Synthesized peptide analogs from Eumenes pomiformis (Hymenoptera: Eumenidae) venom reveals their antibiotic and pesticide activity potential

One natural antimicrobial peptide (EpVP2a, Eumenes pomiformis Venom Peptide 2a) found in the venom of a potter wasp (Eumenes pomiformis) and six analogs were synthesized and tested to compare their antimicrobial, antifungal, pesticide, and hemolytic activity with the wild type. Our results indicated that while the original peptide and the synthetic analogs had no antifungal activity or anti-bacterial activity against Pseudomonas aeruginosa, the original peptide and the analog with substitution of the aspartic acid on the sequence by a lysine (EpVP2a-D2K2) had activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis. This same analog also shows significant insecticide activity. The analog with substitution of lysine with a slightly smaller ornithine had activity against E. coli and B. subtilis. All analogs show low hemolytic activity compared to the natural peptide. The peptide with a reverse sequence to the natural one (EpVp2a Retro) shows low helix structure which can also explain why it has no antibacterial activity and low hemolytic activity. Circular dichroism spectra show that these peptides form an alpha helix structure and their amino acid positions predict an amphipathic nature.

Tangled in a Web: Management Type and Vegetation Shape the Occurrence of Web-Building Spiders in Protected Areas

Land management of parks and vegetation complexity can affect arthropod diversity and subsequently alter trophic interactions between predators and their prey. In this study, we examined spiders in five parks with varying management histories and intensities to determine whether certain spider species were associated with particular plants. We also determined whether web architecture influenced spider occurrence. Our results showed that humpbacked orb-weavers (Eustala anastera) were associated with an invasive plant, Chinese privet (Ligustrum sinense). This study revealed how invasive plants can potentially influence certain spider communities, as evidenced by this native spider species only occurring on invasive plants. Knowing more about spider populations-including species makeup and plants they populate-will give insights into how spider populations are dealing with various ecosystem changes. While we did not assess the effect of invasive plants on the behavior of spiders, it is possible that invasive species may not always be harmful to ecosystems; in the case of spiders, invasive plants may serve as a useful environment to live in. More studies are needed to ascertain whether invasive plants can have adverse effects on spider ecology in the long term.

Barriers to uptake of cervical cancer screening services in low-and-middle-income countries: a systematic review

OBJECTIVES

Low-and-middle-income countries (LMICs) bear a disproportionate burden of cervical cancer mortality. We aimed to identify what is currently known about barriers to cervical cancer screening among women in LMICs and propose remedial actions.

DESIGN

This was a systematic review using Medical Subject Headings (MeSH) terms in Google Scholar, PubMed, Scopus, and Web of Science databases. We also contacted medical associations and universities for grey literature and checked reference lists of eligible articles for relevant literature published in English between 2010 and 2020. We summarized the findings using a descriptive narrative based on themes identified as levels of the social ecological model.

SETTING

We included studies conducted in LMICs published in English between 2010 and 2020.

PARTICIPANTS

We included studies that reported on barriers to cervical cancer screening among women 15 years and older, eligible for cervical cancer screening.

RESULTS

Seventy-nine articles met the inclusion criteria. We identified individual, cultural/traditional and religious, societal, health system, and structural barriers to screening. Lack of knowledge and awareness of cervical cancer in general and of screening were the most frequent individual level barriers. Cultural/traditional and religious barriers included prohibition of screening and unsupportive partners and families, while social barriers were largely driven by community misconceptions. Health system barriers included policy and programmatic factors, and structural barriers were related to geography, education and cost. Underlying reasons for these barriers included limited information about cervical cancer and screening as a preventive strategy, poorly resourced health systems that lacked policies or implemented them poorly, generalised limited access to health services, and gender norms that deprioritize the health needs of women.

CONCLUSION

A wide range of barriers to screening were identified across most LMICs. Urgent implementation of clear policies supported by health system capacity for implementation, community wide advocacy and information dissemination, strengthening of policies that support women's health and gender equality, and targeted further research are needed to effectively address the inequitable burden of cervical cancer in LMICs.

Invasive carp alter trophic niches of consumers and basal resources in African reservoirs

Environmental pollution and biological invasions are key drivers of biodiversity change. However, the effects of invasion and pollution on food webs remain largely unexplored. Here, we used stable isotopes to examine the effects of common carp Cyprinus carpio and pollution on trophic dynamics in six small reservoirs. Our results revealed that the trophic niche widths of invertebrates, vertebrates, and invasive carp did not significantly differ among reservoirs with different pollution statuses. However, we found low niche conservatism among reservoirs, suggesting that while niche width may remain consistent, there is a shift in the position of the niches in isotopic space under both pollution and invasion scenarios. Niche conservatism among reservoirs was generally higher in invertebrates, but this was also regardless of reservoir condition (i.e. presence or absence of pollution and invasion). These results suggest that invasion by species coupled with organic pollution may cause subtle yet differing effects on components of a food web (basal end-members, invertebrates and vertebrates). Our findings provide a baseline measure of the potential in the development of detection and response strategies for carp invasions and organic pollution.

