What's new in infectious diseases

The following represent additions to UpToDate from the past six months that were considered by the editors and authors to be of particular interest. The most recent What's New entries are at the top of each subsection.

COVID-19

Respiratory protection for routine care of persons with COVID-19 (March 2023)

A medical mask or respirator should be used during routine care of persons with COVID-19; however, data supporting the use of one over the other are conflicting. As an example, in a randomized trial of 1009 health care providers from four different countries, the overall rate of RT-PCR-confirmed COVID-19 cases was similar with medical mask versus respirator use (10.46 versus 9.27 percent, respectively) [1]. However, in one country (Canada), the use of a respirator was associated with a lower risk of symptomatic infection. Pending additional high-quality data, we continue to suggest respirators when providing routine care for patients with suspected or confirmed COVID-19 to reduce exposure via the aerosol route. (See "COVID-19: Infection prevention for persons with SARS-CoV-2 infection", section on 'Type of PPE'.)

Updated guidance for preoperative COVID-19 testing (February 2023)

In December 2022 the American Society of Anesthesiologists and the Anesthesia Patient Safety Foundation published a joint statement updating recommendations about preoperative COVID-19 testing [2]. Instead of routine preoperative universal COVID-19 testing in asymptomatic patients, they now recommend preoperative screening for symptoms of COVID-19 and contact with patients with COVID-19, robust infection control measures, and targeted testing taking into account community incidence of COVID-19 and facility ability to distance patients. Asymptomatic screening may be associated with unnecessary procedure delays and additional cost and is unlikely to provide benefit if infection prevention strategies are used. (See "COVID-19: Perioperative risk assessment and anesthetic considerations, including airway management and infection control", section on 'Preoperative screening and testing'.)

Tixagevimab-cilgavimab (Evusheld) no longer authorized for prevention of COVID-19 (January 2023)

The monoclonal antibody combination of tixagevimab-cilgavimab had previously been an effective option for pre-exposure prophylaxis against COVID-19 in certain individuals expected to have suboptimal protection from vaccination or unable to receive vaccination. However, it is not active against certain Omicron subvariants (including BQ.1/BQ.1.1, XBB, and its derivatives XBB.1 and XBB.1.5) (table 1), which accounted for over 90 percent of circulating variants in the United States as of January 2023. Because the emergency use authorization for tixagevimab-cilgavimab is contingent on a lower prevalence of resistant variants, it is no longer authorized in the United States [3]. (See "COVID-19: Epidemiology, virology, and prevention", section on 'Monoclonal antibodies ineffective for pre-exposure prophylaxis'.)

Prevalence of long COVID (December 2022)

The true prevalence of long COVID-19 is unknown due to varying definitions and methods of analysis. A meta-analysis of 54 studies (>1 million patients) estimated that 6.2 percent of individuals who had symptomatic COVID-19 between March 2020 and January 2022 experienced at least one long COVID symptom [4]. Persistent fatigue was most common, followed by ongoing respiratory problems and cognitive dysfunction. The estimated duration was 9 months after hospital discharge and 4 months for individuals who were not hospitalized These data shed light on the true prevalence of long COVID-19. Whether this rate also applies to the omicron variant requires additional study. (See "COVID-19: Evaluation and management of adults with persistent symptoms following acute illness ("Long COVID")".)

Nirmatrelvir-ritonavir in vaccinated individuals with COVID-19 (October 2022)

A large randomized trial previously demonstrated that nirmatrelvir-ritonavir (Paxlovid) substantively reduced hospitalization and death in unvaccinated individuals with COVID-19 and risk factors for severe disease; accumulating observational data suggest that high-risk vaccinated individuals also benefit. In a study of 1130 vaccinated adults who received nirmatrelvir-ritonavir within five days of COVID-19 diagnosis and 1130 controls matched for age, gender, race, and comorbidities, nirmatrelvir-ritonavir was associated with a lower rate of emergency department visits, hospitalization, and death (odds ratio 0.5) [5]. All 10 deaths were among those who had not been treated. In another study, nirmatrelvir-ritonavir was associated with a reduction in hospitalization from 59 to 15 cases per 100,000 person-days among mostly vaccinated patients ≥65 years old [6]. Despite the limitations of observational data, these data highlight the potential clinical impact of nirmatrelvir-ritonavir among vaccinated individuals with Omicron subvariant infection and support our recommendations to treat patients at risk for severe disease, including otherwise healthy individuals ≥65 years old, regardless of vaccination status (algorithm 1). (See "COVID-19: Management of adults with acute illness in the outpatient setting", section on 'Efficacy and rationale'.)

