Brief Report: Self-Reported HIV-Positive Status but Subsequent HIV-Negative Test Results in Population-Based HIV Impact Assessment Survey Participants-11 Sub-Saharan African Countries, 2015-2018

BACKGROUND

HIV testing is a critical step to accessing antiretroviral therapy (ART) because early diagnosis can facilitate earlier initiation of ART. This study presents aggregated data of individuals who self-reported being HIV-positive but subsequently tested HIV-negative during nationally representative Population-Based HIV Impact Assessment surveys conducted in 11 countries from 2015 to 2018.

METHOD

Survey participants aged 15 years or older were interviewed by trained personnel using a standard questionnaire to determine HIV testing history and self-reported HIV status. Home-based HIV testing and counseling using rapid diagnostic tests with return of results were performed by survey staff according to the respective national HIV testing services algorithms on venous blood samples. Laboratory-based confirmatory HIV testing for all participants identified as HIV-positives and self-reported positives, irrespective of HIV testing results, was conducted and included Geenius HIV-1/2 and DNA polymerase chain reaction if Geenius was negative or indeterminate.

RESULTS

Of the 16,630 participants who self-reported as HIV-positive, 16,432 (98.6%) were confirmed as HIV-positive and 198 (1.4%) were HIV-negative by subsequent laboratory-based testing. Participants who self-reported as HIV-positive but tested HIV-negative were significantly younger than 30 years, less likely to have received ART, and less likely to have received a CD4 test compared with participants who self-reported as HIV-positive with laboratory-confirmed infection.

CONCLUSIONS

A small proportion of self-reported HIV-positive individuals could not be confirmed as positive, which could be due to initial misdiagnosis, deliberate wrong self-report, or misunderstanding of the questionnaire. As universal ART access is expanding, it is increasingly important to ensure quality of HIV testing and confirmation of HIV diagnosis before ART initiation.

Estimation of (co)variance components, genetic parameters, and genetic trends of growth traits in community-based breeding programs of Bonga sheep

Community-based sheep breeding programs (CBBPs) have been adopted strategically to improve Bonga sheep, the most popular sheep breed in Ethiopia. The present study was undertaken to estimate genetic parameters and genetic trends for growth traits and inbreeding levels in each Bonga sheep CBBP. Data pertaining to growth traits, spanning a period of seven years (2012-2017), were collected from 14 Bonga sheep CBBPs. Data were analyzed using the General Linear Model procedure of SAS to study the performance of the breed over the years. The genetic parameters were estimated by univariate and multivariate animal model using restricted maximum likelihood method of WOMBAT software. The genetic trends were estimated by the regression of the average breeding values of the animals on the year of birth. The overall least square means ± SE of BW (kg) were 3.10 ± 0.010, 16.1 ± 0.07, 24.7 ± 0.20, 30.4 ± 0.40 and 34.0 ± 0.84 for birth weight (BWT), weaning weight (WWT), six-month weight (SMWT), nine-month weight (NMWT) and yearling weight (YWT), respectively. Direct heritability estimates from selected models were 0.56 ± 0.030, 0.36 ± 0.030, 0.22 ± 0.040, 0.17 ± 0.070 and 0.13 ± 0.150 for BWT, WWT, SMWT, NMWT and YWT, respectively. Six-month weight was the selection trait and presented positive trends for 10 CBBPs, and negative trends for four CBBPs. Moderate to high heritability estimates and positive genetic trends indicated scope for further improvement of BW. Additionally, the positive and high correlation between BW traits indicated that selection for just one trait would also improve the other traits through correlated responses.

Converting multi-trait breeding objectives into operative selection indexes to ensure genetic gains in low-input sheep and goat breeding programmes

