Dengue in travellers: applicability of the 1975–1997 and the 2009 WHO classification system of dengue fever

Objectives The aim of this study was to assess the applicability and benefits of the new WHO dengue fever guidelines in clinical practice, for returning travellers. Methods We compared differences in specificity and sensitivity between the old and the new guidelines for diagnosing dengue and assessed the usefulness in predicting the clinical course of the disease. Also, we investigated whether hypertension, diabetes or allergies, ethnicity or high age influenced the course of disease. Results In our setting, the old classification, compared with the new, had a marginally higher sensitivity for diagnosing dengue. The new classification had a slightly higher specificity and was less rigid. Patients with dengue who had warning signs as postulated in the new classification were admitted more often than those who had no warning signs (RR, 8.09 [1.80–35.48]). We did not find ethnicity, age, hypertension, diabetes mellitus or allergies to be predictive of the clinical course. Conclusions In our cohort of returned travellers, the new classification system did not differ in sensitivity and specificity from the old system to a clinically relevant degree. The guidelines did not improve identification of severe disease.     

Costs of dengue prevention and incremental cost of dengue outbreak control in Guantanamo, Cuba

Objective To assess the economic cost of routine Aedes aegypti control in an at‐risk environment without dengue endemicity and the incremental costs incurred during a sporadic outbreak. Methods The study was conducted in 2006 in the city of Guantanamo, Cuba. We took a societal perspective to calculate costs in months without dengue transmission (January–July) and during an outbreak (August–December). Data sources were bookkeeping records, direct observations and interviews. Results The total economic cost per inhabitant (p.i.) per month. (p.m.) increased from 2.76 USD in months without dengue transmission to 6.05 USD during an outbreak. In months without transmission, the routine Aedes control programme cost 1.67 USD p.i. p.m. Incremental costs during the outbreak were mainly incurred by the population and the primary/secondary level of the healthcare system, hardly by the vector control programme (1.64, 1.44 and 0.21 UDS increment p.i. p.m., respectively). The total cost for managing a hospitalized suspected dengue case was 296.60 USD (62.0% direct medical, 9.0% direct non‐medical and 29.0% indirect costs). In both periods, the main cost drivers for the Aedes control programme, the healthcare system and the community were the value of personnel and volunteer time or productivity losses. Conclusions Intensive efforts to keep A. aegypti infestation low entail important economic costs for society. When a dengue outbreak does occur eventually, costs increase sharply. In‐depth studies should assess which mix of activities and actors could maximize the effectiveness and cost‐effectiveness of routine Aedes control and dengue prevention.     

Contraceptive use among HIV‐positive women in Quang Ninh province,Vietnam

Objective To investigate contraceptive use among HIV‐positive women in Ha long city and Cam Pha town of Quang Ninh, a Northern province of Vietnam. Methods Cross‐sectional questionnaire study among HIV‐positive women identified through the district HIV/AIDS register. Information on socioeconomic characteristics and contraceptive use before and after HIV diagnosis was obtained through structured questionnaires. Chi‐square testing was used to assess whether the included women differed from the target population in terms of age. Crude Odds ratios (ORs) were calculated to show the association between contraceptive use and the women’s socioeconomic characteristics. Logistic regression analyses were applied to adjust for possible confounding. The women’s contraceptive use before HIV testing and after HIV testing was described and compared by Chi‐square testing, and the association between post‐test counselling and the women’s use of condom was assessed by ORs. Results Of the 351 participants, 63% stated they had used contraception before HIV diagnosis and 89% stated they had used contraception after HIV diagnosis. Forty six per cent of the women had been using either the pill or an intrauterine device (IUD) before the diagnosis whereas the same applied for only 8% of the women after diagnosis. Thirty‐nine per cent stated they had been using condom before HIV diagnosis whereas 87% stated condom use after HIV diagnosis. Condom use was more common among women who had received post‐test counselling (OR 3.03, 95% CI 1.03–8.90). Conclusions A change of contraceptive methods from IUD and oral contraception before HIV diagnosis to condom use after HIV diagnosis was observed. The women’s use of condoms after HIV diagnosis was associated with having received post‐test counselling.     

