Pursaethosides A-E, triterpene saponins from Entada pursaetha

Five new triterpenoid saponins, pursaethosides A-E (1-5), were isolated from the n-BuOH extract of the seed kernels of Entada pursaetha along with the known phaseoloidin. The structures of 1-5 were elucidated mainly by spectroscopic data interpretation and chemical degradation. Pursaethosides C-E (3-5) possess as a common structural feature entagenic acid as aglycon, which is rare among triterpene saponins. Compounds 2-4 and phaesolidin were found to be not cytotoxic when tested against HCT 116 and HT-29 human colon cancer cells.

Serological changes in goats experimentally infected with Fasciola gigantica in Buea sub-division of S.W.P. Cameroon

Based on the recent increase in the rearing of West African Dwarf (WAD) goats in this environment, a study of biochemical parameters was carried out in healthy and infected goats to obtain baseline data for monitoring the health and productive indices in breeding programmes for the goats. The results revealed variations in some of the parameters studied. The serum minerals potassium, chlorine and bicarbonate did not show any significant differences (P>0.05) between the infected and control groups of goats, but there was a significant difference (P<0.0001) in sodium, calcium and urea levels. For serum lipids cholesterol and triglyceride, there were significant (P<0.0001) differences between the infected and control group. This goes same for serum proteins, albumin and total proteins. However, serum enzymes, serum glutamic oxaloacetic transaminase (SGOT) and gamma glutamyl transferase (GGT) were not significantly different (P>0.05) between the infected and control groups. There was a significant difference (P<0.0001) in alkaline phosphatase (ALP) and serum glutamic pyruvic transaminase (SGPT) between the infected and control groups.

Low risk of mother-to-child transmission of hepatitis C virus in Yaounde, Cameroon: the ANRS 1262 study

To assess mother-to-child transmission (MTCT) of hepatitis C virus (HCV) in Cameroon, 5,008 pregnant women were screened for HCV antibodies. Eighty-nine (1.8%) were HCV-antibody (HCV-Ab) positive. Among these, 7 (7.9%) were HBsAg positive, 6 (6.7%) HIV-positive, and one (1.1%) was co-infected by both hepatitis B virus (HBV) and HIV. Sixty-eight (76%) out of 89 HCV-Ab positive pregnant women were HCV-RNA positive. The HCV genotype determination indicated the predominance of genotype 4 (45.3%), followed by the genotypes 1 (28.1%) and 2 (26.6%). The mean HCV-RNA levels of 41 women at the time of delivery was 4.8 (range 0.06-34.7) x 10(6) RNA copies/mL. Finally, 35 women delivered 36 live children. None of those screened at 6 weeks and 6 months of age were HCV-RNA positive. The failure to detect HCV vertical transmission suggests that the mother-to-child transmission (MTCT) is not a major route of HCV transmission in Cameroon.

An evidence-based approach to benchmarking the fairness of health-sector reform in developing countries

The Benchmarks of Fairness instrument is an evidence-based policy tool developed in generic form in 2000 for evaluating the effects of health-system reforms on equity, efficiency and accountability. By integrating measures of these effects on the central goal of fairness, the approach fills a gap that has hampered reform efforts for more than two decades. Over the past three years, projects in developing countries on three continents have adapted the generic version of these benchmarks for use at both national and subnational levels. Interdisciplinary teams of managers, providers, academics and advocates agree on the relevant criteria for assessing components of fairness and, depending on which aspects of reform they wish to evaluate, select appropriate indicators that rely on accessible information; they also agree on scoring rules for evaluating the diverse changes in the indicators. In contrast to a comprehensive index that aggregates all measured changes into a single evaluation or rank, the pattern of changes revealed by the benchmarks is used to inform policy deliberation aboutwhich aspects of the reforms have been successfully implemented, and it also allows for improvements to be made in the reforms. This approach permits useful evidence about reform to be gathered in settings where existing information is underused and where there is a weak information infrastructure. Brief descriptions of early results from Cameroon, Ecuador, Guatemala, Thailand and Zambia demonstrate that the method can produce results that are useful for policy and reveal the variety of purposes to which the approach can be put. Collaboration across sites can yield a catalogue of indicators that will facilitate further work.

