Esther Jung

All Publications

• Impact of the COVID-19 pandemic and typhoid conjugate vaccine introduction on typhoid fever in Nepal. PLoS neglected tropical diseases Tamrakar, D., Naga, S. R., Jung, E., Shrestha, B., Bista Roka, P., Pokharel, R. S., Shah, S. B., Bajracharya, A. T., Mahadup, S. K., Katuwal, N., Doyle, K., Seidman, J. C., Carter, A. S., Luby, S. P., Bogoch, I. I., Aiemjoy, K., Garrett, D. O., Shrestha, R., Andrews, J. R. 2026; 20 (1): e0013242

  Abstract

  While typhoid conjugate vaccines (TCV) offer promise for reducing risk in endemic settings, their population-level impact remains unclear. In 2022, Nepal introduced TCV nationally on the heels of the COVID-19 pandemic, which disrupted healthcare services, surveillance, and potentially typhoid transmission dynamics, complicating vaccine impact evaluation. We investigated the impact of TCV introduction amid shifting typhoid burden during the pandemic.We analyzed blood culture data from four Kathmandu Valley health facilities, comparing culture positivity for Salmonella Typhi across three periods: pre-pandemic (January 2018-March 2020); pandemic, pre-vaccine introduction (April 2020-March 2022); post-vaccine introduction (April 2022-April 2024). We used multivariable logistic regression to assess S. Typhi positivity, adjusting for month and site, stratified by TCV-eligible children and older, TCV-ineligible populations.Between January 2018 and April 2024, 62,236 blood cultures were performed. S. Typhi blood culture positivity decreased from 2.11% pre-pandemic to 0.59% during the pandemic (p < 0.001) and remained low at 0.69% after TCV introduction. Among TCV-eligible children (15 months to 15 years), odds of S. Typhi positivity during the pandemic were 47% lower than the pre-COVID period (aOR 0.53, 95% CI 0.29-0.90) and continued to decrease by 75% post-TCV introduction (aOR 0.25, 95% CI 0.11-0.55). In contrast, among vaccine-ineligible individuals (≥16 years), odds of positivity during the pandemic were 77% lower than the pre-COVID period (aOR 0.23, 95% CI 0.16-0.31) but increased by 59% following TCV rollout (aOR 1.59, 95% CI 1.14-2.27). Sensitivity analyses restricted to pathogen-positive cultures yielded similar results.S. Typhi blood culture positivity declined sharply during the pandemic before TCV introduction. The subsequent rollout of TCV substantially reduced typhoid burden in vaccine-eligible children; however, rising cases among older, vaccine-ineligible populations following the relaxation of pandemic measures highlights the need for additional control measures such as improved water and sanitation infrastructure and broader age eligibility for typhoid vaccination.

  View details for DOI 10.1371/journal.pntd.0013242

  View details for PubMedID 41564028

• Role of tuberculosis symptoms in transmission risk to cell contacts in prisons. BMJ public health Bezerra, W. d., Jung, E., Croda, M. G., de Oliveira, R. D., Santos, A. d., Tsuha, D. H., Dos Santos, P. C., Cunha, E. A., Croda, J. H., Andrews, J. R. 2025; 3 (2): e003218

  Abstract

  Understanding determinants of Mycobacterium tuberculosis transmission is critical to devising effective strategies to reduce its burden. Whether and to what extent symptoms influence transmission remains poorly understood.Between 2020 and 2022, we systematically screened persons deprived of liberty (PDL) from three prisons in Brazil for tuberculosis (TB) by symptom assessment and sputum testing with Xpert MTB/RIF Ultra. We performed QuantiFERON-TB Gold Plus (QFT) testing among cell contacts of individuals with TB and in cells with no TB case identified. We evaluated the relationship between TB exposure (symptomatic, asymptomatic and none) and QFT positivity using Bayesian generalised linear mixed models.We screened 7641 PDL for TB and identified 290 cases, yielding a prevalence of 3.8% (290/7641). After applying the exclusion criteria, 686 participants were included for the QFT analysis: 132 contacts of 42 individuals with symptomatic TB, 224 exposed to 52 individuals with asymptomatic TB and 330 with no recent cell exposure. The odds of QFT positivity were higher in symptomatic (adjusted OR (aOR) 2.50, 95% credible interval (CrI) 1.51 to 4.16) and asymptomatic (aOR 1.61, 95% CrI 1.06 to 2.45) exposure groups than in those unexposed. QFT positivity in contacts of symptomatic and asymptomatic TB did not differ (aOR 1.56, 95% CrI 0.92 to 2.63). These associations may be underestimated because of infections acquired outside cell assignments.Approximately two-thirds of individuals with TB lacked symptoms, and their contacts and symptomatic TB contacts had similarly increased risk of QFT positivity compared with individuals without recent cell exposure. These findings indicate that symptom-based screening misses many TB cases. Effective TB control requires systematic screening irrespective of symptoms to interrupt transmission and accelerate diagnosis in high-burden settings.

