Treatment of Salmonella typhi carriers with intravenous ampicillin

Chronic Salmonella Typhi carriage at sites other than the gallbladder

Typhoid fever caused by infection with Salmonella enterica subspecies enterica serotype Typhi (S. Typhi), an important public health problem in many low- and middle-income countries, is transmitted by ingestion of water or food contaminated by feces or urine from individuals with acute or chronic S. Typhi infection. Most chronic S. Typhi carriers (shedding for ≥12 months) harbor infection in their gallbladder wherein preexisting pathologies, particularly cholelithiasis, provide an environment that fosters persistence. Much less appreciated is the existence of non-gallbladder hepatobiliary chronic S. Typhi carriers and urinary carriers. The former includes parasitic liver flukes as a chronic carriage risk factor. Chronic urinary carriers typically have pathology of their urinary tract, with or without renal or bladder stones. Even as the prevalence of multidrug-resistant and extensively drug-resistant S. Typhi strains is rising, global implementation of highly effective typhoid vaccines is increasing. There is also renewed interest in identifying, monitoring, and (where possible) treating chronic carriers who comprise the long-term reservoir of S. Typhi.

Antimicrobial agents for the treatment of enteric fever chronic carriage: A systematic review

Background

Chronic carriage of S. Typhi or S. Paratyphi is an important source of enteric fever transmission. Existing guidance and treatment options for this condition are limited. This systematic review aims to assess the evidence concerning the efficacy of different antimicrobials in treating enteric fever chronic carriage.

Methods

We searched major bibliographic databases using relevant keywords between 1946 and September 2021. We included all interventional studies that included patients with confirmed enteric fever chronic carriage and deployed an antimicrobial that remains in clinical practice today. Case reports and case series of under 10 patients were excluded. Two reviewers screened abstracts, selected articles for final inclusion and quality-assessed the included studies for risk of bias. Extracted data was analysed, with pooling of data and eradication rates for each antimicrobial calculated. As only one randomised controlled trial was identified, no meta-analysis was performed.

Results

Of the 593 papers identified by the initial search, a total of eight studies met the inclusion criteria and were included in the systematic review. Evidence was identified for the use of fluoroquinolones and amoxicillin/ampicillin in the treatment for enteric fever chronic carriage. Fluoroquinolones were superior to amoxicillin/ampicillin with 92% of patients achieving eradication after one antimicrobial course compared to 68% (p = 0.02). The quality of included studies was poor, and all were carried out before 1990.

Conclusion

This review identified fluoroquinolones and amoxicillin/ampicillin as treatment options for enteric fever chronic carriage, with fluoroquinolones the more effective option. However, this evidence pre-dates rises in antimicrobial resistance in enteric fever and therefore the significance of these findings to today’s practice is unclear. Further research is needed to investigate whether these antimicrobials remain appropriate treatment options or whether alternative interventions are more effective.

British Infection Association Guidelines for the Diagnosis and Management of Enteric Fever in England

Enteric fever (EF) is an infection caused by the bacteria called Salmonella Typhi or Paratyphi. Infection is acquired through swallowing contaminated food or water. Most EF in England occurs in people returning from South Asia and other places where EF is common; catching EF in England is rare. The main symptom is fever, but stomach pain, diarrhoea, muscle aches, rash and other symptoms may occur. EF is diagnosed by culturing the bacteria from blood and/or stool in a microbiology laboratory. EF usually responds well to antibiotic treatment. Depending on how unwell the individual is, antibiotics may be administered by mouth or by injection. Over the past several years, there has been an overall increase in resistance to antibiotics used to treat enteric fever, in all endemic areas. Additionally, since 2016, there has been an ongoing outbreak of drug-resistant EF in Pakistan. This infection is called extensively drug-resistant, or XDR, EF and only responds to a limited number of antibiotics. Occasionally individuals develop complications of EF including confusion, bleeding, a hole in the gut or an infection of the bones or elsewhere. Some people may continue to carry the bacteria in their stool for a longtime following treatment for the initial illness. These people may need treatment with a longer course of antibiotics to eradicate infection. Travellers can reduce their risk of acquiring EF by following safe food and water practices and by receiving the vaccine at least a few weeks before travel. These guidelines aim to help doctors do the correct tests and treat patients for enteric fever in England but may also be useful to doctors and public health professionals in other similar countries.

