Diagnosis of enteric fever in the emergency department: a retrospective study from Pakistan

Background:Enteric fever is one of the top differential diagnoses of fever in many parts of the world. Generally, the diagnosis is suspected and treatment is initiated based on clinical and basic laboratory parameters.Aims: The present study identifies the clinical and laboratory parameters predicting enteric fever in Patients visiting the emergency department of a tertiary care hospital in Pakistan.Methods:This is a retrospective chart review of all adult Patients with clinically suspected enteric fever admitted to the hospital through the emergency department during a 5-year period (2000-2005).Results:A total of 421 emergency department Patients were admitted to the hospital with suspected enteric fever. There were 53 cases of blood culture-positive enteric fever and 296 disease-negative cases on culture. The mean age in the blood culture-positive group was 27 years (SD: 10) and in the group with negative blood culture for enteric fever, 35 years (SD: 15) with a male to female ratio of 1:0.6 in both groups. Less than half (48%) of all Patients admitted with suspected enteric fever had the discharge diagnosis of enteric fever, of which only 13% of the Patients had blood culture/serologically confirmed enteric fever. None of the common clinical and laboratory parameters differed between enteric fever-positive Patients and those without it.Conclusion:Commonly cited clinical and laboratory parameters were not able to predict enteric fever

Antimicrobial Resistance in Vibrio

Vibrio infections potentially requiring antimicrobial therapy fall into three distinct clinical syndromes; cholera caused by either Vibrio cholerae O1 or O139 and rarely other V. cholerae serogroups; less severe non-cholera diarrhea caused by non-01 or O139 V. cholerae or other Vibrio species; and soft-tissue infections and sepsis caused by halophilic, marine vibrios.Infections with V. cholerae O1 or the currently much less frequently identified O139 serogroup occur almost exclusively in poor countries where access to clean water and proper sanitation is uncommon. Diarrhea with non-cholera vibrios and tissue invasive infections and sepsis occur wherever marine or seafood exposure takes place. Cholera and non-cholera diarrhea occur in otherwise healthy hosts, and most commonly in children in endemic areas; serious tissue-invasive infections and sepsis with halophilic vibrios is most common in immunocompromised hosts, especially those with hepatic impairment. Acquired multidrug resistance to V. cholerae O1 and O139 is now common and firmly established wherever infections occur.Acquired resistance in V. cholerae O1and O139 is primarily from acquisition of transmissible genetic elements, including conjugative plasmids, integrons, or integrative conjugative elements that carry genes encoding resistance.Circulating strains can both gain and lose resistance during the course of an epidemic, and surveillance of resistance patterns is essential. Because onset of disease is rapid, and disease can be rapidly fatal without appropriate fluid and antimicrobial therapy, antimicrobials should be administered empirically to patients with clinical cholera based on the known prevalence of resistance.In addition, cholera is usually treated in settings where isolation of the infecting organism and susceptibility testing are not routinely available. Thus surveillance programs that monitor resistance, and report to peripheral clinics where cholera patients are cared for, are essential for the management of this disease.. Resistance is not as common in halophilic Vibrios as it is in V. cholerae. Although there are a number of agents that remain active in-vitro against these organisms, because of the relative rarity of infections, and the absence of clinical trials, choice of therapy is predicated upon in-vitro and animal studies, and limited clinical experience

Efficacy of Ciprofloxacin for Treatment of Cholera Associated with Diminished Susceptibility to Ciprofloxacin to Vibrio cholerae O1.

We identified a poor clinical response to treatment of cholera with a single 1 g dose of ciprofloxacin, a standard treatment for cholera.To determine reasons for the poor response and better therapeutic approaches we examined the minimal inhibitor concentration (MIC, n = 275) and disc-diffusion zone sizes (n = 205) for ciprofloxacin and nalidixic acid of V. cholerae O1 strains isolated in Bangladesh from 1994 to 2012, and reexamined data from 161 patients infected with Vibrio cholerae O1 recruited in four clinical trials who received single- or multiple-dose ciprofloxacin for treatment of cholera and compared their clinical response to the V. cholerae O1 susceptibility.Although all 275 isolates of V. cholerae O1 remained susceptible to ciprofloxacin using standard MIC and disc-diffusion thresholds, the MIC90 to ciprofloxacin increased from 0.010 in 1994 to 0.475 μgm/ml in 2012. Isolates became frankly resistant to nalidixic with the MIC90 increasing from 21 μgm/ml in 1994 to >256 μgm/ml and 166 of 205 isolates from 1994 to 2005 being frankly resistant using disc-diffusion testing. Isolates resistant to nalidixic acid by disc-diffusion testing had a median ciprofloxacin MIC of 0.190 μgm/ml (10th-90th centiles 0.022 to 0.380); nalidixic acid-susceptible isolates had a median ciprofloxacin MIC of 0.002 (0.002 to 0.012).The rate of clinical success with single-dose ciprofloxacin treatment for nalidixic acid-susceptible strains was 94% (61 of 65 patients) and bacteriologic success 97% (63/65) compared to 18% (12/67) and 8% (5/67) respectively with nalidixic acid-resistant strains (P<0.001 for both comparisons). Multiple-dose treatment with ciprofloxacin had 86% and 100% clinical and bacteriologic success rates respectively in patients infected with nalidixic acid-susceptible strains of V. cholerae O1 compared to clinical success 67% and bacteriologic success 60% with nalidixic acid-resistant strains.Single-dose ciprofloxacin is not effective for treating cholera caused by V. cholerae O1 with diminished susceptibility to ciprofloxacin, and nalidixic acid disc-diffusion testing effectively screens for such isolates

Clinical and bacteriologic response to single-dose or multiple-dose ciprofloxacin therapy in patients infected with nalidixic acid-resistant strains of <i>V</i>. <i>cholerae</i> O1.

<p>Values are median (25^th–75^th centile) unless noted.</p><p>* Based on weight discharge</p><p>Clinical and bacteriologic response to single-dose or multiple-dose ciprofloxacin therapy in patients infected with nalidixic acid-resistant strains of <i>V</i>. <i>cholerae</i> O1.</p

Randomized controlled trials from which 161 adult patients infected with <i>V</i>. <i>cholerae</i> O1;treated with ciprofloxacin and completed 5day study were included in this analysis.

<p>There were 580 patients in total in these four studies, of whom 161 (28%) were infected with <i>V</i>.<i>cholerae</i> O1; treated with ciprofloxacin and completed 5 day study</p><p>Randomized controlled trials from which 161 adult patients infected with <i>V</i>. <i>cholerae</i> O1;treated with ciprofloxacin and completed 5day study were included in this analysis.</p

Admission characteristics and response to ciprofloxacin therapy in 161 patients infected with nalidixic acid-susceptible and nalidixic acid-resistant strains of <i>V</i>. <i>cholerae</i> O1.

<p>Values are median (25^th, 75^th centiles) unless noted</p><p>* Based on disc-diffusion method</p><p>^‡ Based on discharge weight</p><p>Admission characteristics and response to ciprofloxacin therapy in 161 patients infected with nalidixic acid-susceptible and nalidixic acid-resistant strains of <i>V</i>. <i>cholerae</i> O1.</p