by Salem Yousr Muftah

The author was born on the island of Soqotra in 1979. After graduating in medicine from the University of Hadhramaut he joined the island's nascent health service. In 2010 he was awarded a scholarship funded through the British-Yemeni Society to study for a Master's Degree in tropical paediatrics at the Liverpool School of Tropical Medicine. His year's course in Liverpool involved a field survey which is the subject of the following article.

Chronic suppurative otitis media (CSOM) is a common public health problem in the world and a major cause of hearing impairment among children in developing countries. The disease and its association with disabled hearing impairment (DHI) is a hidden disability (Mackenzie and Smith 2009), and children are at risk of poor school performance, delayed language and speech development, and poor cognition.

The British-Yemeni Society in conjunction with the Liverpool School of Tropical Medicine (LSTM) and others sponsored a survey on Soqotra Island to determine the prevalence of chronic suppurative otitis media in relation to DHI, age, sex, urban or rural settings and other factors. The cross-sectional, community-based survey was conducted from 20 April to 20 June 2011.

36 schools were approached and a total of 686 school age children aged 6"16 years were interviewed and examined for CSOM, and associated DHI and bacterial aetiologies.

The topic of this research was proposed to me by my supervisor, Dr Ian Mackenzie, from the WHO Collaborating Centre for Prevention of Deafness, and the Child & Reproductive Health Group at the Liverpool School of Tropical Medicine (LSTM).Its importance arises from the fact that chronic suppurative otitis media and its relation to the level of hearing impairment is a hidden disability of childhood which has received increased international attention during the last ten years. It is a disease of poverty. Children suffering from the disease are more vulnerable to hearing impairment because they cannot afford the preventive and routine care required to avoid hearing loss nor the hearing aids to make the disability manageable. Hearing impairment also makes it more difficult for them to escape poverty by hindering progress in school or in the workplace and by isolating them socially (WHO, 2010). CSOM contributes significantly to the incidence of disease in children in many developing countries. The WHO recommends early detection and management of ear diseases through school based intervention programmes. In addition to meeting the Millennium Development Goal of improving child survival, early detection and treatment will enhance the learning capacity of schoolchildren who no longer suffer such disabilities. In Yemen, there is evidence of conductive deafness in children with CSOM (Elemraid et al 2007).

Although Soqotra Island, which was listed by UNESCO in 2008 as a World Natural Heritage site, has received some international aid for health, education and the environment, information on the prevalence of CSOM and the level of hearing impairment in children in the area has been lacking. This was the first survey to collect such information as an essential basis for planning future developmental interventions.

The Soqotra Archipelago lies in the north-western part of the Indian Ocean, at the entrance of the Gulf of Aden. It is part of the Republic of Yemen and comes under the provincial administration of Hadhramaut, based in Al Mukalla on the mainland. The Archipelago comprises four Islands: Soqotra, Abd al Kuri, Samha and Darsa (which is uninhabited). It lies about 340km south of the Yemeni mainland, and 250 km east of the Somali coast. Soqotra is the largest island, making up about 95% of the landmass of the Archipelago. It stretches 135km from east to west and is 42km at its widest point. The population is estimated to be at least 59,700 (1994 census). Most people live in the coastal plains and engage mainly in fishing, date cultivation and local trading, while the mountain people of the interior are engaged in livestock production and traditional handicrafts (rug weaving, basket making and pottery). The main towns are Hadibo (the capital), Qalansiya, Nojed and Sharqia. The long isolation from the mainland and the rest of the world makes the Archipelago unique in its culture and biodiversity.
686 children aged between 6 and 16, out of a total school population of 12000, were recruited to participate in this survey as a representative sample of the targeted group. Data collection in the field was carried out by myself. Interviews, the completion of questionnaires, auditory assessment, and the collection of swab samples from discharging ears were undertaken with the help of four study assistants provided by Hadibo General Hospital.
The swab samples were sent to the mainland for laboratory analysis, and each test took 2 to 5 days to complete. Sick children in all the schools we visited received medical advice and treatment free of charge.

In Yemen, there has been no information on the prevalence of hearing impairment and its association with CSOM. The survey which I and my assistants conducted "at an extremely difficult time in Yemen "is the first study of its kind and has yielded information essential in planning better ear care for the children of Soqotra Island and Yemen.

