Infectious disease among enslaved African Americans at Eaton's Estate, Warren County, North Carolina, ca. 1830-1850

The skeletal remains of 17 people buried in the Eaton Ferry Cemetery in northern North Carolina provide a means of examining health and infectious disease experience in the XIX century South. The cemetery appears to contain the remains of African Americans enslaved on the Eaton family estate from approximately 1830-1850, and thus offers a window into the biological impacts of North American slavery in the years preceding the Civil War. The sample includes the remains of six infants, one child, and one young and nine mature adults (five men, four women, and one unknown). Skeletal indices used to characterize health and disease in the Eaton Ferry sample include dental caries, antemortem tooth loss, enamel hypoplasia, porotic hyperostosis, periosteal lesions, lytic lesions, and stature. These indicators reveal a cumulative picture of compromised health, including high rates of dental disease, childhood growth disruption, and infectious disease. Specific diseases identified in the sample include tuberculosis and congenital syphilis. Findings support previous research on the health impacts of slavery, which has shown that infants and children were the most negatively impacted segment of the enslaved African American population.

Case histories of infectious disease management in developing countries: Phnom Penh and Kabul

Healthcare in developing countries is affected by severe poverty, political instability and diseases that may be of lesser importance in industrialized countries. The aim of this paper was to present two cases and histories of physicians working in hospitals in developing countries and to discuss the opportunities for clinical investigation and collaboration. Cases of patients in Phnom Penh, Cambodia, with histoplasmosis, cryptococcal meningitis, crusted scabies, cerebral lesions and human immunodeficiency virus and of patients in Kabul, Afghanistan, with liver cirrhosis, nephrotic syndrome and facial ulcer are discussed. Greater developmental support is required from industrialized nations, and mutually beneficial cooperation is possible since similar clinical problems exist on both sides (e.g. opportunistic cardiovascular infections). Examples for possible support of hospital medicine include physician interchange visits with defined objectives (e.g. infection control or echocardiography training) and collaboration with clinical investigations and projects developed locally (e.g. epidemiology of cardiovascular diseases or nosocomial bloodborne infections).

Invasive candidosis: contrasting the perceptions of infectious disease physicians and intensive care physicians

Introduction We analyze how infectious disease physicians perceive and manage invasive candidosis in Brazil, in comparison to intensive care unit specialists. Methods A 38-question survey was administered to 56 participants. Questions involved clinicians' perceptions of the epidemiology, diagnosis, treatment and prophylaxis of invasive candidosis. P < 0.05 was considered statistically significant. Results The perception that candidemia not caused by Candida albicans occurs in less than 10% of patients is more commonly held by intensive care unit specialists (p=0.018). Infectious disease physicians almost always use antifungal drugs in the treatment of patients with candidemia, and antifungal drugs are not as frequently prescribed by intensive care unit specialists (p=0.006). Infectious disease physicians often do not use voriconazole when a patient's antifungal treatment has failed with fluconazole, which also differs from the behavior of intensive care unit specialists (p=0.019). Many intensive care unit specialists use fluconazole to treat candidemia in neutropenic patients previously exposed to fluconazole, in contrast to infectious disease physicians (p=0.024). Infectious disease physicians prefer echinocandins as a first choice in the treatment of unstable neutropenic patients more frequently than intensive care unit specialists (p=0.013). When candidemia is diagnosed, most infectious disease physicians perform fundoscopy (p=0.015), whereas intensive care unit specialists usually perform echocardiograms on all patients (p=0.054). Conclusions This study reveals a need to better educate physicians in Brazil regarding invasive candidosis. The appropriate management of this disease depends on more drug options being available in our country in addition to global coverage in private and public hospitals, thereby improving health care.

Quantitation of HIV-1 RNA Viral Load Using NASBA Methodology and Comparison with other Surrogate Markers for Disease Progression

In this study, HIV-1 viral load quantitation determined by Nucleic Acid Sequence Based Amplification (NASBA) was compared with other surrogate disease progression markers (antigen p24, CD4/CD8 cell counts and b-2 microglobulin) in 540 patients followed up at São Paulo, SP, Brazil. HIV-1 RNA detection was statistically associated with the presence of antigen p24, but the viral RNA was also detected in 68% of the antigen p24 negative samples, confirming that NASBA is much more sensitive than the determination of antigen p24. Regarding other surrogate markers, no statistically significant association with the detection of viral RNA was found. The reproducibility of this viral load assay was assessed by 14 runs of the same sample, using different reagents batches. Viral load values in this sample ranged from 5.83 to 6.27 log (CV = 36 %), less than the range (0.5 log) established to the determination of significant viral load changes.