Small ruminant breeding programmes in low-input production systems are best organised at the community level. Participant farmers have to agree on goal traits and their relative importance. When BLUP breeding values of goal traits are not available in time, appropriate selection indexes can be used to aid visual selection. Taking Ethiopian Abergelle goat and Bonga sheep community-based breeding programmes (CBBPs) as an example, breeding objective functions were defined and selection indexes were constructed and evaluated. Breeding goals for Abergelle goats included early sale weight, survival and milk production. Breeding goals for Bonga included the number of offspring born, sale weight and survival. Economic weights of objective traits can be used in several ways depending on measured traits and the reliability of their genetic parameters. Selection indexes included combinations of objective traits measured on candidates and their dams and situations when Abergelle communities prefer to restrict genetic changes in number of offspring born or adult weight and when Bonga communities prefer to restrict changes in adult weight. Genetic and economic gains were evaluated as well as sensitivity to feed cost assumptions and to repeated dam records. After independent culling on preponderant traits such as coat colour and horn/tail type, sires in Abergelle goat community breeding programmes should be selected on indexes including at least own early live weight and their dams average milk production records. Sires for Bonga sheep programmes should be selected on own early live weight and desirably also on their dam's number of offspring born. Sensitivity to feed cost assumptions was negligible but repeated measurements of dam records improved index accuracies considerably. Restricting genetic changes in number of offspring born or adult weight is not recommended.

Characterization of the production system and breeding practices of indigenous goat keepers in Hai district, Northern Tanzania: implications for community-based breeding program

Indigenous breeding practices of the farmers and the livestock production system form the bases for designing community-based breeding programs. The aim of this study was to characterize production system and examine breeding practices of the indigenous goat farmers in Hai district in Northern Tanzania to determine their relevance in establishing a community-based breeding program in the area. A cross-sectional survey was conducted in which information was collected from 160 households randomly selected from 6 villages. Average household herd was 29.2 goats with majority keeping less than 20 goats. Major reasons for keeping goats were income generation, meat and milk production. Controlled mating was practiced mainly using apron and castration. Castration was practiced using traditional methods to control breeding and improve meat quality. Farmers in the study area had large goat flocks and a small buck to doe ratio. Farmers do not have a good understanding of inbreeding and its negative effects but practise other good breeding methods which could impact the productivity of their animals. Diseases and feed shortages were the main constraints to production. Opportunities exist for a community-based breeding program to genetically improve goat productivity.

Evaluation of increased feed supply and different fattening strategies for an Ethiopian sheep population by system dynamics modelling

Context The productivity of Ethiopian smallholder farms is considered to be low owing to different factors such as feed shortage, lack of breeding strategies, disease prevalence and missing marketing strategies. Aim The main objective of the study was to develop a dynamic, stochastic herd model by adopting system dynamic modelling methodology for evaluation of the effect of increased feed availability (forage production) in combination with different fattening strategies on herd dynamics and profitability of an Ethiopian sheep population. Methods Forage production utilising part of smallholder farmers’ cropland was built into a dynamic simulation model. Two alternative feed-supply systems were evaluated: turning 25% and 50% of the current cropland into area used for forage production. The simulation period was 20 years, the first 10 years representing the baseline fattening scenario (culled rams fattened). For the last 10 years, genetic selection was introduced and two scenarios were evaluated: fattening of culled rams (Scenario I) and fattening of young rams (Scenario II). Key results Increasing the feed supply resulted in an increase to the herd size when the model balanced dry matter supply and demand of the herd. Fattening of young rams (Scenario II) with genetic selection was significantly more profitable than the baseline and Scenario I in both of the simulated alternative feed-supply systems. This can be used for regular cash generation, which might reduce disposal of animals at lower price in cases of need for emergency cash. Conclusions Overall, the simulation model demonstrates that production of improved forage crops should be combined with selective breeding and an appropriate finishing strategy. The competition for resources (land and labour) with crop production, forage seed shortage and extended family size are other challenges raised by smallholder farmers for the feasibility of the two alternative feed-supply systems.

Identification and characterization of HIV positive Ethiopian elite controllers in both Africa and Israel

OBJECTIVES

HIV elite controllers (ECs) are a unique subgroup of HIV-positive patients who are long-term virologically suppressed in the absence of antiretroviral treatment (ART). The prevalence of this subgroup is estimated to be < 1%. Various cohorts of ECs have been described in developed countries, most of which have been demographically heterogeneous. The aim of this study was to identify ECs in two large African cohorts and to estimate their prevalence in a relatively genetically homogenous population.

METHODS

We screened two cohorts of HIV-positive Ethiopian patients. The first cohort resided in Mekelle, Ethiopia. The second was comprised of HIV-positive Ethiopian immigrants in Israel. In the Mekelle cohort, ART-naïve subjects with stable CD4 counts were prospectively screened using two measurements of viral load 6 months apart. Subjects were defined as ECs when both measurements were undetectable. In the Israeli cohort, subjects with consistently undetectable viral loads (mean of 17 viral load measurements/patient) and stable CD4 count > 500 cells/μL were defined as ECs.

