Fish trypanosomes from the Okavango Delta, Botswana

During 2001 and 2002, blood smears from 37 of 120 fishes belonging to 10 species captured in the Okavango Delta region of Botswana, were found to harbour trypanosomes. These trypanosomes displayed differing staining properties, were morphometrically variable, and ranged in total length from 29.5 to 80.8 microm. Mixed populations of the smaller and larger trypanosomes were found in most fish examined. Despite variations in size and appearance, these specimens are tentatively identified as Trypanosoma mukasai Hoare, 1932, likely adding another 9 new hosts to those known for this parasite. It is possible that Trypanosoma clariense Pienaar, 1962, described from Clarias gariepinus in South Africa, is also a junior synonym of T. mukasai.

A survey of small-scale broiler production systems in Botswana

Aspects of husbandry, productivity parameters, diseases, marketing and farmer attitudes in small-scale broiler farms in Botswana were studied using a questionnaire-based survey. The number of broilers per production cycle in small-scale operations ranged from 100 to 2000, with an average of 640. On average, small-scale producers had 4-5 production cycles per annum with an interval of 2-3 weeks between batches. The average marketing age was 48.3 days at a live weight of 1.79 kg and a carcase weight of 1.42 kg. The average feed conversion ratio was estimated to be 2.72 (kg feed/kg live weight) and the average mortality was 9.15%. Overall, the performance indices of broilers under small-scale farm conditions were much poorer than those obtained elsewhere under improved management conditions, but these lower performance levels are suggestive of the potential that exists for further improvement. The survey also identified several areas of concern that constrain the realization of the full potential of this sector. Factors contributing to the poor performance under small-scale farm conditions are complex, but feed supply and quality, chick quality and farmer training appear to be areas for immediate improvement.

Phenotypic characterization of indigenous Tswana goats and sheep breeds in Botswana: continuous traits

The majority of Tswana sheep and goats in Botswana are indigenous. These animals provide income, employment and food security to the resource-poor farmers. Limited characterization of these species has been done, resulting in poor efforts to fully exploit and conserve them. The objective of this study was to phenotyically characterize indigenous sheep and goats countrywide. Measurements were collected from 2783 goats and 1282 sheep kept by traditional farmers, covering nearly all the districts of Botswana. In each district a total of 15 farmers with sheep and goats were selected randomly and records were taken on 4-12 animals per farm, depending on average district flock size. Traits recorded for each animal were body length, body weight, ear length, heart girth, height at withers, hip width, neck length, rump height, shoulder width, tail length (goats only) and horn length. Age (estimated from dentition) and sex of the animals were also recorded and vegetation type was noted. The data were analysed using the general linear model procedure in Statistical Analysis System. Prior to analyses, a main effects model of sex, age and vegetation type was fitted. Later, two types of analyses were done: (i) within a vegetation type fitting sex and age and their interaction, and (ii) within sex fitting age and vegetation type and their interaction. Least-squares means were separated using Student's t-test. Sex, age and vegetation significantly (p<0.05) affected the magnitude of traits. Phenotypic body measurements of castrates were generally higher than in both females and entire males, which were similar. The body measurements of younger animals were less than those of older age groups since the former were still growing compared to the latter. Different vegetation types promoted different body measurements, which should be expected due to differences in nutrient supply from different vegetation types. The indigenous breeds of sheep and goats can be classified as medium-size breeds. The breeds should be conserved since they are well suited to the harsh environment of Botswana where drought and livestock diseases are ever present. Efforts should be undertaken to characterize them genetically and increase their productivity.

Public-Private Partnerships And Antiretroviral Drugs For HIV/AIDS: Lessons From Botswana

The African Comprehensive HIV/AIDS Partnerships (ACHAP) played a major role in initiating Botswana's antiretroviral (ARV) program in 2001. ACHAP is a prominent public-private partnership involving Merck and its foundation, the Bill and Melinda Gates Foundation, and the government of Botswana. This paper analyzes ACHAP's efforts to assist Botswana with its ARV program, the first and most advanced in sub-Saharan Africa. It identifies five features of the model and shows how they contributed to the ARV program. It also raises questions about ACHAP's role in scaling up and sustaining the program, as Botswana faces the challenges of treating growing numbers of HIV-infected people.