Evolutionary Control of Infectious Disease: Prospects for Vectorborne and Waterborne Pathogens

Evolutionary theory may contribute to practical solutions for control of disease by identifying interventions that may cause pathogens to evolve to reduced virulence. Theory predicts, for example, that pathogens transmitted by water or arthropod vectors should evolve to relatively high levels of virulence because such pathogens can gain the evolutionary benefits of relatively high levels of host exploitation while paying little price from host illness. The entrance of Vibrio cholerae into South America in 1991 has generated a natural experiment that allows testing of this idea by determining whether geographic and temporal variations in toxigenicity correspond to variation in the potential for waterborne transmission. Preliminary studies show such correspondences: toxigenicity is negatively associated with access to uncontaminated water in Brazil; and in Chile, where the potential for waterborne transmission is particularly low, toxigenicity of strains declined between 1991 and 1998. In theory vector-proofing of houses should be similarly associated with benignity of vectorborne pathogens, such as the agents of dengue, malaria, and Chagas' disease. These preliminary studies draw attention to the need for definitive prospective experiments to determine whether interventions such as provisioning of uncontaminated water and vector-proofing of houses cause evolutionary reductions in virulence

A model for intra-familial distribution of an infectious disease (Chagas' disease)

A probabilistic model for intra-familial distribution of infectous disease is proposed and applied to the prevalence of positive serology for Trypanosoma cruzi infection in Northeastern Brazilian sample. This double with one tail excess model fits satisfactorily to the data and its interpretation says that around 51% of these 982 families are free of infection risk; among those that are at risk, 3% have a high risk (0.66), probably due to high domestic infestation of the vector bug; while 97% show a small risk (0.11), probably due to accidental, non-domestic transmission.

Silicon and rice disease management

The element silicon (Si) is not considered an essential nutrient for plant function. Nevertheless, Si is absorbed from soil in large amounts that are several fold higher than those of other essential macronutrients in certain plant species. Its beneficial effects have been reported in various situations, especially under biotic and abiotic stress conditions. The most significant effect of Si on plants, besides improving their fitness in nature and increasing agricultural productivity, is the restriction of parasitism. There has been a considerable amount of research showing the positive effect of Si in controlling diseases in important crops. Rice (Oryza sativa), in particular, is affected by the presence of Si, with diseases such as blast, brown spot and sheath blight becoming more severe on rice plants grown in Si-depleted soils. The hypothesis underlying the control of some diseases in both mono- and di-cots by Si has been confined to that of a mechanical barrier resulting from its polymerization in planta. However, some studies show that Si-mediated resistance against pathogens is associated with the accumulation of phenolics and phytoalexins as well as with the activation of some PR-genes. These findings strongly suggest that Si plays an active role in the resistance of some plants to diseases rather than forming a physical barrier that impedes penetration by fungal pathogens.

MICROCIRCULATION AND CHAGAS' DISEASE: HYPOTHESIS AND RECENT RESULTS

This review focuses on studies that support the microvascular hypothesis, as well as on immunological and neurogenic mechanisms, and the role of the parasite itself, to explain further the pathology and clinical course of myocardial involvement in chagasic cardiomyopathy. The salient features of coronary microcirculation and Chagas' disease are discussed.

