Epidemiological, clinical features and susceptibility pattern of shigellosis in the buea health district, Cameroon
© Njunda et al; licensee BioMed Central Ltd. 2012
Received: 27 September 2011
Accepted: 21 January 2012
Published: 21 January 2012
Shigellosis is an acute invasive enteric infection caused by bacteria belonging to the genus Shigella; it is clinically manifested by bloody diarrhoea. Shigellosis is endemic in many developing countries including Cameroon and also occurs in epidemics causing considerable morbidity and mortality. This study evaluated the epidemiological and clinical features of Shigella and the resistance pattern of isolates to commonly used antibiotics in the Buea Health District in Cameroon, from April to August, 2010.
Of the 223 stool samples cultured, 10 (4.5%) yielded Shigella species. Isolation rate was observed to be more in children below 15 years (7.89%), and also higher in rural areas (6.35%). All 10 isolates showed resistance to at least two antibiotics and 9 (90%) were multi-drug resistant. The highest resistance rates were encountered with cotrimoxazole (90%) and amoxicillin (80%). Least resistance was observed with azithromycin (10%).
Shigellosis is more prevalent in children below 15 years in the Buea District. There is a high level of resistance to most of the antibiotics used for the treatment of shigellosis including extended-spectrum beta-lactamases (ESBLs) as well as evidence of resistance to quinolones. Azithromycin was found to be the drug of choice for shigellosis in this setting.
KeywordsShigellosis Epidemiology Clinical features Antibiotics Susceptibility pattern Cameroon
Shigellosis (bacillary dysentery) is a global health problem, especially in developing countries, where substandard hygienic conditions and unsafe water supplies prevail . Among the bacterial causes of dysentery, Shigella species continue to be the most important, with a high infectivity rate and the development of antimicrobial resistance. Shigellosis is said to be a self-limiting disease, although antimicrobial therapy is recommended . Since 1940, when resistance of Shigella species to sulfonamide was first recognized in Japan , resistance of Shigella species have become progressively recorded to most widely-used antimicrobial agents . Multiple-drug resistance transmitted plasmids among Shigella species have been reported in many countries . So far, limited reports exist on the occurrence and antibiotic resistance patterns of Shigella species in Buea in particular and in Cameroon in general. The purpose of the present study was to determine the epidemiologic profiles of Shigella and their antimicrobial resistance patterns in the Buea Health District, in the South West Region of Cameroon.
Results and discussion
Of the 223 stool specimens cultured for Shigella species, 10 were tested positive with a prevalence of 4.5%. Findings from other authors [6–8] indicate slightly higher prevalence rates of 8.0%, 7.4% and 7.3% respectively, than what is obtained in this study.
The majority of Shigella isolates were from the paediatric population (children < 15 years) with an infection rate of 7.89% while no infection was recorded with individuals aged > 45 years. In line with our findings, a higher prevalence of infection in children was observed in a previous work , in which 70% of all infections occurred in children below 15 years. It was also noted that children of this age group accounted for more than a third of all Shigella positive patients . Scientific findings have revealed that type-specific immunity develops after repeated exposures during childhood . Diarrhoea account for about 16% of all causes of mortality in children , because they are at an immature age, and they are in frequent exposure to contaminated environment due to play-related activities and are not being drilled on the importance of hand-washing after defecation and before eating.
In vitro antimicrobial susceptibility pattern of isolates
Sulfonamide and trimethoprime
Drug resistance patterns of Shigella isolates
Number and percentage of resistant isolates n = 10)
AMX, NA, SXT
A, C, NA, SXT
A, CN, CRO, SXT
AMX, A, CN, SXT
AMX, A, C, NA, SXT
AMX, A, NA, OFX, SXT
AMX, A, C, NA, SXT
AMX, C, CN, CRO, OFX, NA, SXT
This study which highlights the epidemiologic pattern of shigellosis in the Buea Health District however has a limitation including the inability to determine the species of Shigella or to serotype them. Information that could have given an idea of the severity of the species involved. However according to WHO , reporting any isolate of Shigella species is a major step in disease surveillance and helps in taking actions that lessen the risk of serious complications, spreading and death in the population.