Freshwater Rhabdocoela (Platyhelminthes) from ephemeral rock pools from Botswana, with the description of four new species and one new genus

Four new species of freshwater rhabdocoel flatworms from ephemeral rock pools in southeastern Botswana are described and discussed. Two of them, Syringoplana kolasai n. gen. n. sp. and Mesostoma thamagai n. sp. belong to the Typhloplanidae Graff, 1905. The unique construction of the excretory system is the main characteristic of S. kolasai. M. thamagai can be separated from other Mesostoma Ehrenberg, 1837 species by the presence of a bundle of eosinophilic glands at the transition from oviduct to seminal receptacle. The other two taxa, Gieysztoria isoldeae n. sp. and G. faubeli n. sp. belong to the Dalyelliidae Graff, 1905. G. isoldeae is characterised by the presence of four separate hollow spines in the male atrium, which are connected to two accessory glandular organs. G. faubeli can be separated from other Gieysztoria Ruebush and Hayes, 1939 species by the detailed construction of the stylet. Apart from these two species the occurrence of an unidentified Microdalyellia Gieysztor, 1938 species is mentioned.

Adherence to management guidelines in acute respiratory infections and diarrhoea in children under 5 years old in primary health care in Botswana

OBJECTIVE

To evaluate health care providers' adherence to management guidelines for acute respiratory infection and diarrhoea in children under 5 years old in Botswana primary health care.

DESIGN

Cross-sectional prospective field survey. Data collection was carried out through observation of consecutive consultations at 30 randomly assigned clinics and health posts in three purposely chosen districts.

STUDY PARTICIPANTS

This study comprises 185 cases of acute respiratory infection and 85 cases of diarrhoea.

MAIN MEASURE

Criteria for acceptable standards of history taking and physical examination for acute respiratory infection and diarrhoea were defined as well as criteria for categorizing the appropriateness of antibiotic prescription. The percentage of oral dehydration salts provided in cases of diarrhoea was calculated.

RESULTS

Acute respiratory infection and diarrhoea accounted for 270 (including 15 missing cases) of all main diagnoses (n = 539). In 262 cases (97%) health care providers were nurses or enrolled nurses; in 3% family welfare educators. Acceptable history taking, physical examination, and both combined in acute respiratory infection was found in 113 (63%), 32 (18%), and 28 (16%), and in diarrhoea in 45 (58%), 26 (34%) and 20 (26%) cases, respectively. Antibiotics were prescribed in 76 of 255 (30%) cases. Prescription was assessed as inappropriate in 56 of 76 (74%) of all cases; in 41 of 52 (79%) cases with acute respiratory infection, in none of the pneumonia cases, and in all 15 cases of diarrhoea. Oral rehydration salts were prescribed in 74 (87%) of the diarrhoea cases.

CONCLUSIONS

Health care providers' adherence to guidelines on history taking was suboptimal in acute respiratory infection and diarrhoea but poor on examination in both conditions. A high level of inappropriate antibiotic prescription was found in acute respiratory infection and diarrhoea. Overall, there is considerable scope for improving diagnostic and therapeutic management of these major childhood diseases in Botswana primary health care.

MHC class II DRB variability and parasite load in the striped mouse (Rhabdomys pumilio) in the Southern Kalahari

Major histocompatibility complex (MHC) variability is believed to be maintained by pathogen-driven selection, mediated either through heterozygous advantage or frequency-dependent selection. However, empirical support for these hypotheses under natural conditions is rare. In this study, we investigated the genetic constitution of the functionally important MHC class II gene (DRB exon 2) and the parasite load in a population of the striped mouse (Rhabdomys pumilio) in the Southern Kalahari. Fifty-eight individuals were genetically examined and the endoparasite load was quantified by counting fecal helminth eggs by using a modified McMaster technique. Thirty-four animals (58.6%) were infected. We identified 20 different MHC alleles with high levels of sequence divergence between alleles. Particularly, the antigen-binding sites revealed a significant higher rate of nonsynonymous substitutions (d(N)) than synonymous substitutions (d(S)), giving strong evidence of balancing selection. Heterozygosity did influence the infection status (being infected or not) and the individual fecal egg count (FEC) value with significantly higher values observed in homozygous individuals. Furthermore, a positive relationship was found between specific alleles and parasite load. The allele Rhpu-DRB*1 significantly occurred more frequently in infected individuals and in individuals with high FEC values (high parasite load). Individuals with the allele Rhpu-DRB*1 had a 1.5-fold higher chance of being infected than individuals without this allele (odds ratio test, P < 0.05). Contrarily, the allele Rhpu-DRB*8 significantly occurred more frequent in individuals with low FEC values. Our results support the hypotheses that MHC polymorphism in R. pumilio is maintained through pathogen-driven selection acting by both heterozygosity advantage and frequency-dependent selection.

