|Year : 2010 | Volume
| Issue : 2 | Page : 186-187
Department of Microbiology, Bhopal Memorial Hospital and Research Centre, Raisen Bypass Road, Karond, Bhopal - 462 036, India
|Date of Submission||24-Feb-2010|
|Date of Acceptance||13-Mar-2010|
|Date of Web Publication||16-Apr-2010|
Department of Microbiology, Bhopal Memorial Hospital and Research Centre, Raisen Bypass Road, Karond, Bhopal - 462 036
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Desikan P. Snippets. Indian J Med Microbiol 2010;28:186-7
After the swine flu scare, it is now our turn to make our move against the influenza viruses. On the 18th of February, 2010, the WHO published recommendations for the composition of influenza virus vaccines for the forthcoming season in the northern hemisphere, that is, November 2010 to April 2011 ( http://www.who.int/csr/disease/influenza/recommendations2010_11north/en/index.html ). They foresee a trivalent vaccine including the following:
Each year, representatives of the WHO Collaborating Centres on Influenza meet to analyze the data and make recommendations for the following year's vaccine strains. The recommendations are used by pharmaceutical manufacturers to update the composition of the vaccine so that vaccine strains are matched to circulating strains the following year. The WHO also provides the manufacturers with prototype strains for the seasonal vaccine.
- an A/California/7/2009 (H1N1)-like virus;
- an A/Perth/16/2009 (H3N2)-like virus;
- a B/Brisbane/60/2008-like virus.
In addition to prevention modalities, our arsenal to combat the H1N1 influenza virus also needs to be stocked with rapid diagnostic techniques. A study (J. Med. Virol. 82:675-683, 2010) compared real-time and conventional reverse transcription-polymerase chain reaction (rRT-PCR and cRT-PCR) assays for detection of the pandemic H1N1 virus strain with each other, and with WHO reference protocols. The rRT-PCR assays were found to be 10-fold more sensitive as compared to cRT-PCR assays. However, the newly developed cRT-PCR assay targeting the HA gene was found to allow rapid, specific, and sensitive screening, and therefore could serve as an alternative for laboratories which do not have a real-time PCR machine.
Endemic leptospirosis is a grossly under-reported disease. The varied clinical signs and symptoms do not make it easy to generate a clinical suspicion of leptospirosis, which would then warrant a request for laboratory diagnosis of the disease. Although a number of organ systems are involved, cardiac involvement is not considered significant. However, a case series (J. Clin. Pathol 2010 Feb;63(2):119-23) examining gross and light microscopic features of 24 hearts from patients who had died of leptospirosis found myocarditis in 96% and endocardial inflammation in 50% of them. Given these findings, the occurrence of cardiomyopathy as a delayed consequence of severe myocarditis would also require evaluation.
A clinicoepidemiological study to determine the trends of leptospirosis in northern India (PLoS Negl Trop Dis.none 2010 Jan 12;4(1):e579), between January 2004 to December 2008, found that there was an increase in incidence of leptospirosis (11.7% in 2004 to 20.5% in 2008) as diagnosed by IgM ELISA and microscopic agglutination titers in paired acute and convalescent sera. 86 cases of leptospirosis were followed up. The mean age was 32.6 years (2.5 years to 78 years) and males (57%) outnumbered females (43%). Infestation of dwellings with rats (53.7%), working in farm lands (44.2%), and contact with animals (62.1%) were commonly observed epidemiological risk factors. Renal failure (60.5%), respiratory failure (20.9%), neuroleptospirosis (11.6%), and disseminated intravascular coagulation (11.6%) were the commonest complications. Five patients died, giving a case fatality rate of 5.9%.
Reference laboratories play an important role in monitoring quality control for the diagnostics of leptospirosis. Since they also maintain culture collections of strains of Leptospira spp isolated from various geographical areas, it is equally important to monitor the strain collections. In this context, a 16S sequence-based quality control exercise was carried out on two Leptospira strain collections provided by the World Health Organization and maintained at a reference laboratory for leptospirosis in Brazil (Am. J. Trop. Med. Hyg. 2010 Jan;82(1):83-7).noneAmong the 89 serovars evaluated, four conflicting strains were identified in one of the collections. This emphasizes the need for periodical verifications and quality control of Leptospira reference collections.
