Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 64
Filtrar
1.
Vet Pathol ; 50(1): 200-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22446324

RESUMO

Genital Alphapapillomavirus (αPV) infections are one of the most common sexually transmitted human infections worldwide. Women infected with the highly oncogenic genital human papillomavirus (HPV) types 16 and 18 are at high risk for development of cervical cancer. Related oncogenic αPVs exist in rhesus and cynomolgus macaques. Here the authors identified 3 novel genital αPV types (PhPV1, PhPV2, PhPV3) by PCR in cervical samples from 6 of 15 (40%) wild-caught female Kenyan olive baboons (Papio hamadryas anubis). Eleven baboons had koilocytes in the cervix and vagina. Three baboons had dysplastic proliferative changes consistent with cervical squamous intraepithelial neoplasia (CIN). In 2 baboons with PCR-confirmed PhPV1, 1 had moderate (CIN2, n = 1) and 1 had low-grade (CIN1, n = 1) dysplasia. In 2 baboons with PCR-confirmed PhPV2, 1 had low-grade (CIN1, n = 1) dysplasia and the other had only koilocytes. Two baboons with PCR-confirmed PhPV3 had koilocytes only. PhPV1 and PhPV2 were closely related to oncogenic macaque and human αPVs. These findings suggest that αPV-infected baboons may be useful animal models for the pathogenesis, treatment, and prophylaxis of genital αPV neoplasia. Additionally, this discovery suggests that genital αPVs with oncogenic potential may infect a wider spectrum of non-human primate species than previously thought.


Assuntos
Alphapapillomavirus/isolamento & purificação , Doenças dos Macacos/virologia , Papio hamadryas , Displasia do Colo do Útero/veterinária , Neoplasias do Colo do Útero/veterinária , Alphapapillomavirus/classificação , Alphapapillomavirus/genética , Animais , Colo do Útero/química , Colo do Útero/patologia , DNA Viral/genética , Feminino , Humanos , Imuno-Histoquímica/veterinária , Antígeno Ki-67/análise , Doenças dos Macacos/patologia , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/veterinária , Infecções por Papillomavirus/virologia , Filogenia , Reação em Cadeia da Polimerase/veterinária , Análise de Sequência de DNA/veterinária , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Vagina/patologia
2.
Neuropathol Appl Neurobiol ; 38(5): 487-99, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22126319

RESUMO

BACKGROUND: Previous studies have extensively reported the deposition of amyloid ß (Aß) peptide with carboxyl- and amino-terminal heterogeneity in cortical and cerebrovascular deposits in Alzheimer's disease (AD) and in non-human primates except baboons. METHODS: We examined the immunocytochemical distribution of Aß peptides and Aß oligomers in brain tissue from three subspecies of 18- to 28-year-old baboons (Papio) and in other monkeys including the squirrel (Saimiri sciureus) and rhesus (Macaca mulatta) for comparison. RESULTS: A general preponderance of Aß(42) in parenchymal deposits and many vascular deposits in all cortical lobes was evident in the baboons. Aß oligomeric immunoreactivity was also apparent like to amyloid plaques. We found that the amino acid sequence of the Aß domain of the baboon amyloid precursor protein is similar to that of man. In contrast to Aß, immunoreactivity to hyperphosphorylated tau protein was largely intracellular and rare in these baboons. Brain tissues from squirrel and rhesus monkeys examined in parallel exhibited mostly vascular and parenchymal deposits containing Aß(42) peptides. Our results were comparable to AD, but showed that even in younger monkeys exhibiting few deposits, Aß(42) was evident in both parenchymal deposits and cerebral amyloid angiopathy. Perivascular amyloid deposits were frequent and often accompanied by microvascular abnormalities in the form of collapsed degenerated capillaries. CONCLUSIONS: Similar to other primates above and below in the phylogenetic order, our observations and evaluation of the literature implicate pathogenicity of Aß(42) peptide associated with microvascular degeneration in baboons. We suggest baboons are useful animals to investigate the dynamics of AD-related pathology.


