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East African Journal of Public Heath, Vol. 4, No. 2, October 2007, pp. 73-79 TAENIASIS AND ITS SOCIO-ECONOMIC IMPLICATION IN AWASSA TOWN AND ITS SURROUNDINGS, SOUTHERN ETHIOPIA F. Abunna1, G. Tilahun2, B. Megersa1, A. Regassa1 1University of Hawassa, Faculty of Veterinary Medicine,
Awassa, Ethiopia, Correspondent to: B Megersa , P. O. Box 5, University of Hawassa, Faculty of Veterinary Medicine, Awassa, Ethiopia. Received 25 February 2007, revised 10 July 2007; accepted for publication 20 July 2007 Code Number: lp07016 ABSTRACT Objective: The study was conducted between October 2005 and
April 2006 in Awassa town and its surroundings to investigate the status of T.
saginata taeniasis, its socio-economic importance and potential risk factors. Key Words: Prevalence, Questionnaire, Risk factors, Taeniasis, T. saginata, Awassa, Ethiopia Introduction Bovine cysticercosis (T. saginata), refers to the infection of cattle with metacestodes of the human tapeworm (1,2). Globally, there are 77 million human carriers of taeniasis out of which about 40% live in Africa. In developed countries even if the disease has a very low prevalence, the problem with the removal and treatment facilities in their sewage system plays a role in the distribution of eggs as the egg can survive longer in sewage, whereas insufficient use of latrine may worsen the situation in developing countries (3,4). The larvae of T. saginata still cause significant problems in many parts of the world. Most incidents arise as a result of direct exposure to proglottids shed from farm workers, but there have been some reports of large scale outbreaks resulting from sewage-contaminated feed or forage (5). For that reason, T. saginata (bovine cysticercosis) is considered as an important public health and economic problem (6). Taeniasis due to T. saginata is a well-known disease in Ethiopia; based on the stool examination and related techniques. The disease has been reported by different travellers who came to Ethiopia in ancient times as documented in medical history of Ethiopia (7). Studies so far conducted in other parts of Ethiopia showed a wide range of taeniasis prevalence as 13.5%, 10 to 70%, 79.5% and 69.2 % (8-11). Despite the fact that a large proportion of Ethiopian population frequently takes taenicidal drugs, there are limited systematic studies undertaken so far to evaluate the economic importance of Tania saginata infection through the inventory of pharmaceutical shops. There is lack of adequate information on the prevalence of taeniasis particularly in the southern part of the country where raw meat consumption is so popular. This necessitated the current study to investigate the status of taeniasis among human population, potential risk factors for occurrences and to estimate the economic impact of the disease. Methods Study area The study was conducted from October 2005 up to April 2006 in Awassa town and its surroundings, Southern Nations, Nationalities and Peoples Region. Awassa, the capital of Sidama Zone and Region Sate, is located on the shore of one of the Rift Valley lakes at 270 kms south of Addis Ababa. It is geographically located between 7° 03'36''N and 38°28'12'' E, at 1500-2000 meters above sea level. The human population of Awassa is estimated to be 150,000, dwelling over an area of 50 km2. The town has one public hospital, one private hospital, one health station, about 18 pharmaceutical shops and more than 20 clinics. The annual rainfall and temperature ranges of the town are 800-1000 mm and 20.1-25oC, respectively (12). Study population and sample size determination Identification of respondents was based on selection of volunteers from Awassa town residents and it’s surrounding Peasant Associations. The selection was based on different age, sex, and working conditions and accordingly, 120 volunteer individuals were selected at random for questionnaire survey. Questionnaire survey on the disease occurrence and risk factor was administered on 120 respondents from whom pre-informed consents were obtained. The interview was conducted personally by one of the authors using a pre-tested structured questionnaire. The potential risk factors of taeniasis such as age, sex, religion, occupation, educational levels, habit of raw meat consumption, use of spices during meat consumption and marital status were considered. Occupationally high risk groups were those who had a strong relationship with meat, meat products and animals, such as, abattoir workers, butcher men, meat inspectors, cookers and farmers; whereas, the low risk groups were arbitrarily selected as those who do not have such a strong relationship with meat and meat