Gestational diabetes in women living with HIV in Botswana: lower rates with dolutegravir- than with efavirenz-based antiretroviral therapy

BACKGROUND

There are few data on the prevalence of gestational diabetes (GDM) in pregnant women living with HIV (WLHIV) in sub-Saharan Africa, particularly those using integrase strand transfer inhibitors such as dolutegravir (DTG).

METHODS

We prospectively enrolled pregnant WLHIV and pregnant women without HIV ≥18 years old in Gaborone, Botswana, excluding those with pre-existing diabetes. We screened for GDM using a 75 g oral glucose tolerance test (OGTT) performed at 24-28 weeks' gestation or at the earliest prenatal visit for those presenting after 28 weeks. Logistic regression models were fitted to assess the association between maternal HIV infection and GDM. Subgroup analyses were performed among WLHIV to assess the association between maternal antiretroviral therapy (ART) in pregnancy [DTG vs. efavirenz (EFV) with tenofovir/emtricitabine] and GDM.

RESULTS

Of 486 pregnant women, 66.5% were WLHIV, and they were older than women without HIV (median age 30 vs. 25 years, P < 0.01). Among WLHIV, 97.8% had an HIV-1 RNA level < 400 copies/mL at enrolment. Overall, 8.4% had GDM with similar rates between WLHIV and those without HIV (9.0% vs. 7.4%). The WLHIV receiving DTG-based ART had a 60% lower risk for GDM compared with those on EFV-based ART (adjusted odds ratio = 0.40, 95% CI: 0.18-0.92) after adjusting for confounders.

CONCLUSIONS

Pregnant WLHIV on ART in Botswana were not at increased risk of GDM compared with women without HIV. Among WLHIV, the risk of GDM was lower with DTG- than with EFV-based ART. Further studies with larger cohorts are warranted to confirm these findings.

Stable isotope analyses identify trophic niche partitioning between sympatric terrestrial vertebrates in coastal saltmarshes with differing oiling histories

Bioindicator species are commonly used as proxies to help identify the ecological effects of oil spills and other stressors. However, the utility of taxa as bioindicators is dependent on understanding their trophic niche and life history characteristics, as these factors mediate their ecological responses. Seaside sparrows (Ammospiza maritima) and marsh rice rats (Oryzomys palustris) are two ubiquitous terrestrial vertebrates that are thought to be bioindicators of oil spills in saltmarsh ecosystems. To improve the utility of these omnivorous taxa as bioindicators, we used carbon and nitrogen stable isotope analysis to quantify their trophic niches at saltmarshes in coastal Louisiana with differing oiling histories. We found that rats generally had lower trophic positions and incorporated more aquatic prey relative to seaside sparrows. The range of resources used (i.e.,trophic niche width) varied based on oiling history. Seaside sparrows had wider trophic niches than marsh rice rats at unoiled sites, but not at oiled sites. Trophic niche widths of conspecifics were less consistent at oiled sites, although marsh rice rats at oiled sites had wider trophic niches than rats at unoiled sites. These results suggest that past oiling histories may have imparted subtle, yet differing effects on the foraging ecology of these two co-occurring species. However, the temporal lag between initial oiling and our study makes identifying the ultimate drivers of differences between oiled and unoiled sites challenging. Even so, our findings provide a baseline quantification of the trophic niches of sympatric seaside sparrows and marsh rice rats that will aid in the use of these species as indicators of oiling and other environmental stressors in saltmarsh ecosystems.

Persistence and clearance of high-risk human papillomavirus and cervical dysplasia at 1 year in women living with human immunodeficiency virus: a prospective cohort study

OBJECTIVE

Evaluate 1-year outcomes of cervical cancer screening and treatment using primary high-risk human papillomavirus (HPV) testing in women living with human immunodeficiency virus (HIV).

DESIGN

Prospective cohort study.

SETTING

HIV treatment centre in Botswana.

POPULATION

Women living with HIV.

METHODS

Participants underwent cervical cancer screening with high-risk HPV testing and triage evaluation at baseline and 1-year follow up. Excisional treatment was offered as indicated. Histopathology was the reference standard.

MAIN OUTCOME MEASURES

Persistence, clearance and incidence of high-risk HPV infection; and persistence, progression, regression, cure and incidence of cervical dysplasia.

RESULTS

Among 300 women screened at baseline, 237 attended follow up (79%). High-risk HPV positivity significantly decreased from 28% at baseline to 20% at 1 year (P = 0.02). High-risk HPV persistence was 46% and clearance was 54%; incidence was high at 9%. Prevalence of cervical intraepithelial neoplasia Grade 2 (CIN2) or higher was most common in participants with incident high-risk HPV (53%). CIN2 or higher was also common in those with persistent high-risk HPV (32%) and even in those who cleared high-risk HPV (30%). Of the high-risk HPV-positive participants at baseline with <CIN2, 40% progressed to CIN2 or higher at follow up.

