The Role of Viral Load in the Pathogenesis of HIV-2 Infection in West Africa

The role of Human Immunodeficiency Virus type 2 (HTV-2) viral load has been studied in West Africa in order to understand how this infection differs from HIV-1 and why the majority of HIV-2 infected individuals live for long. Using a polymerase chain reaction (PCR) based-assay, it was found that the level of HIV-2 provirus was surprisingly high in HTV-2 seropositive people who live long without sign of immunosuppression; in contrast the rate of HIV-2 replication reflected by RNA viral load was found low. However, HIV-2 replicates to a high titre in some HIV-2-infected people whose disease progresses rapidly to death. Longitudinal follow-up demonstrated that baseline HIV-2 RNA viral load predicts the rate of CD4+ T cell decline and death but the level of proviruses is a less sensitive predictor. Cytotoxic T-lymphocyte activity (CTL) against HIV-2 structural proteins, especially Gag, was found in most HIV-2 infected people and was inversely correlated with HIV-2 proviral load. Strong CTL activity was consistently found in people who did not have progressive disease, suggesting that CTL play an important role in controlling HIV-2 replication. Co-infection with human T-lymphotropic virus type I (HTLV-I) occurred frequently in HIV-2-infected people in a village in Guinea-Bissau but did not seem to enhance HIV-2 viral load. However an increase in HIV-2 viral load was found in an HIV-2-infected individual with malaria parasitaemia, suggesting that malaria infection enhances HIV-2 viral load. The majority of people who are dually seroreactive for both HIV-1 and HIV-2 arc infected with both viruses but some subjects are dually seroreactive because antibodies against one type cross-react with the other type of HIV. These cross-reactive antibodies may be distinguished by antibody dilution analysis. Other dually seroreactive people harbour an undetectable level of HIV-2 provirus and HIV-2 proviral load tended to be low in advanced disease while HIV-1 proviral load was high

Risk Factors for Scrub Typhus, Murine Typhus, and Spotted Fever Seropositivity in Urban Areas, Rural Plains, and Peri-Forest Hill Villages in South India: A Cross-Sectional Study.

Scrub typhus and spotted fever group rickettsioses are thought to be common causes of febrile illness in India, whereas they rarely test for murine typhus. This cross-sectional study explored the risk factors associated with scrub typhus, tick-borne spotted fever, and murine typhus seropositivity in three different geographical settings, urban, rural, and hill villages in Tamil Nadu, South India. We enrolled 1,353 participants living in 48 clusters. The study included a questionnaire survey and blood sampling. Blood was tested for Orientia tsutsugamushi (scrub typhus), Rickettsia typhi (murine typhus), and spotted fever group Rickettsia IgG using ELISA. The seroprevalence of scrub typhus, spotted fever, and murine typhus were 20.4%, 10.4%, and 5.4%, respectively. Scrub typhus had the highest prevalence in rural areas (28.1%), and spotted fever was most common in peri-forested areas (14.9%). Murine typhus was more common in rural (8.7%) than urban areas (5.4%) and absent in peri-forested hill areas. Agricultural workers had a higher relative risk for scrub typhus, especially in urban areas. For murine typhus, proximity to a waterbody and owning a dog were found to be major risk factors. The main risk factors for spotted fever were agricultural work and living in proximity to a forest. Urban, rural plains, and hill settings display distinct epidemiological pattern of Orientia and rickettsial infections. Although scrub typhus and spotted fever were associated with known risk factors in this study, the findings suggest a different ecology of murine typhus transmission compared with other studies conducted in Asia

Who is exposed to smoke at home? A population-based cross-sectional survey in central Vietnam

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Demonstration of pneumococcal capsule under immunoelectron microscopy

It is challenging to demonstrate the capsule of Streptococcus pneumoniae (S. pneumoniae) under immunoelectron microscopy because of the thick mucopeptide cell wall hampering proper fixation. A novel rapid freeze fixation method was established to observe the capsule of S. pneumoniae. A strain of serotype 3 of S. pneumoniae isolate was analyzed after rapid freezing. An ethanol freezing-substitution fixing method was applied and immunohistochemical staining with osmium tetroxide was tested. The capsule was confirmed using the serotype 3 specific polyclonal antibodies labeled with colloidal gold particles. To the best of our knowledge, this is the first report of S. pneumoniae capsule by immunoelectron microscope

Definitive and Indeterminate Pseudomonas aeruginosa Infection in Adults with Community-acquired Pneumonia: A Prospective Observational Study

