Incidence of cystic fibrosis in Bahrain
Shaikha Salem Al Arrayed, MBChB, DHCGm PhD.*
Foud Abdulla, MBBS, DCH.**
التكيس الليفي هو مرض وراثي متعدد يتم توريثه بصبغات متنحية مؤديا إلى مرض رئوي مزمن ونقص في الأنزيم البنكرياسي, واضطراب في الشوارد السكرية. ويعتبر هذا المرض سائد بين العرق القوقازي المنحدر من العرق الأوروبي.
وتعود دراسة المراجعة هذه إلى بحث مكثف لهؤلاء المرضى عن طريق المعلومات السريرية وسجلات المستشفى في مركز السلمانية الطبي وذاك بهدف تحديد نسبة الإصابة بالتكيس الليفي في البحرين.
يحتوى التقرير على 27 إصابة مؤكدة بالتكيس الليفي لأطفال ولدوا بين عام 1987 و1994 وقد تأكد التشخيص من وجود نسب عالية لشوارد الصوديوم والكلورايد السكرية (>70mml/L).بلغت نسبة الإصابة خلال هذه الفترة إصابة واحدة بين كل 7700 وقد تم تشخيص جميع الحالات خلال السنة الأولى بعد الولادة. كما تم تشخيص 60% من الحالات خلال الثلاثة شهور الأولى. بلغت نسبة الذكور إلى 14/13(1:1).. وبلغت نسبة العلوص العقي (16%) . أما نسبة الوفيات في فترة ما بعد الولادة(60%). كما باغت نسبة التزاوج بأبناء الخالات والعمات والعموم والأخوال بين هذه العائلات نسبة (63%).
Cystic Fibrosis (CF) is a hereditary multi system disease transmitted as an autosomal recessive, leading to chronic pulmonary disease, pancreatic enzyme deficiency and abnormally high sweat electrolytes. It is considered predominantly a disorder of Caucasians of European descent. The following study refers to an intensive retrospective search for patients with cystic fibrosis from clinical data, hospital record in Salmanyia Medical (SMC), with the aim of determining the incidence of cystic fibrosis in Bahrain. The survey included 27 confirmed cases of cystic fibrosis born during the period 1978-1994. diagnosis was established by sperence of a high sweat sodium and chloride (70 mmol/1). The mean incidence during this period was found to be one in 7,700, all cases were diagnosed during the first year of life, and 60% were diagnosed in the first three months of life. Male and female ratio was found to be 14/13 (1:1). The incidence of meconium ileus was 16%. Mortality in the neonatal period was 60%. First cousin marriage rate among these families was 63%.
The State of Bahrain consist of a group of islands with a total area of approximately 695.26 square kilometers. Kilometers. It is roughly half-way down the Arabian Gulf. It has a population of 519,000 (medium projection for 1992), approximately 36% of the population is non-Bahraini. The overall crude birth rate is 26.7% per 1000, and the infant mortality rate is 20.5% per thousand of newborns1. Cystic fibrosis is the most frequent lethal genetic disease among white Caucasian children. The commonest syndrome is a triad of chronic lung disease, pancreatic insufficiency, and elevated sweat electrolytes. The disease was first described in 1936, and its prevalence among Caucasian in Europe and North America is estimated between 1 in 1600 to 1 in 2000, it reported to be very rare amongst American Blacks (1in 17,000) and Orientals (1 in 90,000)2-8.
The first Arab child with the disease was documented by Salem from Lebanon in 1962 9. Recently cases were reported from Iraq, Kuwait, Palestine and Jordan. Saudi Arabia and Bahrain. But the incidence in the Arab population is still unknown 10-16. This study is an attempt to find the incidence of cystic fibrosis in Bahrain. It is a retrospective study which include 17 years review case notes of patients diagnosed for cystic fibrosis from SMC, which is the main hospital in Bahrain with a bed capacity of nearly 700.
