Threat of Dengue to Blood Safety in Dengue-Endemic Countries

Dengue, the most common arbovirus infection globally, is transmitted by mosquito vectors. Healthcare-related transmission, including transmission by blood products, has been documented, although the frequency of these occurrences is unknown. Dengue is endemic to Singapore, a city-state in Asia. Using mathematical modeling, we estimated the risk for dengue-infected blood transfusions in Singapore in 2005 to be 1.625-6/10,000 blood transfusions, assuming a ratio of asymptomatic to symptomatic infections of 2:1 to 10:1. However, the level of viremia required to cause clinical dengue cases is person-dependent and unknown. Further studies are needed to establish the magnitude of the threat that dengue poses to blood safety in countries where it is endemic. It will then be possible to assess whether screening is feasible and to identify approaches that are most cost-effective on the basis of characteristics of local populations and seasonality of dengue.

Hantavirus Pulmonary Syndrome, Central Plateau, Southeastern, and Southern Brazil

Hantavirus pulmonary syndrome (HPS) is an increasing health problem in Brazil because of encroachment of sprawling urban, agricultural, and cattle-raising areas into habitats of subfamily Sigmodontinae rodents, which serve as hantavirus reservoirs. From 1993 through June 2007, a total of 884 cases of HIPS were reported in Brazil (case-fatality rate 39%). To better understand this emerging disease, we collected 89 human serum samples and 68 rodent lung samples containing antibodies to hantavirus from a 2,500-km-wide area in Brazil. RNA was isolated from human samples and rodent lung tissues and subjected to reverse transcription-PCR. Partial sequences of nucleocapsid protein and glycoprotein genes from 22 human and 16 rodent sources indicated only Araraquara virus and Juquitiba virus lineages. The case-fatality rate of HPS was higher in the area with Araraquara virus. This virus, which may be the most virulent hantavirus in Brazil, was associated with areas that have had greater anthropogenic changes.

Novel Spotted Fever Group Rickettsiosis, Brazil

We report a clinical case of spotted fever group rickettsiosis acquired in Sao Paulo, Brazil, Definitive diagnosis was supported by seroconversion between acute-phase and convalescent-phase serum samples. Molecular analysis of skin samples indicated the agent was a novel spotted fever group strain closely related to Rickettsia africae, R. parked, and R. sibirica.

Rocky Mountain Spotted Fever in Dogs, Brazil

Clinical illness caused by Rickettsia rickettsii in dogs has been reported solely in the United States. We report 2 natural clinical cases of Rocky Mountain spotted fever in dogs in Brazil. Each case was confirmed by seroconversion and molecular analysis and resolved after doxycycline therapy.

Experimental Infection of Amblyomma aureolatum Ticks with Rickettsia rickettsii

We experimentally infected Amblyomma aureolatum ticks with the bacterium Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever (RMSF). These ticks are a vector for RMSF in Brazil. R. rickettsii was efficiently conserved by both transstadial maintenance and vertical (transovarial) transmission to 100% of the ticks through 4 laboratory generations. However, lower reproductive performance and survival of infected females was attributed to R. rickettsii infection. Therefore, because of the high susceptibility of A. aureola turn ticks to R. rickettsii infection, the deleterious effect that the bacterium causes in these ticks may contribute to the low infection rates (< 1%) usually reported among field populations of A. aureolatum ticks in RMSF-endemic areas of Brazil. Because the number of infected ticks would gradually decrease after each generation, it seems unlikely that A. aureolatum ticks could sustain R. rickettsii infection over multiple successive generations solely by vertical transmission.

