The following represent additions to UpToDate since the last version that were considered by the authors and editors to be of particular interest. The new material described below represents a small subset of the updating that has been performed, since approximately 40 percent of the topic reviews are updated during each four-month cycle.

ANTIBIOTICS AND ANTIMICROBIAL RESISTANCE

Chlorhexidine bathing — Daily chlorhexidine bathing for ICU patients may reduce the acquisition of methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE). The approach may be an important adjunctive intervention to barrier precautions to reduce acquisition of VRE and MRSA and the subsequent development of healthcare-associated bloodstream infection [1]. (See "Epidemiology and prevention and control of vancomycin-resistant enterococci", section on 'Source control' and "Prevention of intravascular catheter-related infections", section on 'Chlorhexidine bathing'.)

BACTERIAL INFECTIONS

Typhoid prevention — Prevention of enteric fever in endemic areas would require implementing immunization for young children. In a study including more than 37,000 children two to five years of age, the parenteral Vi polysaccharide vaccine was useful for inducing both direct and indirect protection (overall protection 57 percent) [2]. These data should inform further efforts in prevention of typhoid in endemic areas. (See "Treatment and prevention of typhoid fever", section on Typhoid vaccine.)

C. difficile — In July 2009 the US Food and Drug Administration approved the Xpert C. difficile test (Cepheid), a real-time polymerase chain reaction (PCR) using primers targeting a region of the toxin B gene. This modality is a rapid, accurate diagnostic tool for C. difficile, which is important for prompt implementation of treatment and infection control measures. (See "Clinical manifestations and diagnosis of Clostridium difficile infection", section on 'Stool toxin assays'.)

HIV INFECTION

Treatment — Raltegravir plus tenofovir and emtricitabine has been demonstrated to be effective first-line therapy for the treatment-naive HIV-infected patient. In a double-blind non-inferiority trial, 563 treatment-naive patients were randomly assigned to raltegravir or efavirenz, both in combination with tenofovir and emtricitabine [3]. Viral suppression rates were similar in the raltegravir and efavirenz arms (86 versus 82 percent). Serious treatment-related adverse events occurred with similar frequency in both treatment groups (<1 percent). Results at 96 weeks of follow-up further support similar durability of viral suppression on raltegravir-containing ART compared to efavirenz-containing regimens (81 versus 79 percent) [4]. (See "Clinical trials of HIV antiretroviral therapy: Integrase inhibitors" and "Selecting antiretroviral regimens for the treatment naive HIV-infected patient".)

IMMUNIZATIONS

Human papillomavirus vaccine — Adverse events following immunization were collected and analyzed within the Vaccine Adverse Event Reporting System (VAERS) from 2006 to 2008 after an estimated 23 million doses of quadrivalent HPV vaccine had been administered in the United States [5]. Most of the adverse event rates were not greater than background rates of other vaccines, although there was a disproportional reporting of syncope and venous thromboembolic events. The observation of increased thrombotic events was mainly noted in those with predisposing risk factors (eg, those on birth control pills or with a positive family history).

Seasonal influenza vaccine — Although in children the live attenuated (intranasal) seasonal influenza vaccine may be more effective than the inactivated (intramuscular) vaccine, studies in adults have shown that the inactivated vaccine is either equivalent to or more effective than the live attenuated vaccine. In a randomized trial that included 1952 adults vaccinated during the 2007 to 2008 influenza season, the inactivated vaccine was superior to the live attenuated vaccine in preventing influenza infection (68 versus 36 percent absolute efficacy, respectively) [6]. (See "Seasonal influenza vaccination in adults", section on 'Comparisons of inactivated and live-attenuated vaccines'.)

Pandemic H1N1 influenza vaccine — Vaccines against pandemic H1N1 influenza began being distributed in the United States in October 2009.

Target groups — The recommended target groups for pandemic H1N1 influenza vaccination differ from those for seasonal influenza. The US Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) has recommended the following prioritization for administration of the pandemic H1N1 influenza vaccine [7]:

• Pregnant women
• Household contacts and caregivers of children younger than 6 months of age (eg, parents, siblings, and daycare providers)
• Healthcare and emergency medical services personnel
• Individuals from 6 months through 24 years of age
• Individuals from 25 through 64 years of age with health conditions associated with increased risk of influenza complications

(See "Prevention of pandemic H1N1 influenza ('swine influenza')", section on 'Target groups'.)

Dosing schedule — Preliminary results from clinical trials have shown that a single dose of pandemic H1N1 vaccine is likely to be immunogenic in a substantial percentage of healthy adults and in children ≥10 years of age [8-10]. Children aged six months to nine years should receive two doses of the vaccine, separated by approximately four weeks; individuals ≥10 years of age should receive one dose [11]. (See "Prevention of pandemic H1N1 influenza ('swine influenza')", section on 'Dosing schedule'.)