The effect of maternal, umbilical cord and placental malaria parasitaemia on the birthweight of newborns from South-western Cameroon

AIM

The impact of maternal, umbilical cord and placental malaria parasitaemia on the incidence of low birthweight was investigated in pregnant women reporting for delivery at the Mutengene Maternity Centre, Fako Division, South West Province, Cameroon.

METHODS

The malaria parasitaemia status of 770 umbilical cords, parturient women and placental impression smears were determined by light microscopy using blood samples collected between June 1999 and September 2001. The birthweights (BW) of the newborns were recorded soon after delivery.

RESULTS

The results show that malaria parasites were present in the blood samples of 57 out of 730 (7.8%), 233/711 (32.8%) and 248/735 (33.7%) cord, maternal and placental biopsies respectively. Low birthweight (LBW) was recorded in 72 (9.6%) newborns, and the incidence was higher in primiparae. Newborns of mothers who had malaria parasites in their peripheral blood (12.4%) had a higher incidence (p=0.014) of LBW when compared with malaria parasite-free mothers (6.8%). Similarly, neonates born from malaria-positive placentas (13.5%) had a significantly higher incidence of LBW (p=0.006) than those from parasite-negative placentas (6.8%). Furthermore, newborns of malaria parasite-positive mothers, umbilical cords, placentas and primiparae had lower mean birthweight than malaria-negative mothers, placentas, umbilical cords and multiparae.

CONCLUSION

We suggest that parity and maternal and placental malaria parasitaemia at delivery have an important negative impact on birthweight, especially in first pregnancies. This observation emphasizes the need for appropriate aggressive intervention strategies such as the use of insecticide-treated bed nets or intermittent preventive treatment to control malaria in pregnancy in the study area.

Linking management and livelihood in environmental conservation: case of the Korup National Park Cameroon

Biodiversity conservation has emerged within the past two decades as one of the most important global challenges confronting national planners, world bodies, professionals and academics. Governments faced with increasing biodiversity loss as a result of human activities have resorted to the creation of protected areas as a strategy to both slow down habitat loss and/or degradation and eventually mitigate species extension and reduction rates. However, the creation of a protected area can have strong implications on the livelihoods of people inhabiting the forest and depending on it, especially those caught within its borders. The involvement of such inhabitants in the management process of the protected area can be profitable. This paper discusses the case of the Korup National Park, Cameroon, considered in the late 1980s by some to be a flagship of conservation and development efforts, and later on in the late 1990s by others as a catastrophic failure as an example of integrated conservation and development. As a means of updating the program's management information base, an in-depth participatory and socio-ecological survey was conducted by some of the program's technical staff. This study aimed at appraising the extent to which the Park's human community of 4200 inhabitants continued to relate to its resources and depend on them for their livelihood. The aim was to evaluate the potential links between the communities' livelihood and the long-term management and survival of the Park as the important biodiversity conservation zone it had been found to be. Results indicate that the successful management of a Park like Korup may well depend on the involvement of the local communities; and that successful management through approaches that minimize the potential contributions and aspirations of the local people is difficult to achieve.

Studies on Plasmodium falciparum isotypic antibodies and numbers of IL-4 and IFN-gamma secreting cells in paired maternal cord blood from South West Cameroon

OBJECTIVES

In this study, the effect of maternal peripheral and placental Plasmodium falciparum parasitaemia on the level of antibody and cytokine immune responses in the neonate was investigated.

METHODS

Malaria parasites were detected by light microscopy. Levels of malaria-specific isotypic antibodies were measured in maternal and cord blood by indirect ELISA. The numbers of IFN-gamma and IL-4 cells produced by maternal/cord blood after in vitro stimulation were enumerated using the ELISPOT assay.

