Enteric fever: a travel medicine oriented view

Abstract

The ongoing emergence of S. Paratyphi A results in partial benefit from current typhoid vaccines in the prevention of enteric fever in travelers. Increasing antimicrobial resistance complicates therapy for travel-related enteric fever. New vaccines, offering protection against both agents of enteric fever, are urgently needed; however, none of the current vaccine candidates is likely to be available for several years.

Pattern of Antimicrobial Susceptibility for Salmonella Typhi in Dhaka Medical College Hospital from 2013-2014

“…1,18 Currently 3 rd generation cephalosporins and azythromycin are the only reasonable therapeutic options for most cases of travel related enteric fever. 14,19,20 In our study azythromycin resistance is increasing (29%) and it also correlates with other study. 12,16 In the present study 100% Salmonella were sensitive to ceftriaxone which is the drug of choice in Dhaka Medical College and other parts of Bangladesh to treat typhoid fever.…”

Live Oral Salmonella enterica Serovar Typhi Vaccines Ty21a and CVD 909 Induce Opsonophagocytic Functional Antibodies in Humans That Cross-React withS. Paratyphi A andS. Paratyphi B

“…Currently available licensed vaccines against typhoid fever offer no effective cross-protection against paratyphoid A fever, and the recent emergence of S. Paratyphi A infection has emphasized the need for a vaccine against this pathogen (5,14,16). The measurement of strain-specific humoral immune responses, including antibody-secreting cells (ASC) and/or serum antibodies, is a fundamental part of assessing the immunogenicity of live oral Salmonella vaccines.…”

“…While less prevalent than typhoid fever, paratyphoid fever occurs in an estimated 5.4 million cases each year (3)(4)(5)(6). Recent reports indicate that paratyphoid A fever is on the rise in areas of endemicity (e.g., South and Southeast Asia, China) and among travelers returning from those areas (3)(4)(5)(6). The emergence of multiple antibiotic-resistant Salmonella strains has increased the health risks posed by these enteric fever infections (7).…”

“…However, infection with Salmonella enterica serovar Paratyphi A (paratyphoid A fever) or Salmonella enterica serovar Paratyphi B (paratyphoid B fever) causes similar clinical manifestations (2). While less prevalent than typhoid fever, paratyphoid fever occurs in an estimated 5.4 million cases each year (3)(4)(5)(6). Recent reports indicate that paratyphoid A fever is on the rise in areas of endemicity (e.g., South and Southeast Asia, China) and among travelers returning from those areas (3)(4)(5)(6).…”

Flagellin Is Required for Host Cell Invasion and Normal Salmonella Pathogenicity Island 1 Expression by Salmonella enterica Serovar Paratyphi A

“…This is an invasive, life-threatening systemic disease with a global annual estimation of over 25 million cases, resulting in more than 200,000 deaths (3). In recent years, the occurrence of infection with S. Paratyphi A has been rising, and in some regions of the world (particularly in eastern and southern Asia), it is accountable for up to 50% of all enteric fever cases (4,5). Increasing rates of infection, the lack of a commercially available vaccine, and steadily increasing resistance of S. Paratyphi A isolates to antimicrobial agents make S. Paratyphi A infections a significant public health concern.…”