Inactivation of SARS-CoV-2 isolates from lineages B.1.1.7 (Alpha), P.1 (Gamma) and B.1.110 by heating and UV irradiation.

Currently, the rapid global spread of SARS-CoV-2 is related to G clade (including GH, GR, GRY and GV clades), which are associated with more than 98 % of sequenced viral isolates worldwide. The unprecedented velocity of spread of SARS-CoV-2 outbreak represents a critical need for prevention strategies. Vaccines are recently being available and antiviral drugs have shown limited efficacy in COVID-19 patients. Thus, it is needed to know how to reduce the infectivity of the virus by different physicochemical conditions in order to prevent exposure to contaminated material. This work describes heating and irradiating UV-C light procedures to reduce the infectivity of SARS-CoV-2 belonging to different three lineages. Results of physicochemical treatment showed no differences among viral lineages. Analytical conditions for efficient inactivation of SARS-CoV-2 were determined.

A simple method for SARS-CoV-2 detection by rRT-PCR without the use of a commercial RNA extraction kit.

The World Health Organization (WHO) has declared a pandemic caused by a new coronavirus named SARS-CoV-2. The growing demand for commercial kits used for automated extraction of SARS-CoV-2 RNA, a key step before rRT-PCR diagnosis, could cause a shortage of stocks that hinders the rapid processing of samples. Although the recommendation is to use automated methods for nucleic acid extraction, alternatives are necessary to replace commercial kits. However, these alternatives should be as reliable as automated methods. This work describes a simple method to detect SARS-CoV-2 from specimens collected in different preservation media. Samples were previously inactivated by heating and precipitating with a PEG/NaCl solution before rRT-PCR assays for Orf1ab, N and S genes. The new method was compared with an automated protocol of nucleic acid extraction. Both procedures showed similar analytical results. Consequently, this simple and inexpensive method is a suitable procedure for laboratory diagnosis of SARS-CoV-2 infection.

Correction: Temporal Patterns of Influenza A and B in Tropical and Temperate Countries: What Are the Lessons for Influenza Vaccination?

[This corrects the article DOI: 10.1371/journal.pone.0152310.].

A report on the outbreak of Zika virus on Easter Island, South Pacific, 2014.

Zika virus (ZIKV) is an emerging mosquito-borne flavivirus circulating in Asia and Africa. In 2013, a large outbreak was reported on the archipelago of French Polynesia. In this study, we report the detection and molecular characterization of Zika virus for the first time in Chile from an outbreak among the inhabitants of Easter Island. A total of 89 samples from patients suspected of having ZIKV infection were collected between the period from January to May, 2014. Molecular diagnosis of the virus was performed by RT-PCR followed by the sequencing of the region containing the NS5 gene. A comparison of the viral nucleic acid sequence with those of other strains of ZIKA virus was performed using the MEGA software. Fifty-one samples were found positive for ZIKV by RT-PCR analysis. Further analysis of the NS5 gene revealed that the ZIKV strains identified in Easter Island were most closely related to those found in French Polynesia (99.8 to 99.9% nt and 100% aa sequence identity). These results strongly suggest that the transmission pathway leading to the introduction of Zika virus on Easter Island has its origin in French Polynesia.

Many respiratory viruses have temporal association with meningococcal disease

BACKGROUND: Previous ecological studies have shown a temporal and spatial association between influenza epidemics and meningococcal disease (MNG); however, none have examined more than two respiratory viruses. METHODS: Data were obtained in Chile between 2000 and 2005 on confirmed cases of MNG and all confirmed cases of respiratory viruses (influenza A and B; parainfluenza; adenovirus; and respiratory syncytial virus [RSV]). Both variables were divided by epidemiological weeks, age range, and regions. Models of transference functions were run for rates of MNG. RESULTS: In this period, 1022 reported cases of MNG and 34,737 cases of respiratory virus were identified (25,137 RSV; 4300 parainfluenza; 2527 influenza-A; 356 influenza-B; and 2417 adenovirus). RSV was the major independent virus temporally associated to MNG (it appears one week before MNG), followed by parainfluenza, influenza-B, adenovirus, and influenza-A. CONCLUSIONS: The rate of MNG in Chile is temporally associated to all of the respiratory viruses studied, but with variability according age range, and regions

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Many respiratory viruses have temporal association with meningococcal disease.

BACKGROUND: Previous ecological studies have shown a temporal and spatial association between influenza epidemics and meningococcal disease (MNG); however, none have examined more than two respiratory viruses. METHODS: Data were obtained in Chile between 2000 and 2005 on confirmed cases of MNG and all confirmed cases of respiratory viruses (influenza A and B; parainfluenza; adenovirus; and respiratory syncytial virus [RSV]). Both variables were divided by epidemiological weeks, age range, and regions. Models of transference functions were run for rates of MNG. RESULTS: In this period, 1022 reported cases of MNG and 34,737 cases of respiratory virus were identified (25,137 RSV; 4300 parainfluenza; 2527 influenza-A; 356 influenza-B; and 2417 adenovirus). RSV was the major independent virus temporally associated to MNG (it appears one week before MNG), followed by parainfluenza, influenza-B, adenovirus, and influenza-A. CONCLUSIONS: The rate of MNG in Chile is temporally associated to all of the respiratory viruses studied, but with variability according age range, and regions.