Assuntos
Envelhecimento , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/análise , Encéfalo/patologia , Microvasos/patologia , Placa Amiloide/patologia , Doença de Alzheimer/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Macaca mulatta , Masculino , Microvasos/metabolismo , Papio , Placa Amiloide/metabolismo , Saimiri
3.
Hum Reprod ; 27(6): 1640-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22454459

RESUMO

BACKGROUND: Uterus transplantation (UTx) may provide the first available treatment for women affected by uterine infertility. The present study aimed to further develop a surgical technique for autologous UTx in a non-human primate species and to assess long-term function. METHODS: Female baboons (n= 16) underwent autologous transplantation of the uterus with the Fallopian tubes and ovaries, performed with a previously published surgical technique (n= 6, Group 1) or using a modified technique (n= 10; Group 2). The uterine arteries were dissected to the proximal end of the anterior branch (Group 1) or the entire (Group 2) internal iliac artery, and the ovarian veins were dissected to the crossing over the ureter (Group 1) or further cranially to include greater lengths and patches of the cava/renal vein (Group 2). Back-table preparation created common venous and arterial ends with arterial anastomosis either end-to-side to the left external iliac artery (Group 1) or end-to-end to the left internal iliac artery (Group 2). RESULTS: Overall short-time survival of the animals was 88% (66% in Group 1 and 100% in Group 2). Of all the operated animals, 75% (66% in Group 1 and 80% in Group 2) resumed ovarian cyclicity. Regular menstruation after UTx was demonstrated only in Group 2 (60%). Menstruating animals (n= 6) were each exposed to timed mating for ≥5 menstrual cycles, but pregnancy did not occur. Adhesions and tubal blockage were seen in post-mortem analysis. CONCLUSIONS: The modified UTx model of Group 2 is a safe procedure and shows resumed long-term uterine function in a majority of the animals, although pregnancy could not be demonstrated.


Assuntos
Papio , Útero/transplante , Animais , Artérias/cirurgia , Cruzamento , Tubas Uterinas/transplante , Feminino , Seguimentos , Artéria Ilíaca/cirurgia , Menstruação , Ovário/irrigação sanguínea , Ovário/transplante , Gravidez , Transplante Autólogo/métodos , Transplante Autólogo/veterinária , Resultado do Tratamento , Útero/irrigação sanguínea , Veias/cirurgia
4.
Vaccine ; 40(46): 6631-6639, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-36210251

RESUMO

Rotavirus vaccination has been shown to reduce rotavirus burden in many countries, but the long-term magnitude of vaccine impacts is unclear, particularly in low-income countries. We use a transmission model to estimate the long-term impact of rotavirus vaccination on deaths and disability adjusted life years (DALYs) from 2006 to 2034 for 112 low- and middle-income countries. We also explore the predicted effectiveness of a one- vs two- dose series and the relative contribution of direct vs indirect effects to overall impacts. To validate the model, we compare predicted percent reductions in severe rotavirus cases with the percent reduction in rotavirus positivity among gastroenteritis hospital admissions for 10 countries with pre- and post-vaccine introduction data. We estimate that vaccination would reduce deaths from rotavirus by 49.1 % (95 % UI: 46.6-54.3 %) by 2034 under realistic coverage scenarios, compared to a scenario without vaccination. Most of this benefit is due to direct benefit to vaccinated individuals (explaining 69-97 % of the overall impact), but indirect protection also appears to enhance impacts. We find that a one-dose schedule would only be about 57 % as effective as a two-dose schedule 12 years after vaccine introduction. Our model closely reproduced observed reductions in rotavirus positivity in the first few years after vaccine introduction in select countries. Rotavirus vaccination is likely to have a substantial impact on rotavirus gastroenteritis and its mortality burden. To sustain this benefit, the complete series of doses is needed.


Assuntos
Gastroenterite , Infecções por Rotavirus , Vacinas contra Rotavirus , Rotavirus , Humanos , Lactente , Infecções por Rotavirus/prevenção & controle , Gastroenterite/prevenção & controle , Vacinação , Análise Custo-Benefício
5.
Hum Reprod ; 25(8): 1980-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20519250

