To investigate age-related differences in dengue severity, 114 infants, 1,211 children, and 346 adults with laboratory-confirmed dengue virus (DEN) infections presenting to three hospitals in major urban centers in Nicaragua were recruited from 1999 to 2001. The age distribution of dengue cases and the circulating serotype (predominantly DEN2) were representative of national data. Similar results were obtained when either dengue hemorrhagic fever/dengue shock syndrome or its principal manifestations (vascular permeability, internal hemorrhage, marked thrombocytopenia, and/or shock) were analyzed in relation to age and immune status. The burden of disease and of severe dengue was found predominantly in infants 4-9 months of age and in children 5-9 years old, and secondary DEN infection was a risk factor for severity in children. Age-related differences were identified in the prevalence of specific clinical manifestations as well as in their association with a confirmed DEN diagnosis. This represents one of the few comprehensive studies to analyze characteristics of dengue in infants, children, and adults in the same population and highlights age-related differences in dengue severity.

In October 1995, epidemic "hemorrhagic fever," without jaundice or renal manifestations, was reported in rural Nicaragua following heavy flooding; 2259 residents were evaluated for nonmalarial febrile illnesses (cumulative incidence, 6.1%) and 15 (0.7%) died with pulmonary hemorrhage. A case-control study found that case-patients were more likely than controls to have ever walked in creeks (matched odds ratio [MOR], 15.0; 95% confidence interval [CI], 1.7-132.3), have household rodents (MOR, 10.4; 95% CI, 1.1-97.1), or own dogs with titers >/=400 to Leptospira species (MOR, 23.4; 95% CI, 3.6-infinity). Twenty-six of 51 case-patients had serologic or postmortem evidence of acute leptospirosis. Leptospira species were isolated from case-patients and potential animal reservoirs. This leptospirosis epidemic likely resulted from exposure to flood waters contaminated by urine from infected animals, particularly dogs. Leptospirosis should be included in the differential diagnosis for nonmalarial febrile illness, particularly during periods of flooding or when pulmonary hemorrhage occurs.

Abstract. From July to December 1998, a hospital-and health center-based surveillance system for dengue was established at selected sites in Nicaragua to better define the epidemiology of this disease. Demographic and clinical information as well as clinical laboratory results were obtained, and virus isolation, reverse transcriptase-polymerase chain reaction, and serologic assays were performed. World Health Organization criteria were used to classify disease severity; however, a number of patients presented with signs of shock in the absence of thrombocytopenia or hemoconcentration. Therefore, a new category was designated as ''dengue with signs associated with shock'' (DSAS). Of 1,027 patients enrolled in the study, 614 (60%) were laboratory-confirmed as positive cases; of these, 268 (44%) were classified as dengue fever (DF); 267 (43%) as DF with hemorrhagic manifestations (DFHem); 40 (7%) as dengue hemorrhagic fever (DHF); 20 (3%) as dengue shock syndrome (DSS); and 17 (3%) as DSAS. Interestingly, secondary infection was not significantly correlated with DHF/DSS, in contrast to previous studies in Southeast Asia. DEN-3 was responsible for the majority of cases, with a minority due to DEN-2; both serotypes contributed to severe disease. As evidenced by the analysis of this epidemic, the epidemiology of dengue can differ according to geographic region and viral serotype.

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BackgroundHIV viral load testing as a component of antiretroviral therapy monitoring is costly. Understanding the full costs and the major sources of inefficiency associated with viral load testing is critical for optimizing the systems and technologies that support the testing process. The objective of our study was to estimate the costs associated with viral load testing performed for antiretroviral therapy monitoring to both patients and the public healthcare system in a low-HIV prevalence, low-resource country.MethodsA detailed cost analysis was performed to understand the costs involved in each step of performing a viral load test in Nicaragua, from initial specimen collection to communication of the test results to each patient's healthcare provider. Data were compiled and cross referenced from multiple information sources: laboratory records, regional surveillance centre records, and scheduled interviews with the key healthcare providers responsible for HIV patient care in five regions of the country.ResultsThe total average cost of performing a viral load test in Nicaragua varied by region, ranging from US$99.01 to US$124.58, the majority of which was at the laboratory level: $88.73 to $97.15 per specimen, depending on batch size. The average cost to clinics at which specimens were collected ranged from $3.31 to $20.92, depending on the region. The average cost per patient for transportation, food, lodging and lost income ranged from $3.70 to $14.93.ConclusionsThe quantitative viral load test remains the single most expensive component of the process. For the patient, the distance of his or her residence from the specimen collection site is a large determinant of cost. Importantly, the efficiency of results reporting has a large impact on the cost per result delivered to the clinician and utility of the result for patient monitoring. Detailed cost analysis can identify opportunities for removing barriers to effective antiretroviral therapy monitoring programmes in limited-resource countries with low HIV prevalence.