CONCLUSION

The high incidence of high-risk HPV and high-grade cervical dysplasia in women living with HIV after one round of high-risk HPV-based screening and treatment raises concern about the rate of progression of high-risk HPV infection to dysplasia. Persistent disease is common. Caution in spacing cervical cancer screening intervals using high-risk HPV testing in women living with HIV is warranted.

TWEETABLE ABSTRACT

High incidence and persistence of HPV and CIN2+ in women living with HIV 1 year after screening and treatment.

Faecal analyses and alimentary tracers reveal the foraging ecology of two sympatric bats

We used three complementary methods to assess the diet of two insectivorous bat species: one an obligate aerial hunter, Miniopterus natalensis, and the other Myotis tricolor whose morphology and taxonomic affiliation to other trawling bats suggests it may be a trawler (capturing insects from the water surface with its feet and tail). We used visual inspection, stable isotope values and fatty acid profiles of insect fragments in bat faeces sampled across five sites to determine the contribution of aquatic and terrestrial arthropods to the diets of the two species. The niche widths of M. tricolor were generally wider than those of Miniopterus natalensis but with much overlap, both taking aquatic and terrestrial insects, albeit in different proportions. The diet of M. tricolor had high proportions of fatty acids (20:5ω3 and 22:6ω3) that are only obtainable from aquatic insects. Furthermore, the diet of M. tricolor had higher proportions of water striders (Gerridae) and whirligig beetles (Gyrinidae), insects obtainable via trawling, than Miniopterus natalensis. These results suggest both species are flexible in their consumption of prey but that M. tricolor may use both aerial hawking and trawling, or at least gleaning, to take insects from water surfaces. The resultant spatial segregation may sufficiently differentiate the niches of the two species, allowing them to co-exist. Furthermore, our results emphasize that using a combination of methods to analyse diets of cryptic animals yields greater insights into animal foraging ecology than any of them on their own.

Preliminary Estimations of Insect Mediated Transfers of Mercury and Physiologically Important Fatty Acids from Water to Land

Aquatic insects provide an energy subsidy to riparian food webs. However, most empirical studies have considered the role of subsidies only in terms of magnitude (using biomass measurements) and quality (using physiologically important fatty acids), negating an aspect of subsidies that may affect their impact on recipient food webs: the potential of insects to transport contaminants (e.g., mercury) to terrestrial ecosystems. To this end, I used empirical data to estimate the magnitude of nutrients (using physiologically important fatty acids as a proxy) and contaminants (total mercury (Hg) and methylmercury (MeHg)) exported by insects from rivers and lacustrine systems in each continent. The results reveal that North American rivers may export more physiologically important fatty acids per unit area (93.0 ± 32.6 Kg Km^-2 year^-1) than other continents. Owing to the amount of variation in Hg and MeHg, there were no significant differences in MeHg and Hg among continents in lakes (Hg: 1.5 × 10^-4 to 1.0 × 10^-3 Kg Km^-2 year^-1; MeHg: 7.7 × 10^-5 to 1.0 × 10^-4 Kg Km^-2 year^-1) and rivers (Hg: 3.2 × 10^-4 to 1.1 × 10^-3 Kg Km^-2 year^-1; MeHg: 3.3 × 10^-4 to 8.9 × 10^-4 Kg Km^-2 year^-1), with rivers exporting significantly larger quantities of mercury across all continents than lakes. Globally, insect export of physiologically important fatty acids by insect was estimated to be ~43.9 × 10⁶ Kg year^-1 while MeHg was ~649.6 Kg year^-1. The calculated estimates add to the growing body of literature, which suggests that emerging aquatic insects are important in supplying essential nutrients to terrestrial consumers; however, with the increase of pollutants in freshwater systems, emergent aquatic insect may also be sentinels of organic contaminants to terrestrial consumers.

A25 Impact of polymorphism in the hepatitis B surface gene on human leukocyte antigen (HLA) class II

