Open Access Open Badges Research article

The incidence and aetiology of hospitalised community-acquired pneumonia among Vietnamese adults: a prospective surveillance in Central Vietnam

Kensuke Takahashi1, Motoi Suzuki1, Le Nhat Minh1, Nguyen Hien Anh2, Luu Thi Minh Huong3, Tran Vo Vinh Son3, Phan The Long3, Nguyen Thi Thuy Ai3, Le Huu Tho4, Konosuke Morimoto1, Paul E Kilgore5, Dang Duc Anh2, Koya Ariyoshi1* and Lay Myint Yoshida1

Author Affiliations

1 Department of Clinical Medicine, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki, Japan

2 National Institute of Hygiene and Epidemiology, 1 Yersin, Hai Ba Trung, Hanoi, Vietnam

3 Khanh Hoa General Hospital, 19 Yersin, Loc Tho, Nha Trang, Khanh Hoa, Vietnam

4 Khanh Hoa Health Service, 3 Han Thuyen, Nha Trang, Khanh Hoa, Vietnam

5 Wayne State University, 5057, Woodward Avenue #3101, Detroit, MI, USA

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BMC Infectious Diseases 2013, 13:296  doi:10.1186/1471-2334-13-296

Published: 1 July 2013



Lower respiratory tract infection (LRTI) including Community-acquired pneumonia (CAP) is a common infectious disease that is associated with significant morbidity and mortality. The patterns of aetiological pathogens differ by region and country. Special attention must be paid to CAP in Southeast Asia (SEA), a region facing rapid demographic transition. Estimates burden and aetiological patterns of CAP are essential for the clinical and public health management. The purposes of the study are to determine the incidence, aetiological pathogens, clinical pictures and risk factors of community-acquired pneumonia (CAP) in the Vietnamese adult population.


A prospective surveillance for hospitalised adult CAP was conducted in Khanh Hoa Province, Central Vietnam. All adults aged ā‰„15 years with lower respiratory tract infections (LRTI) admitted to a provincial hospital from September 2009 to August 2010 were enrolled in the study. Patients were classified into CAP and non-pneumonic LRTI (NPLRTI) according to the radiological findings. Bacterial pathogens were identified from sputum samples by the conventional culture and polymerase chain reaction (PCR) for Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis; 13 respiratory viruses were identified from nasopharyngeal specimens by PCR.


Of all 367 LRTI episodes examined, 174 (47%) were CAP. Older age, the presence of underlying respiratory conditions, and higher index score of smoking were associated with CAP. The one-year estimated incidence of hospitalised adult CAP in our study population was 0.81 per 1,000 person years. The incidence increased considerably with age and was highest among the elderly. The case fatality proportion of hospitalised CAP patients was 9.8%. Among 286 sputum samples tested for bacterial PCR, 79 (28%) were positive for H. influenzae, and 65 (23%) were positive for S. pneumoniae. Among 357 samples tested for viral PCR, 73 (21%) were positive for respiratory viruses; influenza A (nā€‰=ā€‰32, 9%) was the most common.


The current adult CAP incidence in Vietnam was relatively low; this result was mainly attributed to the young age of our study population.

Community-acquired pneumonia; Aetiology; Incidence; Ageing; Southeast Asia; Vietnam; Viral pneumonia; Nasopharyngeal swab; Multiplex PCR