Childhood pneumonia and crowding, bed-sharing and nutrition: a case-control study from The Gambia.

SETTING: Greater Banjul and Upper River Regions, The Gambia. OBJECTIVE: To investigate tractable social, environmental and nutritional risk factors for childhood pneumonia. DESIGN: A case-control study examining the association of crowding, household air pollution (HAP) and nutritional factors with pneumonia was undertaken in children aged 2-59 months: 458 children with severe pneumonia, defined according to the modified WHO criteria, were compared with 322 children with non-severe pneumonia, and these groups were compared to 801 neighbourhood controls. Controls were matched by age, sex, area and season. RESULTS: Strong evidence was found of an association between bed-sharing with someone with a cough and severe pneumonia (adjusted OR [aOR] 5.1, 95%CI 3.2-8.2, P < 0.001) and non-severe pneumonia (aOR 7.3, 95%CI 4.1-13.1, P < 0.001), with 18% of severe cases estimated to be attributable to this risk factor. Malnutrition and pneumonia had clear evidence of association, which was strongest between severe malnutrition and severe pneumonia (aOR 8.7, 95%CI 4.2-17.8, P < 0.001). No association was found between pneumonia and individual carbon monoxide exposure as a measure of HAP. CONCLUSION: Bed-sharing with someone with a cough is an important risk factor for severe pneumonia, and potentially tractable to intervention, while malnutrition remains an important tractable determinant.

Oxygen for treatment of severe pneumonia in The Gambia, West Africa: a situational analysis.

SETTING: Health facilities in The Gambia, West Africa. OBJECTIVES: Oxygen treatment is vital in pneumonia, the leading cause of death in children globally. There are shortages of oxygen in developing countries, but little information is available on the extent of the problem. We assessed national oxygen availability and use in The Gambia, a sub-Saharan African country. METHODS: A government-led team visited 12 health facilities in The Gambia. A modified World Health Organization assessment tool was used to determine oxygen requirements, current provision and capacity to support effective oxygen use. RESULTS: Eleven of the 12 facilities managed severe pneumonia. Oxygen was reliable in three facilities. Requirement and supply were often mismatched. Both oxygen concentrators and oxygen cylinders were used. Suboptimal electricity and maintenance made using concentrators difficult, while logistical problems and cost hampered cylinder use. Children were usually triaged by trained nurses who reported lack of training in oxygen use. Oxygen was given typically by nasal prongs; pulse oximetry was available in two facilities. CONCLUSIONS: National data showed that oxygen availability did not meet needs in most Gambian health facilities. Remedial options must be carefully assessed for real costs, reliability and site-by-site usability. Training is needed to support oxygen use and equipment maintenance.

Milk production of West African Dwarf goats in the Gambia.

Goats are important in the low-input systems of West Africa and their main importance lies in their role for income and saving. In addition, it is known that milk offtake for home consumption is also important. In order to obtain information about the real importance of milk offtake, a recording scheme was operated in 27 villages in the Central River Division of The Gambia from July 1998 until January 2000. Detailed information was obtained from about 1500 kiddings. In the recording scheme, any sheep being milked as well as the goats of the International Trypanotolerance Centre nucleus flock were also recorded. In the villages, 36% of all lactations were used for milk offtake, but the fraction milked was lower for the first two lactations. The average length of lactation was 127 days and the average daily milk offtake was 0.18 L. Goats are milked once a day and the residual milk is left for the kids. Milking starts about one week after parturition and stops when the goat becomes pregnant or the kid(s) die or the goat is drying off. The repeatability of the 90-day milk offtake was 0.24 +/- 0.09. Sixty-five percent of goat owner were women and a large fraction of goat owners also owned cattle. Goat milk was used exclusively for home consumption. It is concluded that in breeding and extension work more attention should be given to aspects of milk production.

Effect of strategic gastrointestinal nematode control on faecal egg count in traditional West African cattle.

This paper reports on the effect of strategic anthelmintic treatments and other determinants on faecal egg counts (FEC) of Trichostrongyles in N'Dama cattle of a west African village. Initially, 527 animals from 13 private N'Dama cattle herds were monitored in a longitudinal study from October 1989 to December 1994. Each herd was stratified by age and animals were sequentially allocated to two groups with similar age distributions. One group received a single anthelmintic treatment of fenbendazole (7.5 mg/kg BW), in October 1989 (n = 250), whereas the other group remained untreated (n = 277) throughout the study. In the next rainy season (June to October), the treated animals were treated twice (in July and September). The same treatment schedule was used in the subsequent rainy seasons until December 1994. Biannual anthelmintic treatments decreased the level of FEC between 31% (late dry season) and 57% (rainy season), when compared to untreated controls. The highest levels of FEC were found during the rainy season from June to October. FEC levels decreased until 4 years of age, after which they remained on a constant low level. The variability of returns to anthelmintic treatments between herds did not seem to be influenced by FEC at the herd level. The financial evaluation of anthelmintic interventions cannot be predicted from FEC and must necessarily rely on the direct monitoring of livestock productivity parameters.

Heritability of gastrointestinal nematode faecal egg counts in West African village N'Dama cattle and its relation to age.

Offspring-dam regression was used to estimate the heritability of strongyle faecal egg counts (FEC) of traditionally raised West African N'Dama cattle in the Central River Division in The Gambia. Faecal samples were taken monthly from June-October 1992, and again from July-October 1993, including 179-463 dams and their calves sampled on each occasion. The only proven genetic relationship was the dam-offspring relationship. Gastrointestinal strongyle FEC was expressed as epg (eggs per gram faeces). Regression of offspring FEC on dam FEC, showed a heritability (h(2)) of 0.18 (95% Confidence Limits 0.10, 0.25). Heritabilities were higher at the beginning and end of the rainy season than during the months of the peak rainy season. This is in line with earlier suggestions that genetic control of faecal egg counts is most effective during periods of low parasite transmission. There was a significant (p<0.001) increase in heritability of 0.086+/-0.018 with each year of age of the corresponding offspring. In view of the virtual absence of national cattle breeding systems in West Africa, which are a precondition for exploitation of heritable traits in cattle, integrated control using improved management and strategic prophylaxis remain the methods of choice to control gastrointestinal nematodes in the given conditions.