There is still no cure for chronic hepatitis B virus infection (CHBV), a major cause of liver cancers and related malignancies. Elucidating the role of CD4+ T-helper cells in activating immunological responses that clear antigenic peptides during primary HBV infection holds a potential strategy for developing potent vaccines. Since the strength of CD4+ T cell responses is dictated by binding of viral epitopes to class-II human leukocyte antigens (HLAs), we hypothesize that the quality of immunological responses in CHBV patients is influenced by host genetics and HBV genotypes. Here, ninety-two non-recombinant complete HBV surface-gene proteins (PreS1/S) from Botswana were sequenced (genotype A 44(47.8%); D 48(52.2%)) and 15-mer binding epitopes restricted to nine HLA-class II molecules (DRB5/1) were mapped in silico. The HLAs used have high population coverage in Botswana. The total predicted epitopes per HLA were 94-(genotype A) and 105-(genotype D) for PreS1, 42 (A and D) for PreS2, and 105 (A and D) for S. Epitope densities (binding peptides to total epitopes) were 3 per cent and 6 per cent (PreS1A&D), 4 per cent and 2 per cent (PreS2A&D), and 23 per cent and 22 per cent (S1A&D). SA&D proteins had most polytopes: CPGYRWMCLRRFII66-81, PGYRWMCLRRFIIF67-82, GYRWMCLRRFIIFL68-83, and YRWMCLRRFIIFLF69-84 binding to 5 (55.6%) HLAs (DRB1*0101/0701/1101/1501 and DRB5*0101) used. HLA-DRB*0101 bound the most epitopes, and the least were bound by HLA-DRB*0302/0701/0401 for both genotypes. PreS1D polytope: PAFRANTANPDWDFN32-46 binds to DRB1*0101/0401/1302 and PreS2 polytopes: TAFHQALQDPRVRG6-19 and AFHQALQDPRVRGL7-20 bind to DRB1*010/1501 alleles. Non-synonymous mutations impair peptide-HLA binding when assessed as combinations of > 2. The least active HLAs may be associated with CHBV and vice-versa for HBV clearance, thus the algorithm may be used to predict HBV prognosis for different haplotypes. The results favor the use of epitopes from S protein as broad genotype vaccine. This study highlights the need to explore further the mechanisms of PreS1 and its effect on the immune system.

Determinants of excellent/good self-rated health among HIV positive individuals in South Africa: evidence from a 2012 nationally representative household survey

BACKGROUND

In South Africa, HIV is increasingly becoming a chronic disease as a result of advances in HIV treatment and prevention in the last three decades. This has changed the perception from a life threating to a potentially manageable disease. However, little is known about self-perceived health status of HIV-infected individuals. Self-rated health (SRH) has been shown to be a sensitive indicator of health-relatedchanges directly linked to HIV, but can also be influenced by differences in social and material conditions. The aim of this paper was to identify determinants of excellent/good SRH among HIV-infected individuals using socio-demographic, life style and health related data.

METHODS

The study used data from the nationally representative 2012 South African population-based household survey on HIV prevalence, incidence and behaviour conducted using multi-stage stratified cluster sampling design. Bivariate and multivariate logistic regression models were used to identify determinants of SRH among HIV-infected individuals.

RESULTS

Out of a total of 2632 HIV positive participants 74.1% (95% CI: 68.4-74.2) reported excellent/good SRH. Increased likelihood of reporting excellent/good SRH was significantly associated with being Black African [OR= 1.97 (95%CI: 1.12-3.46), p = 0.019] and belonging to least poor household [OR= 3.13 (95%CI: 1.26-7.78), p = 0.014]. Decreased likelihood of reporting excellent/good SRH was significantly associated with those aged 25 to 34 years [OR= 0.49 (95% CI: 0.31-0.78), p = 0.003], 35 to 44 years[OR= 0.27 (95% CI: 0.17-0.44), p < 0.001], 45 to 54 years [OR= 0.20 (95% CI: 0.12-0.34), p < 0.001], and those 55 years and older [OR= 0.15 (95% CI: 0.09-0.26), p < 0.001], hospitalization in the past twelve months [OR= 0.40 (95% CI: 0.26-0.60), p < 0.001].

CONCLUSION

To have positive health effects and improve the perceived health status for PLWH social interventions should seek to enhance to support for the elderly HIV-positive individuals, and address the challenge of socio-economic inequalities and underlying comorbid conditions resulting in hospitalization.

Men's knowledge about prostate cancer: a case study of rural Mhondoro-Ngezi, Kadoma District, Zimbabwe

Men in Zimbabwe, like elsewhere in the world, suffer from prostate cancer. Yet ironically, men's awareness of the disease and comprehensive knowledge about the signs and symptoms, screening methods and the age groups predisposed to the risk of the diseases has remained poorly understood. Utilising a survey of 500 men aged between 15 and 79 years, 12 key informant interviews and seven focus group discussions in Mhondoro-Ngezi, the study established that men's awareness and comprehensive knowledge about prostate cancer is very low and marred with misconceptions. Informal sources of communication, especially friends, continue to be the major sources of information about prostate cancer, while formal sources are passive. The aforementioned findings imply that playmakers in the health delivery programmes have an overdue responsibility to rescue men from the catastrophic trap so that they freely enjoy their rights to good health. There is also need for accelerated information, education and communication regarding male reproductive cancers to cater for the future welfare of men given that they are drivers of national economies in their various capacities. Failure to do so would mean that men's reproductive health-seeking behaviour regarding early screening and treatment of prostate cancer will forever remain compromised.

Tuberculosis case finding for vaccine trials in young children in high-incidence settings: a randomised trial

SETTING

A high tuberculosis (TB) burden rural area in South Africa.

OBJECTIVE

To compare TB case yield and disease profile among bacille Calmette-Guérin (BCG) vaccinated children using two case-finding strategies from birth until 2 years of age.

