Libyan International Medical University Journal

: 2018  |  Volume : 3  |  Issue : 2  |  Page : 54--58

Prevalence and types of bacterial infections of the upper respiratory tract at a tertiary care hospital in the City of Tripoli

Ahmed Atia1, Ahmed Abired2, Anees Ammar3, Najla Elyounsi4, Abdulsalam Ashour1,  
1 Department of Anaesthesia and Intensive Care, Faculty of Medical Technology, University of Tripoli, Tripoli, Libya
2 Tripoli Higher Institute for Medical Professions, Tripoli, Libya
3 Department of Pharmacy, Al-Garabulli Higher Institute for Medical Professions, Al-Garabulli, Libya
4 Department of Medical Laboratories, Faculty of Medical Technology, University of Tripoli, Tripoli, Libya

Correspondence Address:
Dr. Ahmed Abired
Tripoli Higher Institute for Medical Professions, Tripoli


Aim: The study aimed to determine the bacterial etiology of upper tract respiratory infection in Abu-Sitta Hospital, Tripoli, Libya. Subjects and Methods: A total of 470 sputum specimens and 60 throat swabs were collected over a period of 1 year (From January 2014 to December 2014) from patients presented with clinical signs of upper respiratory tract infection at Abu-Sitta Hospital. Enrolled patients were sorted as inpatients or outpatients and by gender. Data were entered and analyzed using SPSS version 22.0. Variables were expressed as percentages. Differences in age and gender were analyzed using Chi-square test. Results: Of the total 530 screened samples, 80.5% were culture positive, where bacterial pathogens were detected in 83.7% of sputum specimens and in 56.5% of throat swabs. Streptococcus pneumoniae was the most prevalent (48%), followed by Pseudomonas aeruginosa (23%), Staphylococcus aureus (13%), Enterobacter (8%), Citrobacter freundil (5%), and latest with Klebsiella (3%). Conclusions: The spectrum of pathogenic bacterium causing upper respiratory infection in Abu-Sitta Hospital is considerably wide, with S. pneumoniae and P. aeruginosa being the major causative bacteria.

How to cite this article:
Atia A, Abired A, Ammar A, Elyounsi N, Ashour A. Prevalence and types of bacterial infections of the upper respiratory tract at a tertiary care hospital in the City of Tripoli.Libyan Int Med Univ J 2018;3:54-58

How to cite this URL:
Atia A, Abired A, Ammar A, Elyounsi N, Ashour A. Prevalence and types of bacterial infections of the upper respiratory tract at a tertiary care hospital in the City of Tripoli. Libyan Int Med Univ J [serial online] 2018 [cited 2022 Aug 7 ];3:54-58
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Full Text


Respiratory tract infection (RTI), including upper and lower respiratory tracts, is one of the most important infectious diseases worldwide that may lead to high risk of morbidity and mortality in both developed and developing countries.[1] RTI especially those occur in upper respiratory tract (URTI) is shown with great frequency in both children and adults and has notable economic effect, related to lost output in the workplace and to the frequent antibiotic prescriptions by physicians.[2] In developed countries such as the United Kingdom, around 8 million people are infected by some types of chronic lung diseases that kill one person in each five persons.[3] However, the situation is more complicated in other developing countries, mainly African countries. The World Health Organization has estimated that 9% of Libyan children under-five deaths in 2000–2003 were caused by pneumonia.[4]

URTIs is a contagious disease that remains for hours to few days of exposure. Studies have reported that URTIs symptoms may stay even longer.[5] Several signs and symptoms of URTIs have been mentioned including runny nose, coughing, sneezing, fever, vomiting, sore throat, loss of appetite, and watery eyes.[6] Although the causes of URTI have been attributed to viral, many studies have also shown that the cause of URTI can be also bacterial.[7]Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, and Moraxella catarrhalis are the most common bacteria implicated as causative agents of URTIs.[8],[9]

Considering the high morbidity and mortality rates of URTI in developing countries, and limited number of studies on the prevalence of URTI among patients in Libya, this study was aimed to determine the microbial agents of human upper RTIs in Abu-Sitta Hospital in Tripoli city, Libya.

 Subjects and Methods

Study population

This is an observational study conducted from January 2014 to December 2014. The study population included patients admitted to the medical laboratory of Abu-Sitta Hospital, Tripoli, Libya, with specialist determined clinical evidence of URI. All patients were informed of the study purpose and were assured that all information will remain confidential. This study was approved by the Scientific Committee of Faculty of Medical technology, University of Tripoli, Libya.

