Fungicides Used Alone, in Combinations, and in Rotations for Managing Gladiolus Rust in Mexico.

Gladiolus rust, caused by Uromyces transversalis, is a quarantine-significant pathogen in the United States. However, the fungus is endemic to commercial gladiolus-producing areas in Mexico and has been intercepted frequently on gladiolus plants entering the United States for the cut-flower market. The present study assessed 15 fungicide active ingredients (five quinone outside inhibitors: azoxystrobin, fluoxastrobin, kresoxim-methyl, pyraclostrobin, and trifloxystrobin; six triazoles: cyproconazole, difenoconazole, epoxiconazole, myclobutanil, propiconazole, and tebuconazole; three succinate dehydrogenase inhibitors: boscalid, flutolanil, and oxycarboxin; and one broad-spectrum protectant: chlorothalonil) and one plant activator, acibenzolar-S-methyl, applied alone, in combinations, and in various rotations for efficacy against U. transversalis on field-grown gladiolus plants in Mexico. Experiments were conducted in 2010, 2011, and 2012 in commercial fields in Atlixco and Santa Isabel Cholula in Puebla and Cuautla and Tlayacapan in Morelos. Fungicides were applied at 2-week intervals starting when plants had three full leaves. Disease severity was recorded each week for at least 7 weeks after the first application. Under high disease pressure in 2010, fungicides were less effective than in 2011 and 2012, when disease pressure was not as high. In all 3 years, most fungicide treatments significantly reduced disease severity. Triazoles were more effective than quinone outside inhibitors when applied as individual products in 2010, and combinations of two fungicides in different mode-of-action groups were more effective than fungicides applied individually in 2011. In 2012, rotations of fungicides, either with individual products or with combinations of two products, provided excellent rust management. Reducing disease development by U. transversalis on commercial gladiolus plants in Mexico will reduce the potential for introducing this pathogen on cut flowers into the United States.

Intestinal parasites among young children in the interior of Guyana.

Intestinal parasites contribute greatly to morbidity in developing countries. While there have been several studies of the problem in the Caribbean, including the implementation of control programmes, this has not been done for Guyana. The aim of this study was to determine the prevalence of intestinal parasites among young children in a town located in the interior of Guyana. Eighty-five children under the age of 12 years were studied prospectively for intestinal parasites in Mahdia, Guyana. Stool samples were transported in formalin to the Department of Microbiology, The University of the West Indies, Jamaica, for analysis using the formalin-ether concentration and Ziehl-Neelsen techniques. Data on age and gender of the children were recorded on field data sheets. At least one intestinal parasite was detected in 43.5% (37/85) of the children studied and multiple parasitic infections were recorded in 21.2% (18/85). The most common intestinal helminth parasite was hookworm (28.2%; 24/85), followed by Ascaris lumbricoides (18.8%; 16/85) and then Trichuris trichuria (14.1%; 12/85). Among the protozoan infections Giardia lamblia was detected in 10.5% (9/85) of the study population while Entamoeba histolytica appeared rarely. All stool samples were negative for Cryptosporidium and other intestinal Coccidia. There was no predilection for gender with any of the parasites. The pattern of distribution of worms in this area of Guyana was unlike that seen in other studies. Hookworm infection was the most common among the children and a large proportion had multiple infections. The study established the occurrence and prevalence of a number of intestinal parasites in the population of Guyana. This sets the stage for the design and implementation of more detailed epidemiological studies.

Intestinal parasites among young children in the interior of Guyana

Intestinal parasites contribute greatly to morbidity in developing countries. While there have been several studies of the problem in the Caribbean, including the implementation of control programmes, this has not been done for Guyana. The aim of this study was to determine the prevalence of intestinal parasites among young children in a town located in the interior of Guyana. Eighty-five children under the age of 12 years were studied prospectively for intestinal parasites in Mahdia, Guyana. Stool samples were transported in formalin to the Department of Microbiology, The University of the West Indies, Jamaica, for analysis using the formalin-ether concentration and Ziehl-Neelsen techniques. Data on age and gender of the children were recorded on field data sheets. At least one intestinal parasite was detected in 43.5 (37/85) of the children studied and multiple parasitic infections were recorded in 21.2 (18/85). The most common intestinal helminth parasite was hookworm (28.2; 24/85), followed by Ascaris lumbricoides (18.8; 16/85) and then Trichuris trichuria (14.1; 12/85). Among the protozoan infections Giardia lamblia was detected in 10.5 (9/85) of the study population while Entamoeba histolytica appeared rarely. All stool samples were negative for Cryptosporidium and other intestinal Coccidia. There was no predilection for gender with any of the parasites. The pattern of distribution of worms in this area of Guyana was unlike that seen in other studies. Hookworm infection was the most common among the children and a large proportion had multiple infections. The study established the occurrence and prevalence of a number of intestinal parasites in the population of Guyana. This sets the stage for the design and implementation of more detailed epidemiological studies.