IVIG for vaccine-induced immune thrombotic thrombocytopenia (October 2022)

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare complication of adenoviral-vectored COVID-19 vaccines that presents with thrombocytopenia and thrombosis. Emerging evidence on management continues to support a role for intravenous immune globulin (IVIG) as a component of therapy, along with anticoagulation. In a new nonrandomized study involving 99 individuals with VITT presenting with cerebral venous thrombosis, receipt of IVIG was associated with lower mortality (29 versus 70 percent) [7]. In contrast, the choice of anticoagulant (heparin versus a nonheparin agent) and receipt of a platelet transfusion were not associated with statistically different mortality rates. We continue to suggest IVIG plus a nonheparin agent, especially if there is concern for possible heparin-induced thrombocytopenia (HIT; including delayed or spontaneous HIT). (See "COVID-19: Vaccine-induced immune thrombotic thrombocytopenia (VITT)", section on 'IVIG'.)

Vitamin D trials do not show benefit for COVID-19 outcomes (October 2022)

There is growing interest in the role of vitamin D as a facilitator of the innate immune response during SARS-CoV-2 infection. However, two recent trials evaluating the effect of vitamin D supplementation on COVID-19 outcomes did not show a benefit:

●In a trial from the United Kingdom, in which 6200 adults were randomly assigned to testing of serum 25-hydroxyvitamin D followed by daily low (800 units) or high (3200 units) dose vitamin D supplementation when the concentration was <30 ng/mL (<75 nmol/L) versus no testing/supplementation, there was no difference in the incidence or severity of COVID-19 during six months of follow-up [8].

●In a trial from Norway, in which 34,601 adults were randomly assigned to 5 mL of cod liver oil (400 units vitamin D) or placebo daily for six months, there was no difference in the incidence or severity of COVID-19 during six months of follow-up [9].

In patients with COVID-19, vitamin D supplementation may be necessary to meet the recommended intake or to treat deficiency; however, doses exceeding the upper level intake with the intention of improving COVID outcomes are not advised. (See "Vitamin D and extraskeletal health", section on 'COVID-19'.)

BACTERIAL INFECTIONS

Fecal microbiota rectal suspension for preventing recurrent Clostridioides difficile infection (March 2023)

In 2022, the US Food and Drug Administration approved a fecal microbiota rectal suspension live biotherapeutic product (Rebyota) for preventing recurrent Clostridioides difficile infection (CDI) in adults with ≥2 prior episodes [10]. It is administered rectally via an enema 24 to 72 hours after the last dose of antibiotics for CDI treatment. In clinical trials of this product, 71 percent of participants did not have a recurrence within eight weeks of their prior CDI and none had a serious adverse event [11]. It remains to be seen how this new fecal microbiota rectal suspension will compare with traditional methods of fecal microbiota transplantation and with bezlotoxumab and whether it is a cost-effective preventive tool for CDI recurrences. (See "Fecal microbiota transplantation for treatment of Clostridioides difficile infection", section on 'Stool-based products'.)

Resistant P. aeruginosa outbreak associated with artificial tears (February 2023)

In January 2023, a multistate outbreak caused by a rare strain of extensively drug-resistant Pseudomonas aeruginosa was reported by the United States Centers for Disease Control and Prevention (CDC) [12]. The outbreak was associated with use of artificial tears, especially the over-the-counter EzriCare brand. Clinical infections included keratitis, endophthalmitis, respiratory infections, urinary tract infections, and sepsis. The strain is resistant to almost all available antibiotics (a subset of strains were susceptible to cefiderocol). The CDC recommends immediate discontinuation of EzriCare artificial tears until further notice. (See "Principles of antimicrobial therapy of Pseudomonas aeruginosa infections", section on 'Epidemiology of resistance' and "Dry eye disease", section on 'Artificial tears'.)