This work has revealed that the prevalence rate of shigellosis in the Buea Health District in Cameroon stands at 4.5%. The majority of Shigella isolates are from the paediatric population (children < 15 years) with an infection rate of 7.89%. This condition is linked to the poor hygienic conditions prevailing in the area. The antibiotic susceptibility testing has revealed that these Shigella spp are multiresistant to currently used antibiotics including extended-spectrum beta-lactamses (ESBLs) as well as increasing evidence of resistance to quinolones. Azithromycin was found to be the drug of choice for shigellosis in this setting.
A total of 223 individuals comprising of 90 males and 133 females, aged 1 month to 72 years old were recruited in the study. The participants were patients referred to the laboratory for stool analysis from the in-patient and out-patient departments of the Regional Hospital Annex, Buea and the Kahwa Sumbele Medical Centre Bomaka, all within the Buea Health District. Their informed consent was souk and obtained and an ethical clearance and authorization to collect specimen and data for research was obtained from the South West Regional Delegation of Public Health Ref No. R11/MPH/SWR/RDPH/FP/5489/97 of the 06/04/2010. An estimate of the required number of participants was obtained using a formula for estimating sample size for proportions. The prevalence used in this formula was derived from a previous work . Isolation, morphological and biochemical identification of Shigella spp were done according to standard methods . The confirmed isolates were subjected to antimicrobial susceptibility tests by disc diffusion method [29–31].
(For details of the methods used see Additional file 1).
The authors acknowledge with thanks, the University of Buea Departmental Research Grant (Department of Medical Laboratory Sciences) for sponsoring this work.
- Niyogi SK: Shigellosis. J Microbiol. 2005, 43: 33-43.Google Scholar
- Watanabe T: Infective heredity of multiple drug resistance in bacteria. Bacteriology Review. 1963, 27: 87-115.Google Scholar
- Sack BR, Rahman M, Yunus M, Khan HE: Antimicrobial resistance in organisms causing diarrheal disease. Clinical Infectious Disease. 2007, 24: 102-105.View ArticleGoogle Scholar
- Guyot A: Antibiotic resistance of Shigella in Monrovia, Liberia. Tropical Diseases. 1969, 26: 70-71.Google Scholar
- Brito A, Nij B: Antibiotic resistance pattern and plasmid profiles for Shigella species isolated in Cordoba, Argentina. Antimicrob Agents and Chemotherapy. 1994, 34: 253-259. 10.1093/jac/34.2.253.View ArticleGoogle Scholar
- Nguendo YB: Pathogenic microorganisms associated with childhood diarrhea in low and middle income countries: case study of Yaounde-Cameroon. Int J Environ Res Public Health. 2008, 5: 213-229. 10.3390/ijerph5040213.View ArticleGoogle Scholar
- Fotsing K: Etude sur la prévalence des différents agents pathogènes, bactériens chez les enfants de moins de 5 ans à Yaoundé. 2001, Colloque scientifique des Instituts Pasteur, 239-244.Google Scholar
- Gizachew Y, Challa N, Afework K: A five year antimicrobial resistance pattern observed in Shigella species isolated from stool samples in Gondar University Hospital, Northwest Ethiopia. Ethiopian J Health Development. 2006, 20: 194-198.Google Scholar
- Patrick R, Muray S, Rosenthal K, Michael A: Medical miocrobiology. 2002, USA. Elsevier Mosby, 323-333. 5Google Scholar
- Taylor D, Echeverria P, Pal T: The role of Shigella spp., enteroinvasive Escherichia coli and other enteropathogens as causes of childhood dysentery in Thailand. J Infectious Diseases. 2006, 153: 1132-1138.View ArticleGoogle Scholar
- Pablo VE, Torres A, Freire JM, Hernandez V, Gil A: Factors associated to infant mortality in Sub-Saharan Africa. J Public Health In Africa. 2011, 2: e27-View ArticleGoogle Scholar
- Levine MM: Shigellosis. Strickland GT, Hunter's Tropical Medicine. 2000, Philadelphia WB Saunders Co, 340-344. 7Google Scholar