The effects of Robertsonian fusions on chiasma frequency and distribution in the house mouse (Mus musculus domesticus) from a hybrid zone in northern Scotland.

Chiasma frequency and distribution were studied in male Mus musculus domesticus from the John O'Groats-standard chromosomal hybrid zone in northern Scotland. Individuals of the John O'Groats race (2n=32; homozygous for the Robertsonian fusions 4.10, 6.13, 9.12 and 11.14) and the standard race (2n=40, all telocentric), and hybrids with various karyotypes, were examined. Chiasma frequency was significantly negatively correlated with the number of Robertsonian configurations in the meiotic cell. The decrease of chiasma frequency can be attributed to intrachromosomal effects that reduce the number of chiasmata in Robertsonian bivalents (formed in homozygotes for Robertsonian fusions) and trivalents (formed in heterozygotes). However, the reduction is more pronounced in Robertsonian bivalents and is related to a shift of chiasmata to the distal ends of the chromosome arms. A different type of repatterning occurs in trivalents where there is a significant increase in proximal and interstitial chiasmata.

Identification of Anopheles aquasalis as a possible vector of malaria in Guyana, South America

Adult female mosquitoes were collected in Mahdia, Guyana, to determine the incidence of malaria in Anopheles species found during the month of June 2000. Centers for Disease Control miniature white (incandescent) light traps, model 512, and miniature black (ultraviolet) light traps, model 912, were used to capture female mosquitoes. Numbers of mosquitoes collected were compared between white and black light traps and between traps set outside and inside of buildings. Adult female Anopheles mosquitoes were identified and an ELISA dipstick test for Plasmodium vivax and Plasmodium falciparum was performed on each mosquito. An aquasalis, An oswaldoi, and An braziliensis were attracted to white light traps. An triannulatus and An darlingi were collected from black light traps. Approximately the same numbers of all female Anopheles mosquitoes 28/45 (62) were caught inside buildings as outside. Numbers of female non-anopheles mosquitoes captured in light traps varied between the traps set outside of buildings and inside of buildings with bright light traps collecting 91/122 (75). A total of 45 Anopheles mosquitoes were captured and 122 non-anopheles species. Of the two known vectors of malaria in Guyana, An darlingi mosquitoes were not infected with P vivax but An aquasalis was found to be a carrier. The findings of this study suggest a need for further surveying and identification of current malaria vectors in Guyana.

Identification of Anopheles aquasalis as a possible vector of malaria in Guyana, South America.

Adult female mosquitoes were collected in Mahdia, Guyana, to determine the incidence of malaria in Anopheles species found during the month of June 2000. Centers for Disease Control miniature white (incandescent) light traps, model 512, and miniature black (ultraviolet) light traps, model 912, were used to capture female mosquitoes. Numbers of mosquitoes collected were compared between white and black light traps and between traps set outside and inside of buildings. Adult female Anopheles mosquitoes were identified and an ELISA dipstick test for Plasmodium vivax and Plasmodium falciparum was performed on each mosquito. An aquasalis, An oswaldoi, and An braziliensis were attracted to white light traps. An triannulatus and An darlingi were collected from black light traps. Approximately the same numbers of all female Anopheles mosquitoes 28/45 (62%) were caught inside buildings as outside. Numbers of female non-anopheles mosquitoes captured in light traps varied between the traps set outside of buildings and inside of buildings with bright light traps collecting 91/122 (75%). A total of 45 Anopheles mosquitoes were captured and 122 non-anopheles species. Of the two known vectors of malaria in Guyana, An darlingi mosquitoes were not infected with P vivax but An aquasalis was found to be a carrier. The findings of this study suggest a need for further surveying and identification of current malaria vectors in Guyana.

