Changing Patterns in Enteric Fever Incidence and Increasing Antibiotic Resistance of Enteric Fever Isolates in the United States, 2008–2012

Abstract

Background Enteric fever in the United States has been primarily associated with travel and with worrisome changes in global patterns of antimicrobial resistance. We present the first comprehensive report of National Typhoid and Paratyphoid Fever Surveillance System (NTPFS) data for a 5-year period (2008–2012). Methods We reviewed data on laboratory-confirmed cases reported to NTPFS, and related antimicrobial susceptibility results of Salmonella Typhi and Paratyphi A isolates sent for testing by participating public health laboratories to the Centers for Disease Control and Prevention’s National Antimicrobial Resistance Monitoring System laboratory. Results During 2008–2012, 2341 enteric fever cases were reported, 80% typhoid and 20% paratyphoid A. The proportion caused by paratyphoid A increased from 16% (2008) to 22% (2012). Foreign travel within 30 days preceding illness onset was reported by 1961 (86%) patients (86% typhoid and 92% paratyphoid A). Travel to southern Asia was common (82% for typhoid, 97% for paratyphoid A). Among 1091 (58%) typhoid and 262 (56%) paratyphoid A isolates tested for antimicrobial susceptibility, the proportion resistant to nalidixic acid (NAL-R) increased from 2008 to 2012 (Typhi, 60% to 68%; Paratyphi A, 91% to 94%). Almost all NAL-R isolates were resistant or showed decreased susceptibility to ciprofloxacin. Resistance to at least ampicillin, chloramphenicol, and trimethoprim-sulfamethoxazole (multidrug resistant [MDR]) was limited to Typhi isolates, primarily acquired in southern Asia (13%). Most MDR isolates were also NAL-R. Conclusions Enteric fever in the United States is primarily associated with travel to southern Asia, and increasing resistance is adding to treatment challenges. A bivalent typhoid and paratyphoid vaccine is needed.

Enteric fever caused by Salmonella enterica serovar paratyphi A: An emerging health concern in Nepal

“…Likewise, during 2008 in United States, 2341 enteric fever cases were reported; 80% typhoid and 20% paratyphoid. The proportion caused by paratyphoid A increased from 16 (2008) to 22% (2012) (Date et al, 2016). Nigeria reports the most comprehensive data on S. paratyphi from sub Saharan Africa.…”

Travel Characteristics and Pretravel Health Care Among Pregnant or Breastfeeding U.S. Women Preparing for International Travel

“…Typhoid fever can be a life-threatening illness and is increasingly difficult to treat because of multidrug-resistant organisms. 22 This discordance on risk and concern may suggest additional guidance on use of typhoid polysaccharide vaccine in pregnant women may be useful.…”

Enteric Fever in Travelers: An Updated Insight

“…In one of the recent study conducted from 2008-2012, 86% of typhoid cases were travel-associated [23], compared with 79% during 1999 through 2006 [18]. The travel-associated percentage was even higher (91%) for paratyphoid fever [23].…”

“…Since few decades, the number of enteric fever cases acquired during international travel has substantially increased in the United States [12,[16][17][18] and in other industrialized countries [19][20][21][22]. In one of the recent study conducted from 2008-2012, 86% of typhoid cases were travel-associated [23], compared with 79% during 1999 through 2006 [18]. The travel-associated percentage was even higher (91%) for paratyphoid fever [23].…”