BY ALEXANDRU BUHIMSCHI

More than a third of the four million neonatal deaths occurring annually are caused by severe infections.1 Nearly one million of these annual deaths can be traced to neonatal sepsis, a bacterial infection in newborn infants. Neonatal sepsis can arise early (≤3 days after birth) or late (4-90 days after birth). Three quarters of newborn deaths occur during the first week of life, making early-onset neonatal sepsis (EONS) one of the biggest contributors to neonatal mortality.2 Moreover, since 41% of under-five deaths occur among newborn infants, treating EONS is critical for addressing the United Nations Millennium Development Goal Four, which seeks to reduce under-5 child mortality by two-thirds.3 While certainly challenging, it is estimated that this goal can be reached if effective health measures are provided during the first week of life.1

An infant on day 4 of recovery from neonatal sepsis. Source: Possible Health
An infant on day 4 of recovery from neonatal sepsis. Source: Possible Health

EONS is a global health problem that affects both the developed and the developing world. This is due, in part, to the difficulties associated with recognizing the vague signs and symptoms of the disease. Addressing this difficulty is a high priority for clinicians, and as a result, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) held a workshop in January to provide “evidence-based guidelines for the diagnosis and management of pregnant women and newborn infants suspected of neonatal sepsis”. The confusion amongst healthcare providers arises because the signs of sepsis in a mother and newborn are very nonspecific, making identification of infants in need of treatment very difficult. The constellation of perinatal risk factors guiding suspicion of EONS (e.g. maternal fever, preterm rupture of membranes, intra-amniotic infection, etc.) are neither sensitive nor specific and can lead the mother and newborn down very distinct disease pathways. It is not surprising then that “suspected” sepsis is one of the most common diagnoses made in the neonatal intensive care unit.4 Making the problem even more difficult, current diagnostic tests are not helpful in deciding which newborns are in need of immediate treatment .

The current standard of care in the US for diagnosing and treating EONS is to place any newborns with “suspected” EONS on intravenous antibiotics within 24 hours of birth. This practice is known as “empirical antibiotic therapy.”5 However, even the classification of “suspected” EONS is problematic due to the lack of an established set of criteria and antenatal risk factors for the disease. While antibiotics are effective, this practice of overtreatment has been shown to lead to adverse neonatal outcomes as well as an increased risk of generating antibiotic resistant strains of bacteria.6 Improving antibiotic administration practices is a national priority in the US, as evidenced by a 2014 Executive Order entitled Combatting Antibiotic-Resistant Bacteria. Following classification of the newborn as being “suspected” of EONS, the doctor then seeks to confirm “clinical” EONS. The final diagnosis of “clinical” EONS is made following a blood culture, a diagnostic test that has not seen much refinement since its original development in the early 20th century. It is well known among practicing neonatologists that blood cultures show poor positive predictive value, and doctors will often keep newborns on antibiotics in spite of negative test results. One study even showed the ratio of non-infected to blood-culture-positive neonates treated with antibiotics was between 15:1 and 28:1.7 The technique assumes that conditions required for E. coli or Group B Streptococcus growth will also allow detection of other infectious strains, which is certainly not the case. Furthermore, blood cultures are expensive (often over $50 per test) and require trained lab personnel and equipment to be carried out reliably. As such, blood cultures are impractical in the developing world, where EONS incidence and mortality is the highest. Furthermore, with time as critical as it is for EONS management, the 2-7 day timeframe for blood culture results to return prohibits selective initiation of antibiotic therapy.

Thus, there exists a clinical need for a test that reliably diagnoses EONS so that only newborns in need of treatment receive antibiotics. This would ensure that those who do not have the disease are not unnecessarily exposed to antibiotics and prolonged stays in the hospital environment, which by itself is a risk of late onset sepsis. The ideal EONS diagnostic test should be rapid, non-invasive, and usable without prior training. More than 99% of neonatal deaths occur in the developing world, and a quarter of these deaths can be attributed to neonatal sepsis.8 Given that half of all mothers in such countries do not receive skilled care during or immediately after birth,1 if an EONS diagnostic test is to reach its full global impact, it must be point-of-care and easy to use. In areas of the world where neonatal care is not easily accessible, information provided by such a diagnostic test could help direct limited resources to high-risk newborns in need of immediate care.

Infant mortality rates in 2012, by country. Source: Wikimedia
Infant mortality rates per 1,000 live births in 2012. Source: Wikimedia

Recognizing the global impact of EONS and the lack of a reliable diagnostic test with functionality in the developing world, three Yale undergraduates, Alexandru Buhimschi ’17, Anoj Ilanges ’16, and Jiahe Gu ’16, are currently working on a product that could solve these issues and change the clinical management of EONS worldwide. The team is working with technology that has the potential to give a diagnostic result within an hour, involves no direct puncture of the neonate, and is readily usable by anyone- even an untrained mother. The test relies upon detection of haptoglobin, a protein produced in much higher amounts in the cord blood of EONS newborns. It is well known that haptoglobin is an acute-phase protein and acts as part of the innate immunity to sequester and degrade free hemoglobin in the bloodstream. During infection, it is likely that haptoglobin seeks to limit the oxidative capacity of hemoglobin and the metabolic advantages it confers to bacterial pathogens. A study conducted in 2011 by Buhimschi et al. identified haptoglobin upregulation as being predictive of EONS and poor neonatal outcome in a cohort of 200 women. Moreover, the study showed haptoglobin to be superior to the current methods for classification of clinical EONS. Using haptoglobin as a marker for sepsis would have reclassified nearly 30% of EONS diagnoses, directing treatment to the proper newborns and eliminating unnecessary antibiotic exposure and associated expenses.9 Buhimschi et al. issued a patent with Yale in 2014, describing the use of haptoglobin as a biomarker for EONS.10

While Buhimschi et al. did not translate this work to a commercial product, the three students realized the potential for a haptoglobin test to change global EONS clinical practice. The team has currently developed an alpha prototype test for haptoglobin. The test has been optimized for conditions presented at the point-of-care (e.g. heat stable, minimal sample preparation, etc.). Current focus is directed at building a platform that will allow easy integration of relevant EONS biomarkers before moving to formal product development. Following this phase, the team aims to translate its prototype to a paper-based lateral flow assay by the end of the summer that can then be refined under regulatory constraints following consultation with professional microfluidics companies.