DESIGN

BCG-vaccinated infants were enrolled within 2 weeks of birth and randomised to 3-monthly home visits for questionnaire-based TB screening plus record surveillance of TB registers, hospital admission and X-ray lists at health facilities for TB suspects and cases (Group 1), or record surveillance (as above) only (Group 2). Both groups received a close-out visit after 2 years. Participants were evaluated for suspected TB disease using standardised investigations.

RESULTS

A total of 4786 infants were enrolled: 2392 were randomised to Group 1 and 2394 to Group 2. The case-finding rate was significantly greater in Group 1 (2.2/100 py) than in Group 2 (0.8/100 py), with a case-finding rate ratio of 2.6 (95%CI 1.8-4.0, P < 0.001). Although the proportion of cases with bacteriological confirmation was lower in Group 1, this difference did not reach statistical significance. There was also no significant difference in the proportions with TB symptoms and signs.

CONCLUSION

Home visits combined with record surveillance detected significantly more cases than record surveillance with a single study-end visit. The TB case profile did not differ significantly between the two groups.

Tuberculin skin test and QuantiFERON® assay in young children investigated for tuberculosis in South Africa

SETTING

Although the literature on interferon-gamma release assays on tuberculosis (TB) in children has increased, data pertaining to young children remain relatively limited.

OBJECTIVE

To compare results from the tuberculin skin test (TST) and the QuantiFERON®-TB Gold In-Tube assay (QFT) in children aged <3 years investigated for TB disease.

DESIGN

TB suspects were evaluated by medical history and examination, TST, QFT, chest radiography, induced sputum and gastric washings for smear and culture for Mycobacterium tuberculosis.

RESULTS

A total of 400 children were enrolled. Among 397 children with both test results, 68 (17%) were QFT-positive and 72 (18%) were TST-positive (≥10 mm). Agreement between the tests was excellent (94%, κ = 0.79, 95%CI 0.69-0.89). TB disease was diagnosed in 52/397 (13%) participants: 3 definite, 35 probable and 14 possible TB. QFT sensitivity and specificity for TB disease were respectively 38% and 81%. TST sensitivity and specificity were respectively 35% and 84%.

CONCLUSION

While TST and QFT had excellent concordance in this population, both tests had much lower sensitivity for TB disease than has been reported for other age groups. Our results suggested equivalent performance of QFT and TST in the diagnosis of TB disease in young children in a high-burden setting.

The tuberculin skin test: a comparison of ruler and calliper readings

BACKGROUND

The Mantoux tuberculin skin test (TST) is widely used to diagnose latent infection with Mycobacterium tuberculosis. TST skin induration may be measured either by a transparent ruler or by a pair of callipers. We hypothesised that the type of instrument used may affect the reading.

OBJECTIVE

To determine whether variability in Mantoux TST measurement is affected by the type of reading instrument.

METHOD

A TST (Mantoux method) was performed among healthy adolescents. The indurations were read with among ruler and calliper by two independent readers. Limits of agreement and Kappa (κ) scores at TST positivity cut-off points were calculated. A Bland-Altman graph was constructed.

RESULTS

The 95% limits of agreement between instruments ranged from -5 mm to 3 mm. The limits of agreement between readers ranged from -5 mm to 4 mm. κ scores between instruments were respectively 0.7 and 0.8 at 15 mm and 10 mm cut-offs.

CONCLUSION

The variability between readers of TST indurations is not influenced by changing the reading instrument.

Antiretroviral regimens in pregnancy and breast-feeding in Botswana

BACKGROUND

The most effective highly active antiretroviral therapy (HAART) to prevent mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) in pregnancy and its efficacy during breast-feeding are unknown.

METHODS

We randomly assigned 560 HIV-1-infected pregnant women (CD4+ count, > or = 200 cells per cubic millimeter) to receive coformulated abacavir, zidovudine, and lamivudine (the nucleoside reverse-transcriptase inhibitor [NRTI] group) or lopinavir-ritonavir plus zidovudine-lamivudine (the protease-inhibitor group) from 26 to 34 weeks' gestation through planned weaning by 6 months post partum. A total of 170 women with CD4+ counts of less than 200 cells per cubic millimeter received nevirapine plus zidovudine-lamivudine (the observational group). Infants received single-dose nevirapine and 4 weeks of zidovudine.

RESULTS

The rate of virologic suppression to less than 400 copies per milliliter was high and did not differ significantly among the three groups at delivery (96% in the NRTI group, 93% in the protease-inhibitor group, and 94% in the observational group) or throughout the breast-feeding period (92% in the NRTI group, 93% in the protease-inhibitor group, and 95% in the observational group). By 6 months of age, 8 of 709 live-born infants (1.1%) were infected (95% confidence interval [CI], 0.5 to 2.2): 6 were infected in utero (4 in the NRTI group, 1 in the protease-inhibitor group, and 1 in the observational group), and 2 were infected during the breast-feeding period (in the NRTI group). Treatment-limiting adverse events occurred in 2% of women in the NRTI group, 2% of women in the protease-inhibitor group, and 11% of women in the observational group.