Rationale: Pneumonia due to Pseudomonas aeruginosa (PA) is associated with high mortality and requires antipseudomonal treatment. Because PA can colonize the respiratory tract, the diagnosis of pathogenic PA involvement is challenging.Objectives: To determine the prevalence of definitive and indeterminate PA infection in community-acquired pneumonia, to describe the clinical and microbiological profiles, and to estimate the burden of unnecessary antipseudomonal drug prescriptions.Methods: We prospectively enrolled 2,701 patients with community-acquired pneumonia. Using stringent criteria for diagnosing PA pneumonia, we generated the following three groups: 1) definitive PA, 2) indeterminate PA, and 3) non-PA pneumonia.Results: The prevalence of definitive PA pneumonia was 0.9% (n = 25), and that of indeterminate PA pneumonia was 4.9% (n = 131). Considerable clinical differences were observed among the groups. Patients with definitive PA pneumonia were more likely to have a history of tuberculosis and chronic obstructive pulmonary disease/bronchiectasis and had a higher 30-day mortality (28%) than patients with non-PA pneumonia. Patients with indeterminate PA pneumonia were more likely to have comorbidities than patients with non-PA pneumonia. More than half of the patients with indeterminate PA and 25% of the patients with non-PA pneumonia were treated with an antipseudomonal drug. No patients with definitive PA pneumonia had multidrug resistance.Conclusions: In this population, the prevalence of community-acquired pneumonia due to PA was low. The clinical features and 30-day mortality rates of patients with indeterminate PA pneumonia were different from those of patients with definitive PA pneumonia. Most of the prescribed antipseudomonal drugs for patients with community-acquired pneumonia were potentially unnecessary

Predicting deaths in a resource-limited neonatal intensive care unit in Nepal.

BackgroundThis study aimed to determine whether the Neonatal Acute Physiology (SNAP) scoring system (SNAP II) and with perinatal extension (SNAP II PE) can be used to predict neonatal deaths in a resource-limited neonatal intensive care unit in Nepal.MethodsA prospective observational study was conducted in a neonatal intensive care unit (NICU) of Kanti Children's Hospital in Kathmandu, Nepal. Data required for the SNAP II and SNAP II PE scores were collected. The relationships between the SNAP II and SNAP II PE scores and neonatal mortality were analyzed.ResultsThere were 135 neonates admitted during the 6 month study period, of whom 126 met the inclusion criteria. Of these 126 neonates, 29 (23.0%) died. Mortality was 83% (5/6) when SNAP II was >40, and 66.7% (6/9) when SNAP II PE was >50. A SNAP II score of ≥12 had a sensitivity of 75.9%, and specificity of 73.2% for predicting mortality, and a SNAP II PE score of ≥14 had a sensitivity of 82.8% and specificity of 67.0% for it.ConclusionsSNAP II and SNAP II PE scoring of neonates can be used to predict prognosis of neonates in resource-limited NICUs in Nepal

Progress towards antibiotic use targets in eight high-income countries

OBJECTIVE: To compare antibiotic sales in eight high-income countries using the 2019 World Health Organization (WHO) Access, Watch and Reserve (AWaRe) classification and the target of 60% consumption of Access category antibiotics. METHODS: We analysed data from a commercial database of sales of systemic antibiotics in France, Germany, Italy, Japan, Spain, Switzerland, United Kingdom of Great Britain and Northern Ireland, and United States of America over the years 2013-2018. We classified antibiotics according to the 2019 AWaRe categories: Access, Watch, Reserve and Not Recommended. We measured antibiotic sales per capita in standard units (SU) per capita and calculated Access group sales as a percentage of total antibiotic sales. FINDINGS: In 2018, per capita antibiotic sales ranged from 7.4 SU (Switzerland) to 20.0 SU (France); median sales of Access group antibiotics were 10.9 SU per capita (range: 3.5-15.0). Per capita sales declined moderately over 2013-2018. The median percentage of Access group antibiotics was 68% (range: 22-77 %); the Access group proportion increased in most countries between 2013 and 2018. Five countries exceeded the 60% target; two countries narrowly missed it (\u3e 55% in Germany and Italy). Sales of Access antibiotics in Japan were low (22%), driven by relatively high sales of oral cephalosporins and macrolides. CONCLUSION: We have identified changes to prescribing that could allow countries to achieve the WHO target. The 60% Access group target provides a framework to inform national antibiotic policies and could be complemented by absolute measures and more ambitious values in specific settings

COVID-19 is moving to high-density, poor residential areas in Metropolitan Manila, Philippines.

We describe three waves of COVID-19 infections in Manila. First, imported cases among Chinese nationals; second, infections amongst Filipinos residing in less densely populated areas; and third, infections amongst Filipinos residing in high-density areas. We highlight this using admissions data from the National Infectious Diseases hospital in Manila.</jats:p