Clinical Indicators of Fatal Dengue in Two Endemic Areas of Colombia: A Hospital-Based Case-Control Study

According to the World Health Organization, 98% of fatal dengue cases can be prevented; however, endemic countries such as Colombia have recorded higher case fatality rates during recent epidemics. We aimed to identify the predictors of mortality that allow risk stratification and timely intervention in patients with dengue. We conducted a hospital-based, case-control (1:2) study in two endemic areas of Colombia (2009-2015). Fatal cases were defined as having either 1) positive serological test (IgM or NS1), 2) positive virological test (RT-PCR or viral isolation), or 3) autopsy findings compatible with death from dengue. Controls (matched by state and year) were hospitalized nonfatal patients and had a positive serological or virological dengue test. Exposure data were extracted from medical records by trained staff. We used conditional logistic regression (adjusting for age, gender, disease's duration, and health-care provider) in the context of multiple imputation to estimate exposure to case-control associations. We evaluated 110 cases and 217 controls (mean age: 35.0 versus 18.9; disease's duration pre-admission: 4.9 versus 5.0 days). In multivariable analysis, retro-ocular pain (odds ratios [OR] = 0.23), nausea (OR = 0.29), and diarrhea (OR = 0.19) were less prevalent among fatal than nonfatal cases, whereas increased age (OR = 2.46 per 10 years), respiratory distress (OR = 16.3), impaired consciousness (OR = 15.9), jaundice (OR = 32.2), and increased heart rate (OR = 2.01 per 10 beats per minute) increased the likelihood of death (AUC: 0.97, 95% confidence interval: 0.96, 0.99). These results provide evidence that features of severe dengue are associated with higher mortality, which strengthens the recommendations related to triaging patients in dengue-endemic areas.

Burden of dengue among febrile patients at the time of chikungunya introduction in Piedecuesta, Colombia

Objective

To estimate the age‐specific incidence of symptomatic dengue and chikungunya in Colombia.

Method

A passive facility‐based fever surveillance study was conducted among individuals with undifferentiated fever. Confirmatory diagnostics included serological and molecular tests in paired samples, and surveillance's underreporting was assessed using capture–recapture methods.

Results

Of 839 febrile participants 686 completed the study. There were 33.2% (295/839) dengue infections (51% primary infections), and 35.9% (191/532) of negative dengue cases there were chikungunya cases. On average, dengue cases were younger (median = 18 years) than chikungunya cases (median = 25 years). Thrombocytopaenia and abdominal pain were the main dengue predictors, while presence of rash was the main predictor for chikungunya diagnosis. Underreporting of dengue was 31%; the estimated expansion factors indicate an underreporting rate of dengue cases of threefold for all cases and of almost sixfold for inpatients.

Conclusions

These findings highlight the ongoing coexistence of both arboviruses, a distinct clinical profile of each condition in the study area that could be used by clinicians to generate a differential diagnosis, and the presence of underreporting, mostly among hospitalised cases.

Epidemiology of American tegumentary leishmaniasis in domestic dogs in an endemic zone of western Venezuela

Domestic dogs are not only reservoir hosts of the American zoonotic visceral leishmaniasis (ZVL) but of the American zoonotic tegumentary leishmaniasis (ATL) as well, for different reasons. However it is still controversial to state that dogs are incriminated as ATL reservoir hosts as there is evidence that humans and dogs are likely to be exposed in the same way to sandfly vector. In Venezuela this issue has not been completely addressed, for this reason we selected a location inside Trujillo city to study eco-epidemiological conditions as well as to survey a significant sample of dogs by Montenegro Skin Test (MST). Antigen was prepared according to standard procedure using Leishmania (V) braziliensis promastigotes (80 microg/ml); response was read 48 hours post-inoculation with an induration size > 5 mm being considered as positive. The study place is an endemic mountainous semi-urban area located at 850-950 masl with an average rainfall of 150 mm/year. We evaluated 61 dogs in 46 houses with 168 human beings. Among the human population 27 cases of ATL were reported (16.1%). With the MST we found 19 positive-reaction dogs (31%) (mean MST size of 9.58 mm, 95% CI: 8.41-10.75) in 13 houses (28%). Multivariate analysis did not reveal significant association between domestic MST positive-dog ownership and human ATL cases (RR = 1.48, p = 0.28). Although some studies have indicated that dog ownership and dog infection rates are associated with an increased risk of human disease in different evaluated places, this question has not been completely answered in Venezuelan studied zones, further research is necessary.