The gram-positive anaerobic bacillus Clostridium difficile is the most common identifiable cause of antibiotic-associated diarrhea. The antibiotics most often implicated have been ampicillin, second and third generation cephalosporins, clindamycin and fluoroquinolones. The emergence in recent years of a new, more toxic epidemic strain (BI/NAP1), possibly related to widespread use of fluoroquinolones, has caused a marked increase in the incidence and severity of C. difficile-associated disease (CDAD).

A large mumps outbreak that began in Iowa in December 2005 has spread. About 40% of the cases have been in people 18-25 years old, many of whom are college students and had been vaccinated against the disease.

Bexxar, a combination of the monoclonal antibody tositumomab and radiolabeled Iodine-131 tositumomab (Corixa Corp/GlaxoSmithKline) has been approved by the FDA for a single treatment of relapsed follicular non-Hodgkin's lymphoma (NHL) in patients who are refractory to rituximab (Rituxan - Medical Letter 1998; 40:65). It is the second radioimmunoconjugate to be approved for refractory NHL; yttrium-90 linked to ibritumomab tiuxetan (Zevalin) was approved in 2002. Tositumomab, like ibritumomab, is a monoclonal antibody of mouse origin that binds to the CD20 antigen present on the surface of >90%...

The FDA has approved Trumenba (Pfizer), a vaccine that protects against invasive meningococcal disease caused by Neisseria meningitidis serogroup B, for use in adolescents and young adults 10-25 years old.

Rifaximin (Xifaxan – Salix), a minimally absorbed oral antibiotic approved previously to treat travelers' diarrhea and to reduce the risk of recurrent hepatic encephalopathy, has now been approved by the FDA for treatment of irritable bowel syndrome with diarrhea (IBS-D). Eluxadoline (Viberzi – Actavis), a mu-opioid receptor agonist, was also recently approved for IBS-D and will be reviewed in a future issue.

Tinidazole (Tindamax - Presutti Labs), an oral antiprotozoal drug similar to metronidazole (Flagyl, and others), has been approved by the FDA for treatment of trichomoniasis in adults and for treatment of giardiasis, intestinal amebiasis and amebic liver abcess in adults and children more than 3 years old. Tinidazole has been widely used outside of the US for decades under the trade name Fasigyn (Pfizer).

The FDA has approved Menveo (Novartis), a new quadrivalent conjugated polysaccharide vaccine, for protection against disease caused by Neisseria meningitidis in people 11-55 years old.

The FDA has licensed PreHevbrio (VBI Vaccines), a recombinant, 3-antigen, 3-dose hepatitis B vaccine, for the prevention of infection caused by all known subtypes of hepatitis B virus (HBV) in adults. It has been available in Israel since 2000.

The FDA has licensed Penbraya (Pfizer), a pentavalent polysaccharide conjugate meningococcal vaccine, for prevention of invasive meningococcal disease caused by Neisseria meningitidis serogroups A, B, C, W, or Y (MenABCWY) in persons 10-25 years old. Penbraya is the only meningococcal vaccine that contains all five of these serogroups. Two quadrivalent polysaccharide conjugate meningococcal vaccines containing serogroups A, C, W, and Y (MenACWY; Menveo, MenQuadfi) and two meningococcal serogroup B vaccines (MenB; Bexsero, Trumenba) are available in the US (see Table...

The FDA has licensed the pentavalent vaccine Penmenvy (GSK) for prevention of invasive meningococcal disease caused by Neisseria meningitidis serogroups A, B, C, W, or Y (MenABCWY) in persons 10-25 years old. Penmenvy is the second pentavalent meningococcal vaccine to become available in the US; Penbraya was licensed in 2023.