Increasing invasive group A streptococcal infections among children in Europe (December 2022)

Several European countries, including England, France, Ireland, the Netherlands, and Sweden, have reported an increased rate of invasive group A streptococcal (GAS) infections among children <10 years old during the fall and winter of 2022 to 2023 compared with prior years [13,14]. This increase parallels a >3-fold rise in reported cases of scarlet fever and may reflect an early GAS season coinciding with an increase in circulating respiratory viruses. No increase in antibiotic resistance has been observed among isolated GAS strains. Enhanced surveillance activities have been implemented in the affected areas and public health organizations are emphasizing the importance of early recognition and prompt treatment of GAS infections, particularly scarlet fever. (See "Invasive group A streptococcal infections in children", section on 'Incidence'.)

Drainage or splenectomy for splenic abscess (November 2022)

Splenic abscess is an uncommon infection that typically results from a hematogenous source such as endocarditis. Along with broad-spectrum antibiotics, a procedure is often needed to remove the fluid collection. A new systematic review of splenic abscess treatment in nearly 600 patients found that approximately half were treated with percutaneous drainage and half with splenectomy [15]. There were no statistically significant differences in mortality or complications. Drainage is less invasive and was associated with trends toward lower mortality and complication rates, but this may have reflected differences in patient populations or local expertise. The choice of procedure is individualized; percutaneous drainage may be preferable to some individuals if feasible. (See "Evaluation of splenomegaly and other splenic disorders in adults", section on 'Management (abscess/infarction)'.)

Antibiotic prophylaxis against endocarditis before invasive dental procedures (September 2022)

The efficacy of antibiotic prophylaxis for prevention of infective endocarditis (IE) has not been established. A case-crossover analysis and cohort study performed in nearly 8 million individuals identified an association between invasive dental procedures (particularly extractions and oral surgery) and subsequent IE in individuals at high IE risk [16]. Antibiotic prophylaxis was associated with reduced risk of IE after these procedures. These findings support administration of antibiotic prophylaxis to individuals with high IE risk undergoing invasive dental procedures. (See "Prevention of endocarditis: Antibiotic prophylaxis and other measures", section on 'Impact of procedures on risk of endocarditis'.)

HIV INFECTION

Feeding and antiretroviral prophylaxis for infants born to mothers with HIV (February 2023)

The United States Department of Health and Human Services (DHHS) issued updated guidelines on breastfeeding and antiretroviral prophylaxis for infants born to mothers with HIV [17]:

●Patients who are virologically suppressed and have been on ART consistently through at least the third trimester and at delivery can now consider breastfeeding after discussing the risks and benefits with their clinician. The guidelines continue to strongly recommend against breastfeeding for individuals without virologic suppression.

●Formula-fed infants who are at very low risk of HIV acquisition (full-term and born to mothers who maintained viral suppression on at least 10 consecutive weeks of ART during pregnancy and delivery without adherence concerns) can receive only 2 weeks of zidovudine instead of the previously recommended 4 to 6 weeks. For breastfed infants who are at low risk of HIV acquisition at birth, the guidelines recommend six weeks of zidovudine.

We are in agreement with these recommendations. (See "Intrapartum and postpartum management of pregnant women with HIV and infant prophylaxis in resource-rich settings", section on 'Breastfeeding'.)

ART selection during pregnancy (February 2023)

The United States Department of Health and Human Services issued new recommendations on the selection and continuation of antiretroviral therapy (ART) during pregnancy [17]. The major practical changes include:

● Atazanavir and raltegravir are no longer preferred ART agents during pregnancy but are reasonable alternative agents if preferred agents cannot be used.

● Patients who become pregnant while on the injectable cabotegravir-rilpivirine regimen can now continue the regimen throughout pregnancy with frequent viral load monitoring (every one to two months).

● For patients who acquire HIV despite using cabotegravir as part of an HIV pre-exposure prophylaxis (PrEP) regimen, ritonavir-boosted darunavir is preferred over dolutegravir for ART initiation during pregnancy.

Our approach is consistent with these recommendations, which take into account a patient's preferences regarding use of ART that have less data on pregnancy and also consider the effect of newer ART agents used in PrEP. (See "Antiretroviral selection and management in pregnant individuals with HIV in resource-rich settings", section on 'Selecting the third drug'.)