Effect of strategic gastrointestinal nematode control on growth of N'Dama cattle in Gambia.

From October 1989 to December 1994, a longitudinal study on the control of gastrointestinal nematodes was done on 1000 N'Dama cattle in 20 private herds in Gambia. Each herd was divided into two groups with an even distribution of age and sex. One group received a single anthelmintic treatment of Fenbendazole, Panacur Hoechst Veterinär GmbH, 7.5 mg kg-1 BW in October 1989, whereas the other group served as an untreated control. In July 1990, the herds were subdivided into two different treatment schemes. In the herds of the first scheme the treated animals (Treatment group I) were treated once (in August), whereas in the herds of the second scheme the treated animals (Treatment group II) were treated twice (in July and September). The same treatment schedule was used in the subsequent rainy seasons until December 1994. One group in every herd served as control (Treatment group 0) and received no anthelmintic treatment throughout the study. One annual fenbendazole treatment had no significant effect on liveweights, whereas two annual treatments significantly increased liveweights of the age group 12-24 and 24-36 months by 9.4%, and 17.5%, respectively. Animals less than 12 months old had 6.3% higher liveweights after two treatments, the difference was statistically not significant (P < 0.06). Average weights of 3- and 4-year-old, twice-treated animals were 13.1% and 8.2%, respectively, higher compared with their controls. No effect of anthelminthic treatment on liveweights was found in 5-year-old and older animals. Herd structure analysis demonstrated that overall male offtake rates ranged from 12 to 28% in the 3-, 4- and 5-year-old age categories. The age categories within which deworming improves liveweights thus coincides with the age at which males are mainly sold. These results suggest that biannual metaphylactic treatments (end of July and beginning of September) of all animals from birth to an age of 4 years should be recommended, provided that the financial analysis demonstrates the profitability of this intervention.

Returns from strategic anthelmintic treatments in village cattle in the Gambia.

A large-scale study was undertaken to investigate the effects of two systematic anthelmintic treatments on village cattle productivity in the Gambia. Treated animals had significantly higher performance in terms of live weights and age at first calving, but the mortality rate of 0- to 1-yr-old cattle appeared to be negatively affected. These results and financial data on treatment costs were used in a herd simulation model to assess the profitability of the intervention. Treatment was profitable on average, but the risks of losing money were large and average returns were sensitive to various hypotheses examined. The treatment regimen studied can only be recommended in certain herds and further research is needed to identify the factors determining the negative response in other herds.

Effect of strategic gastrointestinal nematode control on fertility and mortality of N'Dama cattle in The Gambia.

A large-scale longitudinal study was undertaken to investigate the effects of a strategic treatment of gastrointestinal nematodes on the mortality and fertility of N'Dama cattle under village conditions. Initially, 1046 animals from 26 private N'Dama cattle herds, were monitored from October 1989 to December 1994. Each herd was stratified by age and the animals were randomly allocated to two groups with a similar average age. One group received a single anthelmintic treatment of fenbendazole (Panacur, 7.5 mg/kg BW, Hoechst Veterinä AG) in October 1989, whereas the other group remained untreated. In July 1990, the herds were subdivided into two different treatment schemes. In the herds of scheme 1, the treated animals (Treatment group I) were treated once (in August), whereas in the herds of scheme 2, the treated animals (Treatment group II) were treated twice (in July and September). The same treatment schedule was used in the subsequent rainy seasons until December 1994. One group in every herd of both schemes served as control (Treatment group 0) and received no anthelmintic treatment throughout the study. The average annual cumulative incidence mortality between 0-1 year was more than two times higher in treated animals compared to their controls (21% against 7.5%). No differences were found in older age categories. Survival analysis confirmed differences in mortality from 0-1 year, but were not significant in proportional hazard models. The 25% quantiles of age at first calving was used to quantify differences between twice treated animals (50.2 months) and its controls (58.3 months) which represents a decrease of 8 months in twice treated animals. Annual calving rates of twice treated animals were 52.2% compared to 43.6% in the control group (P < 0.001), which is an increase of 8.6% to the control rate. Possible causes of increased mortality in 0-1 year old treated calves are discussed. We can conclude that in the present epidemiological situation and the given parasite spectrum, gastro-intestinal nematodes mainly affect host fertility. Strategic control of gastro-intestinal nematodes is thus recommended for young heifers up to their age of first calving provided the overall financial analysis of the intervention is beneficial.

Prolonged suppression of trichostrongyle egg output of N'Dama cattle by a single larvicidal treatment.

Gambian village cattle herds were treated with a single dose of ivermectine (Ivomec, MSD-AGVET Inc. 1 ml/50 kg body weight) during the dry season. This treatment suppressed the trichostrongyle egg rise prior to the rains and led to delayed egg production for at least 6 months after the onset of the rainy season, compared to untreated animals from neighbouring villages. However, the results clearly indicate that a single treatment with ivermectine during the dry season does not lead to complete suppression of the gastrointestinal strongyle infections, since a worm population still gradually built up. During the second year the ranked level of the egg excretion was significantly lower than that of the control group throughout the year until December, except in August. The results further support the hypothesis that trichostrongyle reinfection is unimportant during the dry season in this climatic zone.