Letter to the Editor
Neonatal mortality continues to be a significant public health burden worldwide. Each year 4 million neonates die during the first four weeks of life. Developing countries account for 98% of reported worldwide neonatal deaths [1]. Neonatal infections currently cause about 1.6 million deaths annually in the developing world, and the major cause of newborn mortality is sepsis [2,3]. In the Republic of Georgia, a former Soviet state, little data exists on causes of infant mortality. Newborns up to eight weeks of age with severe acute illness are sent to NICUs from maternity houses (birthing places) and pediatricians’ offices. No data from the Republic of Georgia has been published on evaluation of the risk factors associated with neonatal mortality in NICUs.
We recently published the results of our study conducted at the NICUs of two pediatric hospitals in Tbilisi, capital city of Georgia, between 09/2003-09/2004, in an article by Macharashvili et al [4] in International Journal of Infectious Diseases. The study evaluated the etiology of neonatal blood stream infections (BSI) in septic neonates, and determined antibiotic susceptibility of the isolated organisms. In this study we found a high overall mortality rate of 34% (68 of 200 neonates died).
We conducted analysis of risk factors for mortality in NICU. Data were analyzed using SAS software version 9.1 (SAS Institute, Cary NC). Prevalence ratios with 95% confidence intervals for risk factors of having positive blood culture were estimated with bivariate and multivariate log-binomial regression modeling. Evaluated risk factors and results of bivariate analysis are shown in Table 1. In multivariate analysis independent predictors of neonatal mortality included: age <7 days at NICU admission (PR=1.68; 95% CI 1.07-2.63; p=.02), Apgar score of ≤6 (PR=2.15; 95% CI 1.48-3.13; p<.001), and a positive blood culture (PR=1.98; 95% CI 1.22-3.10; p=.005).
Table 1.
Demographic and clinical characteristics of died and survived neonates with clinical sepsis and their mothers
| Variable |
|
Died (N=68) n (%) |
Survived (N=132) n (%) |
PR (95% CI) |
P value |
|---|---|---|---|---|---|
| Demographic and clinical characteristics of infants | |||||
| Gender | |||||
| Male | 35 (51.5) | 53 (40.2) | 1.35 (0.92-1.98) | .13 | |
| Female | 33 (48.5) | 79 (59.8) | 1.00 | ||
| Age at NICU admission | |||||
| < 7 days | 51 (75.0) | 77 (58.3) | 1.69 (1.06-2.69) | .03 | |
| ≥7 days | 17 (25.0) | 55 (41.7) | 1.00 | ||
| Birth weight, grams | |||||
| ≤ 2500 | 15 (22.1) | 25 (18.9) | 1.13 (0.72-1.79) | .59 | |
| > 2500 | 53 (77.9) | 107 (81.1) | 1.00 | ||
| Apgar score | |||||
| ≤ 6 | 37 (54.4) | 27 (20.5) | 2.54 (1.75-3.68) | <.001 | |
| > 6 | 31 (45.6) | 105 (79.6) | 1.00 | ||
| Umbilical Discharge | |||||
| Yes | 35 (51.5) | 41 (31.1) | 1.73 (1.18-2.53) | .005 | |
| No | 33 (48.5) | 91 (68.9) | 1.00 | ||
| Blood cultures | |||||
| Positive | 52 (76.5) | 74 (56.1) | 1.91 (1.18-3.09) | .009 | |
| |
Negative |
16 (23.5) |
58 (43.9) |
1.00 |
|
| Mothers’ characteristics | |||||
| Mother's Age | |||||
| ≤ 18 | 16 (23.5) | 16 (12.1) | 1.62 (1.07-2.44) | .02 | |
| > 19 | 52 (76.5) | 116 (87.9) | 1.00 | ||
| Residence | |||||
| Rural | 35 (51.5) | 49 (37.1) | 1.46 (0.99-2.15) | .05 | |
| Urban | 33 (48.5) | 83 (62.9) | 1.00 | ||
| Education | |||||
| High school or lower | 38 (55.9) | 83 (62.9) | 0.83 (0.56-1.22) | .33 | |
| College or higher | 30 (44.1) | 49 (37.1) | 1.00 | ||
| Marriage status | |||||
| Not married | 6 (8.8) | 8 (6.1) | 1.29 (0.68-2.43) | .44 | |