Lenacapavir for treatment of multidrug-resistant HIV (February 2023)

In 2022, the capsid inhibitor lenacapavir was approved for use in the United States as part of a combination regimen for patients with multidrug-resistant HIV-1 [18]. Capsid inhibitors impact key steps necessary for viral entry and virion assembly. In clinical trials evaluating lenacapavir, approximately 80 percent achieved a viral load of less than 50 copies per milliliter by 26 weeks, and none of the patients developed serious adverse events [19]. Patients with multidrug-resistant HIV should be managed in conjunction with an HIV specialist. (See "Overview of antiretroviral agents used to treat HIV", section on 'Capsid inhibitors'.)

IMMUNIZATIONS

Electronic letters may be useful for improving influenza vaccination rates (March 2023)

Use of electronic letters for improving annual influenza vaccination rates was evaluated in a randomized trial including more than 960,000 Danish citizens ≥65 years of age [20]. Prior to the 2022-23 influenza season, participants were assigned to receive no letter (usual care) or one of nine letters that included a behavioral nudge. Compared with usual care, vaccination rates were slightly higher among two of the nine groups: those who received letters highlighting cardiovascular disease protection and those who received a standard electronic letter repeated at 14 days. Although the observed effects were modest (<1 percentage point difference), applying the difference across the entire cohort would amount to vaccination of more than 8500 additional individuals - a meaningful increase for a low-cost, scalable intervention. (See "Seasonal influenza vaccination in adults", section on 'Improving vaccination rates'.)

Meningitis B vaccination in young children (February 2023)

Indications for meningitis B vaccination vary by country and depend on the epidemiology of invasive meningococcal disease. In a case-control study from Spain that evaluated children <5 years of age, complete vaccination with the MenB-4C serogroup B meningococcal vaccine series was 71 percent effective against invasive serogroup B meningococcal disease; receipt of ≥1 dose was 64 percent effective [21]. The MenB-4C vaccine also provided protection against non–serogroup B invasive disease. The findings of this study may inform immunization programs for at-risk children and children from areas with a high prevalence of serogroup group B meningococcal disease. (See "Meningococcal vaccination in children and adults", section on 'Immunogenicity and effectiveness'.)

Updated immunization schedule for adults in the United States (February 2023)

The 2023 United States Advisory Committee on Immunization Practices (ACIP) vaccination schedules for adults have been published by the Centers for Disease Control and Prevention (CDC) (figure 1 and figure 2) [22]. Changes include recommendations for COVID-19 vaccination, quadrivalent influenza vaccine in persons aged ≥ 65, pneumococcal vaccines in previously vaccinated individuals, and poliovirus vaccination for individuals at increased risk of polio exposure. Clarification has been added that zoster vaccination does not require serologic evidence of prior varicella infection. Newly approved vaccines have been included as well (eg, PreHevbrio for hepatitis B and Priorix for MMR vaccination). Healthcare providers in the United States should review these recommendations to guide their vaccination practices for adult patients. (See "Standard immunizations for nonpregnant adults", section on 'Immunization schedule for nonpregnant adults'.)

Novel oral type 2 poliovirus vaccine (nOPV2) in newborn infants (January 2023)

In 2020, the World Health Organization (WHO) authorized emergency use of a novel oral poliovirus vaccine (nOPV2) to prevent outbreaks of polio caused by type 2 vaccine-derived strains; however, data in individuals <18 weeks had previously been limited. In a randomized, placebo-controlled trial of 330 healthy newborn infants with no prior poliovirus vaccination, nOPV2 was safe, well tolerated, and immunogenic (99 percent had protective antibody levels after two doses) [23]. Shedding of vaccine-derived virus in stool was low and of short duration, suggesting that sustained transmission of nOPV2 is unlikely. Many countries, including the United States, use injectable vaccines composed of inactivated poliovirus that cannot cause infection. However, for those countries that still use oral vaccines, these data are reassuring and support continued use of nOPV2 in infants. (See "Poliovirus vaccination", section on 'Monovalent OPV vaccines and nOPV2'.)