Detection of dengue virus type 4 in Easter Island, Chile.

We report the detection of dengue virus type 4 (DENV-4) for the first time in Easter Island, Chile. The virus was detected in serum samples of two patients treated at the Hospital in Easter Island. The two samples were IgM positive, and the infection was confirmed by RT-PCR and genetic sequencing; viral isolation was possible with one of them. The Easter Island isolates were most closely related to genotype II of dengue type 4.

Influenza pneumonia: a comparison between seasonal influenza virus and the H1N1 pandemic.

We compared clinical presentation, complications and outcome in patients with influenza A (H1N1) and seasonal influenza pneumonia. The group of patients with influenza A (H1N1) pneumonia consisted of 75 patients. 52 patients with pneumonia associated with seasonal influenza were included for comparison. Patients with pneumonia associated with novel H1N1 influenza were younger (mean age 39.7 yrs versus 69.6 yrs) and had fewer chronic comorbidities and less alcoholism. Infiltrates were more extensive and frequently interstitial. Respiratory failure was more frequent (those with an arterial oxygen tension/inspiratory oxygen fraction ratio <200 28% versus 12%, p = 0.042), leading to a higher rate of intensive care unit (ICU) admission and mechanical ventilation (29.3% versus 7.7% (p<0.0030) and 18.7% versus 2% (p<0.0045)). Mortality was twice as high in patients with novel H1N1 (12% versus 5.8%; p = 0.238), although this was not significant, and was attributable to pneumonia in most instances (77.8% versus 0%; p = 0.046). Younger age, fewer comorbidities, more extensive radiographic extension and more severe respiratory compromise, and ICU admissions are key features of the clinical presentation of patients with novel H1N1-associated pneumonia compared with seasonal influenza pneumonia.

Impact of limited cephalosporin use on prevalence of methicillin-resistant Staphylococcus aureus in the intensive care unit.

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a leading pathogen causing nosocomial infections. Many studies have shown that the restricted use of antibacterials is associated with a decline in resistance. To establish whether an intervention protocol designed to limit the use of cephalosporins can lower mRSA infection rates and impact on Gram-negative bacteria susceptibility in an intensive Care Unit (ICU), we conducted a prospective, non-randomized, before-after intervention study in an 18-bed ICU in Genoa, Italy. The intervention was a hospital antibiotic control policy and the observation was routine monitoring for nosocomial infections and antibiotic use, recording periodically the incidence density and MRSA prevalence. The intervention included a new antibiotic guideline that restricted the use of cephalosporins for all ICU inpatients. The analysis showed that the intervention determined a significant reduction in cephalosporin usage (-70.3%), while fluoroquinolones, mainly ciprofloxacin, increased after introduction of the antibiotic policy (+46.5%). A significant reduction in the percentage of MRSA infections (-30%) and heterogeneous susceptibility patterns in Klebsiella pneumoniae and Pseudomonas aeruginosa were noted.

Antimicrobial use and resistance among Gram-negative bacilli in an Italian intensive care unit (ICU).

Gram-negative bacilli antimicrobial resistance remains a significant problem for patients in the intensive care unit (ICU). We performed a retrospective analysis of microbiological data and antibiotic consumption over a 4-year period (2000-2003) in an Italian ICU. Pseudomonas aeruginosa and Klebsiella pneumoniae represented approximately 40% of all isolates. The most significant trend in antimicrobial use was an increase in use of 3(rd )generation cephalosporins, imipenem, and ciprofloxacin. A significant trend toward an increase in resistance rates to piperacillin, 3( rd )generation cephalosporins and ciprofloxacin was observed for K. pneumoniae and a positive correlation between resistance and drug-usage was evident for K. pneumoniae and piperacillin, cefotaxime, ceftazidime, cefepime, and ciprofloxacin, but not for piperacillin/tazobactam. No statistically significant correlations were evidenced for P. aeruginosa. Trends in resistances were studied also for Serratia spp and Proteus spp. Isolation rates of extended-spectrum beta-lactamase (ESBL)-producing strains in pathogens studied were high, especially for K. pneumoniae (72%, 160/222) and Proteus spp (41%, 18/43). In conclusion, the study showed high resistance among Gram-negative organisms isolated in the ICU and significant ESBL production. A significant correlation between antibiotic consumption and increasing resistance was evident for K. pneumoniae.

Efficacy of the combination of levofloxacin plus ceftazidime in the treatment of hospital-acquired pneumonia in the intensive care unit.

