Our study indicated an infant mortality rate of 49.76‰ overall. The factors associated with this mortality are the age of the mother under 20 years old, the household size greater than or equal to 7, prematurity, home birth, the inter-reproductive space of less than 12 months and finally no. use of LLINs.
The infant mortality rate obtained in our study (49.76‰) remains lower than the infant mortality rate at the national level in 2015 (58‰) [1] and at the provincial level of South Kivu (92‰) [1]. The areas concerned by our study are two relatively stable areas from a security and humanitarian standpoint at present, with in particular more than 80% of deliveries are attended by staff. In addition, the health structures are well organized and accessible to the population. The province's overall estimate of the mortality rate is high, this would be justified by the fact that there are areas where the health situation remains deplorable as a result of the crisis context making basic structures inaccessible. In South Kivu, some basic health structures have been attacked by armed groups [6]. Despite this decrease, mortality remains high, justifying efforts in terms of reducing infant mortality and geographic inequalities.
The young age of the mother (less than 20 years) is associated with a risk of infant mortality of about 2 times (p = 0.022) unlike a maternal age of 35 years or more. These results corroborate with those from Brazil and France which showed that the age of less than 20 years was associated with infant death [10, 11].
Prematurity is a factor strongly associated with mortality. Prematurity is responsible for more than 290,000 deaths per year in sub-Saharan Africa. According to the WHO, premature infants are 13 times more likely to die than term infants [12]. Other studies have confirmed this association [11, 13, 14, 15, 16].
The inter-reproductive space (EIG) has a great influence on infant mortality (p < 0.001); the more it is less than 12 months the more the risk of death increases. Our results are similar to those of Naoko Kozuki et al who found that the EIG shorter s introduced him in t increased likelihood of neonatal mortality and under-five [17]. The longer the inter-reproductive interval, the greater the chance of survival for the child. An inter-reproductive interval of less than two years not only leads to weaning of the preceding child but also to poor nutritional status and weakening.
Home birth is associated with the death of children. This result is in agreement with those of a study conducted in Uganda [18]. In addition, our results contradict those of Kambale et al who show that there was no difference in the risk of death between birth at home and that of maternity [19] as well as those of Johan et al who Neither have they demonstrated a significant association between childbirth in a sanitary setting by a health professional and reduction in neonatal death [20]. Home births often take place in precarious hygienic conditions and first aid is not administered. This would explain the predisposition of children to diseases and therefore a high mortality.
Non-use of LLINs was associated with infant mortality (p < 0.001). This corroborates the data of Victoria et al [18] pointing out that all perinatal deaths occurred in women who did not sleep under a mosquito net. Malaria is the second most suspect pathology of infant mortality in our study (12.7%). In 2015, worldwide, the number of malaria cases was estimated at 2.4 million with 438,000 deaths [21]. Africa alone has recorded 1.88 million cases with 395,000 deaths [21]. The non-use of LLINs would explain this proportion of malaria among the pathologies suspected of infant mortality, but also the fact that we are in an endemic area with malaria which is the most frequent pathology in the whole country. Malaria, together with diarrheal diseases and respiratory tract infections constitute the most determining pathologies of infant and juvenile death in the DRC [22].
This work has strengths and limitations. The main strength of this work is its relatively large sample size. This study is one of the very few to study, with such a large sample size, the level and factors associated with infant mortality in post-crisis rural areas of eastern DRC. The limitations of this work include the fact that it is based on data collected from health facilities and the generalization of these results to the entire population is therefore limited. In fact, due to logistical difficulties, we reasonably limited our sampling to health areas close to general referral hospitals in these two health areas. This may have introduced a selection bias in that people living further from general hospitals may have poor accessibility to health services and therefore a higher risk of infant mortality compared to those living closer to general referral hospitals. Another limitation of this work is that it is based on data collected from health facilities. It therefore does not allow data to be collected from mothers who had given birth at home. Finally, some important factors have not been studied, including vaccination, pregnancy monitoring and the course of childbirth.