A Multi-country Study of the Household Willingness-to-Pay for Dengue Vaccines: Household Surveys in Vietnam, Thailand, and Colombia.

BACKGROUND: The rise in dengue fever cases and the absence of dengue vaccines will likely cause governments to consider various types of effective means for controlling the disease. Given strong public interests in potential dengue vaccines, it is essential to understand the private economic benefits of dengue vaccines for accelerated introduction of vaccines into the public sector program and private markets of high-risk countries. METHODOLOGY/PRINCIPAL FINDINGS: A contingent valuation study for a hypothetical dengue vaccine was administered to 400 households in a multi-country setting: Vietnam, Thailand, and Colombia. All respondents received a description of the hypothetical dengue vaccine scenarios of 70% or 95% effectiveness for 10 or 30 years with a three dose series. Five price points were determined after pilot tests in order to reflect different local situations such as household income levels and general perceptions towards dengue fever. We adopted either Poisson or negative binomial regression models to calculate average willingness-to-pay (WTP), as well as median WTP. We found that there is a significant demand for dengue vaccines. The parametric median WTP is $26.4 ($8.8 per dose) in Vietnam, $70.3 ($23.4 per dose) in Thailand, and $23 ($7.7 per dose) in Colombia. Our study also suggests that respondents place more value on vaccinating young children than school age children and adults. CONCLUSIONS/SIGNIFICANCE: Knowing that dengue vaccines are not yet available, our study provides critical information to both public and private sectors. The study results can be used to ensure broad coverage with an affordable price and incorporated into cost benefit analyses, which can inform prioritization of alternative health interventions at the national level.

Molecular characterization of mediterranean spotted fever rickettsia isolated from a European traveler in the state of São Paulo, Brazil.

Rickettsial spotted fever is common in southeastern Brazil. Differential diagnosis of pathogens can be performed with proper laboratory methods. A traveler arriving from Portugal developed a fatal febrile hemorrhagic syndrome diagnosed as spotted fever rickettsiosis. We isolated the agent, which was identified as Rickettsia conorii conorii by sequencing rickettsial genes.

Features of Brazilian spotted fever in two different endemic areas in Brazil.

Brazilian spotted fever (BSF) caused by Rickettsia rickettsii is the most important rickettsiosis and the only reportable tick-borne disease in Brazil. In Brazil, the hard tick Amblyomma cajennense is the most important BSF vector; however, in São Paulo State, A. aureolatum was also recognized as a vector species in remaining Atlantic forest areas near the metropolitan area of São Paulo city. We analyzed clinical and epidemiological features of BSF cases from two distinct areas where A. cajennense (Area 1) and A. aureolatum (Area 2) are the incriminated vectors. The clinical features demonstrate the same severity pattern of BSF in both endemic areas. Differences in seasonality, patient characteristics (median age and gender), and epidemiological risk factors (animals host contact and vegetation characteristics) were observed and possibly could be attributed to the characteristics of each vector and their typical biological cycle (hosts and environment).

A novel association of acquired ADAMTS13 inhibitor and acute dengue virus infection.

BACKGROUND: Dengue is a mosquito-borne viral disease with an increasing incidence worldwide. Thrombocytopenia is a common finding in dengue virus (DV) infection; however, the underlying mechanisms remain unknown. CASE REPORT: Here we provide the first evidence of a case of antibody formation against ADAMTS13 (ADAMTS13 inhibitor) in the course of a severe acute DV infection resulting in thrombotic microangiopathy (TMA). The patient presented with classical dengue symptoms (positive epidemiology, high fever, myalgia, predominantly in the lower limbs and lumbar region for 1 week) and, after 11 days of initial symptoms, developed TMA. Clinical and laboratorial investigation of dengue and TMA was performed. RESULTS: The patient presented with ADAMTS13 inhibitor (IgG) during the acute phase of the disease, without anti-platelet antibodies detectable. Dengue infection had laboratorial confirmation. There were excellent clinical and laboratory responses to 11 serial plasma exchanges. Anti-ADAMTS13 inhibitor disappeared after remission of TMA and dengue resolution. No recurrence of TMA symptoms was observed after 2-year follow-up. CONCLUSIONS: Although the real incidence of dengue-related TMA is unknown, this case provides the basis for future epidemiologic studies on acquired ADAMTS13 deficiency in DV infection. The prompt clinical recognition of this complication and early installment of specific therapy with plasma exchange are likely to improve the outcome of severe cases of dengue.