Seroepidemiology of Helicobacter pylori infection in a Jamiaican community

We researched epidemiologic associations between environmental and demographic factors and prevalence of Helicobacter pylori infection in a suburban Jamaican community. Using a clustered sampling technique, 22 domestic yards enclosing 60 separate households were randomly selected from a local community. All household members (n=346) were invited to participate following informed consent; the overall compliance rate was 58.9 percent. A commercial enzyme immunoassay (HM-CAP) was used to detect IgG antibodies raised against H. pylori. Environmental and demographic information was obtained by questionnaire. The seroprevalence of H. pylori was 69.9 percent (n=202). Analysis of the independent variables revealed three major components. Component 1 described, collectively, good personal hygiene and sanitation, indoor water supply and absence of straying animals in the peridomestic area; Component 2 included older age, good personal hygiene and large yard size; Component 3 the presence of domestic animals (cats and dogs) and, again large yard size. These three complexes explained 42.2 percent of the variability in the data set. Logistic regression showed that Components 2 and 3 were independently associated with H. pylori seropositivity, indicating that a combination of demographic environmental and zoonotic factors is involved in the spread of H. pylori infections at the tropical community level (AU)

Field evaluation of the Determine rapid human immunodeficiency virus diagnostic test in Honduras and the Dominican Republic.

Rapid detection of human immunodeficiency virus (HIV) infection can result in improved patient care and/or faster implementation of public health preventive measures. A new rapid test, Determine (Abbott, Abbott Park, Ill.), detects HIV type 1 (HIV-1) and HIV-2 antibodies within 15 min by using 50 microl of serum or plasma. No specialized equipment or ancillary supplies are required, and results are read visually. A positive result is noted by the appearance of a red line. An operational control (red line) indicates proper test performance. We evaluated the Determine rapid HIV detection test with a group of well-characterized serum samples (CD4 counts and viral loads were known) and serum samples from HIV-positive individuals at field sites in Honduras and the Dominican Republic. In the field evaluations, the results obtained by the Determine assay were compared to those obtained by local in-country HIV screening procedures. We evaluated serum from 100 HIV-positive patients and 66 HIV-negative patients. All samples gave the expected results. In a companion study, 42 HIV-positive samples from a Miami, Fla., serum bank were tested by the Determine assay. The samples had been characterized in terms of CD4 counts and viral loads. Fifteen patients had CD4 counts <200 cells/mm(3), while 27 patients had CD4 counts >200 cells/mm(3). Viral loads ranged from 630 to 873,746 log(10) copies/ml. All samples from the Miami serum bank were positive by the Determine test. Combined results from the multicenter studies indicated that the correct results were obtained by the Determine assay for 100% (142 of 142) of the HIV-positive serum samples and 100% (66 of 66) of the HIV-negative serum samples. The Determine test was simple to perform and the results were easy to interpret. The Determine test provides a valuable new method for the rapid identification of HIV-positive individuals, especially in developing countries with limited laboratory infrastructures.

Dengue in Guyana.

There have been dramatic increases in dengue fever (DF) and dengue haemorrhagic fever in South America. Guyana has reported less than five cases per year for most of the past decade. We evaluated patients in a clinic in Georgetown, Guyana, over 2 days and found evidence of 50 cases of dengue infection.

PIP: This research letter evaluates the incidence of dengue fever and dengue hemorrhagic fever in Guyana, South America, in a study conducted at the Vector Control Medical Center on July 20-21, 1998. Venous blood samples were collected from 112 patients (99 men and 13 women ranging in age from 9 to 60 years) who were inflicted with fever, chills, malaise, and/or headache. 50 samples were detected to be dengue virus- positive, illustrating a 45% prevalence of recent dengue virus infection among the tested patients. This study revealed that the incidence of dengue fever in Guyana is under-reported. Thus, improvements should be made in the surveillance measures for dengue infection in Guyana and its surrounding countries.

Total immunoglobulin E levels and dengue infection on San Andrés Island, Colombia.

An evaluation of total immunoglobulin E (IgE) and dengue serostatus in 168 subjects from San Andrés Island, Colombia, revealed altered levels of IgE in 89% of the population. IgE levels were higher in patients with a history of dengue or with a current secondary or current primary infection than in subjects with no exposure (P = 0. 01). Dengue infection accounted for 23% of the variation in IgE levels.