CONCLUSIONS

All regimens of HAART from pregnancy through 6 months post partum resulted in high rates of virologic suppression, with an overall rate of mother-to-child transmission of 1.1%. (ClinicalTrials.gov number, NCT00270296.)

Age-related tuberculosis incidence and severity in children under 5 years of age in Cape Town, South Africa

SETTING

Limited data are available on the characteristics of tuberculosis (TB) disease in young children, especially in high-burden countries.

OBJECTIVE

To assess the incidence and severity of TB in children aged <5 years.

METHODS

TB records and chest radiographs of children born in Cape Town in 1999 and diagnosed with TB between 1999 and 2004 were reviewed retrospectively.

RESULTS

A total of 1607 cases were registered. The cumulative incidence of definite (bacteriologically confirmed) and probable (radiological evidence and > or =1 TB clinical feature) TB in children aged <5 years was 2.9% and was highest between the ages of 12 and 23 months. Of 1233 children with definite or probable TB, 506 (41%) had severe disease (dissemination, cavities or >1 lobe involved). The under 5 years incidence of disseminated TB was 0.33%. Of 239 (15%) cases that were bacteriologically confirmed, clinical features typical of TB disease were individually present in <60%. The most common combined symptoms were cough for >2 weeks and weight loss, occurring in 43/239 (18%).

CONCLUSION

TB incidence was high, and peaked in children aged 12-23 months. Many children experienced severe disease. A fifth of children with microbiologically confirmed disease presented with only one feature typically associated with TB.

Hunger, waiting time and transport costs: Time to confront challenges to ART adherence in Africa

Adherence levels in Africa have been found to be better than those in the US. However around one out of four ART users fail to achieve optimal adherence, risking drug resistance and negative treatment outcomes. A high demand for 2nd line treatments (currently ten times more expensive than 1st line ART) undermines the sustainability of African ART programs. There is an urgent need to identify context-specific constraints to adherence and implement interventions to address them. We used rapid appraisals (involving mainly qualitative methods) to find out why and when people do not adhere to ART in Uganda, Tanzania and Botswana. Multidisciplinary teams of researchers and local health professionals conducted the studies, involving a total of 54 semi-structured interviews with health workers, 73 semi-structured interviews with ARTusers and other key informants, 34 focus group discussions, and 218 exit interviews with ART users. All the facilities studied in Botswana, Tanzania and Uganda provide ARVs free of charge, but ART users report other related costs (e.g. transport expenditures, registration and user fees at the private health facilities, and lost wages due to long waiting times) as main obstacles to optimal adherence. Side effects and hunger in the initial treatment phase are an added concern. We further found that ART users find it hard to take their drugs when they are among people to whom they have not disclosed their HIV status, such as co-workers and friends. The research teams recommend that (i) health care workers inform patients better about adverse effects; (ii) ART programmes provide transport and food support to patients who are too poor to pay; (iii) recurrent costs to users be reduced by providing three-months, rather than the one-month refills once optimal adherence levels have been achieved; and (iv) pharmacists play an important role in this follow-up care.

Optimising growth conditions for the pectinolytic activity of Kluyveromyces wickerhamii by using response surface methodology

This present study was undertaken to find optimum conditions of pH, temperature and, period of incubation for the pectinolytic activity of Kluyveromyces wickerhamii isolated from rotting fruits and to assess the effect of these factors by use of response surface methodology (RSM). A central composite rotatable design was used as an experimental design for the analysis of the allocation of treatment combinations. A second order polynomial regression model was fitted and was found adequate, with an R(2) of 0.94469 (P<0.001). The effects of temperature and pH were the most significant factors in influencing enzyme production. Estimated optimum conditions were as follows: pH 5.0, temperature, 32 degrees C and an incubation period of 91 h. Pectinesterase (PE), pectin lyase (PL), and cellulase activities were not detected. Pectinase production was partially constitutive. Pectin was degraded by the isolated strain of K. wickerhamii in the current study, and the pectinolytic activity is referred to as polygalacturonase (PG) activity. Crude enzyme extract was thermostable at various temperatures and, stimulated by the presence of Ca(2+) ions but inhibited by other ions like Mg(2+), Zn(2+), Co(2+), Mn(2+) and Na(+).

Cantharidin poisoning due to "Blister beetle" ingestion

Cantharidin, the active ingredient of "Spanish Fly", is contained in a number of insects collectively called blister beetles and is a well known toxin and vesicant. We report on a case of ingestion of Mylabris dicincta ("Blister beetle") in Zimbabwe by a 4 year old girl. The ingested beetles were probably mistaken for the edible Eulepida mashona. She presented with many of the classic signs and symptoms of cantharidin poisoning including haematuria and abdominal pains. This was recognised only after consultation with the drug information centre. She was managed conservatively, recovered and was discharged after 9 days. A overview of the clinical effects of cantharidin toxicity and its treatment is presented.

A sero-epidemiological cross-sectional study of hepatitis B virus in Zimbabwe

OBJECTIVE

To estimate the prevalence of hepatitis B viral markers.

DESIGN

A sero-epidemiological community-based cross-sectional study.

