Dengue fever in Brazilian adults and children: assessment of clinical findings and their validity for diagnosis.

Although it is well known that the signs and symptoms of dengue fever (DF) may overlap with those of other diseases, few attempts have been made to assess quantitatively their validity in the diagnosis of DF. The clinical data recorded, in the Brazilian town of Uberlândia between 1993 and 1998, on the notification forms from 495 serologically confirmed cases of DF and 650 patients who tested negative for this disease were therefore compared. Fever, headache, myalgia, retro-orbital pain and arthralgia were the most commonly reported symptoms among the confirmed cases (each occurring in at least 92% of the cases), whereas haemorrhagic manifestations (reported in 7% of cases) were uncommon. Although comparisons between the two groups gave risk ratios (RR) very close to 1 for most signs and symptoms, rash [RR=1.86; 95% confidence interval (CI)=1.63-2.13] and petechiae (RR=1.38; CI=1.07-1.79) were more commonly found among the confirmed cases. As the positive and negative predictive values of all of the signs and symptoms investigated were low, diagnosis of DF should not be based solely on clinical grounds.

Yellow fever vaccination during pregnancy and spontaneous abortion: a case-control study.

OBJECTIVE: To assess a possible association between Yellow fever (YF) vaccine (inadvertently) administered during early pregnancy and spontaneous abortion. METHOD: A hospital-based case-control study conducted in a Brazilian town after a YF vaccine campaign that followed an epidemic of dengue. The study included 39 women who attended a university hospital with spontaneous abortion (cases) and 74 pregnant women attending the antenatal clinic of that hospital (controls). RESULTS: The crude odds ratio (relative risk estimate) of this association was 2.49, which dropped to 2.29 (95% CI 0.65-8.03) when adjusted for several confounders by multiple logistic regression. Dengue and exposure to organophosphate insecticide fogging during pregnancy were not associated with spontaneous abortion. CONCLUSION: This study, although small and with low power, provides some evidence that women vaccinated with YF vaccine during early pregnancy have an increased risk of having spontaneous abortion. Based on these findings a sensible recommendation should be to avoid YF vaccination of pregnant women unless their risk of acquiring YF outweighs the risk of vaccine-related abortion.

Reactivation of Chagas' disease in patients with AIDS: report of three new cases and review of the literature.

Three new cases of reactivation of Chagas' disease in patients with AIDS, with central nervous system and/or cardiac involvement, are reported. One patient had histological evidence of acute esophageal and gastric Trypanosoma cruzi myositis, a previously unrecognized finding in patients with reactivated Chagas' disease. The patients had a low CD4 lymphocyte count and had other AIDS-defining opportunistic infections. One patient's condition improved with benznidazole therapy. Analysis of these three cases and review of the 13 others published in the literature revealed that the central nervous system is the most commonly involved site (75%), followed by the heart (44%). Early diagnosis and treatment with benznidazole or nifurtimox probably improve the survival rate. Long-term secondary prophylaxis should be recommended for patients who respond to therapy, although it is uncertain which drug to use for this purpose. T. cruzi should be included in the list of opportunistic pathogens causing infection in severely immunocompromised patients with AIDS.