The development of predictive tools for pre‐emptive dengue vector control: a study of Aedes aegypti abundance and meteorological variables in North Queensland,Australia

Objectives To describe the meteorological influences on adult dengue vector abundance in Australia for the development of predictive models to trigger pre‐emptive control operation. Methods Multiple linear regression analyses were performed using meteorological data and female Aedes aegypti collection data from BG‐Sentinel Mosquito traps placed at 11 monitoring sites in Cairns, north Queensland. Results Considerable regression coefficients (R² = 0.64 and 0.61) for longer‐ and shorter‐term factor models respectively were derived. Longer‐term factors significantly associated with abundance of adult vectors were mean minimum temperature (lagged 6 month) and mean daily temperature (lagged 4 month), explaining the predictable increase in abundance during the wet season. Factors explaining fluctuation in abundance in the shorter term were mean relative humidity over the previous 2 week and current daily average temperature. Rainfall variables were not found to be strong predictors of A. aegypti abundance in either longer‐ or shorter‐term models. Conclusions The implications of these findings for the development of useful predictive models for vector abundance risks are discussed. Such models can be used to guide the application of pre‐emptive dengue vector control, and thereby enhance disease management.     

Animal livestock and the risk of hospitalized diarrhoea in children under 5 years in Vietnam

Objective To investigate the association between environmental exposure to livestock and incidence of diarrhoea among Vietnamese children. Methods A population‐based cohort of 353 525 individuals, living in 75 828 households in Khanh Hoa Province, Vietnam, with baseline data covering geo‐referenced information on demography, socio‐economic status and household animals was investigated. Geographic information system was applied to calculate the density of livestock. The data were linked to hospitalized diarrhoea cases of children under 5 years recorded at two hospitals treating patients from the area as inpatients in the study area. Results Overall, 3116 children with diarrhoea were hospitalized during the study period. The incidence of diarrhoea hospitalization was 60.8/1000 child‐years. Male gender, age <2 years, higher number of household members and lack of tap water were significantly associated with an increased risk of diarrhoea. There was no evidence that ownership of livestock increased the risk of diarrhoea. In spatial analysis, we found no evidence that a high density of any animals was associated with an increased risk of diarrhoea. Conclusions Exposure to animals near or in households does not seem to constitute a major risk for diarrhoea in children under the age of 5 in Vietnam. Public health interventions to reduce childhood diarrhoea burden should focus on well‐recognized causes such as sanitation, personal hygiene, access to adequate clean water supply and vaccination.     

Ensuring HIV‐infected pregnant women start antiretroviral treatment: an operational cohort study from Lilongwe,Malawi

Objectives HIV‐infected women identified through antenatal care (ANC) often fail to access antiretroviral treatment (ART), leaving them and their infants at risk for declining health or HIV transmission. We describe results of measures to improve uptake of ART among eligible pregnant women. Methods Between October 2006 and December 2009, interventions implemented at ANC and ART facilities in urban Lilongwe aimed to better link services for women with CD4 counts <250/μl. A monitoring system followed women referred for ART to examine trends and improve practices in referral completion, on‐time ART initiation and ART retention. Results Six hundred and twelve women were ART eligible: 604 (99%) received their CD4 result, 344 (56%) reached the clinic, 286 (47%) started ART while pregnant and 261 (43%) were either alive on ART or transferred out after 6 months. Between 2006 and 2009, the median (IQR) time between CD4 blood draw and ART initiation fell from 41 days (17, 349) to 15 days (7,42) (P = 0.183); the proportion of eligible individuals starting ART while pregnant and retained for 6 months improved from 17% to 65% (P < 0.001). Delays generally shortened within the continuum of care from 2006 to 2009; however, time from CD4 blood draw to ART referral increased from 7 to 14 days. Conclusions Referrals between facilities and delays through CD4 count measurements create bottlenecks in patient care. Retention improved over time, but delays within the linkage process remained. ART initiation at ANC plus use of point‐of‐care CD4 tests may further enhance ART uptake.     

Mortality of Chagas’ disease in Brazil: spatial patterns and definition of high‐risk areas

Objective To describe patterns of spatial distribution of mortality associated with Chagas’ disease in Brazil. Methods Nationwide study of all deaths in Brazil from 1999 to 2007, where Chagas’ disease was recorded as a cause of death. Data were obtained from the national Mortality Information System of the Ministry of Health. We calculated the mean mortality rate for each municipality of residence in three‐year intervals and the entire period. Empirical Bayes smoothing was used to minimise random variation in mortality rates because of the population size in the municipalities. To evaluate the existence of spatial autocorrelation, global and local Moran’s I indices were used. Results The nationwide mean mortality rate associated with Chagas’ disease was 3.37/100 000 inhabitants/year, with a maximum of 138.06/100 000 in one municipality. Independently from the statistical approach, spatial analysis identified a large cluster of high risk for mortality by Chagas’ disease, involving nine states in the Central region of Brazil. Conclusion This study defined geographical priority areas for the management of Chagas’ disease and consequently reducing disease‐associated mortality in Brazil. Different spatial‐analytical approaches can be integrated to provide data for planning, monitoring and evaluating specific intervention measures.