Latent tuberculosis is an entity that requires to be examined particularly in the context of HIV infection. Treatment of latent TB infection (LTBI), also referred to as TB preventive therapy or chemoprophylaxis, helps to prevent progression to active disease in HIV negative populations. However, the extent and magnitude of protection (if any) associated with preventive therapy in those infected with HIV should be quantified. A Cochrane database systematic review (Cochrane Database Syst. Rev. none 2010 Jan 20;(1):CD000171) was therefore carried out to determine the effectiveness of TB preventive therapy in reducing the risk of active tuberculosis and death in HIV-infected persons. It was found that treatment of latent tuberculosis infection reduces the risk of active TB in HIV-positive individuals especially in those with a positive tuberculin skin test. The choice of regimen, however, would depend on factors such as availability, cost, adverse effects, adherence, and drug resistance.
Among the 53 serotypes of human adenoviruses (HAdVs), identified to date, only a limited number have been associated with human respiratory infections. A study (J. Med. Virol.none 2010 Feb 17;82(4):624-31) was performed to elucidate the epidemiology of HAdV respiratory infections over 17 consecutive years (1991-2007). The viruses were typed by the neutralization test, two-sets of multiplex PCR assays, and/or sequence analysis of the hexon gene. Thirteen different serotypes were identified, which included HAdV serotypes 1-8, 11, 19, 34, 37, and 41. HAdV-3 (n = 285, 37.7%) and HAdV-7 (n = 181, 23.9%) were the predominant serotypes; HAdV-8, -11, -19, -34, -37, and -41 were not usually associated with respiratory diseases. HAdV-3 was present both during outbreaks and in sporadic cases. HAdV-7 emerged in a very large outbreak, followed by smaller outbreaks. HAdV-1, -2, -4, -5, and -6 were isolated sporadically throughout the study period.
Viral respiratory infections are responsible for much morbidity in winter, particularly among infants. A 3-year prospective study was conducted on infants admitted to hospital, to determine the frequency of 16 respiratory viruses. Clinical characteristics of RSV-only infections were compared with other single agent viral infections (Acta Paediatr.none 2010 Feb 16. [Epub ahead of print]). Of the 318 children studied, a single virus was detected in 196 patients and 79 were dual or multiple viral infections. RSV was detected in 61.3% of patients, rhinovirus (RV) in 17.4%, followed by human bocavirus (HBoV), adenovirus, and metapneumovirus (hMPV). Only RV, HBoV, and hMPV were significant as single infections. Clinical characteristics were similar among them, but seasonality was clearly different.
Constant surveillance for fungemia is imperative, particularly in an intensive care setting. A retrospective observational study of bloodstream yeast infections over 5 years (2004-2008) in a tertiary-care hospital ((Med Mycol.none 2010 Feb 18. [Epub ahead of print]) detected 52 bloodstream yeast infections, at a rate of 2.4 per 1000 hospital admissions. Non -C. albicans Candida species and other genera were responsible for 82% of infections, with C. tropicalis and C. parapsilosis being the most common. And 19% of the isolates tested were resistant to fluconazole, and all were susceptible to itraconazole and amphotericin. The overall mortality rate was 50%.
And, finally, to understand where India stands with respect to HIV-related mortality, a nationally representative mortality survey of 1.1 million homes (BMJ 2010;340:c621 ) found that HIV accounted for 8.1% (99% confidence interval 5.0% to 11.2%) of all deaths among adults aged 25-34 years. In this age group, about 40% of deaths from HIV were due to AIDS, 26% were due to tuberculosis, and the rest were attributable to other causes. Nationally, HIV infection accounted for about 100 000 (59 000-140 000) deaths or 3.2% (1.9-4.6%) of all deaths among people aged 15-59 years. The data suggest that India had about 1.4-1.6 million HIV-infected adults aged 15-49 years in 2004-2006, about 40% lower than the official estimate of 2.3 million for 2006. The good news is that HIV prevalence in young pregnant women, a proxy measure of the incidence in the general population, fell between 2000 and 2007.