RESULTS

In the Mekelle cohort, 16 of 9515 patients (0.16%) fitted the definition of EC, whereas seven of 1160 (0.6%) in the Israeli cohort were identified as ECs (P = 0.011).

CONCLUSIONS

This is the first large-scale screening for HIV-positive ECs to be performed in entirely African cohorts. The overall prevalence of ECs is within the range of that previously described in developing countries. The significant difference in prevalence between the two cohorts of similar genetic background is probably a consequence of selection bias but warrants further investigation into possible environmental factors which may underlie the EC state.

Investigations into nematode parasites of goats in pastoral and crop livestock systems of Ethiopia

We generated epidemiological information on the prevalence of nematode parasites and possible resistance/resilience of goats in three areas, Bati, Shinille, and Borana, of Ethiopia. A total of 350 breeding does were randomly selected and monitored for one year. Fecal egg counts (FEC), packed cell volume (PCV), body weight (BW), body condition score (BC), and fecal larvae identification were done. In Borana, the long rainy season had higher FEC, lower PCV, lower BC, and smaller BW compared to dry and short rainy seasons (p < 0.01). For Bati and Shinille, the differences between the seasons were significant (p < 0.01) but not clear-cut. Breed differences were also evident (p < 0.01) on FEC, PCV, and BW. The mean FEC for Borana goat was 158.5 ± 1.12, whereas for Bati it was 38.9 ± 1.12. Age differences did not have effect on FECs, PCV, and BC. No differences in parasite load, as reflected by FEC, was verified between male and female goats. In the wet season, large numbers of larvae were recovered from the study sites except for Bati. In the three sites, Haemonchus contortus followed by Trichostrongylus colubriformis were the dominant species. In the dry season, however, very little number of larvae was recovered, only of H. contortus in Bati and of H. contortus and T. colubriformis in Borana. Generally, the level of nematode infection was low. Therefore, nematode parasites are not a major problem and strategic control program using broad spectrum anthelmintic is not advisable. Rather, monitoring parasite load and selective de-worming should be sufficient to reduce productivity loses and pasture contamination.

System dynamics modeling in designing breeding schemes: The case of Menz sheep in Ethiopian highlands

A comprehensive dynamic simulation model was developed to describe a community-based breeding program for the Menz sheep population of Ethiopia. Selection of male and female animals based on their own and maternal performance was simulated. The breeding goal traits were 6-mo weight, preweaning survival, and fertility rate. The model input data were obtained from the flock book, questionnaires, and references. The simulation model used a mix of deterministic and stochastic procedures to model the complex system. In the baseline scenario, the proportion of selected male and female animals varied between 20 and 30% and between 70 and 80%, respectively. A reasonable annual genetic gain was predicted for the breeding goal traits at the village level. For 6-mo weight and preweaning survival rate, the annual genetic gain varied from 0.213 to 0.214 kg and 0.255 to 0.256%, respectively. For fertility rate, an annual genetic gain of 0.063% was obtained. The predicted rate of inbreeding per year was between 0.094 and 0.116%. Furthermore, a scenario analysis was conducted by varying the proportions of selected animals. Annual genetic gains of 0.230 kg, 0.277%, and 0.069% were obtained for 6-mo weight, preweaning survival rate, and fertility rate, respectively, when the proportion of selected male and female animals decreased by 10%. The annual genetic gains decreased to 0.198 kg, 0.236%, and 0.059%, respectively, when the selection proportion of male and female animals increased by 10%. The lowest rate of inbreeding per year, ranging from 0.065 to 0.079%, was achieved when the selection proportion of selected male and female animals increased. The model is relevant for the step-by-step evaluation of more than one round of selection. It is flexible and usage driven. The model is a valuable tool to design different population structures and can be easily expanded to adopt different breeding strategies. Hence, the system dynamics modeling approach is a potential tool to describe complex breeding programs.