| Married | 62 (91.2) | 124 (93.9) | 1.00 | ||
| Tobacco use | |||||
| Yes | 5 (7.3) | 8 (6.1) | 1.14 (0.56-2.34) | .72 | |
| No | 63 (92.7) | 124 (93.9) | 1.00 | ||
| Syphilis (TP antibody test) | |||||
| Seropositive | 5 (7.3) | 8 (6.1) | 1.14 (0.56-2.34) | .72 | |
| Seronegative | 63 (92.7) | 124 (93.9) | 1.00 | ||
| Hepatitis B surface antibodies (anti-HBs) | |||||
| Positive | 25 (36.8) | 43 (32.6) | 1.13 (0.76-1.68) | .55 | |
| Negative | 43 (63.2) | 89 (67.4) | 1.00 | ||
| Anti-HCV antibodies (ELISA) | |||||
| Positive | 3 (4.4) | 7 (5.3) | 0.88 (0.33-2.31) | .79 | |
| |
Negative |
65 (95.6) |
125 (94.7) |
1.00 |
|
| Pregnancy and delivery characteristics | |||||
| First child | |||||
| Yes | 16 (23.5) | 25 (18.9) | 1.19 (0.77-1.86) | .43 | |
| No | 52 (76.5) | 107 (81.1) | 1.00 | ||
| Prenatal Care | |||||
| No | 13 (19.1) | 11 (8.3) | 1.73 (1.13-2.66) | .01 | |
| Yes | 55 (80.9) | 121 (91.7) | 1.00 | ||
| Premature delivery | |||||
| Yes | 15 (22.1) | 14 (10.6) | 1.67 (1.10-2.53) | .02 | |
| No | 53 (77.9) | 118 (89.4) | 1.00 | ||
| Premature Membrane Rupture | |||||
| Yes | 7 (10.3) | 17 (12.9) | 0.84 (0.44-1.62) | .61 | |
| No | 61 (89.7) | 115 (87.1) | 1.00 | ||
| Type of delivery | |||||
| Caesarean section | 12 (17.7) | 24 (18.2) | 0.98 (0.59-1.62) | .93 | |
| Vaginal | 56 (82.3) | 108 (81.8) | 1.00 | ||
This study demonstrated an important contribution of neonatal bacteremia in high mortality rates among NICU patients in Tbilisi: 76% of newborns who died had positive blood cultures compared to 56% of survived newborns. Age <7 days at NICU admission and an Apgar score of ≤6 as independent predictors of neonatal mortality were likely multifactorial, but beyond the scope of this study.
Effort to reduce the risk of infection is of paramount importance to improved material and newborn care. Improving infection control in birth centres is important to prevent some cases of sepsis as well as reduce the risk of transmission of other infectious organisms.
Acknowledgements
Funding. This research was supported in part by the New York State International Training and Research Program grants, 1D43TW007384-01, 2D43TW000233-11, NIH Fogarty International Center, and National Institutes of Health/Fogarty International Center grants D43 TW007124 and D43 TW01042.
Footnotes
Conflict of Interest. There was no conflict of interest for all authors. No competing interests to declare.
Ethical approval. The study was approved by Institutional Review Boards (IRB) of the Rehabilitation Center of the Republic of Georgia and State University of New York (SUNY) at Albany, NY.
References
- 1.Zupan J. Perinatal mortality in developing countries. N Engl J Med. 2005 May 19;352(20):2047–8. doi: 10.1056/NEJMp058032. [DOI] [PubMed] [Google Scholar]
- 2.Vergnano S, Sharland M, Kazembe P, Mwansambo C, Heath PT. Neonatal sepsis: an international perspective. Arch Dis Child Fetal Neonatal Ed. 2005 May;90(3):F220–4. doi: 10.1136/adc.2002.022863. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Lawn JE, Cousens S, Darmstadt GL, Paul V, Martines J. Why are 4 million newborn babies dying every year? Lancet. 2004 Dec 4-10;364(9450):2020. doi: 10.1016/S0140-6736(04)17511-9. [DOI] [PubMed] [Google Scholar]
- 4.Macharashvili N, Kourbatova E, Butsashvili M, Tsertsvadze T, McNutt LA, Leonard MK. Etiology of neonatal blood stream infections in Tbilisi, Republic of Georgia. Int J Infect Dis. 2008 Dec 4; doi: 10.1016/j.ijid.2008.08.020. [DOI] [PMC free article] [PubMed] [Google Scholar]