SETTING

All nine provinces of Zimbabwe.

PARTICIPANTS

From April 1989 to December 1991 serum samples were collected from 1,461 males and 1,933 females in the age group 10-61 years, the majority in the younger age groups.

MAIN OUTCOME MEASURES

Sera were tested for hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), antibody to HBs-Ag (anti-HBs), antibody to hepatitis B core antigen (anti-HBc) and antibody to hepatitis B e antigen (anti-HBe). All sera were tested for HBsAg, anti-HBs and anti-HBc but for the detection of HBeAg and anti-HBe, only samples positive for HBsAg were examined.

MAIN RESULTS

The male-to-female ratio in rural and urban settings was 0.82 and 0.66 respectively. The median age for males and females in rural areas was 21 and 22 years and 28 and 26 years respectively in urban areas. The overall prevalence of HBsAg was 15.4% (males 16.8%, females 14.3%). The difference between sexes was consistent in all age groups and statistically significant (P < 0.05). The prevalences in urban and rural areas were almost identical (15.7% v. 15.3%). However, the prevalence was significantly higher among males in the age group 40-49 years in urban areas compared with rural areas (P < 0.0001). Using the case-referent approach, with HbsAg-positive patients as cases and HBsAg-negative ones as referents, the crude odds ratio for rural areas compared with urban areas was 0,97. However, standardisation for year of data collection and province resulted in a relative risk of 2.0, i.e. the risk of being HBsAg-positive in rural areas is twice as high as in urban areas. Similarly, the crude odds ratio for females compared with males was 0.83, and was reduced significantly to 0.7 when standardised for year of data collection and province. The prevalences of HBeAg, anti-HBe, anti-HBs and anti-HBc were 25%, 25%, 45% and 36% respectively. The prevalences of anti-HBs and anti-HBc increased continuously with age and were about 70% higher in the age group 50 years and above compared with those under 20 years. The prevalence of any of the HBV markers-HBsAg, or anti-HBc -was 66% in males and 61% in females.

CONCLUSIONS

The results indicate that hepatitis B is hyperendemic in both rural and urban areas of Zimbabwe.

A survey of synthetic HIV-1 peptides with natural and chimeric sequences for differential reactivity with Zimbabwean, Tanzanian and Swedish HIV-1-positive sera

OBJECTIVE

To determine whether the known sequence differences between African and non-African HIV-1 strains are reflected in the serological response.

DESIGN AND METHODS

We investigated the antibody reactivity of 34 Swedish, 30 Tanzanian and 42 Zimbabwean HIV-1-positive sera to 67 synthetic peptides with sequences from North American and African HIV-1 isolates, mostly derived from regions of gag and env known to be antigenic. Not all sera were tested against all peptides.

RESULTS

Differences in frequency of reactivity were noted with peptides covering the entire third variable domain (V3), which is a primary neutralization determinant, and the carboxyl terminus of gp120, in two regions of gp41, and the carboxyl terminus of p24. In env Tanzanian sera reacted preferentially with a V3 peptide from the strain JY1 (Zaire). Gradual substitutions in the central motif in V3 of ELI from GLGQ to GPGR, typical of many non-African strains, led to a gradual increase in reactivity of many Swedish sera, but did not affect Tanzanian and Zimbabwean sera, suggesting that the major epitopes recognized by these African sera are outside GPGR. V3 peptides from the MN and Z3 strains reacted with most sera, but missed 30% of those of Tanzanian origin. In the carboxyl terminus of gp120 both sets of African sera reacted preferentially with peptides from strains JY1 and MAL. Swedish sera reacted strongest with analogues from strains Z321 and HXB2. In gp41, Swedish sera showed a weak preference for reactivity with HXB2-derived peptides in the immunodominant region (amino acids 590-620), and further towards the carboxyl terminus (amino acids 620-665).

CONCLUSION

The differences in serological reactivity were as great between Zimbabwe and Tanzania as between the two African sets and the Swedish. The geographical differences in the pattern of reactivity with HIV peptides probably depend on both host and viral variation and may be developed into a seroepidemiological tool, useful for optimization of future HIV vaccines.

Effect of birth date on growth performance of calves of seasonally-bred range cattle

