Intestinal perforation, the gravest complication of typhoid fever in the developing world, presents a substantial challenge to surgeons due to its high morbidity and mortality rates. Additionally, the unpredictable onset of perforation further complicates management strategies(6),(7),(8),(9).
The incidence of typhoid fever varies significantly across different regions globally(9).In most parts of the world, perforation rates range from 0.6–4.9% globally(9),(1) with rates in America (1.8%), Asia (0.7%), and Oceania (0.7%) and Africa, with higher rates of 7.6–33% have been reported(10),(11),(12),(9) more pronounced in sub Saharan regions(13). The variations in disease incidence reflect disparities in the prevalence of risk factors for typhoid intestinal perforation from one country to another(9).
In the context of this review, the occurrence of typhoid intestinal perforation comprised 13.9% of typhoid fever cases, which is notably higher than the global averages reported in existing literature(9),(10). Nevertheless, this rate aligns with previous findings from most of Africa settings, where even higher incidences have been documented(9),(14),(13),(15),(5).
The increased incidence in our setting may stem from inadequate hygiene practices, the prevalence of more virulent strains of Salmonella Typhi, and an augmented hypersensitivity reaction in Peyer’s patches, mirroring observations in similar low-income settings in West Africa(9).
In this study, most typhoid intestinal perforations occurred in individuals aged 20–40 years, consistent with the Birkhold study's findings where over 47.1% of perforations occurred in the 2nd and 3rd decades(15). Chalya et al. suggested that the increasing prevalence of typhoid intestinal perforation among this economically active age group in our setting stems from their propensity for adventurous and mobile lifestyles, often leading to the consumption of unhygienic food away from home. Furthermore, their frequent use of school or public toilets heightens the risk of fecal contamination, which in turn negatively affects the economy of the country(9).
More males (75.7%), as also observed by earlier studies sustained more typhoid perorations compared to females(16),(6),(17),(8),. This trend is likely due to males consuming more food outdoors, resulting in increased exposure compared to females(9).
Majority of the participants did not have any formal education and were unemployed, affecting their socio-economic status. This correlates with studies done by Ugwu and other researchers who reported more typhoid perforations occurring in patients of low economic status due to related poor hygiene conditions (6),(9).
The clinical presentation of typhoid intestinal perforation in our patient population is consistent with findings from various geographic regions(18),(6),(17),(8),(19),(9). Specifically, abdominal pain and fever were universally present in all patients in our study. This observation corresponds with previous studies where abdominal pain was the predominant symptom, occurring in over 75% of cases, while fever was reported in 95% of cases(15),(16), (20).
In our study, perforation occurred early in the disease course, within less than 14 days of symptom onset, a pattern also observed by other researchers and linked with a more favorable prognosis(21),(9),(11),(12). While typhoid intestinal perforation typically arises between 8–21 days of illness, in developing countries, most cases are reported early within the first week of illness(9). This early onset is speculated to result from factors such as diminished immune response, alterations in bacterial virulence and heightened sensitivity to Peyer's patches and ileal contents of bacteria in these contexts(9),(23). This trend was also observed in our study, where more than sixty percent of patients developed perforation within 1–2 weeks of the illness(9).
Consistent with findings from other studies(9),(6),(24), suspicion of intestinal perforation in our study relied on clinical evaluation, laboratory investigation e.g. Widal’s test, identification of free air under the diaphragm on chest radiographs, and operative findings such as typical perforation on the antimesenteric border, purulent collection, and adhesion of bowel loops with friable pussy flecks. However in this review, final diagnosis of typhoid perforation was confirmed with biopsy post operatively.
Radiological investigations have shown diagnostic accuracy ranging from 80–90% when compared with other writers and current radiological techniques. In our study, free gas under the diaphragm chest radiographs was observed in more than 90% of cases, consistent with findings from other studies where most patents with perforation demonstrated air under diaphragm on chest x-ray(9),(25).