RESULTS

Malaria parasite rate of maternal, placental biopsy and cord blood was 32.8%, 33.7% and 7.8% respectively. Overall, ELISA seropositivity rates for P. falciparum-specific IgG, IgM, IgE and IgA in the maternal plasma samples were 71%, 85%, 29.3%, and 0% respectively, while those for the cord samples were 69%, 6.0%, 4.4% and 0% respectively. Mean IgM ELISA OD(405) values of neonates born from positive placentas, or whose mothers had peripheral malaria parasitaemia were higher than those who were parasite negative. The mean number of maternal cells producing IFN-gamma was higher (P=0.0001) than that of the paired cord samples. The mean number of IL-4 producing cells of neonates born of mothers who were positive (P<0.05) or from malaria-positive placentas (P<0.025) was higher than from those who were malaria negative. Neonates born of malaria-positive mothers or from parasitized placentas mounted predominantly Th2 type immune responses.

CONCLUSION

It appears from this study that neonates born from malaria-infected mothers or placentas may relatively be more susceptible to malaria attack during the first years of life.

Treatment failure in a typhoid patient infected with nalidixic acid resistant S. enterica serovar Typhi with reduced susceptibility to ciprofloxacin: a case report from Cameroon

Background

Fluoroquinolones or third generation cephalosporins are the drugs of choice for the treatment of typhoid fever. Treatment failure with fluoroquinolones has been reported in Asia and Europe. We report a case of ciprofloxacin treatment failure in typhoid fever in Cameroon.

Case presentation

A 29-year-old female patient with suspected typhoid fever from Kumba, Cameroon, yielded growth of Salmonella enterica serovar Typhi in blood culture. The isolate was resistant to nalidixic acid but sensitive to ciprofloxacin by disc diffusion test. However, the patient did not respond to treatment with ciprofloxacin, although the isolate was apparently susceptible to ciprofloxacin.

Conclusion

Treatment failure with ciprofloxacin in our case indicates the presence of nalidixic acid resistant S. enterica serovar Typhi (NARST) with reduced susceptibility to ciprofloxacin in Cameroon (Central Africa).

Gene flow between chromosomal forms of the malaria vector Anopheles funestus in Cameroon, Central Africa, and its relevance in malaria fighting

Knowledge of population structure in a major vector species is fundamental to an understanding of malaria epidemiology and becomes crucial in the context of genetic control strategies that are being developed. Despite its epidemiological importance, the major African malaria vector Anopheles funestus has received far less attention than members of the Anopheles gambiae complex. Previous chromosomal data have shown a high degree of structuring within populations from West Africa and have led to the characterization of two chromosomal forms, "Kiribina" and "Folonzo." In Central Africa, few data were available. We thus undertook assessment of genetic structure of An. funestus populations from Cameroon using chromosomal inversions and microsatellite markers. Microsatellite markers revealed no particular departure from panmixia within each local population and a genetic structure consistent with isolation by distance. However, cytogenetic studies demonstrated high levels of chromosomal heterogeneity, both within and between populations. Distribution of chromosomal inversions was not random and a cline of frequency was observed, according to ecotypic conditions. Strong deficiency of heterokaryotypes was found in certain localities in the transition area, indicating a subdivision of An. funestus in chromosomal forms. An. funestus microsatellite genetic markers located within the breakpoints of inversions are not differentiated in populations, whereas in An. gambiae inversions can affect gene flow at marker loci. These results are relevant to strategies for control of malaria by introduction of transgenes into populations of vectors.

Outcome versus service based payments in health care: lessons from African traditional healers

We compare the more common physician compensation method of fee-for-service to the less common payment-for-outcomes method. This paper combines an investigation of the theoretical properties of both of these payment regimes with a unique data set from rural Cameroon in which patients can choose between outcome and service based payments. We show that consideration of the role of patient effort in the production of health leads to important differences in the performance of these contracts. Theory and empirical evidence show that when illnesses require (or are responsive to) large amounts of both patient and practitioner effort, outcome based payment schemes are superior to effort based schemes. The traditional healer--a practitioner who offers health services on an outcome-contingent basis--is advanced as an important example of how patient effort can be better understood and tapped in health care.

