Search

The diet, habitat use and mercury concentration of the small fish species, the straight fin barb Barbus paludinosus, were studied in Lake Awassa, Ethiopia, for a period of 1 year from February 2003 to January 2004. Stable isotope signatures of nitrogen and carbon in different total length ( LT) classes were used to determine trophic positions and organic carbon sources, respectively. Barbus paludinosus mainly occupied the protected benthic habitats (littoral and profundal) of the lake. The δ13C values were in the range from −24 to −19‰, indicating that the carbon source for B. paludinosus was benthic, as well. Small individuals (≤ 60 mm LT) mainly preyed upon ostracods, intermediate sizes (60–100 mm) on aquatic insects and gastropods, while a tiny cyprinodont fish Aplocheilichthys antinorii dominated the diet of large individuals (100–160 mm). The progressively increase in δ15N with increasing LT also indicated a diet shift towards piscivory in larger individuals. The mercury concentration ranging from 0·02 to 0·74 mg kg−1 wet mass (wm), was unexpectedly high in this small species, and was significantly positively related to LT, as well as to δ15N. Some large individuals had mercury concentrations < 0·1 mg kg−1 wm, and low δ15N, indicating substantial variations in diet between individuals of same size. The study suggests that other piscivorous species which include B. paludinosus in their diet may have a high mercury intake risk. [ABSTRACT FROM AUTHOR]

The concentrations of total mercury (THg), stable isotopes of nitrogen (delta(15)N) and carbon (delta(13)C), and the diet of the African sharptooth catfish Clarias gariepinus in Lake Awassa, Ethiopia, were studied from January 2003 to February 2004. Values of the delta(15)N were used as an index of trophic position in four length groups and compared to actual stomach contents. The diet of C. gariepinus within the length range of 201-600 mm L(T) mainly consisted of the small barb Barbus paludinosus, aquatic insects, and mollusks. The proportion of fish prey in the diet was 60% by volume, irrespective of fish size. The differences in delta(15)N values of individuals within and between length classes were less than 3 per thousand, and were not significantly related to total length, showing the similarity in trophic niche of the different sizes, which corresponded to recorded stomach contents. Mercury concentrations were in the range of 0.002-0.154 mg kg(-1) ww, and had no significant relationship to total length. Hence, even large specimens of C. gariepinus have Hg values below the WHO threshold of 0.2 mg kg(-1) ww. The slope of the regression line between log [Hg] and delta(15)N was small, 0.06, indicating the absence of trophic shifts and biomagnification of Hg in larger specimens in our samples. The low Hg concentrations in C. gariepinus compared to the Hg concentrations in other piscivorous fish species in Lake Awassa, such as Barbus intermedius and B. paludinosus, may be due to its dependence on invertebrate preys at small size, diet switching towards low Hg prey fish at larger size, and growth biodilution owing to higher growth rate.

A study on rational drug use was undertaken in nine health centres (HCs) and nine health stations (HSs) in Ethiopia. Prescribing, patient care and facility specific factors were measured using drug use indicators. Prescribing patterns of drugs were also assessed. With only few exceptions, the drug use indicators in HCs and HSs and between retrospective and prospective studies were similar despite differences in manpower and facilities. The average consultation time (in minutes) in HSs and HCs was 5.1 +/- 0.8 and 5.8 +/- 1.06, respectively. The dispensing time (in minutes) was 1.5 +/- 0.7 in HSs and 1.9 +/- 0.6 in HCs. Both patient care indicators seem to be adequate to influence patient satisfaction to the overall health service and patient knowledge of important dosage instructions. Most drugs (more than 89% in HCs and 71% in HSs) were actually dispensed from the health facilities and labelling was satisfactory. Prescribing by generic names (average: 75% in HCs and 83% in HSs) was encouraging. While the availability of key drugs was ensured, essential documents were missing in most facilities or they were unpopular for use, and those available required revision and updating. Polypharmacy in which the number of drugs/encounter was < 2.5 was minimal, but that a large proportion of the prescriptions contained two or more drugs could result in adverse drug-drug interactions. The most frequently prescribed drugs were anti-infectives and analgesics accounting for over 76% in HCs and 82% in HSs and in most cases they are probably prescribed with little justification. The exposure of patients to antibiotics (average: 60% in HCs and 65% in HSs) was unacceptably high to justify epidemiological trends. The high exposure of patients to injections, especially in the HSs (over 37%), should be seen from the health and economic points of view. The results revealed priority areas for intervention. They also provide standard references to compare drug use situations and their change over time in different settings, area and time in Ethiopia.

A total of 19,119 prescriptions consecutively written between January-July 1992 were collected from Gondar outpatient hospital selling pharmacy and reviewed to determine physician's adherence to the basic principles of prescription order writing. In 36.6%, 16.8% and 12.4% of the prescriptions, respectively, age, sex and chart numbers of patients were not recorded. Twelve percent, 7%, 6.4%, 5.8% and 1.6% of the prescriptions did not indicate routes of drug administration, directions for drug use, frequency of drug administration, drug dose and duration of treatment, respectively. No prescription order had special advice or warnings to the patient and in 10.8% of the cases date was omitted. Out of the dispensed drugs, 82.9% were written in generic names and over 70% were included in the Essential Drug List of Ethiopia. The five most commonly dispensed individual drugs were ampicillin (10.4%), paracetamol (9.5%), TB 450 + isoniazid (7.4%), penicillin G (6.8%) and aspirin (5.8%). As therapeutic classes, antiinfectives were most common (47.8%) of which antibacterials constituted 38.1%, followed by analgesic-antipyretics (17.5%). Most drugs were prescribed by young medical interns and dispensed by less qualified personnel. Our preliminary survey indicates that essential components of a prescription order were omitted to a great extent and suggested to modify the existing undergraduate pharmacotherapeutic teaching in order to promote rational use and prescribing before bad habits get a chance to develop. The type of drugs dispensed at the selling pharmacy could not be beneficial to the patient without competent professional patient counselling, delivery of correct information as well as appropriate prescription monitoring.

The prescribing pattern of antibacterial agents was analyzed by reviewing case notes of 407 patients discharged between October and November 1992 from a teaching hospital in Gondar, North-West Ethiopia. Seventy percent had received one or more antibacterials. Most exposure was in surgical ward (84%) followed by paediatric (82%), orthopaedic (78%), medical (72%), gynaecologic (58%) and obstetric (20%) wards. The antibacterials most frequently prescribed were penicillin G (25%), chloramphenical (24%), and ampicillin (20%). The total list numbered 13 and included no cephalosporines or quinoline derivatives. The preliminary survey indicated an inappropriate use of antibacterials and suggested the need to develop a policy on hospital antibacterial use.