand IMPY) were measured in urine before and after applications. TCPY concentrations peaked at 27 and 8.5 hours post-application for applicators and children, respectively (geometric means, 26 and 3.0 microg/L). Proximity to spraying and spray mixture preparation in homes were important exposure factors. IMPY concentrations differed substantially across workers at two plantations (geometric means, 1.3 and 168 mirog/L); however, their children had little or no diazinon exposure. These workers and children were also exposed to chlorpyrifos, most likely through contact with chlorpyrifos-impregnated bags used in banana production. Several recommendations are offered: (1) monitor children's activities during applications; (2) do not store or prepare pesticides in homes; (3) institute sound occupational hygiene practices at banana plantations; (4) dispose of plastic insecticide bags properly at the worksite.
|
|
| 45. |
- Bucardo, Filemon, et al.
(författare)
-
Genetic susceptibility to symptomatic norovirus infection in Nicaragua
- 2009
-
Ingår i: Journal of Medical Virology. - : John Wiley & Sons. - 0146-6615 .- 1096-9071. ; 81:4, s. 728-735
-
Tidskriftsartikel (refereegranskat)abstract
- Host genetic resistance to Norovirus (NoV) has been observed in challenge and outbreak studies in populations from Europe, Asia, and USA. In this study, we have investigated if histo-blood group antigens can predict susceptibility to diarrhea caused by NoV in Nicaragua, Central America, and if this can be reflected in antibody-prevalence and titer to NoV among individuals with different histo-blood group antigen phenotypes. Investigation of 28 individuals infected with NoV and 131 population controls revealed 6% of non-secretors in the population and nil non-secretors among patients infected with NoV, suggesting that non-secretors may be protected against NoV disease in Nicaragua. Surprisingly, 25% of the population was Lewis negative (Le(a-b-)). NoV infections with genogroup I (GI) and GII occurred irrespective of Lewis genotype, but none of the Lewis a positive (Le(a + b-)) were infected. The globally dominating GII.4 virus infected individuals of all blood groups except AB (n = 5), while the GI viruses (n = 4) infected only blood type O individuals. Furthermore, O blood types were susceptible to infections with GI.4, GII.4, GII.7, GII.17, and GII.18-Nica viruses, suggesting that secretors with blood type O are susceptible (OR = 1.52) and non-secretors resistant. The overall antibody-prevalence to NoV GII.3 VLP was 62% with the highest prevalence among blood type B carriers (70%) followed by A (68%) and O (62%). All four investigated individuals carrying blood type AB were antibody-negative. Among secretors, 63% were antibody-positive compared to 33% among non-secretors (P = 0.151). This study extends previous knowledge about the histo-blood group antigens role in NoV disease in a population with different genetic background than North American and European.
|
|
| 46. |
|
|
| 47. |
- Korsak, Larisa, et al.
(författare)
-
Evaluation of anaerobic sludge activity in wastewater treatment plants in Nicaragua
- 2006
-
Ingår i: Water Pollution VIII. - 184564042X ; , s. 571-579
-
Konferensbidrag (refereegranskat)abstract
- Sludge of three municipal anaerobic wastewater treatment plants was evaluated. This study was initiated due to the low activity observed in the anaerobic wastewater treatment plants in Nicaragua. An additional goal to select one of them, if possible, as an inoculum for the brewery treatment plant was proposed. Two of these plants work with an Imhoff tank and one with a Septic tank followed by an anaerobic upflow filter. The study consisted in the characterization of biomass in terms of Specific Methanogenic Activity (SMA), Volatile Suspended Solids (VSS), density, pH, and redox potential (RP). The treated waters were also analysed for nutrients, heavy metals and the organic load. The substrate used in the experiments for determining the methanogenic activity was acetic acid. NaHCO3 was added to maintain pH in the normal range of operation. The tests were carried out at a sludge load of 1.5 g VSS/l. The results indicate that treated wastewater does not have any impediment to proper development of microorganisms; no presence of toxic substances and enough essential nutrients were detected. The specific methanogenic activity of sludge (SMA) in the Imhoff tanks is relatively close and oscillates between 0.16-0.28 g CH4-COD/g VSS/day, and in the septic tank is 0.09 g CH4-COD/g VSS/day. These values agree with the methanogenic activity found in the literature for septic tanks (0.02-0.1 g CH4-COD/gVSS/day). The highest methanogenic activity measured during the test was 0.28g CH4-COD/g VSS/day in the sludge of the Imhoff tank in The Viejo city, so this sludge could be proposed as a seed for the brewery treatment plant.
|
|
| 48. |
- García, Indiana, et al.