Prevalence and antibiotic resistance profiles of Escherichia coli O157:H7 in beef products from retail outlets in Gaborone, Botswana

Four hundred meat samples (134 meat cubes, 133 minced meat, 133 fresh sausages) were collected from 15 supermarkets and butcheries in Gaborone, Botswana, between the summer months of October 2002 and March 2003. Samples were assayed for Escherichia coli O157 by selective enrichment in modified E. coli broth containing novobiocin, followed by immunomagnetic separation and plating onto sorbitol MacConkey agar supplemented with potassium tellurite. The isolates were biochemically and serologically confirmed by API 20E and O157 antisera, respectively. The prevalence rates for E. coli O157 were 5.22% in meat cube samples, 3.76% in minced meat samples, and 2.26% in fresh sausages. The isolates showed single, double, and triple antibiotic resistance. Fifty-three percent of them were resistant to cephalothin. Resistance was also recorded for sulphatriad (33%), colistin sulphate (26%), streptomycin (0.7%), and tetracycline (26%). It is recommended that the cause for antibiotic resistance be investigated using a larger number of samples from cattle, especially from ranching areas of the country.

Presence of Bacillus cereus in street foods in Gaborone, Botswana

The purpose of this study was to evaluate the microbiological safety and quality of street foods sold in Gaborone, Botswana. A total of 148 point-of-sale composite street food samples were bought and analyzed between June 2001 and May 2002. The analysis focused on the level of contamination of various street foods with Bacillus cereus. The B. cereus (vegetative and spores), total spore, and total viable counts were determined on all the samples. Also B. cereus isolates from 444 individual point-of-sale food samples were characterized with respect to their biochemical profiles and enterotoxigenic properties. The B. cereus contamination rate for point-of-sale foods was 65%. The B. cereus counts ranged from not detectable to levels as high as 9.1 log CFU/g. Despite the high rate of contamination of some samples, generally, most samples had B. cereus counts of less than 4 log CFU/g; hence, they were of acceptable microbiological quality. Bacillus diarrheal enterotoxin was detected from 52 isolates from individual portions of meals using the B. cereus enterotoxin reversed passive latex agglutination kit. Results of the assay revealed that 59.6% of the B. cereus isolates were enterotoxigenic. Most of the enterotoxigenic isolates were obtained from vegetable samples.

Identification of polymorphic motifs using probabilistic search algorithms

The problem of identifying motifs comprising nucleotides at a set of polymorphic DNA sites, not necessarily contiguous, arises in many human genetic problems. However, when the sites are not contiguous, no efficient algorithm exists for polymorphic motif identification. A search based on complete enumeration is computationally inefficient. We have developed probabilistic search algorithms to discover motifs of known or unknown lengths. We have developed statistical tests of significance for assessing a motif discovery, and a statistical criterion for simultaneously estimating motif length and discovering it. We have tested these algorithms on various synthetic data sets and have shown that they are very efficient, in the sense that the "true" motifs can be detected in the vast majority of replications and in a small number of iterations. Additionally, we have applied them to some real data sets and have shown that they are able to identify known motifs. In certain applications, it is pertinent to find motifs that contain contrasting nucleotides at the sites included in the motif (e.g., motifs identified in case-control association studies). For this, we have suggested appropriate modifications. Using simulations, we have discovered that the success rate of identification of the correct motif is high in case-control studies except when relative risks are small. Our analyses of evolutionary data sets resulted in the identification of some motifs that appear to have important implications on human evolutionary inference. These algorithms can easily be implemented to discover motifs from multilocus genotype data by simple numerical recoding of genotypes.