Expanded ACIP recommendations for oral cholera vaccine (October 2022)

CVD 103-HgR (Vaxchora) is a single-dose, live attenuated oral cholera vaccine derived from Vibrio cholerae serotype O1; it was licensed by the US Food and Drug Administration and recommended by the Advisory Committee on Immunization Practices (ACIP) in 2016 for adults age 18 to 64 years traveling to areas of active cholera transmission. In 2022, the ACIP expanded the age group to include individuals age 2 to 17 years who meet these criteria [24]. Thus far, assessment of CVD 103-HgR vaccine benefit in children has been based on safety and immunogenicity data rather than direct assessment of vaccine efficacy. We are in agreement with this guidance. (See "Cholera: Clinical features, diagnosis, treatment, and prevention", section on 'For travelers to high-risk areas'.)

INFECTION CONTROL

Routine glove and instrument change prior to closure of abdominal incisions (December 2022)

Whether changing gloves and using new instruments prior to wound closure affects surgical site infection (SSI) rates is uncertain. In an unblinded cluster randomized trial of over 13,000 patients undergoing intra-abdominal surgery in low- to middle-income (LMIC) countries, the risk of SSI was lower when routine glove and sterile instrument change was performed prior to closure compared with no glove or instrument change (16 versus 19 percent) [25]. The results from this study support a theoretical advantage of changing gloves before closure as a method to reduce the risk of SSI. The LMIC setting may limit generalizability to other settings. (See "Overview of control measures for prevention of surgical site infection in adults", section on 'Surgical attire and barrier devices'.)

Topical antiseptics to reduce infection of contaminated or dirty wounds (December 2022)

The efficacy of various antiseptic agents applied preoperatively to contaminated or dirty wounds to reduce infection is not well studied. In a multiple-period, cluster-randomized, crossover trial comparing aqueous chlorhexidine gluconate with aqueous povidone-iodine for wound preparation in over 1600 open-fracture repairs, the surgical site infection (SSI) rate was 7 percent in both groups [26]. Other aspects of SSI prevention were at the provider's discretion; thus, 63 percent of patients also received an alcohol-based prewash ostensibly of the intact skin of the operative extremity and all patients received intravenous antibiotics (mean duration three days). Further study is needed to determine the optimal preparation of contaminated or dirty wounds and whether any topical agent influences SSI independent of other factors (eg, prophylactic systemic antibiotics, surgery duration, presence of ischemia). (See "Overview of control measures for prevention of surgical site infection in adults", section on 'Topical antiseptics'.)

MYCOBACTERIAL INFECTIONS

Adaptive treatment approach for tuberculosis (March 2023)

Adjusting tuberculosis (TB) treatment regimens based on clinical response facilitate a shorter treatment course. In an open-label trial, 675 patients with rifampin-susceptible TB were randomly assigned to a standard regimen (24 weeks) or one of two intensified regimens (either bedaquiline or high-dose rifampin, each in combination with multiple other agents) [27]. Patients completed the intensified regimen at 8 weeks if they had no evidence of persistent disease; otherwise, they continued therapy for a duration dependent on subsequent response. At 96 weeks, rates of death, ongoing treatment, or active disease were largely similar with the standard regimen and the bedaquiline regimen, and slightly higher with the rifampin regimen (4, 6, and 11 percent, respectively). It is uncertain whether an adaptive treatment approach would be effective outside the context of a clinical trial; further evaluation is warranted. (See "Treatment of drug-susceptible pulmonary tuberculosis in nonpregnant adults without HIV infection", section on 'Evaluating shorter regimens'.)

Abbreviated regimens for treatment of drug-resistant tuberculosis (December 2022, Modified January 2023)

Several new trials in patients with uncomplicated pulmonary multidrug-resistant tuberculosis (TB) have highlighted a similar or greater rate of favorable outcomes (eg, less treatment failure, treatment discontinuation, or disease relapse) with abbreviated, all-oral regimens compared with longer or injectable-containing regimens. These include a 6-month regimen of bedaquiline, pretomanid, linezolid, and moxifloxacin compared with 9- to 20-month standard regimens for rifampin-resistant TB [28], a 9-month bedaquiline- and fluoroquinolone-based regimen compared with a 9-month injectable-containing regimen for rifampin-resistant TB [29], and a 9-month regimen of delamanid, linezolid, levofloxacin, and pyrazinamide compared with a >20-month injectable-containing regimen for isoniazid- and rifampin-resistant TB [30]. A 6-month regimen of bedaquiline, pretomanid, and linezolid, with or without moxifloxacin, is emerging as a preferred treatment approach internationally, including in the United States; other bedaquiline-containing regimens and the delamanid regimen are potential alternatives. (See "Treatment of drug-resistant pulmonary tuberculosis in adults", section on 'Abbreviated regimens'.)