Evaluation of the MRL diagnostics dengue fever virus IgM capture ELISA and the PanBio Rapid Immunochromatographic Test for diagnosis of dengue fever in Jamaica.

We evaluated two new commercial dengue diagnostic tests, the MRL Diagnostics Dengue Fever Virus IgM Capture ELISA and the PanBio Rapid Immunochromatographic Test, on serum samples collected during a dengue epidemic in Jamaica. The MRL ELISA method correctly identified 98% (78 of 80) of the samples as dengue positive, while the PanBio test identified 100% (80 of 80). Both tests were 100% (20 samples of 20) specific.

Seroepidemiology of Helicobacter pylori infection in a Jamaican community.

We researched epidemiologic associations between environmental and demographic factors and prevalence of Helicobacter pylori infection in a suburban Jamaican community. Using a clustered sampling technique, 22 domestic yards enclosing 60 separate households were randomly selected from a local community. All household members (n = 346) were invited to participate following informed consent; the overall compliance rate was 58.9%. A commercial enzyme immunoassay (HMáCAP) was used to detect IgG antibodies raised against H. pylori. Environmental and demographic information was obtained by questionnaire. The seroprevalence of H. pylori was 69.9% (n = 202). Analysis of the independent variables revealed three major components: Component 1 described, collectively, good personal hygiene and sanitation, indoor water supply and absence of straying animals in the peridomestic area; Component 2 included older age, good personal hygiene and large yard size; Component 3 the presence of domestic animals (cats and dogs) and, again, large yard size. These three complexes explained 42.2% of the variability in the data set. Logistic regression showed that Components 2 and 3 were independently associated with H. pylori seropositivity, indicating that a combination of demographic, environmental and zoonotic factors is involved in the spread of H. pylori infections at the tropical community level.

Epidemiology of giardiasis and cryptosporidiosis in Jamaica.

We report the findings of a cross-sectional epidemiologic study of Giardia lamblia and Cryptosporidum infections in Jamaica. Three hundred twenty eight stool samples from patients less than one to 81 years of age were examined using formalin-ether concentration for G. lamblia, Zeihl-Neelsen staining for Cryptosporidium, and the Prospect rapid enzyme immunoassay (EIA; Alexon, Sunnyvale, CA) for parasite diagnosis. The Prospect Giardia rapid assay detected 17 cases of G. lamblia infection compared with six by formalin-ether concentration. However, the Prospect Cryptosporidum EIA did not increase the rate of detection of Cryptosporidum when compared with Zeihl-Neelsen staining. Cryptosporidum infections were most frequently diagnosed in children less than five years old and prevalence decreased with age. In contrast, the prevalence of giardiasis increased as children became older. There were no associations between the infections and stool consistency, clinical manifestations, or sex of the individuals. The contribution of the parasites to childhood morbidity will depend on accurate laboratory diagnosis.

Increased prevalence of Plasmodium falciparum malaria in Honduras, Central America.

We report on our investigation of a malaria outbreak in Honduras, Central America, in January 1997. We tested 202 patients with fever and chills using thin and thick blood film microscopy. Sixteen patients lived in the city and the rest lived in rural areas. A total of 95 samples (47%) were positive for malaria parasites. Seventy-nine percent (63/80) of the rural patients were infected with Plasmodium vivax and 21% (17/80) were infected with P. falciparum. In the urban area, all 15 infected patients had P. vivax malaria and none showed evidence of P. falciparum. Since previous reports indicate that falciparum malaria accounts for only 2% of the overall malaria infections in Honduras, the results reported here suggest that there is a dramatic increase in falciparum malaria in the area of Honduras investigated in this study.

Intestinal parasitic infections in human immunodeficiency virus (HIV)-positive and HIV-negative individuals in San Pedro Sula, Honduras.