Predictors of food variety and dietary diversity among older persons in Botswana

OBJECTIVE

We investigated whether food variety and diversity are associated with physical and cognitive functioning in older adults in Botswana and designed a simple set of screening questions that predict food variety in this population.

METHODS

Data were collected (1998) as a national household survey of 1085 subjects 60 y and older. A food variety score, based on a food frequency checklist, was calculated by summing the frequency of weekly intakes of 16 food items (0 to 66). A dietary diversity score was calculated as the number of food groups consumed weekly (0 to 5). A representative subsample (n = 393) was randomly selected for the clinical component of the survey, and measurements on dependency and cognitive function were conducted.

RESULTS

Low food variety was found: 35.2%, 59.3%, and 22.4% of subjects consumed no dairy products, fruits, and vegetables, respectively. A higher food variety score was associated with urban residence, ownership of cattle, higher education, and more frequent meals, and these indicators were used to construct a nutritional risk indicator. Higher food variety score was associated with better self-reported health and better cognitive function. Similarly, a higher score on the nutritional risk indicator screening tool was associated with desirable health outcomes.

CONCLUSION

A limited number of foods is consumed, leading to an overall pattern of poor food variety. Higher food variety was associated with improved physical and cognitive functions. A screening tool that predicts food variety in this population has been developed and is recommended to be incorporated at a primary care level to identify older adults most at risk of a poor quality diet.

Spatially explicit analyses unveil density dependence

Density-dependent processes are fundamental in the understanding of species population dynamics. Whereas the benefits of considering the spatial dimension in population biology are widely acknowledged, the implications of doing so for the statistical detection of spatial density dependence have not been examined. The outcome of traditional tests may therefore differ from those that include ecologically relevant locational information on both the prey species and natural enemy. Here, we explicitly incorporate spatial information on individual counts when testing for density dependence between an insect herbivore and its parasitoids. The spatially explicit approach used identified significant density dependence more frequently and in different instances than traditional methods. The form of density dependence detected also differed between methods. These results demonstrate that the explicit consideration of patch location in density-dependence analyses is likely to significantly alter current understanding of the prevalence and form of spatial density dependence in natural populations.

Association between major histocompatibility complex class II DRB alleles and parasite load in the hairy-footed gerbil, Gerbillurus paeba, in the southern Kalahari

We investigated the importance of the MHC-constitution (major histocompatibility complex-constitution) on the endoparasite load in free-range hairy-footed gerbils (Gerbillurus paeba) in the southern Kalahari Desert. While the number of alleles of the duplicated DRB exon 2 gene had no significant effects on the individual status of being 'not infected' or 'infected' and on the number of helminth morphotype infections per individual, it significantly affected the faecal egg count values. One allele (Gepa-DRB*15) was only found in uninfected mice. Our results support the hypotheses that MHC polymorphism in G. paeba is maintained by pathogen-driven selection. The present study is the first investigation on associations between duplicated DRB gene loci and the parasite load in mammals.

Picturing AIDS: using images to raise community awareness

In Botswana, explicit color photos of people with AIDS have been used to spread knowledge, with the aim of saving lives