The impact on condom use of the "100% Jeune" social marketing program in Cameroon

PURPOSE

To measure the reach of the "100% Jeune" social marketing campaign and to assess its impact on condom use and on the predictors of condom use. The campaign aims to improve condom use through intensive youth-oriented mass media and interpersonal communications and widespread distribution of subsidized condoms.

METHODS

We analyzed data from the 2000 and 2002 waves of a reproductive health survey of youth aged 15-24 years, with sample sizes of 2097 and 3536, respectively.

RESULTS

Exposure to campaign activities was high. During the course of the intervention, there were significant changes in perceived condom attributes and access, self-efficacy, and perceived social support. Consistent with these changes, the percentage of youth who used a condom in last sex with their regular partner increased from 32% to 45% for females (p < .05) and from 44% to 61% for males (p < .01). Additional analyses suggest that exposure to the "100% Jeune" campaign has contributed to these trends.

CONCLUSIONS

The multi-faceted mass media and interpersonal communication campaign was effective for reaching youth. During the first 18 months of the campaign, significant changes occurred in perceived social support and condom use self-efficacy. Significant increases in levels of condom use also were achieved. However, the program was more effective among males than females. This indicates a need for more and possibly different campaign activities to focus specifically on risk perception and self-efficacy among females. The results also show that repeated program exposure is needed to achieve behavior change. Hence, future programs can enhance their effectiveness by using a mix of mass media and interpersonal communications to repeatedly expose youth to key campaign messages.

Acute Plasmodium falciparum Malaria Following Splenectomy for Suspected Lymphoma in 2 Patients

Two black African immigrants, with no history of recent travel outside France, received a diagnosis of a malignant lymphoproliferative disorder and splenomegaly, and they subsequently underwent splenectomy. A few weeks after surgery, both patients experienced an acute episode of Plasmodium falciparum malaria, so the initial diagnosis was corrected retrospectively and changed to hyperreactive malarial splenomegaly. These cases illustrate the difficulty in distinguishing hyperreactive malarial splenomegaly from malignant lymphoproliferative disorders and therefore underline the role of the spleen in the immune system's defense against malaria.

Discovery of a new human T-cell lymphotropic virus (HTLV-3) in Central Africa

Human T-cell Leukemia virus type 1 (HTLV-1) and type 2 (HTLV-2) are pathogenic retroviruses that infect humans and cause severe hematological and neurological diseases. Both viruses have simian counterparts (STLV-1 and STLV-2). STLV-3 belongs to a third group of lymphotropic viruses which infect numerous African monkeys species. Among 240 Cameroonian plasma tested for the presence of HTLV-1 and/or HTLV-2 antibodies, 48 scored positive by immunofluorescence. Among those, 27 had indeterminate western-blot pattern. PCR amplification of pol and tax regions, using HTLV-1, -2 and STLV-3 highly conserved primers, demonstrated the presence of a new human retrovirus in one DNA sample. tax (180 bp) and pol (318 bp) phylogenetic analyses demonstrated the strong relationships between the novel human strain (Pyl43) and STLV-3 isolates from Cameroon. The virus, that we tentatively named HTLV-3, originated from a 62 years old Bakola Pygmy living in a remote settlement in the rain forest of Southern Cameroon. The plasma was reactive on MT2 cells but was negative on C19 cells. The HTLV 2.4 western-blot exhibited a strong reactivity to p19 and a faint one to MTA-1. On the INNO-LIA strip, it reacted faintly with the generic p19 (I/II), but strongly to the generic gp46 (I/II) and to the specific HTLV-2 gp46. The molecular relationships between Pyl43 and STLV-3 are thus not paralleled by the serological results, as most of the STLV-3 infected monkeys have an "HTLV-2 like" WB pattern. In the context of the multiple interspecies transmissions which occurred in the past, and led to the present-day distribution of the PTLV-1, it is thus very tempting to speculate that this newly discovered human retrovirus HTLV-3 might be widespread, at least in the African continent.