(författare)
-
Presence of trihalomethanes in drinking water plants in Nicaragua
- 2006
-
Ingår i: Journal of Water Supply. - 0003-7214 .- 1365-2087. ; 55:3, s. 221-231
-
Tidskriftsartikel (refereegranskat)abstract
- The impact of enhanced coagulation on the formation of trihalomethanes (THMS) from drinking water was studied in four treatment plants in Nicaragua. Enhanced and conventional coagulation techniques were compared with regard to the removal of natural organic matter (NOM), which was measured by surrogate paramametres. The enhanced coagulation process showed a better removal of NOM, and as a consequence the THM formation was up to 50% lower than with conventional coagulation. The influences of chlorine dosage, temperature, PH and contact time on the THM formation in water treated by enhanced and conventional coagulation were also studied.
|
|
| 49. |
- Wedel, Johan, 1962
(författare)
-
Bridging the Gap between Western and Indigenous Medicine in Eastern Nicaragua
- 2009
-
Ingår i: Anthropological Notebooks. ; 15:1, s. 49-64
-
Tidskriftsartikel (refereegranskat)abstract
- In Nicaragua there are attempts, at various levels, to bridge the gap between Western and indigenous medicine and to create more equal forms of therapeutic cooperation. This article, based on anthropological fieldwork, focuses on this process in the North Atlantic Autonomous Region a province dominated by the Miskitu people. It examines illness beliefs among the Miskitu, and how therapeutic cooperation is understood and acted upon by medical personnel, health authorities and Miskitu healers. The study focuses on ailments locally considered to be caused by spirits and sorcery and problems that fall outside the scope of biomedical knowledge. Of special interest is the mass-possession phenomena grisi siknis where Miskitu healing methods have been the preferred alternative, even from the perspective of the biomedical health authorities. The paper shows that Miskitu healing knowledge is only used to compensate for biomedicine’s failure and not as a real alternative, despite the intentions in the new Nicaraguan National Health Plan. This article calls for more equal forms of therapeutic cooperation through ontological engagement by ongoing negotiation and mediation between local and biomedical ways of perceiving the world.
|
|
| 50. |
- Corriols Molina, Marianela
(författare)
-
Acute pesticide poisonings in Nicaragua : underreporting, incidence and determinants
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Acute pesticide poisonings (APP) are a public health problem in Nicaragua. The quality and coverage of APP´s register, the real incidence of APP, the main determinants, the economic cost of treating cases and the effectiveness of educational intervention are not well known. Aim: The overall aim was to investigate the acute health impact of pesticide use and to discuss the possible effectiveness of preventive measures in Nicaragua. The specific aims were to calculate the proportion of APP cases officially registered, to estimate one year cumulative incidence of APP cases among population 15 years and older, to identify the main determinants related to APP among pesticide sprayers and to evaluate the impact of an integrated pest management (IPM) training intervention. Methods: For studies 1, 2, and 3, data concerning pesticide exposure and health effects were assessed in a nationally representative survey of 3169 persons 15 years and older in year 2000. For study 1, to estimate the proportion of underreporting of APP cases, the cases reported at the official surveillance system were cross matched with the cases reported through the survey. In study 2, based on self reported cases we estimated the one year incidence rate and the number of expected cases of APP in the country. In study 3, after regression analysis, the main determinants for APP among agricultural sprayers were identified. Study 4 assessed the impact of a 2 years IPM training to reduce economic costs and acute adverse health effects among 1200 basic grain farmers comparing the group of trained farmers and a group of "control" farmers who did not receive training. Results: Less than 5% of medically treated APP cases were reported to the official register. The one year APP incidence among general population was 2.3% (95%CI 1.7-2.8). The rate was higher among men, rural population and agricultural workers. More than 66,000 cases were estimated to occur yearly. The national incidence rate of APP among sprayers was extremely high, 8.3% (95% CI 5.8-10.8) and more than 34,000 cases were estimated to occur among pesticide sprayers, and representing 52% of all APP s estimated in year 2000. Although most of the cases were minor and moderate, the poisonings caused near 340,000 disability days. The causal agents for APP in 95% of cases were WHO Class I-II pesticides. The main determinants of APP among sprayers were: backpack pump leakage and incomplete or no use of personal protective equipment. Seventy seven percent of cases were caused by pesticides proposed to be banned or restricted in Central America. The IPM training prevented acute health effects and maintained productivity: after two years of training, the trained farmers used fewer pesticides, spent less money on pest control, made higher net returns, and suffered less exposure to cholinesterase-inhibiting pesticides compared to farmers who did not receive IPM training. Conclusion: Underreport figures leads to an erroneous interpretation of acute pesticide health effects. There is a high APP incidence rate in the general population, but it is four times higher among sprayers, causing important loss of or productivity and important economic costs. IPM interventions were successful in prevent the occurrence of APP cases and economic losses. Traditional prevention and control measures are insufficient and structural changes, including pesticides banning and restriction, and change to IPM agriculture models, are needed to transform the underlying determinants.
|
|