Introduction of routine HIV testing in prenatal care--Botswana, 2004

In 2003, approximately 37% of pregnant women in Botswana (2001 population: 1.7 million; approximately 40,000 births per year) were infected with human immunodeficiency virus (HIV). Since 2001, all prenatal clinics in Botswana have offered HIV screening and interventions for prevention of mother-to-child transmission of HIV (PMTCT), which can decrease vertical transmission of HIV from 35%-40% to 5%-10%. Historically, HIV testing in Botswana has been performed after individual pretest counseling, with patients actively choosing whether to be tested (i.e., an "opt-in" approach). In 2003, 52% of pregnant women receiving prenatal care nationwide learned their HIV status. In 2004, to increase use of free national PMTCT and antiretroviral treatment (ARV) programs, Botswana began routine, noncompulsory (i.e., "opt-out") HIV screening in prenatal and other health-care settings. Concerns have been raised that routine testing in Africa might deter women from seeking prenatal care and might result in fewer women returning for their test results and HIV care after testing. To assess the early impact of routine testing on HIV-test acceptance and rates of return for care, the CDC Global AIDS Program and the PMTCT program in Botswana evaluated routine prenatal HIV testing at four clinics in Francistown, the second largest city in Botswana, where HIV prevalence has been > or =40% since 1995. This report describes the results of that assessment, which indicated that, during February-April 2004, the first 3 months of routine testing, 314 (90.5%) of 347 pregnant women were tested for HIV, compared with 381 (75.3%) of 506 women during October 2003-January 2004, the last 4 months of the opt-in testing period (p<0.001). However, many women who were tested never learned their HIV status because of logistical problems or not returning to the clinic. Substantial increases in HIV testing of pregnant women were also observed at the Francistown referral hospital and at prenatal clinics nationwide. These findings highlight the potential public health impact of routine HIV testing with rapid, same-day results for programs seeking to increase the number of persons with access to HIV-prevention and treatment services.

Chlamydia and gonorrhoea in pregnancy: effectiveness of diagnosis and treatment in Botswana

BACKGROUND

Millions of patients are prescribed drugs for sexually transmitted infections (STIs) in developing countries each year, yet the treatment effect of these prescriptions is largely unknown.

OBJECTIVES

To determine if the prescribing of erythromycin and ceftriaxone to pregnant women with STI symptoms leads to a reduction in the prevalence among these women of chlamydia and gonorrhoea, respectively.

METHODS

We compared the prevalence of chlamydia among 116 pregnant women who had been prescribed erythromycin for a history of STI symptoms in their current pregnancy with the prevalence in a control group of 557 pregnant women who had not been prescribed this drug. Similarly we compared the prevalence of gonorrhoea among 110 pregnant women who had and 561 women who had not been prescribed ceftriaxone.

RESULTS

There was no significant difference in the prevalence of chlamydia among the women who had and the women who had not been prescribed erythromycin four times daily for 10 days (7% v 8%). Contrarily, none of the women who had been prescribed a single dose of ceftriaxone had gonorrhoea, whereas 4% of the women who had not had this drug prescribed did have gonorrhoea.

CONCLUSIONS

The prescribing of erythromycin seems to have had a limited effect on chlamydia in this population, whereas the prescribing of ceftriaxone led to the curing of gonorrhoea. Ceftriaxone is provided as a single dose injection at the point of care, and the differential effectiveness between the two drugs may reflect low compliance with the complex erythromycin regimen. Interventions to increase compliance could improve cure rates. The use of a simpler drug regimen should be considered when low compliance is likely.

Botswana: Industrial Court tackles HIV testing in the workplace

The Botswana Industrial Court recently decided two cases regarding mandatory HIV testing in the workplace. One case addressed constitutional rights of HIV-infected people, expanding the reach of the Bill of Rights to the private sphere and potentially offering wide protection to people living with HIV/AIDS. Both cases highlight the glaring need for HIV-related legislation in Botswana.

The return of the giants: ecological effects of an increasing elephant population

Northern Botswana and adjacent areas, have the world's largest population of African elephant (Loxodonta africana). However, a 100 years ago elephants were rare following excessive hunting. Simultaneously, ungulate populations were severely reduced by decease. The ecological effects of the reduction in large herbivores must have been substantial, but are little known. Today, however, ecosystem changes following the increase in elephant numbers cause considerable concern in Botswana. This was the background for the "BONIC" project, investigating the interactions between the increasing elephant population and other ecosystem components and processes. Results confirm that the ecosystem is changing following the increase in elephant and ungulate populations, and, presumably, developing towards a situation resembling that before the reduction of large herbivores. We see no ecological reasons to artificially change elephant numbers. There are, however, economic and social reasons to control elephants, and their range in northern Botswana may have to be artificially restricted.