This paper presents a standardized procedure for the detection of IgM antibodies to dengue virus in blood samples taken from filter paper. The samples were obtained from 118 patients, of whom 91 had been clinically diagnosed with dengue and 27 with a viral infection unrelated to that disease. The first group of patients came from Costa Rica and Nicaragua and the second group from Cuba. All the samples were tested for IgM antibody against dengue virus by means of a capture enzyme immunoassay (EIA). Analysis of the results for patients from all three countries together yielded a sensitivity of 98.1% and a specificity of 98.5% for the test done on whole blood on filter paper stored at 4 degrees C; agreement between the results of that test and those of the EIA using serum samples was 96%. In a comparison of the results obtained with three samples from the same patient--whole blood on filter paper stored at room temperature, the same type of sample stored at 4 degrees C, and serum--the agreement was 86%. This study demonstrates the high diagnostic sensitivity and specificity achieved when whole blood absorbed on filter paper is processed in the manner described in detail in the article. The authors recommend the use of this method in the dengue surveillance programs in the Region.

The genital candidiasis is one of the pathogenic demonstrations of yeast. Candida albicans is the most frequent species; it is usually isolated in 85 to 90% from the vaginal mycoses (Odds et al. 1988).Vaginal candidiasis affects females at least once during their lifetime, at an estimated rate of 70 to 75%, of whom 40 to 50% will experience a recurrence (Sobel 1999).In Nicaragua, we know very little about the prevalence and incidence of vaginal candidiasis and no study of the biology of C. albicans has been carried out. In this country, diagnosis of vaginal candidiasis is mainly based on the clinical presentation. Laboratories of the hospitals and health centres (peripheral laboratories) carry out only the microscopic diagnosis from the vaginal fluid. In the laboratory of the National Centre of Diagnosis and Reference of Nicaragua (CNDR), the yeast identification is based on the observation of the microscopic aspects, culture and biochemical tests.Most of the genetic studies revealed that C. albicans is predominantly clonal (Pujol et al. 1993, Helstein et al. 1993, Lockhart et al. 1995, Xu et al. 1999. Some authors have proposed that clonal propagation with a remaining capacity of recombination, shape the population structure of C. albicans (Caugant & Sandven 1993, Gräser et al. 1996, Tibayrenc 1997 Southern blot hybridization with the moderately repetitive DNA Ca3 probe, not only clustered moderately related isolates in a similar fashion but also afforded similar levels of resolution of microevolution within a clonal population.The goal of this study was to use the RAPD method to examine the patterns of yeast genetic diversity among women with vaginitis from a single geographic area. We were specifically interested to know the frequency of yeast in vulvovaginal secretions. We also compared the conventional methods of yeast diagnosis from vaginal samples used in Nicaragua and yeast culture method. MATERIALS AND METHODSThe vaginal swabs were taken from 106 women exhibiting symptoms of vulvovaginitis, who were attended in the outpatient ward of the CNDR in Managua, Nicaragua, between June and August 1997. Swabs were processed by the method routinely used for the detection of germinated yeast pathogens: microscopic examination of wet mount, with a 10% potassium hydroxide (KOH) preparation, and the Gram's stain. Samples were inoculated into Sabouraud-glucose agar, supplemented with chloramphenicol, and were incubated at 37°C for 48 h. For identification of C. albicans, isolates were placed in foetal calf serum for 4 h to test for the production of germ tubes and were incubated on Rice-Agar-Tween (RAT ® ) BioMérieux Laboratories, France for 48 h to induce chlamydospores. All yeast isolates were preliminary identified to the species level according to the CHROMagar Albicans® Test (Mycoplasme International, Toulon, France). This medium contains a chromogene substrate for immediate identification of C. albicans (green), C. tropicalis (metallic blue), C. glabrata (pink) and C. krusei (pale pink). Yeast species were conf...