- World Health Organization: Guidelines for the control of shigellosis, including epidemics due to Shigella dysenteriae 1. 2005, WHO Document Production Services, Geneva, Switzerland, 1-64.Google Scholar
- Neu H: The crisis in antibiotics resistance. J Science. 1992, 257: 1064-10.1126/science.257.5073.1064.View ArticleGoogle Scholar
- Toukam M, Lyonga EE, Assoumou MCO, Fokunang CN, Atashili J, Kechia AF, Gonsu HK, Mesembe M, Eyoh A, Ikomey G, Akongnwi E, Ndumbe P: Quinolone and fluoroquinolone resistance in Enterobacteriaceae isolated from hospitalised and community patients in Cameroon. J Med Med Sci. 2010, 1: 490-494.Google Scholar
- Belay R, Solomon W, Shiferaw T, Nina A: Antimicrobial susceptibility pattern of Shigella isolates in Awasa, Ethiopian. Ethiopian J Health and Dev. 2000, 14: 149-154.View ArticleGoogle Scholar
- Khan-Mohammed Z, Adesiyun AA, Swanston WH, Chadee DD: Frequency characteristics of selected enteropathogens in fecal and rectal specimens from childhood dirrhoea in Trinidad, 1998-2000. Rev Panam Salud Publica. 2005, 17: 170-177. 10.1590/S1020-49892005000300004.PubMedView ArticleGoogle Scholar
- Tenover FC: Mechanisms of antimicrobial resistance in bacteria. Amer J Inf Control. 2006, 34: S3-S10. 10.1016/j.ajic.2006.05.219.View ArticleGoogle Scholar
- Rahbar M, Deldari M, Hajia M: Changing prevalence and antibiotic susceptibility patterns of different Shigella species in Teheran, Iran. The Internet J Microbiol. 2007, 3: 2-Google Scholar
- Wilson G, Joshy ME, Chiranjoy M, Shivananda PG: Isolation and antimicrobial susceptibility of shigella from patients with acute gastroenteritis in western Nepal. Indian J Med. 2006, 1: 145-150.Google Scholar
- Shah A, Hasan F, Ahmed S, Hameed A: Extended-Spectrum β-Lactamases (ESBLs): Characterization, Epidemiology and Detection. Critical Reviews in Microbiology. 2004, 30: 25-32. 10.1080/10408410490266429.PubMedView ArticleGoogle Scholar
- Admoni O, Yagupsky P, Avivit G, Schifron G, Horowitz I: Epidemiological, Clinical and Microbiological Features of Shigellosis among Hospitalized Children in Northern Israel. Scand J Infect Dis. 1995, 27: 139-144. 10.3109/00365549509018994.PubMedView ArticleGoogle Scholar
- Ruiz J: Mechanisms of resistance to quinolones: target alterations, decreased accumulation and DNA gyrase protection. J Antimicrob Chemother. 2003, 51: 1109-1117. 10.1093/jac/dkg222.PubMedView ArticleGoogle Scholar
- Mensa L, Marco F, Vila J, Gasco J, Ruiz NJ: Quinolone resistance among Shigella spp. isolated from travellers returning from India. Clin Microbiol Infect. 2008, 14: 279-281. 10.1111/j.1469-0691.2007.01903.x.PubMedView ArticleGoogle Scholar
- Mache A: Antibiotic resistance and serogroups of Shigella among pediatric outpatients in Southwest Ethiopia. East African Medical J. 2001, 78: 6-View ArticleGoogle Scholar
- Assefa A, Gedlu E, Ashmelash T: Antibiotic resistance of prevalent Salmonella and Shigella strains in Northwest Ethiopia. East Afr Med J. 2006, 74: 36-41.Google Scholar
- Murray BE: Resistance of Salmonella, Shigella and other selected enteric pathogens to antimicrobial agents. Infect Dis Rev. 2002, 8: 172-181.View ArticleGoogle Scholar
- Bopp CA, Brenner FW, Wells J, Strockbine NA: Escherichia, Shigella and Salmonella. Manual of Clinical Microbiology. Edited by: Murray PR, Pfaller MA, Tenover FC, Baron EJ, Yolken RH. 2000, Washington, DC: ASM Press, 459-474. 7Google Scholar
- Cheesbrough M: Antibiotic sensitivity testing, Enterobactereaceae. In Medical Laboratory Manual for tropical countries. 2000, Cambridge University Press, 2: 132-138. Microbiology EIBS pub. Low price EditionGoogle Scholar
- Bauer AW, Kirby WW, Sheris JC, Tuek M: Antibiotic susceptibility testing by standardized single disc method. American J Clinical Pathology. 1966, 36: 493-496.Google Scholar
- National Committee for Clinical Laboratory Standards: Performance standard for antimicrobial disk susceptibility tests: approved standards. 2003, Wayne, NCCLS document M2-A6, 6Google Scholar
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.