Meningococcal vaccine — In September 2009, the US Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) published updated recommendations regarding revaccination of individuals at prolonged increased risk for meningococcal disease [12]. Individuals who were previously vaccinated with either the quadrivalent meningococcal polysaccharide vaccine conjugated to diphtheria toxoid (Menactra, MCV4) or the meningococcal polysaccharide vaccine (Menomune, MPSV4) who remain at increased risk for meningococcal disease should be revaccinated with MCV4 according to the following schedule:

• Individuals who were vaccinated at two to six years of age should be revaccinated three years after receiving their previous meningococcal vaccine
• Individuals who were vaccinated at seven years of age or older should be revaccinated five years after receiving their previous meningococcal vaccine.
• Individuals who remain at increased risk for meningococcal disease should continue to be revaccinated at five-year intervals.

The ACIP states that college freshmen living in dormitories who were previously vaccinated with MCV4 do not need to be revaccinated, and that those who were vaccinated with MPSV4 more than five years earlier should be vaccinated with MCV4. We would suggest that it is also reasonable to revaccinate college freshmen who received MCV4 more than five years earlier. (See "Meningococcal vaccines", section on 'Revaccination'.)

MYCOBACTERIA

Nucleic acid amplification — The New York City Department of Health has demonstrated the utility of nucleic acid amplification (NAA) testing for diagnosis of tuberculosis (TB) in a large public health setting [13]. This further supports recent recommendations from the CDC that NAA testing be performed on at least one respiratory specimen from patients with suspected pulmonary TB. The findings should encourage wider use of NAA testing for TB. (See "Diagnosis of tuberculosis in HIV-seronegative patients", section on 'Nucleic acid amplification'.)

Moxifloxacin — In a trial of 328 patients with active pulmonary TB randomized to receive moxifloxacin or isoniazid (in addition to rifampin, ethambutol and pyrazinamide), comparable rates of sputum culture negativity after eight weeks were observed (55 and 60 percent) [14]. Based on these findings, moxifloxacin may be a suitable alternative for patients who are intolerant of INH or infected with INH-resistant Mycobacterium tuberculosis. Pending further data, however, fluoroquinolones should be used only in persons with intolerance of or resistance to first-line agents. (See "Treatment of tuberculosis in HIV-seronegative patients" and "Diagnosis and treatment of drug-resistant tuberculosis", section on .) Fluoroquinolones).

PARASITIC INFECTIONS

Artesunate resistance — P. falciparum with reduced in vivo susceptibility to artesunate is emerging in western Cambodia [15]. The most likely cause is widespread use of artemisinin monotherapy in the region. An intensive campaign has been launched by the World Health Organization (WHO) to contain artemisinin resistance, as there is no alternative class of malaria drugs to replace the artemisinin derivatives. (See "Treatment of uncomplicated falciparum malaria", section on 'Resistance'.)

PUBLIC HEALTH

Mumps — The Centers for Disease Control and Prevention, American Academy of Pediatrics, and the Healthcare Infection Control Practices Advisory Committees have recommended that the needed isolation time for patients with mumps infection be reduced from nine days to five days since the risk of transmission after this time appears to be low [16].

SEXUALLY TRANSMITTED DISEASES

HIV transmission — In Uganda, 922 HIV-seropositive men were randomly assigned to immediate versus delayed circumcision to assess the effect of the intervention on HIV transmission to female sexual partners [17]. Circumcision did not reduce HIV transmission to female partners over the 24 month period of the study. Furthermore, excess HIV transmission occurred within the first six months in the male circumcision arm, particularly among those who resumed intercourse prior to wound healing. (See "Prevention of sexually transmitted diseases".)

TRAVEL

Japanese encephalitis — In June 2009 the United States Advisory Committee on Immunization Practices (ACIP) approved revised recommendations for the use of JE vaccine in travelers [18]. (See "Japanese encephalitis: Epidemiology, diagnosis, treatment and prevention".)

VIRAL INFECTIONS, NON-HIV

Pandemic H1N1 influenza — There is currently a pandemic of a novel strain of H1N1 influenza that represents a quadruple reassortment of two swine strains, one human strain, and one avian strain of influenza. The United States Centers for Disease Control and Prevention is monitoring the epidemiology of the pandemic and has released guidelines for the treatment and prevention of pandemic H1N1 influenza. The World Health Organization is also monitoring and making recommendations regarding the H1N1 influenza pandemic. (See "Epidemiology, clinical manifestations, and diagnosis of pandemic H1N1 influenza ('swine influenza')" and "Treatment of pandemic H1N1 influenza ('swine influenza')" and "Prevention of pandemic H1N1 influenza ('swine influenza')".)

Rabies — The guidelines for rabies vaccine administration for post-exposure prophylaxis in unvaccinated persons changed in 2009. The Advisory Committee on Immunization Practices has advised that the five-dose schedule be changed to four doses, eliminating the last dose administered on day 28 [19]. (See "Rabies immune globulin and vaccine".)

Norovirus — In a case series of 12 patients, norovirus was identified as a cause of persistent diarrhea and weight loss among adult allogeneic hematopoietic stem cell transplant recipients [20]. (See "Epidemiology, clinical manifestations, and diagnosis of noroviruses, astroviruses and sapoviruses".)