Causes of Death among Children Aged 5 to 14 Years Old from 2008 to 2013 in Kersa Health and Demographic Surveillance System (Kersa HDSS), Ethiopia

Background

The global burden of mortality among children is still very huge though its trend has started declining following the improvements in the living standard. It presents serious challenges to the well-being of children in many African countries. Today, Sub-Saharan Africa alone accounts for about 50% of global child mortality. The overall objective of this study was to determine the magnitude and distribution of causes of death among children aged 5 to 14 year olds in the population of Kersa HDSS using verbal autopsy method for the period 2008 to 2013.

Methods

Kersa Health and Demographic Surveillance System(Kersa HDSS) was established in September 2007. The center consists of 10 rural and 2 urban kebeles which were selected randomly from 38 kebeles in the district. Thus this study was conducted in Kersa HDSS and data was taken from Kersa HDSS database. The study population included all children aged 5 to 14 years registered during the period of 2008 to 2013 in Kersa HDSS using age specific VA questionnaires. Data were extracted from SPSS database and analyzed using STATA.

Results

A total of 229 deaths were recorded over the period of six years with a crude death rate of 219.6 per 100,000 population of this age group over the study period. This death rate was 217.5 and 221.5 per 100,000 populations for females and males, respectively. 75% of deaths took place at home. The study identified severe malnutrition(33.9%), intestinal infectious diseases(13.8%) and acute lower respiratory infections(9.2%) to be the three most leading causes of death. In broad causes of death classification, injuries have been found to be the second most cause of death next to communicable diseases(56.3%) attributing to 13.1% of the total deaths.

Conclusion and Recommendation

In specific causes of death classification severe malnutrition, intestinal infectious diseases and acute lower respiratory infections were the three leading causes of death where, in broad causes of death communicable diseases and injuries were among the leading causes of death. Hence, concerned bodies should take measures to avert the situation of mortality from these causes of death and further inferential analysis into the prevention and management of infectious diseases should also be taken.

Evaluation of non-genetic factors affecting calf growth, reproductive performance and milk yield of traditionally managed Sheko cattle in southwest Ethiopia

The study was conducted to estimate calf growth, reproductive performance and milk yield of Ethiopia Sheko cattle and to assess non-genetic factors affecting their performance in their home tract as a step towards designing sustainable cattle conservation and improvement strategy. All the growth traits considered in the study were significantly affected by all non-genetic factors considered except for the fixed effects of Agro ecological zones (AEZs) and season of birth which were not significant for post weaning daily gain. Calving interval (CI) and days open (DO) were significantly influenced by AEZs, season and dam parity. Cows that calved in lowland had shorter CI and DO than cows which calved in midland. Cows that calved in short rainy season had Short CI and DO than those calved during dry season or long rainy season. Cows which calved for the first time had the longest CI and DO from the other parities whereas cows on their fifth parity had the shortest CI and DO. AEZ significantly affected lactation milk yield (LMY) and lactation length (LL), but not significant on daily milk yield (DMY) and 305 days yield (305DY). Season was significant on all milk traits considered except DMY. Parity effect was significant on LMY and 305DY, whereas DMY and LL were not affected. The non-genetic factors had significant effects for all of the reproductive; and many of the growth and milk performance traits considered and hence will need to be considered in cattle breed improvement program.

Poor linkages in maternal health care services-evidence on antenatal care and institutional delivery from a community-based longitudinal study in Tigray region, Ethiopia

Background

Progress towards attaining the maternal mortality and maternal health targets set by Millennium Development Goal 5 has been slow in most African countries. Assessing antenatal care and institutional delivery service utilization and their determinants is an important step towards improving maternal health care services.

Methods

Data were drawn from the longitudinal database of Kilite-Awlaelo Health and Demographic Surveillance System. A total of 2361 mothers who were pregnant and who gave birth between September 2009 and August 2013 were included in the analysis. Potential variables to explain antenatal care and institutional delivery service utilization were extracted, and descriptive statistics and logistic regression were used to determine the magnitude of maternal health care service utilization and associated factors, respectively.

Results

More than three-quarters, 76% [95% CI: 74.8%-78.2%] (n = 1806), of mothers had undergone at least one antenatal care visit during their previous pregnancy. However, only 27% [95% CI: 25.3%-28.9%] (n = 639) of mothers gave birth at a health institution. Older mothers, urban residents, mothers with higher education attainment, and farmer mothers were more likely to use antenatal care. Institutional delivery services were more likely to be used among older mothers, urban residents, women with secondary education, mothers who visited antenatal care, and mothers with lower parity.