products, such as other government and private workers. Inventories of pharmaceutical shops Drug inventory was conducted on 12 randomly selected volunteer pharmaceutical shops out of 18 shops existing in the town. Accordingly, annual adult dose of taenicidal drug sales (based on prescription and patient complaints) during 2002 to 2005 were gathered to analyze the socio-economic impacts of taeniasis in the area. Data management and analysis The data were collected and recorded on Excel spread sheet and preliminary descriptive analysis such as prevalence and annual summary of adult dose and value of respective drugs was done. Associations of various potential risk factors with the prevalence of human taeniasis were analyzed by logistic regression using Intercooled Stata 7.0 (Stata Corp. 1984-2001, College Station, Texas 77845, USA). The variations odds ratio (OR) was calculated to assess strength of association of different factors to the occurrence of the disease in humans. Ethical consideration The study, which involved human subjects randomly selected from Awassa town and its surroundings, was consulted for ethical clearance. Accordingly, the questionnaire was accepted with some revision so that it does not cause any ethical consequences. Informed consent was obtained from the participants with the understanding that the names and any identification of the subjects were kept confidential. Results Of the total 120 interviewed volunteer respondents of Awassa town, 77 (64.2%) individuals had contracted T. saginata. Of the infected individuals 71.43% (55 out of 77) had more than one infection per year with maximum of 5 times repeated infections (Figure 1). Considerable proportion of the respondents (55%) had habit of raw meat consumption due to traditional and cultural practices. Traditionally, most of the residents of the study area had an experience of using spices with raw or roasted meat, believing to increase their appetite and palatability. The spice locally used was prepared from mixture of water, ox bile, powder of red pepper or green pepper, garlic and other ingredients. The prevalence of taeniasis was significantly varied between religions, occupation, raw meat consumption, use of spices during meat consumption. Accordingly, Christian communities (OR = 5.20, 95% CI=1.20-22.50), high-risk groups (OR = 4.05, 95% CI=1.27-12.93), raw meat eaters (OR = 7.95, 95% CI=2.46 - 5.66), spice users (OR = 11.60, 95% CI=2.85- 47.28) had higher likelihood of acquiring infection than Muslims, low risk groups, cooked meat eaters and non-spices users, respectively (Table 1). Conversely, there was no significant difference in the prevalence of taeniasis between sexes, the age of the respondents, marital status and educational backgrounds. Pharmaceutical shops inventories showed that modern taenicidal drugs sold in those shops were either produced in the country or imported from abroad (United States of America, Europe, Far East and some other African countries). Drugs were more often purchased from Red Cross and government pharmacies than from private drug shops, due to difference in price. The yearly adult taenicidal dose and its worth collected from pharmaceutical records (Table 2), from 2002 to 2005 was estimated to be 4,913,346 doses and 820,343 USD (7219021 Eth. Birr, as per rate of 2006). The average cost per single dose, 0.17 USD (1.50 Eth Birr) was so small and economically insignificant at individual level. However, there exists an enormous annual economic loss from the whole population of Awassa town and its surrounding, which incurred an average annual cost of 164, 068.6 USD (1,443,804.2 Eth Birr). The taenicidal drugs preference trend of the respondents were 46.8%, 24.7%, 15.6%, and 13% for Niclosamide, Mebendazole, Albendazole and Praziquantel, respectively. Interestingly, there was strong linear relationship (R2 = 0.92) between dose sold at pharmaceutical shops and respondents’ preferences (Figure 2). In addition to modern drugs, considerable proportion of the respondents (28.6%), particularly resource poor households reported to have used traditional herbal remedy called ‘Kosso’. Discussion The quality of questionnaire is an important tool in individual cases and in mass investigation for the detection of T. saginata in the carrier population (3). The respondents who were questioned in this study disclosed finding proglottids in their faeces, underwear or on their body, which indicate the presence of T. saginata. According to WHO report, T. saginata is known by its more frequent expulsion through anus than T. solium (13). Almost all of the residents of the town do not eat pork due to religious cult which confirms the current finding to be T. saginata, ruling out