Linezolid dosing for drug-resistant tuberculosis (September 2022)

The bedaquiline-pretomanid-linezolid (BPaL) regimen is effective against drug-resistant tuberculosis (TB); however, the optimal linezolid dose is uncertain. In a randomized trial including 181 patients with highly resistant TB, use of this regimen with various linezolid doses (1200 mg for six months, 1200 mg for two months, 600 mg for six months, or 600 mg for two months) resulted in high success rates (93, 89, 91, and 84 percent, respectively) [31]. Peripheral neuropathy and myelosuppression occurred more frequently with the higher doses, which were more likely to be modified. Based on these findings, we administer the linezolid component of BPaL at a dose of 600 mg for 26 weeks; this group had the most favorable risk-benefit ratio with respect to adverse events and dose modifications. (See "Treatment of drug-resistant pulmonary tuberculosis in adults", section on 'Bedaquiline, pretomanid, linezolid'.)

PARASITIC INFECTIONS

Malaria prevention regimens and pregnancy outcomes in East Africa (March 2023)

Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) is important for reducing malaria-associated adverse birth outcomes, but dihydroartemisinin-piperaquine (DP) is a promising alternative in areas with SP resistance. A randomized trial of nearly 4700 pregnant women without human immunodeficiency virus (HIV) infection in East Africa randomly assigned participants to receive IPTp with: SP alone, DP alone, or DP with azithromycin [32]. Compared with SP alone, DP resulted in a 41 percent reduction in clinical malaria but a higher composite rate of adverse pregnancy outcomes (low birth weight, small for gestational age, preterm birth, death: 28 versus 23 percent). Thus, while DP-IPTp may have superior antimalarial effects in areas with SP resistance, SP-IPTp may have other benefits on pregnancy outcomes. Further study of malaria prevention tools in areas with SP resistance is needed. (See "Malaria in pregnancy: Prevention and treatment", section on 'Intermittent preventive treatment in pregnancy (IPTp)'.)

Chlorfenapyr-pyrethroid insecticidal nets for malaria control (February 2023)

Use of long-lasting insecticidal nets (LLINs) treated with more than one insecticide of different classes has been proposed for malaria control. A cluster-randomized study assigned more than 53,000 households in Benin to receive LLINs treated with chlorfenapyr-pyrethroid, pyriproxyfen-pyrethroid, or pyrethroid only [33]. More than two years later, malaria incidence in clusters where chlorfenapyr-pyrethroid LLINs were used was lower than where pyrethroid only or pyriproxyfen-pyrethroid LLINs were used. Comparable findings had been described in Tanzania, and chlorfenapyr-pyrethroid LLINs are anticipated to become the first WHO-recommended LLINs impregnated with an insecticide class other than pyrethroids. (See "Malaria: Epidemiology, prevention, and control", section on 'Long-lasting insecticide-treated nets (LLINs)'.)

First trimester treatment of malaria with artemisinin derivatives (December 2022)

Artemisinin combination therapy (ACT) has become the preferred treatment for uncomplicated malaria in most patients, but use for treatment of chloroquine-resistant malaria in the first trimester has been avoided because of limited safety data. However, in a 2022 meta-analysis of prospective data from >700 pregnancies with confirmed first trimester exposure to ACT and >1000 pregnancies with confirmed first trimester exposure to non-ACTs, adverse pregnancy outcomes occurred less often among those who received ACT, although the result was not statistically significant (5.7 versus 8.9 percent; adjusted hazard ratio [aHR] 0.71, 95% CI 0.49-1.03) [34]. Artemether-lumefantrine accounted for 70 percent of the ACT exposures and was associated with a lower risk of adverse pregnancy outcome compared with oral quinine (4.8 versus 9.2 percent; aHR 0.58, 95% CI 0.36-0.92). Based on these data, we now suggest artemether-lumefantrine for treatment of chloroquine-resistant malaria during the first trimester. (See "Malaria in pregnancy: Prevention and treatment", section on 'Drug safety'.)