Honduras has at least five-times more human immunodeficiency virus (HIV)-infected individuals than any other country in Central America. The relationship between HIV status and the presence of intestinal parasites in this part of the world is unknown. This study presents the results from a prospective, comparative study for the presence of parasites in 52 HIV-positive and 48 HIV-negative persons in San Pedro Sula, Honduras. Infection with HIV was determined by microagglutination and confirmed by Western blot analysis. Parasites were detected in stools using formalin-ether concentration, and Kinyoun and trichrome staining. Age, sex, and clinical state of HIV infection were recorded for each study participant. Our results indicate that Cryptosporidium parvum and Strongyloides stercoralis, which are intracellular or live in the mucosa, were found exclusively in persons infected with HIV. In comparison, the prevalence of the extracellular parasites Giardia lamblia, Ascaris lumbricoides, and Trichuris trichiura was significantly higher (P < 0.05) in persons who were HIV-negative. Trichuris worms are in contact with the gut epithelium and less so with the mucosa, whereas Strongyloides lives within the gut mucosa. It is possible that changes in the gut epithelium due to HIV infection do not affect the mucosa and therefore would not affect Strongyloides. We conclude that infection with HIV may selectively deter the establishment of certain intestinal parasites. This may be due to the fact that HIV-induced enteropathy does not favor the establishment of extracellular parasites. Intracellular and mucosal dwelling organisms, however, may benefit from pathologic changes and reduced local immune responses induced by the virus, which, in turn, may lead to higher prevalence among HIV-infected individuals.

Occurrence of Cryptosporidium oocysts and Giardia cysts in water supplies of San Pedro Sula, Honduras.

During June 1996, water supplies of the city of San Pedro Sula, Honduras, were sampled to obtain an assessment of Cryptosporidium oocyst and Giardia cyst concentrations. Each sample was concentrated and stained with an indirect immunofluorescent antibody, and parasites were counted through microscopic analysis. In three surface water supplies, Cryptosporidium oocyst concentrations ranged from 58 to 260 oocysts per 100 L, and Giardia cysts were present in concentrations ranging from 380 to 2100 cysts per 100 L. Unlike the surface water samples, groundwater had a higher concentration of Cryptosporidium oocysts (26/100 L) than Giardia cysts (6/100 L), suggesting that the groundwater aquifer protects the water supply more effectively from larger Giardia cysts. Cryptosporidium oocyst concentrations are within the typical range for surface water supplies in North America whereas Giardia cyst concentrations are elevated. Efforts should be made to protect raw water from sources of contamination.

Effect of a bicultural community health worker on completion of diabetes education in a Hispanic population.

OBJECTIVE: To determine the effect of a bicultural community health worker (CHW) on completion of diabetes education in an inner-city Hispanic patient population and to evaluate the impact of completion of the education program on patient knowledge, self-care behaviors, and glycemic control. RESEARCH DESIGN AND METHODS: Patients were randomized into CHW intervention and non-CHW intervention groups. All patients received individualized, comprehensive diabetes education from a certified diabetes nurse educator after baseline demographic information, diabetes knowledge, diabetes self-care practices, and glycohemoglobin levels were assessed. Rates of education program completion were determined. Diabetes knowledge, self-care practices, and glycohemoglobin levels were reassessed at program completion and at a later postprogram follow-up medical appointment and compared to baseline. Logistic regression analysis and the Mantel-Haenszel chi 2 statistic were used to determine the effect of the CHW assignment on program completion. Analyses of covariance were performed with end-of-treatment behavior scores, knowledge scores, and glycohemoglobin levels as outcome variables, controlling for baseline values and testing for the effect of CHW assignment. RESULTS: Of 64 patients enrolled in the study, 40 (63%) completed and 24 (37%) dropped out before completing the diabetes education program. Of the patients having CHW intervention, 80% completed the education program, compared with 47% of patients without CHW intervention (P = 0.01). "Dropouts" were younger (age 47.5 +/- 12.5 years [mean +/- SD]) compared with patients who completed the program (55.9 +/- 9.9 years) (P = 0.004). Dropout status showed no significant relationship to educational level achieved or literacy level. For the program "completers," knowledge levels and selected self-care practices significantly improved, and glycohemoglobin levels improved from a baseline level of 11.7% to 9.9% at program completion (P = 0.004) and 9.5% at the postprogram follow-up (P < 0.001). The effect of the CHW assignment on program completion, controlling for financial status and language spoken, was extremely robust (P = 0.007). The effect of the CHW on knowledge, self-care behavior, or glycohemoglobin outcome variables was not statistically significant. CONCLUSIONS: These findings suggest that intervention with a bicultural CHW improved rates of completion of a diabetes education program in an inner-city Hispanic patient population irrespective of literacy or educational levels attained. Our data further suggests that completion of individualized diabetes educational strategies leads to improved patient knowledge, self-care behaviors, and glycemic control.