Addressing the concerns of rural communities about access to plants and knowledge in a sui generis legislation in Cameroon

This article assesses the traditional systems of accessing and using plant genetic resources as well as the benefit sharing and systems of sanctioning infringement in the context of biodiversity related activities in specific areas in the Northwest province of Cameroon. The article also addresses the type research and development activities using plant genetic resources and associated traditional knowledge in the context of Cameroon, the current laws regulating such activities and the extent to which these activities and laws affect and/or protect the customary biodiversity rights of rural communities. The article uses these assessments to suggest the context under which a sui generis legislation for the protection of the biodiversity rights of rural communities can be established in Cameroon.

Die Variante Raubitschekii von Trichophyton rubrum hat Deutschland erreicht

This is the second report on an isolation of the variety raubitschekii of Trichophyton (T.) rubrum in Germany. The patient was a young man born in Cameroon who presented with an extensive tinea corporis et manuum. The variety raubitschekii can be distinguished from similar looking dermatophytes by its brownish color, by the formation of abundant T. rubrum-like macroconidia, by the production of urease, by a negative hair perforation test, and by DNA analysis. In addition, further characteristics of this variety were determined. So far, the variety raubitschekii has been primarily found as a cause of tinea corporis in patients from Asia or Africa. In the future, it should be considered as a potential pathogen in Germany as well.

Enfuvirtide binding domain is highly conserved in non-B HIV type 1 strains from Cameroon, West Central Africa

Recently T-20 or enfuvirtide, the first drug of a new class of antiretrovirals targeting the entry stage of the virus life cycle, has been clinically approved. Enfuvirtide is a peptide derived from the HR2 region of the transmembrane glycoprotein from the HXB2 HIV-1 subtype B prototype strain that binds to the HR1 region. Drug resistance seems to occur in the HR1 region between amino acids 36 and 45. We examined to what extent this region is conserved in 184 non-B strains from Cameroon: 132 (71.7%) CRF02-AG, 14 (7.6%) subtype A, 11 (5.9%) F2, 9 (4.8%) subtype D, 8 (4.3%) subtype G, 4 (2.1%) CRF01-AE, 4 (2.1%) CRF11-cpx, and 2 (1.1%) CRF06-cpx. Among the 184 strains studied, no amino acid mutation was found in the highly conserved three amino acid motif at codons 36-38 (GIV) that are important determinants of viral susceptibility to enfuvirtide. Other common substitutions like Q40H and N42T were also absent. The N42S polymorphism was present in 148 (80.4%) strains. Analysis of the HR2 domain, from which the peptide is derived, indicated a much greater genetic variability as compared to HR1.

Evidence for macrofilaricidal activity of ivermectin against female Onchocerca volvulus: further analysis of a clinical trial in the Republic of Cameroon indicating two distinct killing mechanisms

During a 3-year trial of the effects of ivermectin (Mectizan) on adult worms and microfilariae of Onchocerca volvulus in the Republic of Cameroon, comparison was made between the percentages of calcified and uncalcified moribund (M) and dead (D) adult female worms dying following (a) the standard dose (150 microg/kg) given annually; (b) high doses (400, then 800 microg/kg) given annually; and (c and d) these same doses given at 3-monthly intervals. In the killing of adult female O. volvulus worms, the relative rôles of (a) natural causes; (b) a presumed, direct, anthelminthic, macrofilaricidal action of ivermectin; and (c) a potentially fatal pleomorphic ovarian neoplasm (PN), of which the incidence is increased by ivermectin treatment, are herein further investigated and discussed. It is concluded that ivermectin per se has a considerable direct macrofilaricidal action against female worms and that this lethal effect is supplemented by the drug's ability in some worms to increase the incidence, and the spread throughout the body of the worm, of the potentially fatal PN ovarian tumour. In moribund and dead ivermectin-treated female worms that were heavily invaded by PN, it is probable that the neoplasm was chiefly responsible for their death, but the additional direct anthelminthic action of the drug, which by itself has been responsible for the death of many other female worms, cannot be excluded as having played a supplementary lethal rôle. Similar problems as to the exact means by which adult female worms are killed may arise now that ivermectin is used in Africa for the mass treatment of lymphatic filariasis; or if and when the macrofilaricidal actions on O. volvulus of other drugs, which are closely related to ivermectin, come to be investigated.