Yellow Fever Virus in Haemagogus leucocelaenus and Aedes serratus Mosquitoes, Southern Brazil, 2008

Yellow fever virus (YFV) was isolated from Haemagogus leucocelaenus mosquitoes during an epizootic in 2001 in the Rio Grande do Sul State in southern Brazil In October 2008 a yellow fever outbreak was reported there with nonhuman primate deaths and human cases This latter outbreak led to intensification of surveillance measures for early detection of YFV and support for vaccination programs We report entomologic surveillance in 2 municipalities that recorded nonhuman primate deaths Mosquitoes were collected at ground level identified and processed for virus isolation and molecular analyses Eight YFV strains were isolated (7 from pools of Hg leucocelaenus mosquitoes and another from Aedes serratus mosquitoes) 6 were sequenced and they grouped in the YFV South American genotype I The results confirmed the role of Hg leucocelaenus mosquitoes as the main YFV vector in southern Brazil and suggest that Ae serratus mosquitoes may have a potential role as a secondary vector

Hemoplasma Infection in HIV-positive Patient, Brazil

Hemotrophic mycoplasmas infect a variety of mammals. Although infection in humans is rarely reported, an association with an immunocompromised state has been suggested. We report a case of a Mycoplasma haemofelis-like infection in an HIV-positive patient co-infected with Bartonella henselae.

Cost-effectiveness of Sick Leave Policies for Health Care Workers with Influenza-like Illness, Brazil, 2009

We describe the effect of influenza-like illness (ILI) during the outbreak of pandemic (H1N1) 2009 on health care worker (HCW) absenteeism and compare the effectiveness and cost of 2 sick leave policies for HCWs with suspected influenza. We assessed initial 2-day sick leaves plus reassessment until the HOW was asymptomatic (2-day + reassessment policy), and initial 7-day sick leaves (7-day policy). Sick leaves peaked in August 2009: 3% of the workforce received leave for ILI. Costs during May October reached R$798,051.87 (approximate to US $443,362). The 7-day policy led to a higher monthly rate of sick leave days per 100 HCWs than did the 2-day + reassessment policy (8.72 vs. 3.47 days/100 HCWs; p<0.0001) and resulted in higher costs (US $609 vs. US $1,128 per HCW on leave). ILI affected HCW absenteeism. The 7-day policy was more costly and not more effective in preventing transmission to patients than the 2-day + reassessment policy.

Rapid diagnosis in pediatric infectious diseases: The past, the present and the future

The focus of rapid diagnosis of infectious diseases of children in the last decade has shifted from variations of the conventional laboratory techniques of antigen detection, microscopy and culture to that of molecular diagnosis of infectious agents. Pediatricians will need to be able to interpret the use, limitations and results of molecular diagnostic techniques as they are increasingly integrated into routine clinical microbiology laboratory protocols. PCR is the best known and most successfully implemented diagnostic molecular technology to date. It can detect specific infectious agents and determine their virulence and antimicrobial genotypes with greater speed, sensitivity and specificity than conventional microbiology methods. Inherent technical limitations of PCR are present, although they are reduced in laboratories that follow suitable validation and quality control procedures. Variations of PCR together with advances in nucleic acid amplification technology have broadened its diagnostic capabilities in clinical infectious disease to now rival and even surpass traditional methods in some situations. Automation of all components of PCR is now possible. The completion of the genome sequencing projects for significant microbial pathogens, in combination with PCR and DNA chip technology, will revolutionize the diagnosis and management of infectious diseases.

Telehealth responses to bio-terrorism and emerging infections

Emerging infectious diseases, such as severe acute respiratory syndrome (SARS), are of huge economic importance. They are difficult to predict. The World Health Organization has a Global Outbreak Alert and Response Network, which was involved at an early stage in the SARS outbreak in 2003. Three major lessons were learned as a result of the SARS epidemic in 2003, involving communication, evidence-based action and global partnerships. It is proposed that a series of broadband global response networks should be developed. At a technical level the networks are essentially in place, such as the Internet2 global network. Suitable peripheral devices also exist. What has not yet been created is the appropriate software to allow the use of these networks, although a number of commercial products are in the process of development.