  View details for DOI 10.1136/bmjph-2025-003218

  View details for PubMedID 41262782

  View details for PubMedCentralID PMC12625964

• Longitudinal symptom transitions predict incident tuberculosis risk among persons deprived of liberty in Brazil. medRxiv : the preprint server for health sciences Jung, E., Bampi, J. V., da Silva, A. M., Liu, Y. E., Tsuha, D. H., Salindri, A. D., Santos, A. d., de Oliveira, R. D., Croda, J., Andrews, J. R. 2025

  Abstract

  Tuberculosis (TB) screening often relies on cross-sectional symptom assessment. To determine the added value of longitudinal symptom monitoring, we conducted a prospective cohort study among 2,282 incarcerated men in Brazil without TB. Every four months, participants were assessed for symptoms and incident TB (Xpert or culture positive). At baseline, 23% of participants reported symptoms. Among those asymptomatic at baseline, 43% developed symptoms within two years. Compared to remaining asymptomatic, developing symptoms was associated with higher TB risk, while remaining symptomatic was not associated. Longitudinal symptom monitoring may provide value beyond cross-sectional symptom assessment and enhance TB screening in high-risk settings.

  View details for DOI 10.1101/2025.10.26.25338759

  View details for PubMedID 41282748

  View details for PubMedCentralID PMC12636690

• National Active Case-Finding Program for Tuberculosis in Prisons, Peru, 2024. Emerging infectious diseases Jung, E., Alarcón, V. A., Solís Tupes, W. S., Avalos-Cruz, T., Tovar, M., Abregu, E., Yang, M. Z., Andrews, J. R., Huaman, M. A. 2025; 31 (3): 564-568

  Abstract

  During January-September 2024, a national active case-finding program in Peru's prisons screened >38,000 persons for tuberculosis (TB) using chest radiography with automated interpretation and rapid molecular tests. The program found high percentages of TB, rifampin-resistant TB, and asymptomatic infections, demonstrating the urgent need for systematic screening among incarcerated populations.

  View details for DOI 10.3201/eid3103.241727

  View details for PubMedID 40023810

• Child wasting and concurrent stunting in low- and middle-income countries. Nature Mertens, A., Benjamin-Chung, J., Colford, J. M., Hubbard, A. E., van der Laan, M. J., Coyle, J., Sofrygin, O., Cai, W., Jilek, W., Rosete, S., Nguyen, A., Pokpongkiat, N. N., Djajadi, S., Seth, A., Jung, E., Chung, E. O., Malenica, I., Hejazi, N., Li, H., Hafen, R., Subramoney, V., Häggström, J., Norman, T., Christian, P., Brown, K. H., Arnold, B. F. 2023

  Abstract

  Sustainable Development Goal 2.2-to end malnutrition by 2030-includes the elimination of child wasting, defined as a weight-for-length z-score that is more than two standard deviations below the median of the World Health Organization standards for child growth1. Prevailing methods to measure wasting rely on cross-sectional surveys that cannot measure onset, recovery and persistence-key features that inform preventive interventions and estimates of disease burden. Here we analyse 21 longitudinal cohorts and show that wasting is a highly dynamic process of onset and recovery, with incidence peaking between birth and 3 months. Many more children experience an episode of wasting at some point during their first 24 months than prevalent cases at a single point in time suggest. For example, at the age of 24 months, 5.6% of children were wasted, but by the same age (24 months), 29.2% of children had experienced at least one wasting episode and 10.0% had experienced two or more episodes. Children who were wasted before the age of 6 months had a faster recovery and shorter episodes than did children who were wasted at older ages; however, early wasting increased the risk of later growth faltering, including concurrent wasting and stunting (low length-for-age z-score), and thus increased the risk of mortality. In diverse populations with high seasonal rainfall, the population average weight-for-length z-score varied substantially (more than 0.5 z in some cohorts), with the lowest mean z-scores occurring during the rainiest months; this indicates that seasonally targeted interventions could be considered. Our results show the importance of establishing interventions to prevent wasting from birth to the age of 6 months, probably through improved maternal nutrition, to complement current programmes that focus on children aged 6-59 months.