Abundance, dispersion and parasitism of the stem borer Busseola fusca (Lepidoptera: Noctuidae) in maize in the humid forest zone of southern Cameroon

This study was conducted in the humid forest zone of Cameroon, in 2002 and 2003. The main objective was to investigate the effects of intercropping on infestation levels and parasitism of the noctuid maize stem borer Busseola fusca Fuller. Two trials were planted per year, one during the long and one during the short rainy season. Maize monocrops were compared with maize/legume or maize/cassava intercrops in two spatial arrangements: maize on alternate hills or in alternate rows. Spatial analyses showed that the stemborer egg batches were regularly dispersed in the maize monocrop and aggregated in the intercrops, as indicated by b, the index of dispersion of Taylor's power law. Depending on the crop association and planting pattern, intercrops reduced the percentage of plants with stem borer eggs by 47.4-58.4% and egg densities by 41.2-54.5% compared to monocropped maize. Consequently, larval densities were 44.4-61.5% lower in intercrops compared to monocrops. Intercropping maize with non-host plants did not affect larval parasitism. Up to two-fold higher levels of egg parasitism by scelionid Telenomus spp. were recorded in inter- compared to monocrops during the short rainy seasons of 2002 and 2003. No differences were found among the mixed cropping treatments and parasitism was lower during the long compared to the short rainy seasons. It was proposed that differences in levels of parasitism were due to density dependence effects rather than the effect of the presence of non-host plants in the system.

LEUCOCYTOZOON (APICOMPLEXA: LEUCOCYTOZOIDAE) FROM WEST AFRICAN BIRDS, WITH DESCRIPTIONS OF TWO SPECIES

Five species of Leucocytozoon were recovered from 35/828 birds of 95 species examined from 6 sites in West Africa between May 1995 and June 2001. Leucocytozoon pogoniuli n. sp. is described from the tinker barbets Pogoniulus subsulphureus and Pogoniulus atroflavus. Leucocytozoon trachyphoni n. sp. is described from the barbet Trachyphonus purpureus. No leucocytozoids have been reported previously in species of Pogoniulus. Leucocytozoon nectariniae was identified from the sunbird Nectarinia olivacea, and Leucocytozoon brimonti was recovered from 4 species of Pycnonotidae (bulbuls), all of which are new host records. We also report the first Leucocytozoon to be recovered from the phylogenetically isolated bird, Picathartes sp. (Picathartidae). This parasite is similar in appearance to Leucocytozoon sakharoffi, and probably represents a previously undescribed species. In view of the intraspecific variability and, frequently, relatively minor interspecific differences within Leucocytozoidae, we suggest that the development and application of molecular techniques would greatly advance understanding of speciation and relationships within this family.

Visual inspection with acetic acid and cytology as screening methods for cervical lesions in Cameroon

OBJECTIVES

To assess the accuracy of visual inspection with acetic acid (VIA) as a screening method for cervical lesions.

METHODS

VIA and cytological smears were carried out on the cervices of non-pregnant women aged 30-60 years with no previous history of cervical cancer. Cervices with aceto white lesions or positive Pap smears, and one in ten negative cervices (control), were biopsied.

RESULTS

5010 women were enrolled, 4813 (96.1%) were screened. 4767 (99.%) had adequate cytology smears. 574 (11.9%) had colposcopy. 1743 biopsies were obtained of which 528 were controls. The sensitivity of VIA was 70.4% versus 47.7% for Pap smear. VIA specificity was 77.6% versus 94.2% for Pap smear; PPV for VIA was 44.0% versus 67.2% for Pap smear; and NPV for VIA was 91.3% versus 87.8% for Pap smear.

CONCLUSIONS

VIA has acceptable test qualities and may in low resource settings be implemented as a large scale screening method.