Review of genitourinary tuberculosis with focus on end-stage renal disease

Tuberculosis (TB) is a current public health problem, remaining the most common worldwide cause of mortality from infectious disease. Recent studies indicate that genitourinary TB is the third most common form of extra-pulmonary disease. The diagnosis of renal TB can be hypothesized in a non-specific bacterial cystitis associated with a therapeutic failure or a urinalysis with a persistent leukocyturia in the absence of bacteriuria. We report on the case of a 33-year-old man who presented on admission end stage renal disease (ESRD) secondary to renal TB and a past history of pulmonary TB with important radiologic findings. The diagnosis was based on clinical findings despite all cultures being negative. Empiric treatment with tuberculostatic drugs was started and the patient became stable. He was discharged with no symptom, but without renal function recovery. He is on maintenance hemodialysis three times a week. TB is an important cause of kidney disease and can lead to irreversible renal function loss.

Neurological disease in HIV-infected patients in the era of highly active antiretroviral treatment: a Brazilian experience

To study characteristics of neurological disorders in HIV/AIDS patients and their relationship to highly active antiretroviral treatment, a cross-sectional study was conducted in an infectious disease public hospital in Belo Horizonte, Brazil, between February 1999 and March 2000. Of the 417 patients enrolled, neurological disease was observed in 194 (46.5%) and a new AIDS-defining neurological event developed in 23.7% of individuals. Toxoplasmosis (42.3%), cryptococcosis meningitis (12.9%) and tuberculosis (10.8%) were the most common causes of neurological complications. The majority (79.3%) of patients were on highly active antiretroviral treatment and these individuals using HAART showed higher CD4 cell counts (p = 0.014) and presented stable neurological disease (p= 0.0001), although no difference was found with respect to the profile of neurological complications. The neurological diseases continue to be a frequent complication of HIV/AIDS and infections are still its main causes in Brazil, even in the highly active antiretroviral treatment era.

Toscana virus in Spain

Toscana virus (TOSV, Phlebovirus, family Bunyaviridae) infection is one of the most prevalent arboviruses in Spain. Within the objectives of a multidisciplinary network, a study on the epidemiology of TOSV was conducted in Granada, in southern Spain. The overall seroprevalence rate was 24.9%, significantly increasing with age. TOSV was detected in 3 of 103 sandfly pools by viral culture or reverse transcription-polymerase chain reaction from a region of the L gene. Nucleotide sequence homology was 99%-100% in TOSV from vectors and patients and 80%-81% compared to the Italian strain ISS Phl.3. Sequencing of the N gene of TOSV isolates from patients and vectors indicated 87%-88% and 100% homology at the nucleotide and amino acid levels, respectively, compared to the Italian strain. These findings demonstrate the circulation of at least 2 different lineages of TOSV in the Mediterranean basin, the Italian lineage and the Spanish lineage.

Pediatric parapneumonic empyema, Spain

Pediatric parapneumonic empyema (PPE) has been increasing in several countries including Spain. Streptococcus pneumoniae is a major PPE pathogen; however, antimicrobial pretreatment before pleural fluid (PF) sampling frequently results in negative diagnostic cultures, thus greatly underestimating the contribution of pneumococci, especially pneumococci susceptible to antimicrobial agents, to PPE. The study aim was to identify the serotypes and genotypes that cause PPE by using molecular diagnostics and relate these data to disease incidence and severity. A total of 208 children with PPE were prospectively enrolled; blood and PF samples were collected. Pneumococci were detected in 79% of culture-positive and 84% of culture-negative samples. All pneumococci were genotyped by multilocus sequence typing. Serotypes were determined for 111 PPE cases; 48% were serotype 1, of 3 major genotypes previously circulating in Spain. Variance in patient complication rates was statistically significant by serotype. The recent PPE increase is principally due to nonvaccine serotypes, especially the highly invasive serotype 1.

Vertical Transmission of Pneumocystis jirovecii in Humans

This study is part of the project “Pneumocystis Pathogenomics: Unravelling the Colonization-to-Disease Shift,” a Coordination Action supported by the European Commission (ERANET PathoGenoMics). This study was partially supported by the Spanish Ministry of Health (FIS 03/1743). M.A.M.-C. and C.d.l.H. were supported by the Spanish Ministry of Health (FIS CP-04/217 and FIS CM-04/146).