possible differential diagnosis for T. solium. The prevalence of T. saginata recorded in this study (64.2%) illustrated the significance of taeniasis in the population of Awassa town and it is very close to the other findings 79.5%, 69.2%, and 94.5% in Ethiopia (10,11,14). On the other hand, Woldemikael reported relatively lower prevalence (13.5%) than the present report (8). The important scenario of taeniasis in the study area is its increased frequency of re-infection in that individuals at risk had higher chances of being infected more than once per year. This may play role in contributing continuously to the life cycle of the parasite in cases where proper use of latrine and sewage disposal is insufficient. According to Wayne et al, there has been large scale outbreak of bovine cysticercosis resulting from sewage contaminated feed or forage (6). Reports on taeniasis prevalence showed contrasting picture in that more than 80% of native stockmen in Africa were reported to be infected with T.saginata (4). Based on the questionnaire survey, Cheruiyot and Onyango reported the prevalence of taeniasis to be 2-63% in Kenya (15). The prevalence of 65% in Serbia and Montenegro and 18% in Taiwan were also recorded (13,16). The prevalence of T. saginata varies from country to country and even differs within the same country from area to area. This could be due to the fact that differences in the habit of raw meat consumption, patient awareness, personal and environmental hygiene, public health services and close contact with animals are attributable to the variation in the prevalence of taeniasis among countries. The observed strong association between the prevalence of taeniasis and religion indicating occurrences of higher infection (OR = 5.20, 95% CI=1.20- 22.50) in the Christian community was in line with the findings of Hailu, Dawitand Tembo in Ethiopia (10,11,13). This could be justified by the fact that raw meat is more favourite dish among Christians than Muslims of the country. Furthermore, Christians celebrate several annual festivals with the tradition of raw meat consumption on the occasions, which certainly increase the chance of contracting taeniasis. The prevalence was also significantly (P<0.05) varied among the residents from different occupational backgrounds with the high-risk groups found to be more prone to infection than low-risk groups. Similarly, higher taeniasis prevalences were reported in the high-risk groups due to more likelihood of coming in contact with meat and meat products which subsequently resulted in getting infection with T. saginata (10,11,13). The observed significant association (P<0.001) between raw meat eaters and infection with taeniasis in the present study, demonstrated also that raw meat consumption is the major risk factors to be controlled in order to avoid the infection C. bovis in humans. The transmission of T.saginata infection from animals to human beings depends on the habit of eating raw “kurti”or semi-raw meat dishes ‘kitifo’ in Ethiopia and in other countries like meat tartar shashlik in Union Soviet Socialist Republic, baserterma in near East, shish kebab and tikka in India, larb in Thailand or pieces of meat simply roasted over an open fire in Central and East Africa (16-19). There was a strong association (OR = 11.60, 95% CI=2.85- 47.28) between the use of spice with meat and taeniasis. This locally prepared spice contains the ox bile, which may facilitate the evagination of the viable cysts, decreasing the evagination time in the intestine and thereby increasing the chance of infection. However, as there is no other supportive finding, it needs further investigation. Although there was no statistically significant difference in the prevalence of taeniasis between age and marital status of the respondents by logistic regression analysis, univariate analysis showed the presence of association indicating that the middle-aged groups and married individuals were relatively at higher risk of infection than youngsters and elders, and singles, respectively. This result was in agreement with other findings in Ethiopia (10,11,20). The probable explanation of contracting taenia infection in middle age category could be due to their frequent visit to butchers and restaurants. The higher infection rate in the married individuals could be due to the fact that married individuals may have better economic capacity to visit butchers and restaurants and furthermore, there could be chance of being infected while tasting, mixing and cooking at home. WHO reported that in urbanized society, for instance, in Poland, of the 90% carriers who admitted to eating raw meat, 44% ate exclusively at home (mostly married women and children), 