TICK-BORNE DISEASES

Duration of doxycycline for early localized Lyme disease (March 2023)

The duration of doxycycline treatment for early localized Lyme disease is typically 10 days. In a randomized, open-label trial of 300 adults in Slovenia with solitary erythema migrans, the failure rates following 7 versus 14 days of oral doxycycline were similar (3 versus 2 percent) [35]. No patients in either arm developed later-stage symptoms of Lyme disease. Borrelia afzelii was the documented cause in 90 percent. Although this study suggests that 7 days of oral doxycycline is adequate to treat solitary erythema migrans caused by B. afzelii, we continue to suggest a 10-day course until larger studies are performed from different locales, including regions where other Borrelia species (eg, Borrelia burgdorferi) are the main causes of Lyme. (See "Treatment of Lyme disease", section on 'Preferred regimens'.)

VIRAL INFECTIONS, NON-HIV

Change in monkeypox terminology (December 2022)

In November 2022, the World Health Organization changed the name of the disease referred to as “monkeypox” to “mpox” [36]. This change was made to follow current best practices of not naming diseases after animals or geographic locations, and to reduce any stigma that could be associated with the original name. The virus that causes mpox will continue to be referred to as monkeypox virus until the International Committee on the Taxonomy of Viruses officially decides what the name of the virus is. (See "Epidemiology, clinical manifestations, and diagnosis of mpox (monkeypox)", section on 'Terminology'.)

Palivizumab for prevention of hospitalization during the 2022-2023 RSV season (November 2022)

During the COVID-19 pandemic, interseasonal respiratory syncytial virus (RSV) activity increased in some regions, resulting in increased pediatric hospitalizations. In regions with interseasonal activity similar to that in a typical fall-winter season, expert groups supported administration of palivizumab to eligible children outside of the typically recommended schedule. If regional RSV activity persists at high levels through the fall and winter of the 2022-2023 RSV season, the American Academy of Pediatrics supports administration of more than five consecutive doses of palivizumab to eligible children who initiated palivizumab earlier than typically recommended [37]. Information about state-level RSV activity in the United States is available from the Centers for Disease Control and Prevention. We agree with this endorsement. (See "Respiratory syncytial virus infection: Prevention in infants and children", section on 'Increased interseasonal activity during COVID-19 pandemic'.)

Outbreak of Ebola virus disease due to Sudan species in Uganda (September 2022)

Most outbreaks of Ebola virus disease in the recent past have been due to the Zaire species. On September 20, 2022, an outbreak of Ebola disease caused by Sudan species was reported in Uganda [38]. The first recognized patient presented with high fever, vomiting, diarrhea, and other signs consistent with Ebola virus disease. There are concerns about ongoing spread of this virus since vaccination with the single-dose recombinant vesicular stomatitis virus vaccine, which elicits a rapid immune response against the Zaire species, is not expected to protect against the Sudan virus. Although a two-dose vaccine that expresses the Sudan virus surface glycoprotein (among other antigens) is available, it requires a 56-day interval between doses and would offer little protection in a rapidly spreading outbreak. (See "Epidemiology and pathogenesis of Ebola virus disease", section on 'Uganda'.)

OTHER INFECTIOUS DISEASES

Role of wound packing after drainage of perianal and perirectal abscess (September 2022)

After incision and drainage of a perianal or perirectal abscess, it is common practice to pack the wound, under the assumption that this will facilitate further drainage by wicking and prevent premature skin closure. In the PPAC2 trial of 443 patients with a primary perianal abscess, nonpacking, compared with packing, resulted in similar rates of fistula formation (11 versus 15 percent) and abscess recurrence (6 versus 3 percent), differences that were not statistically significant [39]. However, the nonpacking group had lower average pain scores (28 versus 38 on a 100-point visual analog scale). Given these and similar findings from two earlier small trials, we now suggest not packing the wound after drainage of perianal or perirectal abscess. (See "Perianal and perirectal abscess", section on 'Role of wound packing'.)