Prevalence of nosocomial infections and anti-infective therapy in Benin: results of the first nationwide survey in 2012

Nosocomial infections, also named healthcare-associated infections (HAI), are a global problem in every hospital around the world. Quantification of HAI is needed to help justify resources dedicated to infection control. Recognition of the problem and its characteristics vary considerably from country to country [1‐3], but the “Hospitals in Europe Link for Infection Control through Surveillance” (HELICS) project has resolved this issue by creating a consensus prevalence protocol [4].

Hospital infection control practices remain rudimentary in the developing world, mostly due to severely limited resources [5, 6]. Furthermore, the concept of interrupting HAI transmission takes on another meaning when patients’ relatives have to take up temporary residence in the hospital to provide food, care, and comfort [5, 7]. Reports of HAI rates in African countries are scarce, particularly at national level [6, 7]. However, several reports in the literature of the occurrence of HAI outbreaks and hospital-wide prevalence surveys have revealed rates ranging between 2.5% and 14.8% [8, 9]. Data on causative pathogens are available from a few studies only and highlight the importance of Gram-negative rods, particularly in surgical site infections [10, 11], and coagulase-negative staphylococci (CNS) responsible for bloodstream infection [11].

HAI surveillance helps to assess the magnitude of disease in populations and constitutes the first step to prevention [12, 13]. We describe the results of the first national prevalence survey of HAI and antimicrobial resistance in Benin and provide a global picture of the epidemiological situation in this country.

The first national point prevalence study was organized in the context of the 1st International Conference of Health Ministers of Africa (CIMSEF 2012) held in Cotonou, Benin, from 10–12 December 2012 as data from Benin were not available. The one-day prevalence survey methodology was selected as the most effective way to generate necessary data in a short time and with the potential to provide valuable information to guide future infection control interventions using limited resources. Participation was high and the global estimated coverage was approximately 87% of all hospitals in Benin, thus constituting a representative sample of acute care institutions in terms of region, type of wards, hospital size, and teaching status. The total number of patients surveyed was 3130, corresponding to 65% of the full capacity of participating centres. Occupancy rate did not reach 100%.

Although the overall bed occupancy rate did not reach 100%, some hospitals exceeded their bed capacity occasionally with more than one patient occupying the same bed [3, 5].

We observed an overall HAI prevalence of 19.1%. Surgical and medical wards showed high rates (22.3% and 24.5%, respectively) and comprised approximately half of the total number of HAIs observed. These findings are higher than previously reported by Bagheri Nejad et al. and Simon et al. [5, 8]. The difference might be accounted for by different diagnostic strategies and criteria used. The availability and use of microbiology laboratory data contribute also to the increased identification of HAI. These rates are much higher than in developed countries, where they range from 5-10% [11, 12] and well illustrate the urgent need to identify and implement feasible and sustainable approaches to strengthen HAI prevention, surveillance, and control in Africa.

The successful application of the HELICS project protocol to determine the presence of HAI patient symptoms in a standardized manner represents a remarkable aspect of our study. This method, often employed in Europe, was easy to use and is probably more accurate and less variable than previous methods, which relied heavily on interpretation by the local observer and could have contributed to higher estimates. Despite the high prevalence rate, most infected patients probably go undiagnosed, mainly due to the lack of routine surveillance and absence of facilities for microbiological diagnosis. This reference protocol has some limitations for use in developing countries. First, the available resources are modest and the cultural context is different. Second, the classical community-acquired infectious diseases, such as typhoid fever, are largely controlled in developed countries [16, 17], but continue to be a common occurrence in most African countries.

Staphylococci were the most prevalent bacteria and were isolated from almost all types of clinical samples considered. This result is not surprising because of its opportunistic and ubiquitous nature [18]. S. aureus was the most common hospital-acquired pathogen among inpatients in our study, followed by Escherichia coli, P. aeruginosa, and enterococci.

The prevalence of antibiotic use was 64.6%, similar to published data from Tanzania (71%) or Greece (51.4%), but much higher than the rate reported from France (16%) [12, 19]. The most extensive use of antimicrobials in non-infected patients was in surgical (27%) and obstetrics/gynaecology (18%) wards.

In our study, the treatment of 13,8% of infected patients was a challenge by the fact that the prohibitive cost of second-line antimicrobial drug, when available, places them out of the reach of majority of patients.

It is imperative to preserve the effectiveness of common antibiotics by promoting their rational use based on sound knowledge of local resistance patterns.

Several resistant strains were identified in agreement with previously reported findings [19, 20], e.g., methicillin-resistant S. aureus (52.5%), ceftazidime-resistant P. aeruginosa (68.5%), and vancomycin-resistant enterococci (67.5%). This might be due to the fact that certain classes of antibiotics are easily accessible in Benin and frequently used by patients without a medical prescription; this represents 40% of patients on antibiotics. In our context the self-medication was related both to other illnesses and HAI treatment.

These results are in acccordance with data reporting the increasing antimicrobial resistance of Gram-negative bacteria [19, 21, 22]. In addition, the high proportion of multiresistant bacteria in Benin may be explained by the practice of patient self-medication and the availability and low price of antibiotics that can be bought without prescription. An additional concern is the fact that some available pharmaceuticals are of doubtful quality and fail basic quality tests, thus raising fears that many of these drugs may not be having the desired impact on patients. It is therefore critical to treat HAI appropriately by starting antimicrobial therapy early in the course of infection, using the correct agent at the most appropriate dose, and for an adequate duration. Furthermore, antibiotic stewardship should include patient education.

Of note, no resistance to imipenem was recorded among pathogens identified in this nationwide survey of HAI. In Benin, the repertoire of first-line drugs is limited to ampicillin, chloramphenicol, erythromycin, gentamicin, penicillin, tetracycline and trimethoprim-sulphathoxazole. Second-line antibiotics include imipenen, which is currently unavailable in Benin. Furthermore, when available, its prohibitive cost would place it out of the reach of most patients. Thus, the lack of use explains the absence of identified resistance to imipenem in Benin.

Our study has limitations. First, and similar to all point-prevalence studies, this approach tends to underestimate true prevalence rates and, in particular, HAI of shorter duration. In addition, HAI that developed after hospital discharge was not recorded. A realistic picture of the disease pattern over time would require the conduct of prospective surveillance of HAIs, which is far beyond available resources in Benin. Second, antibiotic resistance detection was not conducted at a central laboratory, but the surveillance method employed did use international standardized techniques. As multiresistant nosocomial pathogens of high epidemiological interest (i.e., vancomycin-resistant S. aureus) were not kept, further diagnostic validation could not be conducted. Differences in the sensitivity and specificity of laboratory diagnostic techniques have been described, which might impact on stain identification [23].

To our knowledge, this is the first study that provides national prevalence data for HAI in Benin. Moreover, the methodology proved feasible in the African setting and is probably more accurate than previous methods used. In the light of these findings, appropriate prevention measures can be proposed, such as reminders regarding hygiene rules and recommendations and isolation protocol, completed by HAI surveillance. We suggest that the combination of a prevalence (cheap and short, and providing a one-day snapshot) and an incidence survey (targeted surveillance of high-risk areas) provide the best picture of HAI in settings with limited resources.

Our results suggest that the prevalence of HAI in Benin is at least as high as published reports from neighbouring countries and that continued infection control efforts are warranted. This is also the first report of national prevalence of HAI in Benin. We believe there is a need for a standardized approach to HAI surveillance in Africa region. More attention should be paid to the indiscriminate use of antimicrobials in non-infected patients.