SUMMARY

This study was undertaken to investigate the relationship between date of birth and growth performance of calves born to seasonally-bred range beef cows. Late-born calves exhibited an apparent superiority in preweaning growth over that of their early-born counterparts. This was attributed to a positive residual effect of maternal environment arising from the fact that calves born late were those whose dams had a substantial proportion of the critical last trimester of the gestation period in a favourable season. This advantage soon disappeared and early-born calves gained more weight and at a faster rate between 90 days and weaning. A combination of the effect of weaning stress and unfavourable nutritional environment in the immediate postweaning period had a check on calf growth but late born calves suffered most. It was concluded that, in this environment, nutrition was most limiting to calf growth between weaning and 12 months of age and it was during this period that a clear advantage of early birth of calves appeared; A 1 day delay in BD was associated with a 9.1 kg (P < .01) decrease in net weight change in this period. However, due to compensatory growth, the corresponding figure for the 12 months to 18 months period was an increase of 11.6 kg (P < .01) in weight change. In terms of actual postweaning weights (not age-adjusted), early BD was superior to late BD at all ages except at 18 month. A 1 day delay in BD was associated with a .7 kg reduction (P < .01) in liveweight between 90 days and weaning, a 6.7 kg reduction (P < .01) in actual weaning weight, a 6.8 kg reduction (P < .01) in actual 12 months liveweight, and a non significant (P > .05) 0.7 kg reduction in actual 18 months liveweight. Under seasonal breeding and group management of calves, all animals from a calf crop are expected to go to market at the same time, thereby rendering age-adjustment of liveweights irrelevant. However, the sale of late calves could be delayed by a few months to take advantage of the rainy season and to exploit compensatory growth. The benefit of this practice should, however, be weighed against both the direct cost (of feeding, veterinary care, labour and so on) and the indirect cost - the competition factor -introduced on the next calf crop. ZUSAMMENFASSUNG: Beziehung zwischen Geburtsdatum und Wachstumsleistung von Kälbern saisongedeckter Fleischrinder Spätgeborene Kälber zeigten eine scheinbare Überlegenheit im Saugperiodenwachstum, was den positiven Restwirkungen maternaler Umwelt zugeschrieben wird, die auf günstige Umwelteinflüsse während des letzten, dann regenreichen Trimesters der Trächtigkeitsperiode zurückzuführen sind. Dieser Vorteil ist bald verschwunden, und frühgeborene Kälber hatten ein rascheres Wachstum zwischen 90 Tagen und dem Absetzen. Eine Kombination von Absetzstreß und ungünstiger Ernährungssituation unmittelbar nach dem Absetzen bremste das Jungtierwachstum, wobei spätgeborene Kälber den meisten Schaden zeigten. In der gegebenen Umwelt hat mangelnde Ernährung den stärksten begrenzenden Einfluß auf Wachstum zwischen Absetzen und Jährlingsalter, so daß sich in dieser Periode der Vorteil von frühen Geburten zeigte. Eine Verzögerung von 1 Tag bei der Geburtszeit führte zu 9,1 kg Verminderung des Nettogewichts-Zuwachses in dieser Periode. Aufgrund kompensatorischen Wachstums änderte sich das zwischen 12 und 18 Monaten auf plus 11,6 kg Zuwachs. In bezug auf Jungtiergewichte (nicht alterskorrigiert) waren Tiere mit frühem Geburtsdatum in allen Altersklassen, außer bei 18 Monaten, überlegen. Eine Verzögerung von 1 Tag im Geburtsdatum war verbunden mit 0,7 kg Reduktion im Körpergewichtszuwachs zwischen 90 Tagen und Absetzen, mit einer 6,7 kg Reduktion im Absatzgewicht und 6,8 kg im Jährlingsgewicht. Das 18 Monate Gewicht war insignifikant um 0,7 kg reduziert. Unter saisonaler Zucht und Management gehen alle Tiere zur selben Zeit auf den Markt, so daß Alterskorrekturen irrelevant sind. Allerdings könnte der Verkauf spätgeborener Kälber um einige Monate verzögert werden, um die Vorteile der Regenzeit und des damit verbundenen kompensatorischen Wachstums auszunutzen. Vorteile einer solchen Praxis aber sollten sowohl gegen die direkten (Futter, Veterinäre, Arbeit usw). wie auch gegen indirekte Kosten (Wettbewerb durch die nächsten Kälber) balanciert werden.

Seroprevalence of HIV infection amongst antenatal women in greater Harare, Zimbabwe

Prevalence of HIV infection appears to be rising in many African countries. HIV infection in the pregnant woman poses a dilemma for the mother as well as for her unborn child. There are no data on HIV prevalence in Zimbabwe. This prospective study designed to determine HIV prevalence, enrolled pregnant women booking for antenatal care at Harare hospital and two of its peripheral municipal clinic. Two Elisa and a confirmatory Western Blot test on 1008 blood samples provided an HIV sero-prevalence rate in the studied population of 18 pc. High groups included unskilled labourers who were unbooked, single, divorced or cohabiting and below 30 years of age. Regarding education and income, women with over 11 years of education or earning over $600 per month constituted a lower risk category. Implications of this high prevalence rate are discussed and the urgency to examine feto maternal transmission and the effect of pregnancy on HIV status is expressed. Further more, intensification of preventive information and education programmes is recommended.

[Filarial meningoencephalitis: discussion of a case]

Loiasis treatment by diethylcarbamazine (DEC) may be complicated by a meningoencephalitis that is often fatal. Following one case, four others have been reviewed in the literature and the therapeutic approach in resuscitation departments discussed. Until the discovery of other less-dangerous microfilaricidal or macrofilaricidal drugs, we raise the question of the opportunity to treat loiasis by DEC, while many authors consider it as a simple nuisance.