Paracoccidioides brasilienses isolates obtained from patients with acute and chronic disease exhibit morphological differences after animal passage

The basis for virulence in Paracoccidioides brasiliensis is not completely understood. There is a consensus that the sequencial in vitro subcultivation of P. brasiliensis leads to loss of its pathogenicity, which can be reverted by reisolation from animal passage. Attention to morphological and biochemical properties that are regained or demonstrated after animal passage may provide new insights into factors related to the pathogenicity and virulence of P. brasiliensis. We evaluated morphological characters: the percentage of budding cells, number of buds by cell and the diameter of 100 mother cells of yeast-like cells of 30 P. brasiliensis isolates, before and after animal passage. The isolates were obtained from patients with different clinical forms of paracoccidioidomycosis (PCM): acute form (group A, n=15) and chronic form (group C, n=15). The measurement of the yeast cell sizes was carried out with the aid of an Olympus CBB microscope coupled with a micrometer disc. We measured the major transverse and longitudinal axes of 100 viable cells of each preparation. The percentage of budding cells as also the number of buds by cell was not influenced by animal passage, regardless of the source of the strain (acute or chronic groups). The size values of P. brasiliensis isolates from groups A and C, measured before the animal passage exhibited the same behavior. After animal passage, there was a statistically significant difference between the cell sizes of P. brasiliensis isolates recovered from testicles inoculated with strains from groups A and C. The maximum diameter of mother cells from group A isolates exhibited a size of 42.1mm in contrast with 32.9mm exhibited by mother cells from group C (p<0.05). The diameter of 1500 mother cells from group A isolates exhibited a medium size of 16.0mm (SD ± 4.0), a value significantly higher than the 14.1mm (SD = ± 3.3) exhibited by 1500 mother cells from group C isolates (p<0.05). Our results reinforce the polymorphism exhibited by P. brasiliensis in biological material and the need for further investigations to elucidate the role of morphological parameters of the fungus in the natural history of the disease.

Echovirus 4 associated to hand, foot and mouth disease

Hand, foot and mouth disease (HFMD) is a contagious enteroviral infection occurring primarily in children and characterized by vesicular palmoplantar eruptions and erosive stomatitis. Echovirus 4 (EV-4) has been commonly associated with aseptic meningitis. The association of HFMD with EV-4 has not been reported previously. Two samples of a 14-month child who presented mild fever, sores in the mouth, rash with blisters on the palm of hands and soles of feet were sent to Enteric Viruses Laboratory of Adolfo Lutz Institute. Clinical samples were inoculated in three different cell lines, and those which presented cytopathic effect (CPE), were submitted to Indirect Immunofluorescence Assay (IFA) and "one step" RT-PCR. Agarose gel electrophoresis from RT-PCR product, showed a product with 437 bp, which is characteristic of Enterovirus group. Echovirus 4 was identified by IFA. Although HFMD is a viral infection associated mainly with Enterovirus 71 (HEV-71) and Coxsackievirus A16 (CV-A16), our results demonstrate a diversity of serotype related to HFMD and stress the importance of epidemiological surveillance to this disease and its complications.

HAND-FOOT-AND-MOUTH DISEASE EPIDEMIOLOGICAL STATUS AND RELATIONSHIP WITH METEOROLOGICAL VARIABLES IN GUANGZHOU, SOUTHERN CHINA, 2008-2012

Hand-foot-and-mouth disease (HFMD) is becoming one of the extremely common airborne and contact transmission diseases in Guangzhou, southern China, leading public health authorities to be concerned about its increased incidence. In this study, it was used an ecological study plus the negative binomial regression to identify the epidemic status of HFMD and its relationship with meteorological variables. During 2008-2012, a total of 173,524 HFMD confirmed cases were reported, 12 cases of death, yielding a fatality rate of 0.69 per 10,000. The annual incidence rates from 2008 to 2012 were 60.56, 132.44, 311.40, 402.76, and 468.59 (per 100,000), respectively, showing a rapid increasing trend. Each 1 °C rise in temperature corresponded to an increase of 9.47% (95% CI 9.36% to 9.58%) in the weekly number of HFMD cases, while a one hPa rise in atmospheric pressure corresponded to a decrease in the number of cases by 7.53% (95% CI -7.60% to -7.45%). Similarly, each one percent rise in relative humidity corresponded to an increase of 1.48% or 3.3%, and a one meter per hour rise in wind speed corresponded to an increase of 2.18% or 4.57%, in the weekly number of HFMD cases, depending on the variables considered in the model. These findings revealed that epidemic status of HFMD in Guangzhou is characterized by high morbidity but low fatality. Weather factors had a significant influence on the incidence of HFMD.