A phylogeographic study of the circumtropical glasseye Heteropriacanthus cruentatus was conducted... more A phylogeographic study of the circumtropical glasseye Heteropriacanthus cruentatus was conducted. Molecular analyses indicate two mitochondrial cytochrome c oxidase subunit I (coI) lineages that are 10·4% divergent: one in the western Atlantic (Caribbean) and another that was detected across the Indo-Pacific. A fixed single nucleotide polymorphism (SNP) was detected at a nuclear locus (S7 ribosomal protein) and is consistent with this finding. There is evidence of recent dispersal from the Atlantic to the Indian Ocean with individuals of mixed lineages detected in South Africa and the Mozambique Channel. Using coalescent analyses of the mitochondrial dataset, time of divergence between lineages was estimated to be c. 15·3 million years. The deep divergence between these two lineages indicates distinct evolutionary units, however, due to the lack of morphological differences and evidence of hybridization between lineages, taxonomic revision is not suggested at this time.
ABSTRACT The slinger, Chrysoblephus puniceus, a seabream of the family Sparidae, is an important ... more ABSTRACT The slinger, Chrysoblephus puniceus, a seabream of the family Sparidae, is an important commercial linefish species in South Africa and Mozambique. Despites its fisheries importance little is known about the population structure of the species and it is currently managed separately by both countries. The genetic connectivity between localities throughout C. puniceus’ core distributional range was investigated using the mitochondrial control region and ten microsatellite loci. The majority of pairwise population comparisons were not significant (P > 0.05) and none remained significant after Bonferroni corrections. While one AMOVA grouping using mtDNA found weak levels of structure separating Gaza and Inhaca in southern Mozambique from other localities, all other groupings for both data sets found no significant among group variation. Similarly, SAMOVA, Mantel tests (P > 0.05) and STRUCTURE analysis using—ln likelihoods were unable to identify genetic structuring through C. puniceus’ distribution. MIGRATE-n analysis showed asymmetrical migration between sites with net migration probably influenced by the prevailing oceanographic feature. The results of the study failed to reject panmixia suggesting a single C. puniceus stock. The transboundary nature of a single stock coupled with the uneven temporal and spatial distribution of historical fishing effort likely made the species resilient to exploitation. This raises concerns as current management strategies are not aligned and the species is now harvested throughout most of its core distribution excluding the Ponta do Ouro, Maputaland, St Lucia marine protected areas.KeywordsLinefishGeneticsStock structureTransboundaryManagement
The first record of the Cape hagfish Myxine capensis in Mozambican waters is reported based on a ... more The first record of the Cape hagfish Myxine capensis in Mozambican waters is reported based on a single 356 mm total length specimen taken by bottom trawl off Maputo, 25° 52·9' S; 34° 42·7' E - 25° 54·1' S; 34° 41·0' E, at depths from 557 to 564 m. This account also represents the northernmost record of a hagfish in the western Indian Ocean. Morphometric and meristic data are provided and compared with those of 27 specimens (including the holotype) caught off Namibia and South Africa.
JAIDS Journal of Acquired Immune Deficiency Syndromes, 2008
To estimate oral disease prevalence among Zimbabwean women by HIV serostatus and CD4 cell count a... more To estimate oral disease prevalence among Zimbabwean women by HIV serostatus and CD4 cell count and to assess accuracy of oral disease diagnoses made by nurses as compared with an oral surgeon. Standardized oral mucosa examinations were performed by trained nurse-examiners and by an oral surgeon among women recruited in Harare, Zimbabwe. A total of 461 women (320 HIV-infected, 141 uninfected) were seen by nurses and an oral surgeon within a 2-week period. Oral candidiasis (OC) was the most common lesion diagnosed in nearly one quarter of HIV-infected women, whereas hairy leukoplakia and Kaposi sarcoma were found in <3%. The prevalence of OC diagnosed by nurses or the surgeon was significantly higher among women with a CD4 count <200 cells/mm than in women with a CD4 count from 200 to 499 cells/mm3 or a CD4 count >499 cells/mm3. The sensitivity of nurse examinations compared with examinations by the oral surgeon among HIV-infected women for the diagnosis of OC was 73%, the specificity was 95%, and the kappa-statistic was 0.71. OC was the most common lesion in HIV-infected women and was strongly associated with a low CD4 cell count. Interexaminer agreement was good for the diagnosis of OC among HIV-infected women. This study suggests that OC may play a role, in combination with other clinical indicators as a marker of disease progression in resource-poor settings.
A cross-sectional study was conducted on women attending family planning clinics in Harare, Zimba... more A cross-sectional study was conducted on women attending family planning clinics in Harare, Zimbabwe to determine the prevalence of cervical neoplasia among HIV-1 positive women relative to an HIV-1 negative control group. Five hundred and fifty four women were recruited and the prevalence of HIV-1 was 36.8%. Cervical cytology was abnormal in 25.6% of HIV-infected women compared to only 6.7% HIV-1 seronegative women. Cervical neoplasia was significantly associated with HIV infection (chi(2)=42.4, P<0.001). Cellular changes typical of HPV infection (koilocytocis) were recorded in 6.4% of HIV infected women compared with 1.7% of HIV-1-uninfected women (chi(2)=8.43, P=0.004). HIV-1-positive women had twice the risk of having abnormal cervical cells than HIV-negative women (relative risk 2.47, odds ratio 10.14, P<0.001). Therefore the introduction of national cervical screening programme in HIV-1 endemic countries like Zimbabwe where the highest burden of pre-malignant lesions is among HIV-1-infected women needs careful planning because these women have other competing health needs including high rates of opportunistic infections.