Conclusions

Despite a relatively high proportion of mothers attending antenatal care services at least once, we found low levels of institutional delivery service utilization. Health service providers in Kilite-Awlaelo should be particularly vigilant regarding the additional maternal health needs of rural and less educated women with high parity.

Breeding programs for smallholder sheep farming systems: I. Evaluation of alternative designs of breeding schemes

Village- and central nucleus-based schemes were simulated and evaluated for their relative bio-economic efficiencies, using Ethiopia's Menz sheep as example. The schemes were: village-based 2-tier (Scheme-1) and 1-tier (Scheme-2) cooperative village breeding schemes, dispersed village-based nuclei scheme (Scheme-3), conventional 2-tier central nucleus-based scheme (Scheme-4), and schemes linking a central nucleus and village multiplier nuclei with selection in central nucleus (Scheme-5) or in both central and village nuclei (Scheme-6). Among village-based schemes, Scheme-1 gave the highest genetic progress, while Scheme-2 was economically the most efficient with genetic gain in the breeding objective of Birr 5.6 and a profit of Birr 37.2/ewe/year. The central nucleus schemes were more efficient than the village schemes. Scheme-4 was the most efficient with genetic gain in the breeding objective of Birr 13.5 and a profit of Birr 71.2, but is operationally more difficult as it requires a very large central nucleus. The choice between village and central nucleus-based schemes would depend on local conditions (availability of infrastructure, logistics and technical knowhow and support). Linking central nucleus with village-based nuclei (Scheme-6) would be a feasible option to overcome the operational difficulties of the conventional central nucleus scheme. If a village-based breeding program is envisaged as should be the 1st step in most low-input systems, then Scheme-2 is the most efficient. To scale out to an entire Menz breed level, Scheme-3 would be recommended.

Genetic evaluation of Ethiopian Boran cattle and their crosses with Holstein Friesian for growth performance in central Ethiopia

Breed additive and non-additive effects, and heritabilities of birth weight (BWT), weaning weight (WWT), 6 months weight (SMWT), yearling weight (YWT), eighteen months weight (EWT), 2 years weight (TWT) and average daily weight gain from birth to 6 months (ADG1) and from 6 months to 2 years (ADG2) were estimated in Ethiopian Boran (B) cattle and their crosses with Holstein Friesian (F) in central Ethiopia. The data analysed were spread over 15 years. Ethiopian Boran were consistently lighter (p < 0.01) than the B-F crosses at all ages. Ethiopian Boran also gained lower weight than all the crosses. At birth, 50% F crosses were significantly (p < 0.01) lighter than all the other crosses. However, the differences in SMWT, YWT, EWT, TWT, ADG1 and ADG2 were all non-significant among the crosses. The individual additive breed differences between B and F breeds were positive and significant (p < 0.01) for all traits. The individual heterosis effects were significant (p < 0.05) for all traits except WWT for which the effect was non-significant. The maternal heterosis effects were significant (p < 0.01) for BWT (2.5 kg) and WWT (-3.0 kg). The heritability estimates for all traits in B and crosses were generally moderate to high indicating that there is scope for genetic improvement through selection. Selection within B and crossbreeding should be the strategy to enhance the growth performance under such production systems.

Behçets' disease: a case report

A 20 year old male patient presented with recurrent panuveitis associated with painful buccal and genital ulcers, subcutaneous nodules and pustules (dermatographia) on the trunk, and positive pathergy (skin hypersensitivity to needle pricks) test. Laboratory examinations were nonrevealing except for a minimal rise in ESR. This patient meets the criteria set by James and Spiteri for Beçhets' Disease. This disease and its prognosis is discussed. Early recognition and treatment of this blinding and potentially fatal disorder is emphasised.