RESUMO

BACKGROUND: Techniques for uterus transplantation (UTx) have been developed in rodent/domestic animals towards future clinical introduction of UTx to treat uterine factor infertility. The aim of this study was to extend the UTx research into a non-human primate species by developing surgical techniques for uterus retrieval and transplantation in the baboon. METHODS: Female baboons (n = 15) underwent surgery, with the initial five animals used for studies of pelvic vascular anatomy. Retrieval surgery included isolation of the ovarian veins and the uterine arteries together with the anterior branches of the internal iliacs. The utero-tubal-ovarian specimen was removed, flushed and kept ex vivo for 2 h when the two arterial ends and two venous ends were anastomosed side-to-side to construct one arterial and one venous end. These were, at auto-transplantation, anastomosed end-to-side to the external iliacs and the animals (n = 10) were evaluated concerning cyclicity and later by laparoscopy/laparotomy. RESULTS: The total duration of organ retrieval, backtable preparation and transplantation was around 6 h with an overall ischaemic time of the specimen of about 3 h. One animal died due to cardiomyopathy. Five out of the nine surviving animals resumed cyclicity, as a sign of re-established ovarian function. Only two out of these five animals exhibited resumed menstruation, indicating re-established ovarian and uterine function. Laparoscopy confirmed normal-sized uteri in these two animals. CONCLUSIONS: This study demonstrates the feasibility of UTx by vascular anastomosis in a non-human primate species. The low success rate demonstrates the complexity involved in UTx surgery and the need for further methodological developments.


Assuntos
Fertilidade/fisiologia , Útero/transplante , Anastomose Cirúrgica , Animais , Tubas Uterinas/irrigação sanguínea , Tubas Uterinas/fisiologia , Tubas Uterinas/transplante , Feminino , Procedimentos Cirúrgicos em Ginecologia/métodos , Ovário/irrigação sanguínea , Ovário/fisiologia , Ovário/transplante , Papio , Transplante Autólogo , Resultado do Tratamento , Útero/irrigação sanguínea , Útero/fisiologia
6.
J Appl Microbiol ; 109(3): 818-28, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20337763

RESUMO

AIM: To determine the occurrence of eight human enteric viruses in surface water and sewage samples from different geographical areas in Kenya. METHODS AND RESULTS: Enteric viruses were recovered from the water and sewage sources by glass-wool adsorption elution and/or polyethylene glycol/NaCl precipitation and detected by singleplex real-time and conventional PCR and reverse transcriptase-PCR assays. One or more enteric viruses were detected in nearly all sewage and river water samples except the urban Mbagathi River. The VP7 (G types) and the VP4 (P types) of the rotaviruses (RV) were characterized by multiplex nested PCR methods. The G and P types could be determined in 95·5% of the RV strains, respectively. Mixed G types were detected with G12 and G1 predominating, and unusual G types, G5 and G10, were present. P[4] predominated in the urban Karen sewage samples, while P[8] predominated in the urban and rural streams. CONCLUSIONS: The high prevalence of RVs in surface water highlights the importance of assessing the water sources used for domestic purposes for viral contamination. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the benefit of environmental surveillance as an additional tool to determine the epidemiology of RVs and other enteric viruses circulating in a given community.


Assuntos
Rios/virologia , Rotavirus/isolamento & purificação , Esgotos/virologia , Vírus/isolamento & purificação , Adenovírus Humanos/genética , Adenovírus Humanos/isolamento & purificação , Cidades , Enterovirus/genética , Enterovirus/isolamento & purificação , Genótipo , Vírus da Hepatite A/genética , Vírus da Hepatite A/isolamento & purificação , Quênia , Mamastrovirus/genética , Mamastrovirus/isolamento & purificação , Norovirus/genética , Norovirus/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rotavirus/genética , Sapovirus/genética , Sapovirus/isolamento & purificação
7.
J Med Primatol ; 38(2): 145-50, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19367739

RESUMO

BACKGROUND: Baboon in vitro fertilization requires capacitated sperm inappropriate media. In this study, we compared the effect of baboon serum (Bas), human serum albumin (HSA) and bovine serum albumin (BSA) on baboon sperm capacitation. METHODS: Five males (n = 5) were electroejaculated and 43 oocytes retrieved from super-ovulated female baboons (n = 10). Each sperm sample was assessed for initial motility and concentration before and after swim-up. For swim-up, each sperm sample was incubated separately in Biggers-Whitten-Whittingham media containing either BaS, HSA, BSA or without protein supplementation (control). After swim-up, each sperm aliquot was incubated with two to three oocytes. The number of sperm bound to the zona was evaluated after overnight incubation. RESULTS: Sperm motility and zona binding was significantly higher after capacitation in media supplemented with BaS than in HSA or BSA or in media without protein supplementation (P < 0.05). CONCLUSION: Baboon serum is superior to HSA or BSA for baboon sperm capacitation and zona binding.