Travel trouble: typhoid fever--A case presentation and review

Endogenously contracted typhoid fever has decreased dramatically in the industrialized world. A practicing physician may not see a case in a lifetime, but health professionals should not allow typhoid to recede from their consciousness. Typhoid is still endemic in much of the developing world, and as travel increases, illnesses can and do skip around the world in a day. College students are at particular risk because they often travel on a low budget for extended periods, mix freely with local populations in endemic regions, and are not aware of the risks of such travel. College health professionals need to be able to recognize typhoid fever, should it present, and give advice to patients on primary prevention. The author includes a case presentation that is not completely classical for typhoid fever, as well as a state-of-the-art review, including description, epidemiology, signs and symptoms, diagnosis, treatment, and prevention. Special attention is given to the question of who should be immunized and which vaccines are effective.

Quinolones in Salmonella typhi infection

The quinolones possess a high degree of in vitro activity against enteric bacteria, including Salmonella. This observation, coupled with the limitations of current antityphoid agents, has resulted in the evaluation of quinolones in the therapy of S. typhi infection, including both enteric fever and chronic intestinal carriage. In open uncontrolled trials, norfloxacin, ciprofloxacin, ofloxacin and pefloxacin have been used successfully to treat more than 200 patients with culture-proven typhoid fever. In comparative clinical trials, ciprofloxacin, ofloxacin, pefloxacin or fleroxacin were equivalent or superior to standard antityphoid therapy. In separate studies, norfloxacin and ciprofloxacin were each effective in eliminating intestinal excretion of S. typhi in chronic carriers. Because of increasing resistance worldwide to conventional antityphoid drugs, and in view of the efficacy of the quinolones in the therapy of both typhoid fever and typhoid intestinal carriage, these drugs may become the treatment of choice for these important enteric infections.

Vi serology in detection of chronic Salmonella typhi carriers in an endemic area

A passive haemagglutination assay measuring antibody to highly purified Vi antigen, known to be sensitive and specific for the detection of chronic Salmonella typhi carriers in a non-endemic area, was assessed in an endemic area. A reciprocal serum Vi antibody titre of 160 was found to have a sensitivity of 75%, specificity of 92%, and a high predictive value in screening for chronic S typhi carriers in high-risk population group (eg, women over 40 years). This simple assay can screen for chronic S typhi carriers even in areas where typhoid fever is highly endemic.

Caroli's disease with intrahepatic gall-stones and salmonella infection

At operation for small bowel intussusception, a 26-year-old man was found to have an enlarged liver and spleen. Subsequent investigations suggested bile passage infection associated with numerous intrahepatic gall-stones but symptomatic cholangitis did not present until 5 months later. Retrograde cholangiography showed cavernous ectasia of the bile ducts which contained gall-stones.

Systemic mastocytosis--central nervous system features and lymphographic demonstration of lymph node involvement

Systemic mastocytosis is uncommon. A patient is reported with many of the characteristic lesions of this disorder but with two features not before described--the occurrence of mixed pyramidal and neuromyopathic neurological signs and the demonstration of lymph nodes with abnormal architecture by lymphography.

Chemotherapy of typhoid fever: a review of literature

Until the last few years, chloramphenicol was recognized positively as the drug of choice in the treatment of acute typhoid fever. Its hematoxicity, as well as the recently observed epidemic and the present endemic occurrence of S. typhi strains with R-factor-mediated resistance to chloramphenicol in Mexico, India and South-EAst Asia, render the clinical evaluation of new antibacterial agents extremely important. By means of a literature review on controlled comparative trials, the value of thiamphenicol, ampicillin, amoxycillin, furazolidone and co-trimoxazole as alternative drugs for the treatment of acute typhoid fever is examined. Co-trimoxazole seems to be the drug of choice in the treatment of acute typhoid fever. For the treatment of the chronic typhoid carrier ampicillin is most frequently used, but amoxycillin and co-trimoxazole seem to be just as effective.

Treatment of chronic typhoid carriers with ampicillin

Ten chronic enteric typhoid carriers treated with oral ampicillin have been followed for 4 to 9 years and no relapses have occurred. Patients are probably cured if relapse does not occur within 2 years.