Hybrid and allogeneic resistance to T cell grafts mediated by murine NK and CD8+ T cells

Lethally irradiated mice can reject H-2 allogeneic or parental strain stem cells in bone marrow cell (BMC) grafts within 48 h after transplantation. This rapid rejection of BMC grafts occurs without prior sensitization and is mediated by NK1.1+ NK cells. One hypothesis to account for the ability of host NK cells to mediate acute rejection of allogenic and parental stem cells is that these effector cells recognize hemopoietic histocompatibility (Hh-1) Ags on the donor stem cells. T cells present in the donor BMC can prevent NK cell-mediated rejection. However, lethally irradiated mice can also reject T cells present in lymph node cell preparations that respond to alloantigens of the host. T cell grafts from H-2k/Hh-1k, H-2r/Hh-1null, and H-2ia1/Hh-1null donors were rejected by CD8+ NK1.1- T cells. Ags other than Hh-1 Ags appeared to be recognized by these CD8+ T cells. In contrast, host NK cells rejected H-2d/Hh-1d T cell grafts, whereas both NK cells and CD8+ TCR-alpha beta + T cells rejected H-2b/Hh-1b T cell grafts. Therefore, both CD8+ TCR-alpha beta T cells and NK cells mediate allogeneic and hybrid resistance to T cell grafts.

Hybrid and allogeneic resistance to T cell grafts mediated by murine NK and CD8+ T cells

Lethally irradiated mice can reject H-2 allogeneic or parental strain stem cells in bone marrow cell (BMC) grafts within 48 h after transplantation. This rapid rejection of BMC grafts occurs without prior sensitization and is mediated by NK1.1+ NK cells. One hypothesis to account for the ability of host NK cells to mediate acute rejection of allogenic and parental stem cells is that these effector cells recognize hemopoietic histocompatibility (Hh-1) Ags on the donor stem cells. T cells present in the donor BMC can prevent NK cell-mediated rejection. However, lethally irradiated mice can also reject T cells present in lymph node cell preparations that respond to alloantigens of the host. T cell grafts from H-2k/Hh-1k, H-2r/Hh-1null, and H-2ia1/Hh-1null donors were rejected by CD8+ NK1.1- T cells. Ags other than Hh-1 Ags appeared to be recognized by these CD8+ T cells. In contrast, host NK cells rejected H-2d/Hh-1d T cell grafts, whereas both NK cells and CD8+ TCR-alpha beta + T cells rejected H-2b/Hh-1b T cell grafts. Therefore, both CD8+ TCR-alpha beta T cells and NK cells mediate allogeneic and hybrid resistance to T cell grafts.

Unintended conception and unwanted fertility in Gondar, Ethiopia

This is a report on unintended conception and unwanted fertility in Gondar, Northwestern Ethiopia. The purpose of the study was to explore the extent of the problem and to inquire whether there is a need for fertility regulation. To this end, relatively numerous questions on reproductive history of women aged 15-49 have been raised. Results showed that the proportion of abortion to delivery was 0.3984 to 0.6016 and the ratio of unintended conception to intended conception was 0.4043 to 0.5957. The proportion of unwanted fertility to wanted was 0.4099 to 0.5901. Mean desired interpregnancy interval was substantially higher than actual interpregnancy interval. The relatively high rate of abortion, high proportion of unintended conception and unwanted fertility combined with the wide difference between desired interpregnancy interval and current interpregnancy interval all point to the need for a policy that increases the capacity to regulate fertility.

Fertility conditions in Gondar, northwestern Ethiopia: an appraisal of current status

In order to study current fertility conditions, this study examines the sociocultural, economic, and demographic characteristics of 734 women aged 15-55 in the Gondar administrative region of northwestern Ethiopia. Women over age 45 in the sample were found to have, on average, 7.27 pregnancies, 0.88 abortions, 6.39 children ever-born, 1.51 child deaths, and 4.88 live offspring. The total infertility rate was 8.5 percent, and the subfertility rate was 12.7 percent. Fertility levels in the region were relatively high, compared to other developing countries. Contraceptive use was estimated at 3.6 per 1,000 women (for ages 15-49). The need for more effective family planning services is strongly indicated. The study suggests that, among other goals, policy efforts should focus on the reduction of unintended conception and unwanted fertility.

Clindamycin versus metronidazole in the treatment of bacterial vaginosis

One hundred forty-three women with complaints of vaginitis were assigned to receive either 500 mg of metronidazole twice daily for 7 days or clindamycin 300 mg twice daily for 7 days. There was no significant difference in the failure rate between patients treated with clindamycin (6.1%) and those treated with metronidazole (4%). Adverse reactions were infrequent and mild in both treatment groups. Three patients who received clindamycin developed non-bloody diarrhea, which was mild and did not necessitate discontinuing therapy. We conclude that clindamycin may be a safe and effective alternative to metronidazole for treating women with bacterial vaginosis.