22% exclusively outside of the home (mostly single men and women), and 24% both at home and public places, mostly married men (13). Hailu, Dawit, Tembo and Mulugeta in Ethiopia and Dada in Nigeria and Fan in Taiwan reported a higher prevalence of taeniasis in males than females in contrast to the finding of Gracey et al who reported that females were found to be more frequently affected than males in a ratio of 2:1 (10,11,14,16,20-24). In contrary to the report of others, significant variation was not observed between the two sexes, perhaps as there was no difference between them with regard to meat consumption in restaurants. Additionally, males often invite their female partners outside the home. Similarly, variation was not observed among the people with different educational backgrounds, perhaps due to the existence of deep-rooted tradition of raw and undercooked meat consumption regardless of their education levels. The pathogenic significance of C. bovis is considered to be very low except its economic significance as a result of carcass or organ contamination (23). However, human taeniasis has economic and health importance. Sick individuals may have poor appetite, abdominal pain, weight loss that may subsequently reduce their working performances. Occasional findings of detached proglottids in their faeces, underwear or on body were reported to bring about awful aesthetic impression or repulsive feeling. Evaluation of the economic and public health impact of taeniasis is very difficult particularly in developing countries like Ethiopia, where necessary information is so scant and considerable proportions of infected people treat themselves with traditional herbal drugs like “kosso” and others. One of the possible sources of information to evaluate the economic feature is to carry out inventories of pharmaceutical shops, which still cannot reflect the actual economic impact of the disease as it only shows the loss due to drug cost. The other impact such as working efficiency of sick individuals and its disgusting impression may not be estimated in monetary terms. Estimates of yearly adult taenicidal drugs dose and its worth collected from pharmaceutical records, from 2002 to 2005 revealed that a total of 4,913,346 adult taenicidal drug doses with a total worth of 820,343 USD or 7219021 Eth. Birr (Table 2) were purchased. Its economic importance may be insignificant at individual level as taeniacidal drugs were not expensive per single individual dose treatment. However, it could not be neglected due to existence of more repeated infections per year and existence of more than one infected individual per household. Moreover, there exists an enormous cumulative annual economic loss from the whole population of Awassa town and its surrounding, which incurred an average annual cost of 1,443,804.2 Eth Birr or 164, 068.6 USD. This may magnify the economic significance of taeniasis in the study area. Similarity of taeniacidal drug dose sold at pharmaceutical shops to respondents drug preferences (Figure 2) with strong linear relationship (R2 = 0.92) may suggest that patients’ preference to drugs appeared to govern drugs sold at pharmaceutical shops. Accordingly, Niclosamide that has been a well known taenacidal drug among the society was found to be the drug of first choice and the highest dose sold whereas Praziquantel which is less familiar to residents (in addition to its price) was the least. Niclosamide was introduced into human medicine for the treatment of tapeworm infections in 1960 and it is claimed to be the drug of choice with a high level of safety (13). Conclusion T. saginata is a medically and economically important cestode parasite in humans, while infection with the cysticercus larval stage in cattle causes economic loss in the meat industry. This study indicated that taeniasis is a widespread problem with higher prevalence among the residents of Awassa town and its surroundings. Religion, occupation, consumption of raw meat and the use of spices were identified to be important risk factors for the disease occurrence. The study showed that taeniasis is causing considerable public health and economic constraints to the population of the area. Owing to its public health and economic importance, taeniasis deserves serious attention in order to safeguard the public of the country. Acknowledgement This study was conducted with the willingness of respondents and individuals in charge in the pharmaceutical drug shops to cooperate. Financial sponsor was the postgraduate office of the Addis Ababa University, Faculty of Veterinary Medicine. All contributions are gratefully acknowledged. References
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