Evidence of sexual recombination among Cryptococcus neoformans serotype A isolates in sub-Saharan Africa

The most common cause of fungal meningitis in humans, Cryptococcus neoformans serotype A, is a basidiomycetous yeast with a bipolar mating system. However, the vast majority (>99.9%) of C. neoformans serotype A isolates possess only one of the two mating type alleles (MATalpha). Isolates with the other allele (MATa) were recently discovered and proven to mate in the laboratory. It has been a mystery whether and where C. neoformans strains undergo sexual reproduction. Here, we applied population genetic approaches to demonstrate that a population of C. neoformans serotype A clinical isolates from Botswana contains an unprecedented proportion of fertile MATa isolates and exhibits evidence of both clonal expansion and recombination within two partially genetically isolated subgroups. Our findings provide evidence for sexual recombination among some populations of C. neoformans serotype A from sub-Saharan Africa, which may have a direct impact on their evolution.

Sampling household waste at source: lessons learnt in Gaborone

Municipal solid waste (MSW) quantity and composition analysis is fundamental for the planning of municipal waste management services. The purpose of this paper is to report the results and experiences of sampling household waste at the source of generation in Gaborone, Botswana. The average generation rate, in kg capita(-1) day(-1), and percentages of various components of waste in Gaborone were determined using a statistically designed household sampling survey. The survey covered 47 households with different socio-economic characteristics over 21 days with 893 samples obtained. The results showed that the average waste generation rate for Gaborone was 0.33 kg capita(-1) day(-1). Contrary to common belief, the waste generation rate measured as in weight units was found not be directly related to household income. However, the packaging fractions of plastic and paper measured as volume had a direct relationship with household income. Across all income groups, the putrescible waste fraction constituted the highest proportion of the waste stream at approximately 68%. The main general conclusion is on the importance of practical considerations. As much as statistically designed sampling procedures provide a useful means of estimating the quantity and composition of household waste at source of generation, there are some practical issues that should be carefully considered during sampling to improve the accuracy and relevance of the results.

IMPACT OF PEER GROUP EDUCATION ON HIV PREVENTION AMONG WOMEN IN BOTSWANA

A peer group HIV prevention intervention based on social-cognitive learning theory, gender inequality, and the primary health care model for community-based health promotion was developed for more than 300 urban employed women in Botswana. All women volunteered to participate in the intervention. To control for self-selection, matched workplaces were assigned to the intervention group or to the delayed control group. Compared with women in the delayed control group, women in the intervention group had significantly higher postintervention levels of knowledge of HIV transmission, sexually transmitted diseases (STDs), and HIV prevention behaviors; positive condom attitudes and confidence in condom use; personal safer sex behaviors; and positive attitudes toward persons living with HIV/AIDS and community HIV/AIDS-related activities. The peer group leaders have sustained the program for more than 5 years after the end of research funding. Peer groups are a low-cost and sustainable intervention that can change HIV prevention knowledge, attitudes, and behaviors for ordinary urban employed women in sub-Saharan Africa.

The cost of HIV/AIDS to businesses in southern Africa

BACKGROUND

Information on the potential costs of HIV/AIDS to the private sector is needed if companies are to be given a financial incentive to invest in prevention and treatment interventions.

OBJECTIVES

To estimate the cost of HIV/AIDS to businesses in southern Africa using company-specific data on employees, costs, and HIV prevalence.

METHODS

: Six formal sector enterprises in South Africa and Botswana provided detailed human resource, financial, and medical data and carried out voluntary, anonymous HIV seroprevalence surveys. The present value of incident HIV infections with a 9-year median survival and 7% real discount rate was estimated. Costs included were sick leave; productivity loss; supervisory time; retirement, death, disability, and medical benefits; and recruitment and training of replacement workers.

RESULTS

HIV prevalence in the workforces studied ranged from 7.9 to 25.0%. HIV/AIDS among employees added 0.4-5.9% to the companies' annual salary and wage bills. The present value of an incident HIV infection ranged from 0.5 to 3.6 times the annual salary of the affected worker. Costs varied widely across firms and among job levels within firms. Key reasons for the differences included HIV prevalence, levels and stability of employee benefits, and the contractual status of unskilled workers. Some costs were omitted from the analysis because of lack of data, and results should be regarded as quite conservative.

CONCLUSIONS

AIDS is causing labor costs for businesses in southern Africa to rise and threatens the competitiveness of African industry. Research on the effectiveness of workplace interventions is urgently needed.