A new diagnostic test for EONS would impact clinical management of the disease worldwide. Understandably, when bringing a new diagnostic test to market, clinicians are most concerned with the test’s ability to change clinical practice and improve patient outcome. In developed countries, the problems with EONS management lie in the overtreatment of non-EONS newborns with empirical antibiotics. Such a test, in the developed world market, would help to lower the number of unnecessary antibiotic administrations, decreasing associated long term consequences for the newborn as well as the risk of antibiotic resistances. In the developing world, where the burden of EONS mortality is the highest, this test would promptly identify the high-risk neonates in need of immediate care. The team has identified India as an initial market due to its high incidence of EONS (~140,000 deaths per year), coupled with the need for rapid point-of-care tests in the rural regions of the country.11 To enter the market, they seek to target under-resourced Indian hospitals in urban environments with the facilities to administer treatment before moving the product into more rural areas of the country.

With the homebirth market comprising the majority of annual Indian births (15/25 million births occur at home), the test would be ideal for untrained birth attendants seeking to identify newborns in need of higher levels of care. However, by targeting urban hospitals initially, the team believes it can build a network amongst Indian clinicians to facilitate a progression built to enable fast adoption across the country. Rural clinics with fewer well-trained personnel will be more willing to integrate the test into their management of EONS newborns, once success is demonstrated both in reducing hospital expenditures and in improving patient outcomes at higher levels of care. Due to the low manufacturing costs associated with lateral flow devices, this test could cost clinics and hospitals as little as $3 per test.

The team was recently accepted as part of the third cohort of the Yale Entrepreneurial Institute’s Venture Creation Program. They aim to continue product development into the coming semesters with the final goal of attaining FDA approval within two years. Successful development and implementation of such a device would reliably diagnose neonatal sepsis, change clinical practice, and most importantly, save lives.

We would like to acknowledge the valuable support we have received from Wendy Davis, Drs. Irina and Catalina Buhimschi, and Dr. Vineet Bhandari.
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REFERENCES

  1. Neonatal sepsis – a major killer to be tackled in communities. (2009). World Health Organization. Retrieved from http://www.who.int/maternal_child_adolescent/news_events/news/2009/19_01/en/.
  2. Newborn death and illness: Millennium development goals. (2011). The Partnership for Maternal and Child Health – World Health Organization. Retrieved from http://www.who.int/pmnch/media/press_materials/fs/fs_newborndealth_illness/en/.
  3. Goal 4: reduce child mortality. (n.d.) United Nations: Millennium Development Goals. Retrieved from http://www.un.org/millenniumgoals/childhealth.shtml.
  4. Polin, R.A. & The Committee on Fetus and Newborn. (2012). Management of neonates with suspected or proven early-onset bacterial sepsis. Pediatrics, 129, 1006-1015.
  5. Sivanandan, S., Soraisham, A.S., Swarnam, K. (2011). Choice and duration of antimicrobial therapy for neonatal sepsis and meningitis. International Journal of Pediatrics.
  6. Alexander, V.N., Northrup, V., & Bizzarro, M.J. (2011). Antibiotic exposure in the newborn intensive care unit and the risk of necrotizing enterocolitis. Journal of Pediatrics, 159(3), 392–397. Retrieved from http://dx.doi.org/10.1016/j.jpeds.2011.02.035
  7.  Hammerschlag, M.R., Klein, J.O., Herschel, M., Chen, F.C., Fermin, R. (1977). Patterns of use of antibiotics in two newborn nurseries. The New England Journal of Medicine, 296(22), 1268–1269.
  8. Lawn, J.E., Cousens, S., Zupan, J. (2005). 4 Million neonatal deaths: When? Where? Why? Lancet, 365(9462), 891–900. Retrieved from http://dx.doi.org/10.1016/S0140-6736(05)71048-5.
  9. Buhimschi, C.S., Bhandari, V., Dulay, A.T., Nayeri, U.A., Abdel-Razeq, S.S., Pettker, C.M., … Buhimschi, I.A. (2011). Proteomics mapping of cord blood identifies haptoglobin “switch-on” pattern as biomarker of early-onset neonatal sepsis in preterm newborns. PLoS One, 6(10), e26111. Retrieved from http://dx.doi.org/10.1371/journal.pone.0026111.
  10. Buhimschi, C.S., Buhimschi, I.A., Bhandari V. (2014.) Novel markers for detection of complications resulting from in utero encounters. Patent 8,697,367.
  11. Seale, A.C., Blencowe, H., Zaidi, A., Ganatra, H., Syed, S., Engmann, C., …Lawn, J.E. (2013). Neonatal severe bacterial infection impairment estimates in South Asia, sub-Saharan Africa, and Latin America for 2010. Pediatric Research, 74, 73–85. Retrieved from http://dx.doi.org/10.1038/pr.2013.207.
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