It is noteworthy that the epidemiology of CSOM in the current study belongs to the highest category with an overall prevalence of 7.4%. According to WHO, a prevalence of 1% of CSOM in children in a defined community indicates that the issue is manageable, while a prevalence of 4% indicates a massive public health problem needing urgent attention (WHO/CIBA,1996).The Saudi prevalence of CSOMat 1.3%belongs to the low rate category (Zakzouk and Hajjaj 2002).The wide variation in the rates of CSOM between Soqotra and Saudi Arabia is probably due to the far better access to health care enjoyed by Saudi children, while in the case of Soqotra, access to medical facilities is very limited, and most children live in very poor conditions.

The study found significant hearing impairment among children with CSOM, which is consistent with reports from other parts of the world (WHO 2004). The strongest predicting factors were the presence of ear discharge, recurrent upper respiratory tract infections and the co-habitation of more than three families in a single dwelling. Evidence from other studies supports this finding (Jacoby et al 2011).

The commonest isolated pathogens were proteusspp (39.2%), staphylococcusaureus(23.5%),and pseudomonasspp(19.6%). The current findings are in agreement with many reports about the developing world (Adoga et al 2010).

Dr Salem Yousr testing child at Hafij school, Hadibo

Children in Dehamdh school, Soqotra

Rural school, Nojed, Soqotra Qadib school

Dr Salem at work in Qadib school

Qadib school

Local football team advertising the Field Survey

Conclusions and recommendations 

Before undertaking this survey I was under the impression that hearing impairment and CSOM would not be a major problem, but the results of my research have shown otherwise:

• The incidence of CSOM on Soqotra Island is found to be high measured by WHO criteria;
• Conductive hearing impairment is significantly high among children with CSOM;
• The level of hearing impairment ranged from mild to moderate;
• The main predicting factors for CSOM are the presence of ear discharge, recurrent upper respiratory tract infection and the cohabitation of more than three families;
• Commonly isolated organisms from children with chronic suppurative otitis media are: proteus spp, staphylococcus aureus, and pseudomonas aeruguinosa.
• Ciprofloxacillin andceforuxime are the most susceptible antibiotics to the causative pathogens.
• There is a need for better ear care, early detection and management of CSOM.
• There is a need for the research on the long term efficacy of ciprofloxacillin and other antibiotics in the management of CSOM.

Acknowledgments: 

This work is due to the help of many people, but I owe especial thanks for their generous support and sponsorship to the British-Yemeni Society, the Hadhramaut East Fund for Human Development, and the Liverpool School of Tropical Medicine. My profound gratitude goes to my supervisor, Dr Ian Mackenzie, and to Professor Bernard Brabin.

References: 

Mackenzie, I. and Smith, A., 2009. Deafness "the neglected and hidden disability, Annals of Tropical Medicine and Parasitology, vol. 103, no. 7, pp. 565-571.

World Health Organization. 2004. Chronic suppurative otitis media; burden of illness and management options. Geneva, Switzerland. World Health Organization.

Jacoby, P., Carville, K. S., Hall, G,. Riley, T. V., Bowman, J., Leach, A. J., Lehmann, D.; on Behalf of the kalqoorlie otitis media research project team, (2011), 'Crowding and other strong predictors of upper respiratory tract carriage of otitis media-related bacteria in Australian Aboriginal and non-aboriginal children', Pediatric infectious Disease Journal, vol. 30(6), pp. 480-485.

Muhaimeid, H., Zakzouk, S., and Bafaqueeh, S., (1993), 'Epidemiology of chronic suppurative otitis media in Saudi children', Int. J. Pediatr. Otorhinolaryngol.vol. 26, pp. 101-108.

Zakzouk, S. M., and Hajjaj, M. F., (2002), 'Epidemiology of chronic suppurative otitis media among Saudi children "a comparative study of two decades', International Journal of Pediatric Otorhinolaryngology, vol. 62, pp. 215-218.

World Health Organization (1998) Prevention of hearing impairment from chronic otitis media.

Report of a WHO/CIBA Foundation Workshop, held at The CIBA Foundation. World Health Organization, London, U.K. 19-21 November 1996.

[WHO/PDH/98.4 http://www.who.int/pbd/deafness/en/chronic_otitis_media.pdf] 

Elemraid, M.A., Brabin, B.J., Fraser, W.D., Harper, G., Faragher, B., Atef, Z., Al-Aghbari, N., Mackenzie, I., (2010), 'Characteristics of hearing impairment in Yemeni children with chronic suppurative otitis media: A case-control study', International Journal of Pediatric Otorhinolaryngology, vol. 74, pp.283-286.

Vol 19. 2011