Updated Recommendations for the Use of Typhoid Vaccine — Advisory Committee on Immunization Practices, United States, 2015

Brendan R. Jackson, MD; Shahed Iqbal, PhD; Barbara Mahon, MD

Disclosures

Morbidity and Mortality Weekly Report. 2015;64(11):305-308. 

In This Article

Abstract and Introduction

Abstract

These revised recommendations of the Advisory Committee on Immunization Practices update recommendations published in MMWR in 1994[1] and include updated information on the two currently available vaccines and on vaccine safety. They also include an update on the epidemiology of enteric fever in the United States, focusing on increasing drug resistance in Salmonella enterica serotype Typhi, the cause of typhoid fever, as well as the emergence of Salmonella serotype Paratyphi A, a cause of paratyphoid fever, against which typhoid vaccines offer little or no protection.

Introduction

Salmonella enterica serotypes Typhi and Paratyphi A, Paratyphi B (tartrate negative), and Paratyphi C cause a protracted bacteremic illness referred to respectively as typhoid and paratyphoid fever, and collectively as enteric fever. Enteric fever can be severe and even life-threatening. It is most commonly acquired from water or food contaminated by the feces of an infected person. The incubation period is 6–30 days, and illness onset is insidious, with gradually increasing fatigue and fever. Malaise, headache, and anorexia are nearly universal. A transient macular rash can occur. When serious complications (e.g., intestinal hemorrhage or perforation) occur, it is generally after 2–3 weeks of illness. Untreated illness can last a month.[2] Patients with untreated typhoid fever were reported to have case-fatality rates >10%;[3] the overall case-fatality rate with early and appropriate antibiotic treatment is typically <1%.[4]

Typhoid fever is uncommon in the United States, with an average of about 400 cases reported annually during 2007–2011.[5] Approximately 90% of U.S. cases occur among persons returning from foreign travel, and >75% of travelers had been in India, Bangladesh, or Pakistan.[5] Most travelers (≥55%) reported that their reason for travel was visiting friends or relatives.[5] Even short-term travel to high-incidence areas is associated with risk for typhoid fever.[6] CDC recommends typhoid vaccination for travelers to many Asian, African, and Latin American countries, but, as of 2010, no longer recommends typhoid vaccine for travelers to certain Eastern European and Asian countries;[7] the most recent pre-travel vaccination guidelines are available at http://wwwnc.cdc.gov/travel.

The importance of vaccination and other preventive measures for typhoid fever is heightened by increasing resistance of Salmonella serotype Typhi to antimicrobial agents, including fluoroquinolones, in many parts of the world.[8]

Paratyphoid fever, caused primarily by Salmonella enterica serotype Paratyphi A, but also by serotypes Paratyphi B (tartrate negative) and C, is an illness clinically indistinguishable from typhoid fever.[9] Serotype Paratyphi A is responsible for a growing proportion of enteric fever cases in many countries, accounting for as much as half of the cases.[8] Neither typhoid vaccine available in the United States is licensed by the Food and Drug Administration for prevention of paratyphoid fever, although limited observational data suggest the oral, live-attenuated Ty21a vaccine might offer some protection against Paratyphi B (tartrate negative).[10]

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....