Influenza
James M. Rippe in Lifestyle Medicine, 2019
Antiviral medicines taken daily during a period of exposure are 79%–90% effective at preventing influenza. Chemoprophylaxis should be started within 48 h of exposure to be effective. Indiscriminate use of prophylaxis is not recommended as it can promote antiviral resistance, but can be considered if there is an outbreak in a long-term care facility or on a case-by-case basis after exposure in a person at high risk of complications from influenza vaccine. The recommended dose of oseltamivir for chemoprophylaxis against influenza in adults is 75 mg orally once a day. The recommended dose of zanamivir for prophylaxis of influenza (types A and B) in adults in a household setting is two inhalations (5 mg per inhalation) orally once daily. The recommended duration of post exposure prophylaxis is generally 10 days after a household exposure or seven days following exposure in other situations. The dose should be given at approximately the same time each day.27
An Overview of Microbes Pathogenic for Humans
Nancy Khardori in Bench to Bedside, 2018
Hepatitis C virus (HCV): is another widely studied type of hepatitis virus. When individuals become acutely infected with HCV, they often are asymptomatic or experience negligible to mild clinical symptoms. Jaundice is present in roughly 25% of cases (El Lakkis and Khardori 2014). Unlike HBV, up to 80% of individuals who experience an acute HCV infection will become chronic carriers; additionally, the most common mode of transmission is via the percutaneous route. While sexual transmission is possible, it is uncommon; therefore, HCV-positive patients with a single long-term steady sexual partner do not need to change their sexual practices (El Lakkis and Khardori 2014). However, individuals with HIV infection (homosexual and heterosexual) or with multiple intimate partners should use condoms. Women should be counseled that roughly 6 in every 100 infants born to HCV positive mothers develop HCV infection (El Lakkis and Khardori 2014); however, breastfeeding has not been shown to directly transmit HCV infection. Presently, there is no post-exposure prophylaxis available. However, recent pharmacologic advances, starting with the 2014 introduction of Ledipasvir/Sofosbuvir have led to effective and convenient options for treatment of all HCV genotypes.
Hepatic disorders in pregnancy
Hung N. Winn, Frank A. Chervenak, Roberto Romero in Clinical Maternal-Fetal Medicine Online, 2021
Hepatitis A virus (HAV) is a small, spherical RNA virus that usually causes a self-limiting clinical hepatitis. The virus is transmitted by the fecal–oral route and replicates exclusively within the hepatocytes and is excreted in bile. HAV infection does not lead to chronic hepatitis but relapsing cholestatic hepatitis have been described (7). The average incubation period is about 28 days (range 15–50 days). Fecal shedding occurs for about 2 weekes after infection. The overall case-fatality ratio is less than 1%. Intrauterine transmission of HAV is very rare but perinatal infection could occur. Acute HAV infection during pregnancy is associated with high risk of maternal complications and preterm labor (8). Serologic diagnosis of acute HAV is made by the presence of anti-HAV IgM. Anti-HAV IgM is typically present for several weeks but may be present for up to 1year. The presence of anti-HAV IgG antibody denotes immunity either by previous infection or vaccination and confers long-lasting immunity. Intrauterine transmission of HAV is very rare; however, perinatal transmission can occur. Neonates of mothers who acquire HAV in the last trimester should receive immune globulin (IG) at the time of delivery (9). Pregnant women who travel to an endemic area should receive prophylactic IG. Individuals who are exposed to acute HAV should receive IG within 10 days of exposure. Studies show that post-exposure prophylaxis can prevent infection or lessen its severity in those who become infected. Mothers infected with HAV are encouraged to breast-feed and HAV infection is not a contraindication for breast-feeding (10).
Does hydroxychloroquine still have any role in the COVID-19 pandemic?
Published in Expert Opinion on Pharmacotherapy, 2021
William HK Schilling, Nicholas J White
In contrast to the wealth of observational data, there have been few RCTs reported. Two pre-exposure prophylaxis trials and three post-exposure prophylaxis trials have now been published in peer-reviewed journals [5–8,11]. Post-exposure prophylaxis (PEP), which may be regarded as a hybrid of prevention and early treatment, would be expected a priori to provide less benefit than pre-exposure prophylaxis. These published studies were relatively small and were powered therefore only to demonstrate large benefits (a minimum of 50% reduction in cases). None were able to reject the null hypothesis. However, the majority did demonstrate non-significant reductions in cases of the order of 15% [63]. So, although the available data from the prevention studies are currently indicative of small benefit, the results are far from conclusive. Dose is also a consideration. Rajasingham et al. in their pre-exposure prophylaxis study used low doses (once weekly and twice weekly dosing, which are closer to those used in malaria chemoprophylaxis) which meant that the levels of hydroxychloroquine were significantly lower than those achieved in the treatment of rheumatological conditions with once daily dosing. This would have reduced the likelihood of a significant antiviral effect [11] although there was a non-statistically significant trend to increased benefit at the higher dose.
Prophylaxis and treatment of HIV-1 infection in pregnancy – Swedish Recommendations 2017
Published in Infectious Diseases, 2018
Lars Navér, Jan Albert, Christina Carlander, Leo Flamholc, Magnus Gisslén, Olof Karlström, Veronica Svedhem-Johansson, Anders Sönnerborg, Katarina Westling, Aylin Yilmaz, Karin Pettersson
A decreased risk for MTCT by use of prophylactic therapy was initially shown in the ACTG 076 study [12], where the mother was given oral zidovudine monotherapy during pregnancy, with addition of intravenous zidovudine during labour, and with zidovudine for the newborn during the first six weeks of life. Since then, zidovudine has been traditionally used as one part of ART regimens aimed at preventing MTCT ever since. However, there is no evidence supporting that zidovudine is superior to other nucleoside reverse-transcriptase inhibitors (NRTIs) for prophylaxis against MTCT or that intravenous zidovudine further decreases the risk for transmission if added to other ART in women with HIV RNA <50 copies/mL close to delivery [13]. Post-exposure prophylaxis after delivery has been proven to be effective for infants at high risk for infection and combination therapy to be more effective than monotherapy [14,15]. In a study of post-exposure prophylaxis, comparing two and three drug regimens, no difference in outcome was observed [16].
The prevention of severe pertussis and pertussis deaths in young infants
Published in Expert Review of Vaccines, 2019
Postexposure prophylaxis is recommended by the Committee of Infection Diseases of the American Academy of Pediatrics and the ACIP for all household contacts of an index case. Postexposure prophylaxis is also recommended for close other contacts and for children in childcare. Post-exposure prophylaxis should be employed for all of the above regardless of their immunization status. A close content is a face-to-face exposure within 3 ft. of a symptomatic person; or direct contact with respiratory, nasal or oral secretions of a symptomatic person; or the sharing of the same contained space in close proximity to a symptomatic person for ≥1 h. Azithromycin, erythromycin or trimethoprim-sulfamethoxazole are all recommended for postexposure prophylaxis. However, trimethoprim-sulfamethoxazole is generally contraindicated in infants <2 months of age. Clarithromycin can be used instead of azithromycin or erythromycin. In general, compliance is best with azithromycin because the treatment course is only 5 days. Since some B. pertussis strains are resistant to macrolides, trimethoprim-sulfamethoxazole should be used in apparent treatment failures.
Related Knowledge Centers
- Antibody
- Rabies Vaccine
- Pathogen
- Tetanus
- Preventive Healthcare
- Emergency Use Authorization
- Bamlanivimab/Etesevimab
- Covid-19
- Ensitrelvir
- Rabies