To ensure an accurate diagnosis of typhoid intestinal perforation, comprehensive diagnostic tests including blood, urine, and stool cultures, complete blood count, and bone marrow examination are necessary(9). However, isolating Salmonella Typhi from urine and stool specimens in most developing countries poses significant challenges due to various factors, including limited availability of culture media and expertise(9). In our study, only complete blood count and biopsy were conducted, primarily due to the lack of facilities capable of performing all the required tests. Notably, leukocytosis was observed in 85.7% of patients with typhoid perforations on complete blood count and was elevated risk of intestinal perforation in cases of typhoid disease, a finding consistent with those reported by other authors [11]
The clinical presentation of typhoid intestinal perforation may present complexities in cases where patients are co-infected with HIV(9),(26). However, limited literature exists regarding the influence of HIV infection on the outcomes of patients with typhoid intestinal perforation. In our study, the prevalence of HIV infection among patients with typhoid intestinal perforation was 12.9%, exceeding the 5.4% prevalence reported in the general population of Uganda. The reasons underlying this elevated sero-prevalence of HIV among these patients could not be definitively established; nevertheless, it is plausible that these individuals may face an augmented risk of HIV exposure. Interestingly, our study found no association between HIV infection and adverse postoperative outcomes, in contrast to findings from a Tanzanian study(9).
Early surgical intervention remains the gold standard treatment for typhoid perforation(27),(9). Commonly employed surgical techniques include simple peritoneal drainage under local anesthesia in critically ill patients, excision of the edges of the ileal perforation followed by simple transverse closure in two layers, segmental intestinal resection with primary anastomosis in cases of multiple perforations, or right hemicolectomy if the caecum is involved [12].
In our study, all participants underwent surgical management. Patients with uncomplicated perforations (54.1%, n = 46) underwent excision of the edges of the perforation followed by simple transverse primary repair in two layers only. For patients with significant peritoneal contamination, either an ileostomy or distal primary repair with proximal loop ileostomy was performed. Excised tissues were collected for histo-pathological examination for all patients. This is consistent with other studies where majority of the patients underwent primary repair, versus 4 patients who underwent resection [14].
The prevalence of single intestinal perforations in the majority (87%) of our patients aligns with findings from previous reports(18),(6),(11),(9). While the number of intestinal perforations in patients with typhoid intestinal perforation has been documented to impact prognosis in some studies(9), our research found no such association with outcome.
Although typhoid ulcers may manifest anywhere from the stomach to the rectum(7), they predominantly occur in the terminal ileum, primarily due to the high concentration of Peyer's patches(9). In our study, the ileum (84.7%) was the most frequently affected site of typhoid perforation, whereas colonic (2.4%) involvement was rare, a finding consistent with other studies(28),(6),(7),(24), (29),(9). This discrepancy in involvement patterns suggests that colonic lesions may result from direct bacterial invasion, while ileal lesions may stem from the enterotoxin produced by parasitized macrophages, leading to hyperplasia, necrosis, and ulceration(9).
In this study, we recorded outcomes including mortality, surgical site infections (SSI), the necessity for re-laparotomy, and the duration of hospital stay following surgery. The overall complication rate in this series was 44.3%. Notably, Kouame et al.(30)documented a notably higher incidence of complications. This discrepancy in complication rates could potentially be elucidated by variations in antibiotic protocols, meticulous preoperative management, adequate patient resuscitation pre-surgery, advancements in anesthesia practices, and overall enhancements in hospital infrastructure and care standards.
Consistent with findings in other research, the primary postoperative complication observed in our study was surgical site infection, affecting 52% of patients(18),(31),(6),(9). This high incidence could be attributed to contamination of laparotomy wounds by both patients and caregivers during post-operative care. Additionally, the use of drains in all study participants, necessitated by severe peritoneal contamination, may have facilitated the entry of microorganisms into the abdominal cavities, further contributing to the prevalence of surgical site infections. Intraoperative wound contamination is also plausible, given that the majority of our patients exhibited severe peritoneal contamination.
In our study, patients typically stayed in the hospital for about 25.7 days, which was shorter than the 28.57-day average reported by Conventi et al.(21) However, a significant number of our participants (84.28%) experienced prolonged stays exceeding 7 days after surgery(32). This could be due to complications like surgical site infections (SSI) or the need for reoperation(33).
In the developing world, mortality rates attributed to typhoid perforation typically span between 9% and 22%(Factors et al., 2020),(9). However, our investigation documented a somewhat elevated mortality rate of 35%. Notably, our observed mortality rate aligns with the predicted range of 5–80% in resource-poor nations, as elucidated by a comprehensive review published in 2017(33). Conversely, certain developed regions exhibit notably diminished mortality rates, ranging from 1.5–2%, attributable to their robust socioeconomic infrastructures(34).
The elevated mortality rate in our study can be attributed to various factors, including delayed presentation, delayed surgical intervention, multiple perforations, severe peritoneal contamination, and the presence of postoperative complications as reported in other similar settings(21),(9).