To investigate the efficacy and tolerability of treatment with a combination of levofloxacin and ceftazidime in Gram-negative hospital-acquired pneumonia (HAP) in the Intensive Care Unit (ICU), we performed a prospective, open-label, non-comparative, 1-year study in an Italian ICU. Patients received levofloxacin 500 mg twice a day intravenously plus ceftazidime 2 g three times a day intravenously for 7-14 days. Primary efficacy variables were clinical and microbiological responses at test-of-cure visit. Twenty-one patients were enrolled. Pseudomonas aeruginosa and Klebsiella pneumoniae were the most frequently identified pathogens. Clinical success was achieved in 17/21 clinically evaluable patients (81%) and in 12/15 microbiologically evaluable patients (80%). Regarding only the group with ventilator-associated pneumonia, cure was achieved in 10/14 clinically evaluable patients (71%) and in 11/14 microbiologically evaluable patients (79%). Therapy was well tolerated. We conclude that this combination regimen is safe and clinically and microbiologically efficacious in the treatment of Gram-negative HAP.

[Immune status against measles and rubella among 4 Chilean groups of different ages]. / Estado inmunitario de 4 grupos de edad de población chilena contra sarampión y rubeola.

BACKGROUND: Results of clinical and epidemiological studies confirm that no cases of measles have occurred in Chile since 1993. However, since covering of vaccination programs do not exceed 95%, an immunological surveillance for this disease is warranted. AIM: To know the immune status against measles and rubella in the Chilean population. MATERIAL AND METHODS: A serological census of a representative sample of communities with high (90% or more) or low immunization coverings was performed. Four sub samples along the country were selected: 122 children aged 18 months of age (stratum A), 1,276 children attending the first years of basic school (stratum B), 899 teenagers in their last high school year (stratum C) and 399 women attending a family planning clinic (stratum D). IgG antibodies against measles and rubella were measured using ELISA and hemagglutination inhibition techniques, respectively. RESULTS: Antibodies against measles and rubella were found in 96% and 94% of study subjects. No differences in these titres were found between different strata or communities with high or low vaccination covering. There is a high percentage of positive antibodies against measles among children of 18 months of age and a high percentage of antibodies against rubella among teenagers and women in family planning. Only 3% of the sample had not received any vaccine at the moment of the study. CONCLUSIONS: The high prevalence of antibodies against rubella allows to conclude that it is not necessary to consider this antigen in the next vaccination campaign. Due to the high prevalence of antibodies against measles, only the population older than 20 years old should be affected by the disease if this virus enters the country.

[Laboratory surveillance of measles. Chile, 1992-1995]. / Vigilancia de laboratorio en sarampión. Chile, 1992-1995.

BACKGROUND: The first massive national measles vaccination campaign in Chile was done in 1992. Since then a laboratory surveillance of the disease has been undertaken at the Instituto de Salud Pública. AIM: To report the results of laboratory surveillance of measles between 1992 and 1995. MATERIAL AND METHODS: Paired serum samples from suspected cases of measles were received at the Institute. Measles specific IgG was determined with indirect immunofluorescence methods. IgG and IgM immunoenzymatic methods were used as complementary techniques, and rubella infections were ruled out by hemmaglutination inhibition tests. RESULTS: Sera from 1087 presumptive cases (489 in 1992, 196 in 1993, 180 in 1994 and 222 in 1995) were analyzed. Only two cases of wild imported measles were confirmed, one in Arica in 1992 and the other in Santiago in 1993. Five additional post vaccine cases were detected. Eighty eight percent of samples in 1992 and 75% in 1994 were seropositive. A high percentage of cases were confirmed as rubella (55% in 1992 and 19% in 1994). CONCLUSIONS: Absence of wild measles virus circulation in Chile from 1992 to 1995 emphasizes the importance of laboratory surveillance of the disease.

Treatment of allergic diseases during pregnancy.

Pregnancy may variously modify the natural history of allergic disorders through occurring endocrinologic, functional and immunological changes. A pharmacologic treatment of allergic diseases (mainly asthma) is often necessary during pregnancy. On the other hand, a drug should be not potentially teratogenic and should not have serious side effects, both for the mother and the fetus. This paper reviews current knowledge about allergic diseases during pregnancy, considering the points of view of the different specialists involved in their management. Topical mucosal agents seem to be the safest, due to their minimal or absent absorption which should reflect reduced side effects. Preferred agents should be topical antihistamines (for rhinitis and conjunctivitis), and cromones and topical steroids (for asthma), as they are both safe and effective.

[Molecular study of 6 episodes of nosocomial infections produced by methicillin resistant Staphylococcus aureus]. / Estudio molecular de 6 episodios de infección intrahospitalaria causados por Staphylococcus aureus meticilino-resistente.

A critical step in any epidemiologic research concerning nosocomial infections is the precise identification of the responsible pathogen. The present work utilized a molecular approach -plasmids identification, restriction length polymorphism DNA analysis, and random amplified polymorphic DNA- for the characterization of 6 nosocomial outbreaks due to 52 strains of methicillin-resistant Staphylococcus aureus (MRSA). In these episodes, the clinic-epidemiologic and phenotypic analysis (antibiotype) pointed to a nosocomial infection. Through molecular analysis it was possible to establish, in a very precise way, clonality due to MRSA strains in 2 of the studied outbreaks; the same type of analysis allowed to eliminate a MRSA clonal origin in the remainder 4 episodes. The antibiogram was not an useful analytic tool due to its poor discriminatory power. Also, through a PCR procedure, it was possible to identify the presence of the gen mecA in every of the 52 MRSA strains studied.