Patients and Methods
This survey included all cystic fibrosis cases born in Bahrain in the years 1978-1994 and registered in the record department in SMC. The survey included statistical information on the births, date of confirmed diagnosis, date of death where applicable , sex, nationality, family data including consanguinity and affected sibships, clinical picture including meconium ileus, and information about investigation and treatment. All the data were confirmed from the original medical record for each patient. The clinical diagnosis of cystic fibrosis was confirmed by a sweat chloride test. The mean incidence of cystic fibrosis in Bahrain was calculated indecently for each year from the ratio of the number of children born in each year who were ascertained to have CF to the total number of live births in that year.
The survey included a total of 27 patients (14 male/13 females) born between January 1978- and December 1994 and confirmed to have cystic fibrosis. The series included 13 families each having one affected child and 7 families each having , two affected children. Thirteen of those families had history of early child hood deaths(28 infants) these cases were not included in the study as they were not confirmed to have CF. the minimum incidence of CF was found to be one in 7,700 over the 17 years period (table 1). All these patients were Bahraini except two, one was Saudi the other Syrian.
The sex ratio was found to be M/F 1:1 (14:13), all patients were diagnosed within the first year of life, and 60% were diagnosed by 3 month of age. The consanguinity rate was high among the parents (80%). First cousin marriage accounted for 63% of the total (Fig 2). Average birth weight was 1.5 kg. Six out of 27 (22%) had sickle cell trait one patients had sickle beta thalasaemia and 98% of patients had glucose six phosphate dehydrogenase deficiency. Mean hemoglobin concentration was 9.8 gm/dl. Meconium ileus was reported in 4 of the 27 patients giving an overall incidence of meconium of 15% in patients with cystic fibrosis. The most common pathogens found in the sputum were pseudomonas, Klebsiella and Candida. Table 2 shows the common signs and symptoms found in these patients. The mortality rate was60% as only eleven patients are still alive. The eldest patient is now nine years old.
Incidence of Cystic fibrosis in Bahrain
Between 1978 and 1994
No. of birth
No. of cases
Incidence per Thousand
Clinical picture & Complications Observed
In Cystic fibrosis Cases in Bahrain
Between 1978 and 1994
SIGN & SYMPTOMS
Failure to thrive
From this study the incidence of CF in Bahrain is estimated to be 1/7,700. this represents a minimum incidence for Bahrain. Not accounted for in this estimate are undiagnosed patients, patients who died before diagnosis and patients with milder forms of the disease who may not be diagnosed until later in life. Until a widespread screening programme is established for CF, it will not be possible to determine the actual incidence of this disease in Bahrain or elsewhere. Warwick 1980 has proposed that the actual incidence of cystic fibrosis may be tow to three times greater than the minimum incidence. We found that the consanguinity rate was high among the families studied. First cousin marriages accounted for 63% of the total as compared to 21% in the general population. This is consistent with an autosomal receive inheritance pattern. the common presenting clinical was failure to thrive 66%, pneumonia62%, hypochloremic alkalosis 44%, and anemia 37% (table 2).
Our study chows that the incidence of meconium ileus in cystic fibrosis is 16% which is similar to other studies, as earlier reports describe the incidence of meconium ileus in a range from 7-25% of CF subject 19. Sixty percent of CF patients died (16 patients) and (70%) of these died before the first year of life (11 patients). While 11 are still alive. Pneumonia in the first place as a cause of death which is expected 20-21. these patients were treated by using chest physiotherapy, Salbutamol, Hydrocortisone, Panox capsules 10% Propylene glycol, and vitamins and different types of antibiotics.
The minimum incidence of CF in Bahrain is 1/7,700 and the mortality rate is high. Registration for theses cases together with molecular genetic studies to identify the defect causing the disease in our population is needed. Early diagnosis and management together with early genetic counseling may improve the outcome for CF patients.
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Journal of the Bahrain Medical Society, Volume 8, No. 3 December 1996