  View details for DOI 10.1038/s41586-023-06480-z

  View details for PubMedID 37704720

  View details for PubMedCentralID 4143239

• Causes and consequences of child growth faltering in low-resource settings. Nature Mertens, A., Benjamin-Chung, J., Colford, J. M., Coyle, J., van der Laan, M. J., Hubbard, A. E., Rosete, S., Malenica, I., Hejazi, N., Sofrygin, O., Cai, W., Li, H., Nguyen, A., Pokpongkiat, N. N., Djajadi, S., Seth, A., Jung, E., Chung, E. O., Jilek, W., Subramoney, V., Hafen, R., Häggström, J., Norman, T., Brown, K. H., Christian, P., Arnold, B. F. 2023

  Abstract

  Growth faltering in children (low length for age or low weight for length) during the first 1,000 days of life (from conception to 2 years of age) influences short-term and long-term health and survival1,2. Interventions such as nutritional supplementation during pregnancy and the postnatal period could help prevent growth faltering, but programmatic action has been insufficient to eliminate the high burden of stunting and wasting in low- and middle-income countries. Identification of age windows and population subgroups on which to focus will benefit future preventive efforts. Here we use a population intervention effects analysis of 33 longitudinal cohorts (83,671 children, 662,763 measurements) and 30 separate exposures to show that improving maternal anthropometry and child condition at birth accounted for population increases in length-for-age z-scores of up to 0.40 and weight-for-length z-scores of up to 0.15 by 24 months of age. Boys had consistently higher risk of all forms of growth faltering than girls. Early postnatal growth faltering predisposed children to subsequent and persistent growth faltering. Children with multiple growth deficits exhibited higher mortality rates from birth to 2 years of age than children without growth deficits (hazard ratios 1.9 to 8.7). The importance of prenatal causes and severe consequences for children who experienced early growth faltering support a focus on pre-conception and pregnancy as a key opportunity for new preventive interventions.

  View details for DOI 10.1038/s41586-023-06501-x

  View details for PubMedID 37704722

  View details for PubMedCentralID 2270351

• Early-childhood linear growth faltering in low- and middle-income countries. Nature Benjamin-Chung, J., Mertens, A., Colford, J. M., Hubbard, A. E., van der Laan, M. J., Coyle, J., Sofrygin, O., Cai, W., Nguyen, A., Pokpongkiat, N. N., Djajadi, S., Seth, A., Jilek, W., Jung, E., Chung, E. O., Rosete, S., Hejazi, N., Malenica, I., Li, H., Hafen, R., Subramoney, V., Häggström, J., Norman, T., Brown, K. H., Christian, P., Arnold, B. F. 2023

  Abstract

  Globally, 149 million children under 5 years of age are estimated to be stunted (length more than 2 standard deviations below international growth standards)1,2. Stunting, a form of linear growth faltering, increases the risk of illness, impaired cognitive development and mortality. Global stunting estimates rely on cross-sectional surveys, which cannot provide direct information about the timing of onset or persistence of growth faltering-a key consideration for defining critical windows to deliver preventive interventions. Here we completed a pooled analysis of longitudinal studies in low- and middle-income countries (n = 32 cohorts, 52,640 children, ages 0-24 months), allowing us to identify the typical age of onset of linear growth faltering and to investigate recurrent faltering in early life. The highest incidence of stunting onset occurred from birth to the age of 3 months, with substantially higher stunting at birth in South Asia. From 0 to 15 months, stunting reversal was rare; children who reversed their stunting status frequently relapsed, and relapse rates were substantially higher among children born stunted. Early onset and low reversal rates suggest that improving children's linear growth will require life course interventions for women of childbearing age and a greater emphasis on interventions for children under 6 months of age.

  View details for DOI 10.1038/s41586-023-06418-5

  View details for PubMedID 37704719

  View details for PubMedCentralID 5084763