Incidence of Enteric Fever in a Pediatric Cohort in North India: Comparison with Estimates from 20 Years Earlier

Typhoid conjugate vaccine implementation in India: A review of supportive evidence

Background

Typhoid conjugate vaccines are available in the private market in India and are also recommended by the National Technical Advisory Group on Immunisation (NTAGI) for inclusion in India's Universal Immunisation Programme in 2022 to control and prevent typhoid fever. Our study aims to synthesise the supportive evidence for typhoid conjugate vaccine implementation in the routine immunisation programme of India.

Methods

We conducted a literature review to identify supportive evidence for typhoid conjugate vaccine implementation in India based on the key criteria of the World Health Organisation's Evidence-to-Recommendation framework for National Immunisation Technical Advisory Groups.

Results

We synthesised evidence on typhoid disease burden, benefits and harms of typhoid conjugate vaccine, cost-effectiveness analysis, and implementation feasibility. However, the in-country evidence on budget impact analysis, vaccine demand and supply forecast, equity analysis, target population values and preferences, immunisation service providers' acceptability, co-administration safety, and antimicrobial resistance tracking were limited.

Conclusion

Based on the literature review, we identified evidence gaps. We recommend identifying research priorities for supporting typhoid conjugate vaccine implementation decision-making in India by combining evidence gaps with the perceived importance of the same evidence criteria and factors among immunisation stakeholders.

Clinical and antimicrobial susceptibility profile of typhoid fever in children in the era of antibiotic resistance

Enteric fever remains a significant public health problem in low- and middle-income countries with further challenges from emerging antimicrobial resistance. Our prospective study evaluated the current clinical and antimicrobial susceptibility profile of enteric fever in 88 children and compared it to previously established literature. Enteric fever usually presents with nonspecific signs and symptoms, with predominant respiratory complaints. A paradigm shift in the antimicrobial sensitivity pattern has been noted, with increasing resistance for first-line antibiotics and older antibiotics such as ampicillin, cotrimoxazole, and chloramphenicol showing good sensitivity. Thus, the introduction of the latter merits consideration.

A pattern of antibiotic drug resistance of Salmonella Typhi and Salmonella Paratyphi among children with enteric fever in a tertiary care hospital in Lahore, Pakistan

AIM

To establish the pattern of antibiotic resistance and assess the frequency of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Salmonella Typhi and Salmonella Paratyphi among children with enteric fever.

METHODS

This cross-sectional study was carried out in the Department of Pediatrics, Sharif Medical City Hospital, Lahore, from July 2020 to January 2021. The study involved patients aged between 0 to 15 years who attended our outpatient department or were admitted to the ward with the suspicion of typhoid fever. A convenience sample of patients with blood cultures positive for S. Typhi and S. Paratyphi was enrolled.

RESULTS

Of the 105 participants, 70 (66.7%) were male. The mean age was 8.48±4.18 years, and the most affected age group was 6-10 years (n=46, 43.8%). Among the cultured organisms, 95 (90.5%) isolates were S. Typhi and 10 (9.5%) were S. Paratyphi A. Antibiotic resistance was highest against ampicillin (n=91, 86.7%), and all of the isolates were sensitive to imipenem and meropenem. Twenty-three (21.9%) cultured organisms were MDR and 54 (56.8%) were XDR.

CONCLUSION

An alarming antibiotic drug resistance pattern was observed among children with enteric fever in Lahore. The lowest resistance was noted for azithromycin, meropenem, and imipenem. Our findings warrant the immediate implementation of tailored antibiotic stewardship and infection control strategies.

Typhoid Control in an Era of Antimicrobial Resistance: Challenges and Opportunities

Historically, typhoid control has been achieved with water and sanitation interventions. Today, in an era of rising antimicrobial resistance (AMR), two World Health Organization-prequalified vaccines are available to accelerate control in the shorter term. Meanwhile, water and sanitation interventions could be implemented in the longer term to sustainably prevent typhoid in low- and middle-income countries. This article first approaches typhoid control from a historical perspective, subsequently presents how vaccination could complement water and sanitation activities, and finally discusses the challenges and opportunities for impactful control of typhoid infection. It also addresses data blind spots and knowledge gaps to focus on for typhoid control and to ultimately progress towards elimination. This article presents a synthesis of discussions held in December 2021 during a roundtable session at the "12th International Conference on Typhoid and Other Invasive Salmonelloses".

The Prevalence of Undiagnosed Salmonella enterica Serovar Typhi in Healthy School-Aged Children in Osun State, Nigeria

Typhoid fever remains a significant public health concern due to cases of mis-/overdiagnosis. Asymptomatic carriers play a role in the transmission and persistence of typhoid fever, especially among children, where limited data exist in Nigeria and other endemic countries. We aim to elucidate the burden of typhoid fever among healthy school-aged children using the best surveillance tool(s). In a semi-urban/urban state (Osun), 120 healthy school-aged children under 15 years were enrolled. Whole blood and fecal samples were obtained from consenting children. ELISA targeting the antigen lipopolysaccharide (LPS) and anti-LPS antibodies of Salmonella Typhi, culture, polymerase chain reaction (PCR), and next-generation sequencing (NGS) were used to analyze the samples. At least one of the immunological markers was detected in 65.8% of children, with 40.8%, 37.5%, and 39% of children testing positive for IgM, IgG, and antigen, respectively. Culture, PCR, and NGS assays did not detect the presence of Salmonella Typhi in the isolates. This study demonstrates a high seroprevalence of Salmonella Typhi in these healthy children but no carriage, indicating the inability to sustain transmission. We also demonstrate that using a single technique is insufficient for typhoid fever surveillance in healthy children living in endemic areas.

Association of water, sanitation, hygiene and food practices with enteric fever in a paediatric cohort in North India

BACKGROUND

Our aim was to assess the association of water, sanitation and hygiene (WASH) and food practices with culture-confirmed enteric fever in children <15 years of age.

METHODS

We followed a cohort of 6000 children from an urban low socioeconomic neighbourhood in South Delhi for 2 years to estimate burden of culture-confirmed enteric fever. Risk ratios (RRs) were estimated to study the association between WASH practices and enteric fever. We assessed the microbiological quality of drinking water and conducted geospatial analysis to evaluate the distribution of enteric fever cases around households with contaminated drinking water.

RESULTS

A total of 5916 children in 3123 households completed survey. Piped water (82%) was the major source of household drinking water. One-third (32%) of the households treated water before consumption. Almost all households had sanitary toilets (99.9%) and 16% used shared toilets. Consumption of food from street vendors and unnamed ice creams more than once a week was observed in children from 12.7% and 38.4% households, respectively. Eighty culture-confirmed enteric fever cases were reported. The risk of enteric fever was 71% higher in children belonging to households having food from outside once a week or more (RR 1.71, 95% CI 1.00 to 2.94). The RR for enteric fever in children living in households with availability of safe drinking water was 0.75 (95% CI 0.45 to 1.26). We found that 14.8% of the households had presence of coliforms or Escherichia coli in their household drinking water. The odds of having a case of enteric fever within a 5 and 25 m buffer zone around households with contaminated drinking water were 4.07 (95% CI 0.81 to 20.5) and 1.44 (95% CI 0.69 to 3.00), respectively.

CONCLUSION

In addition to WASH practices, optimal food hygiene may have a role in urban low socioeconomic population to control enteric fever.

TRIAL REGISTRATION NUMBER

CTRI/2017/09/009719.