Economic impact of a rotavirus vaccine in Brazil.

The study was done to evaluate the cost-effectiveness of a national rotavirus vaccination programme in Brazilian children from the healthcare system perspective. A hypothetical annual birth-cohort was followed for a five-year period. Published and national administrative data were incorporated into a model to quantify the consequences of vaccination versus no vaccination. Main outcome measures included the reduction in disease burden, lives saved, and disability-adjusted life-years (DALYs) averted. A rotavirus vaccination programme in Brazil would prevent an estimated 1,804 deaths associated with gastroenteritis due to rotavirus, 91,127 hospitalizations, and 550,198 outpatient visits. Vaccination is likely to reduce 76% of the overall healthcare burden of rotavirus-associated gastroenteritis in Brazil. At a vaccine price of US$ 7-8 per dose, the cost-effectiveness ratio would be US$ 643 per DALY averted. Rotavirus vaccination can reduce the burden of gastroenteritis due to rotavirus at a reasonable cost-effectiveness ratio.

Human asymptomatic infection in visceral leishmaniasis: a seroprevalence study in an urban area of low endemicity. Preliminary results.

Many aspects of the human asymptomatic visceral leishmaniasis (VL) remain not elucidated, and moreover, almost all the data come from highly endemic areas. The recent appearance of American VL (AVL) in the northeastern region of the state of São Paulo, Brazil, offered a good opportunity for further understanding. We present the preliminary results from a seroprevalence study on AVL in humans in Araçatuba, São Paulo. This was a cross-sectional survey on a random sample of the population (one-stage simple random sampling) in two areas, using rK39 dipstick tests. The sex ratios and age distributions in the two areas were comparable. Detectable antibodies were found in 23 subjects (20%) in area A1 and in 6 subjects (4.8%) in area A2. There was no significant difference in age distribution of seropositivity between the areas. We observed a difference in asymptomatic infection rates between the two areas, possibly associated with socioeconomic levels and transmission intensity.

Brazilian spotted fever: a case series from an endemic area in southeastern Brazil: epidemiological aspects.

Brazilian spotted fever (BSF) is the most important tick-borne disease in Brazil and is caused by Rickettsia rickettsii and transmitted by the Ixodid tick Amblyomma cajennense, its main vector. We present epidemiologic aspects of a case series of patients admitted to the Hospital das Clínicas da UNICAMP from 1985 to 2003 with a confirmed diagnosis of BSF either by a fourfold rise in indirect immunofluorescence (IFA) titers of IgG antibodies reactive with R. rickettsii or isolation of R. rickettsii from blood or skin specimens. Seasonal variation of case occurrence seems to be associated with the life cycle of the tick. The recent reemergence of cases seems to be associated with the growing numbers of the capybara (Hydrochaeris hydrochaeris) and their expansion into urban areas.

Brazilian spotted fever: a case series from an endemic area in southeastern Brazil: clinical aspects.

This case series study is based on a retrospective review of medical records and case notification files of patients admitted to The Hospital das Clínicas da UNICAMP from 1985 to 2003 with a confirmed diagnosis of BSF either by fourfold rise in indirect immunofluorescence assay (IFA) titers of IgG antibodies reactive with R. rickettsii or isolation of R. rickettsii from blood or skin specimens. A median lethality of 41.9 % was observed between 1985 and 2004. The case-fatality ratio of 30 % in our study, lower than the overall São Paulo state ratio, could be explained by a higher index of suspicion and a larger experience in our hospital, a regional referral center for BSF. The presence of the classical triad of fever, rash, and headache as described in RMSF was observed in fever than half (35.2%) of our patients.