A phylogeographic study of the circumtropical glasseye Heteropriacanthus cruentatus was conducted... more A phylogeographic study of the circumtropical glasseye Heteropriacanthus cruentatus was conducted. Molecular analyses indicate two mitochondrial cytochrome c oxidase subunit I (coI) lineages that are 10·4% divergent: one in the western Atlantic (Caribbean) and another that was detected across the Indo-Pacific. A fixed single nucleotide polymorphism (SNP) was detected at a nuclear locus (S7 ribosomal protein) and is consistent with this finding. There is evidence of recent dispersal from the Atlantic to the Indian Ocean with individuals of mixed lineages detected in South Africa and the Mozambique Channel. Using coalescent analyses of the mitochondrial dataset, time of divergence between lineages was estimated to be c. 15·3 million years. The deep divergence between these two lineages indicates distinct evolutionary units, however, due to the lack of morphological differences and evidence of hybridization between lineages, taxonomic revision is not suggested at this time.
ABSTRACT The slinger, Chrysoblephus puniceus, a seabream of the family Sparidae, is an important ... more ABSTRACT The slinger, Chrysoblephus puniceus, a seabream of the family Sparidae, is an important commercial linefish species in South Africa and Mozambique. Despites its fisheries importance little is known about the population structure of the species and it is currently managed separately by both countries. The genetic connectivity between localities throughout C. puniceus’ core distributional range was investigated using the mitochondrial control region and ten microsatellite loci. The majority of pairwise population comparisons were not significant (P > 0.05) and none remained significant after Bonferroni corrections. While one AMOVA grouping using mtDNA found weak levels of structure separating Gaza and Inhaca in southern Mozambique from other localities, all other groupings for both data sets found no significant among group variation. Similarly, SAMOVA, Mantel tests (P > 0.05) and STRUCTURE analysis using—ln likelihoods were unable to identify genetic structuring through C. puniceus’ distribution. MIGRATE-n analysis showed asymmetrical migration between sites with net migration probably influenced by the prevailing oceanographic feature. The results of the study failed to reject panmixia suggesting a single C. puniceus stock. The transboundary nature of a single stock coupled with the uneven temporal and spatial distribution of historical fishing effort likely made the species resilient to exploitation. This raises concerns as current management strategies are not aligned and the species is now harvested throughout most of its core distribution excluding the Ponta do Ouro, Maputaland, St Lucia marine protected areas.KeywordsLinefishGeneticsStock structureTransboundaryManagement
The first record of the Cape hagfish Myxine capensis in Mozambican waters is reported based on a ... more The first record of the Cape hagfish Myxine capensis in Mozambican waters is reported based on a single 356 mm total length specimen taken by bottom trawl off Maputo, 25° 52·9' S; 34° 42·7' E - 25° 54·1' S; 34° 41·0' E, at depths from 557 to 564 m. This account also represents the northernmost record of a hagfish in the western Indian Ocean. Morphometric and meristic data are provided and compared with those of 27 specimens (including the holotype) caught off Namibia and South Africa.
JAIDS Journal of Acquired Immune Deficiency Syndromes, 2008
To estimate oral disease prevalence among Zimbabwean women by HIV serostatus and CD4 cell count a... more To estimate oral disease prevalence among Zimbabwean women by HIV serostatus and CD4 cell count and to assess accuracy of oral disease diagnoses made by nurses as compared with an oral surgeon. Standardized oral mucosa examinations were performed by trained nurse-examiners and by an oral surgeon among women recruited in Harare, Zimbabwe. A total of 461 women (320 HIV-infected, 141 uninfected) were seen by nurses and an oral surgeon within a 2-week period. Oral candidiasis (OC) was the most common lesion diagnosed in nearly one quarter of HIV-infected women, whereas hairy leukoplakia and Kaposi sarcoma were found in <3%. The prevalence of OC diagnosed by nurses or the surgeon was significantly higher among women with a CD4 count <200 cells/mm than in women with a CD4 count from 200 to 499 cells/mm3 or a CD4 count >499 cells/mm3. The sensitivity of nurse examinations compared with examinations by the oral surgeon among HIV-infected women for the diagnosis of OC was 73%, the specificity was 95%, and the kappa-statistic was 0.71. OC was the most common lesion in HIV-infected women and was strongly associated with a low CD4 cell count. Interexaminer agreement was good for the diagnosis of OC among HIV-infected women. This study suggests that OC may play a role, in combination with other clinical indicators as a marker of disease progression in resource-poor settings.
A cross-sectional study was conducted on women attending family planning clinics in Harare, Zimba... more A cross-sectional study was conducted on women attending family planning clinics in Harare, Zimbabwe to determine the prevalence of cervical neoplasia among HIV-1 positive women relative to an HIV-1 negative control group. Five hundred and fifty four women were recruited and the prevalence of HIV-1 was 36.8%. Cervical cytology was abnormal in 25.6% of HIV-infected women compared to only 6.7% HIV-1 seronegative women. Cervical neoplasia was significantly associated with HIV infection (chi(2)=42.4, P<0.001). Cellular changes typical of HPV infection (koilocytocis) were recorded in 6.4% of HIV infected women compared with 1.7% of HIV-1-uninfected women (chi(2)=8.43, P=0.004). HIV-1-positive women had twice the risk of having abnormal cervical cells than HIV-negative women (relative risk 2.47, odds ratio 10.14, P<0.001). Therefore the introduction of national cervical screening programme in HIV-1 endemic countries like Zimbabwe where the highest burden of pre-malignant lesions is among HIV-1-infected women needs careful planning because these women have other competing health needs including high rates of opportunistic infections.
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Papers by M. Mwale