Nosocomial infections:Epidemiology,prevention,control and surveillance

Nosocomial infections or healthcare associated infections occur in patients under medical care.These infections occur worldwide both in developed and developing countries.Nosocomial infections accounts for 7% in developed and 10% in developing countries.As these infections occur during hospital stay,they cause prolonged stay,disability,and economic burden.Frequently prevalent infections include central line-associated bloodstream infections,catheter-associated urinary tract infections,surgical site infections and ventilator-associated pneumonia.Nosocomial pathogens include bacteria,viruses and fungal parasites.According to WHO estimates,approximately 15% of all hospitalized patients suffer from these infections.During hospitalization,patient is exposed to pathogens through different sources environment,healthcare staff,and other infected patients.Transmission of these infections should be restricted for prevention.Hospital waste serves as potential source of pathogens and about 20%–25% of hospital waste is termed as hazardous.Nosocomial infections can be controlled by practicing infection control programs,keep check on antimicrobial use and its resistance,adopting antibiotic control policy.Efficient surveillance system can play its part at national and international level.Efforts are required by all stakeholders to prevent and control nosocomial infections.

Nosocomial infections and their control strategies

Nosocomial infections are also known as hospital-acquired/associated infections. National Healthcare Safety Network along with Centers for Disease Control for surveillance has classified nosocomial infection sites into 13 types with 50 infection sites, which are specific on the basis of biological and clinical criteria. The agents that are usually involved in hospitalacquired infections include Streptococcus spp., Acinetobacter spp., enterococci, Pseudomonas aeruginosa, coagulase-negative staphylococci, Staphylococcus aureus, Bacillus cereus, Legionella and Enterobacteriaceae family members, namely, Proteus mirablis, Klebsiella pneumonia, Escherichia coli, Serratia marcescens. Nosocomial pathogens can be transmitted through person to person, environment or contaminated water and food, infected individuals, contaminated healthcare personnel's skin or contact via shared items and surfaces. Mainly, multi-drug-resistant nosocomial organisms include methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Pseudomonas aeruginosa and Klebsiella pneumonia, whereas Clostridium difficile shows natural resistance. Excessive and improper use of broadspectrum antibiotics, especially in healthcare settings, is elevating nosocomial infections, which not only becomes a big health care problem but also causes great economic and production loss in the community. Nosocomial infections can be controlled by measuring and comparing the infection rates within healthcare settings and sticking to the best healthcare practices. Centers for Disease Control and Prevention provides the methodology for surveillance of nosocomial infections along with investigation of major outbreaks. By means of this surveillance, hospitals can devise a strategy comprising of infection control practices.

Association of retinoblastoma with clinical and histopathological risk factors

A study was conducted to see the association of retinoblastoma with age, bilaterism, Tumor size, site, grades, involvement of anterior chamber, iris, ciliary body, choroid, sclera and optic nerve, and extraocular extension. This was a retrospective descriptive analytical study. The records of the Institute of Ophthalmology, King Edward Medical University/Mayo hospital, Lahore: Pakistan January 2006-Dec 2011 was analyzed. Five years biopsies (June 2006 to June 2012) of the retinoblastoma, from the Pathology department, was retrieved to see optic nerve involvement in all the retrieved specimens. The mean age was 3.54 ± 1.686 years. There were 15 cases of bilateral retinoblastoma and 37 cases with unilateral neoplasms. The age range of bilateral tumors was 2 - 6 years while the range in unilateral tumor was 1 - 10 years male to female ratio was 1:1.5. Among 52 cases, 37 (71.2%) patients were unilateral retinoblastoma and 15 (28.28%) patients were with bilateral disease. On radiological examination of patients suffering from retinoblastoma by B-Scan (Ultrasound), there were 33 (63.5%) cases with exophytic presentation while 18 (34.6%) cases showed endophytic morphology. On clinical examinations, 28 patients presented with proptosis of (it was the most common presenting sign in our patients, accounting for about 53.8% of cases), 20 cases presented with leucocoria eye with strabismus. 29/52 patients showed involvement with optic nerve, 17 were from 1 - 3 years age and 12 were from 4 - 6 years. Statistically there was no difference in the involvement of optic nerve, disc involvement and extra ocular extension with the age of patients (p = 0.217). There was also no statistical difference seen in age and gender for but a strong association was seen with patient’s presentation, symptoms and size of the tumors and anterior chamber, iris, ciliary body, choroid, sclera and optic nerve, and extra ocular extension. We concluded that a positive association was seen with tumor size and tumor extension (optic nerve, and extraocular extension). No Association was seen with age, gender and laterality of the tumors.

Prognostic significance of retinoblastoma gene mutation in retinoblastoma eye with respect to pathological risk factors

Retinoblastoma (Rb) was reported firstly by Benedict is the commonest pediatric intraocular malignant tumor in children younger than 5 years of age. The study was conducted to detect the RB-1 gene for prognostic evaluation in retinoblastoma and to see the frequency of RB-1 gene in our population. This was a retrospective descriptive analytical study. Five years biopsies (January, 2006 to December 2011) of the retinoblastoma, from the Pathology department, was retrieved to see optic nerve involvement in all the retrieved specimens. The study was taken to see the mutation of RB1 gene by immunohistochemistry and PCR. The study plan was approved from Institutional Review Board (IRB) of the University. All the cases showed positivity of abnormal Rb-1 gene proteins expression by Immunohistochemistry staining. On PCR, 51/52 (98%) tumors expressed gene mutation as compared to 100% expression shown by IHC. Out of these, 28/51 (55%) cases showed ONI and ODI with positivity for mutated RB gene. A positive association was seen among RB gene mutation with ONI and ODI (p = 0.05). There were 33/51 (65%) cases who did not show any EOE but showed PCR positivity for RB gene mutation. While there were 18/51 (35%) cases who showed EOE and positivity of PCR for Rb-1 gene mutation and a positive association was seen with EOE and gene mutation (p = 0.005). The most common sequence of mutation was on 13 with 33 cases for double mutation, 12 cases for single and 6 patients for triple pattern of mutation. Most of the double and triple sequences of mutations were associated with ONI, ODI and EOE. We concluded that mutation of RB-1 gene is responsible in causation of the tumors with a positive association with tumor size and tumor extension (optic nerve, and extraocular extension), and mutation affects patients with all ages, both gender and unilateral and bilateral tumors.

Novel strategy to diagnose and grade hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the most common malignancies worldwide, particularly in South and South East Asia. Unfortunately due to lack of appropriate facilities and awareness only limited information is available about its early diagnosis. Aim of the present study was to determine the efficacy of p53 by immunohistochemistry and Argyrophilicnucleolar organizer regions (AgNORs) in diagnosis of HCC and cirrhosis of liver. A total of 100 liver biopsies were studied, it included 20 cases of HCC, 60 cases of cirrhosis of the liver and 20 cases of normal liver from autopsy specimens as a control. Out of 20 cases of HCC, 15 were positive for p53 stain and 5 were negative. None of the 60 cases of cirrhosis or 20 with normal histology revealed p53 expression. A statistically significant (p . It helps in differentiation from well differentiated to moderately and to poorly differentiated HCC.