Murine (endemic) typhus in Brazil: case report and review.

Murine typhus has been increasingly recognized worldwide and is becoming a relevant differential diagnosis in febrile conditions. In Brazil, murine typhus has never received much attention. We present a recently diagnosed case and a literature review that suggests that the disease could be more prevalent in Southeastern Brazil than acknowledged until now.

Murine (endemic) typhus in Brazil: case report and review

O tifo murino tem sido reconhecido com freqüência crescente em todo o mundo e vem se tornando um relevante diagnóstico diferencial de quadros febris. No Brasill, o tifo murino nunca mereceu grande atenção. Descrevemos um caso clínico e fazemos revisão da literatura que sugere que a doença poderia ser mais prevalente no sudeste brasileiro do que reconhecido até então.

Tétano acidental: análise do perfil clínico e epidemiológico de casos internados em hospital universitário / Acquired tetanus: clinical and epidemiological characteristics of patients in an university hospital

O número de casos nodificados de tétano acidental no Estado de Säo Paulo sofreu reduçäo. O declínio do número de casos de qualquer doença sempre traz transformaçöes no seu perfil epidemiológico, que devem sempre ser analisadas para aprimorar as medidas preventivas. Assim, foi analisado o perfil clínico e epidemiológico dos casos de tétano internados em hospital universitário de Campinas de 1989 a 1996. Estudo descritivo e retrospectivo (série de casos). Todos os pacientes com diagnóstico de tétano de janeiro de 1989 a março de 1996, internados no hospital universitário, foram analisados. Catorze (28 por cento) eram da zona rural e 36 (72 por cento) da zona urbana. A idade média foi de 47,6 anos e a mediana de 49,5. Dos pacientes da zona rural, 42,8 por cento tinham até 30 anos e 21,42 por cento tinham mais de 50 anos, sendo a média 36,21 e a mediana 34,5: dos pacientes da zona urbana, 13,9 por cento tinham até 30 anos e 58,3 por cento mais de 50 anos, sendo a média de 52,2 a a mediana de 54,5. A letalidade foi de 20 por cento, mais elevada nos pacientes curarizados (60 por cento). Na regiäo estudada existem dois padröes epidemiológicos: o rural, com maior número de jovens, refletindo uma vacinaçäo inadequada, e o urbano, semelhante ao dos países desenvolvidos, com predomínio das faixas etárias mais altas

Trajetória das doenças infecciosas: da eliminaçäo da poliomielite à reintroduçäo da cólera / Trajectory of infectious diseases: elimination of poliomyelitis and reintroduce of cholera

Aborda a tendência geral da morbidade por doenças infecciosas e parasitárias nos últimos vinte anos, o ressurgimento de doenças infecciosas há muito consideradas erradicadas e o aparecimento de outras até entäo desconhecidas

Total serum IgE and parasite-specific IgG and IgA antibodies in human strongyloidiasis

Total serum IgE, and Strongyloides-specific IgG and IgA antibodies were studied in 27 patients with parasitologically proven strongyloidiasis. Clinical manifestations in this case series were investigated by a retrospective study of the patient's records. Total serum IgE levels were elevated (greater than 250 IU/ml) in 59 of the patients (mean concentration = 1364 IU/ml). Parasite-specific IgG and IgA antibodies were detected by ELISA in the serum of 23 (85.2) and 21 (77.8) patients, respectively. Elevated serum IgE and clinical manifestations were not useful indexes of the presence of strongyloidiasis. On the other hand, our results support the view that serologic tests, particularly ELISA for detecting Strongyloides-specific IgG antibodies, can be usefully exploited for diagnostic purposes in strongyloidiasis.