Sample collection

Samples were collected from 530 patients (468 sputum, 62 wet throat swab). First, the collected samples were labeled with patients information including age, gender, and clinical symptoms and then were immediately taken to the microbiology laboratory for isolation and identification of presence of any potential bacterial pathogen using morphological, microscopy, and biochemical tests. The sputum samples were collected into well-labeled sterile, wide-mouthed glass bottles with screw cap tops. The swabs were transported directly to the laboratory. For a collection of throat samples, the tongue was depressed by the handle of a spoon to observe the mouth for the presence of inflamed membrane, pus, or exudates.

Bacterial isolates

In the microbiological laboratory, each sample was inoculated onto chocolate agar, blood agar, and eosin methylene blue agar. The inoculum on the plates was streaked out to separate colonies with sterile wire loop. The culture plates were incubated for 24–48 h at 37°C. After incubation, microscopic and macroscopic observations of colonies on culture plates were achieved, and suspect colonies were subcultured on a suitable solid culture media for purification. All pure cultures were identified depended on their cultural and morphological features on differential and selective media.[10] Data were entered and analyzed using SPSS version 22.0 (SPSS Inc., Chicago, IL, USA). Variables were expressed as percentages. Differences in age and gender were analyzed using Chi-square test.


A total of 530 samples (sample per each participant) were collected, of which 59% were female and 41% were male patients, giving male: female ratio of 1:0.7 [Table 1]. The mean age of the participants was 28 ± 15.8 years with a minimum and maximum age of 8 and 69 years, respectively. The ages of the participants were categorized into three groups: below 20 years, between 20 and 45 years, and above 45 years. Majority of the patients were in the age group Streptococcus pneumoniae was the most prevalent (48%), followed by Pseudomonas aeruginosa (23%), S. aureus (13%), Enterobacter (8%), Citrobacter freundii (5%), and latest with Klebsiella (3%) [Table 3].{Table 3}

With regard to gender variation, females show higher percentage of infection acquisition and ultimately following the same bacterial strain predominance pattern with streptococcus pneumonia at the top and Klebsiella at the bottom [Table 4].{Table 4}

As for age variation, no differences can be noted in the bacterial prominence order among the defined three age groups, yet overall participant aged below 20 years showed the highest percentage of infection acquisition, whereas participants aged 20–45 years old presented the least percentage [Table 5].{Table 5}


The primary goal of this study was to ascertain the current prevalence of bacteria causing URI in Abu-Sitta Hospital, Tripoli, Libya. The secondary objective was to find out the influence of age and gender variables on the general pattern of causative pathogenic bacteria.

S. pneumoniae was the most frequently recovered pathogen (48%), followed by P. aeruginosa (23%), S. aureus (13%), Enterobacter (8%), C. freundii (5%), and latest with Klebsiella (3%). Numerous studies have previously reported these isolates as a major cause of RTI in human. In Libya, a study carried out in 2006 including 322 patients revealed that S. aureus were the most prevalent organism, followed by Streptococcus pyogenes and Klebsiella pneumoniae.[11] Earlier international studies reported the prevalence of Streptococcus spp to be 22% in Iceland, 14% in Brazil, 11% in Cameroon, and 8% in the Netherlands.[12],[13],[14],[15] The number of positive pathogenic cultures in relation to the total number of enrolled participants was considerably high in our study as compared to similar studies done worldwide; such a result is highly attributed to the fact that the place where the study took place is a specialized hospital for respiratory diseases.

Most of the bacteria isolated during the study such as S. pneumonia, P. aeruginosa, S. aureus, and Enterobacter spp, fall in either nosocomial or community-acquired pattern of infection, suggesting that proper protective actions could limit bacterial involvement in URTIs.

Contrary to other reported studies,[16],[17] our study found that gender or age had no effect on the ratio of infection acquisition.


The spectrum of the pathogenic bacterium causing upper respiratory infection in Abu-Sitta Hospital is considerably wide. As per the revealed pattern of predominant causative bacteria, no significant change noted for either age or gender variations.

Financial support and sponsorship

The authors are grateful to University of Tripoli for their support.

Conflicts of interest

There are no conflicts of interest.



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