Assuntos
Fertilização in vitro , Papio/fisiologia , Soro/fisiologia , Capacitação Espermática , Animais , Bovinos , Meios de Cultura , Feminino , Humanos , Masculino , Especificidade da Espécie
8.
East Afr Med J ; 86(4): 166-72, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20085000

RESUMO

BACKGROUND: A baboon, a non-human primate, is phylogenetically close to human and has been used to study in detail aspects of reproductive physiology that cannot be studied in humans for ethical reasons. OBJECTIVE: To determine the histological changes in baboon vagina associated with cyclic variations during normal menstrual cycle. SETTING: The experiments were carried out at Institute of Primate Research (IPR), Karen, Nairobi, Kenya. SUBJECTS: Nine adult healthy female olive baboons were used in this study. These baboons were monitored over a period of one year and found to have regular menstrual cycles. The vaginal biopsies were taken at different menstrual stages, fixed in 10% formalin and processed to evaluate histological changes. RESULTS: Observation of the histological sections of the biopsies by light microscopy showed that there were histological changes associated with cyclic variations in female olive baboon. During the luteal phase, menstrual phase and pregnancy the squamous epithelium was very thin. The layer gradually thickens throughout the proliferative phase and was thickest during the ovulation period. CONCLUSION: The changes in squamous epithelium suggest that the baboon vagina undergoes histological changes throughout the menstrual cycle which may be associated with hormonal variations. The data from this study also suggest that olive baboon is a good model for investigating possible effects of hormonal contraceptives on vaginal epithelium and the mechanism of female heterosexual transmission of HIV.


Assuntos
Ciclo Menstrual/fisiologia , Papio/fisiologia , Prenhez/fisiologia , Vagina/anatomia & histologia , Animais , Epitélio/anatomia & histologia , Epitélio/fisiologia , Feminino , Papio/anatomia & histologia , Períneo/anatomia & histologia , Períneo/fisiologia , Gravidez , Vagina/fisiologia
9.
Vaccine ; 37(43): 6324-6328, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31530468

RESUMO

BACKGROUND: Globally, rotavirus is the leading cause of acute gastroenteritis (AGE) in children aged <5 years. Botswana introduced the monovalent rotavirus vaccine (Rotarix) in July 2012. To study the impact of this vaccine on rotavirus genotypes circulating in Botswana, a comparison of the genotypes pre-vaccination (2011-2012) and post-vaccination (2013-2018) periods was conducted. SUBJECTS AND METHODS: Residual samples from 284 children <5 years of age that tested positive for rotavirus by enzyme immunoassay were genotyped. One hundred and five samples were from the pre-vaccination period and 179 were from the post-vaccination period. Genotyping was performed using two multiplexed one-step reverse transcription polymerase chain reaction (RT-PCR) assays for the amplification and genotyping of rotavirus VP7 (G) and VP4 (P) genes. RESULTS: Prior to vaccine introduction, the predominant rotavirus circulating genotypes were G9P[8] (n = 63, 60%) and G1P[8] (n = 22, 21%). During the vaccine period, G2P[4] was the predominant genotype (n = 49, 28%), followed by G9P[8] (n = 40, 22%) and G1P[8] (n = 33, 18.5%). There was a significant decline in the prevalence of G9P[8] (p = 0.001) in the post-vaccination period. There was also a notable decline in G1P[8]. A spike in G2P[4] was observed in 2013, one year post-vaccine introduction. Rotavirus strain G3P[4] (n = 8) was only detected in the post-vaccine introduction period. In 2018 there was a marked increase in genotype G3P[8] (p = 0.0003). CONCLUSIONS: The distribution of circulating rotavirus genotypes in Botswana changed after vaccine implementation. Further studies are needed to examine whether these changes are related to vaccination or simply represent natural secular variation.


Assuntos
Variação Genética , Programas de Imunização , Vacinas contra Rotavirus/administração & dosagem , Rotavirus/classificação , Vacinação/estatística & dados numéricos , Antígenos Virais/genética , Botsuana , Pré-Escolar , Fezes/virologia , Feminino , Gastroenterite/prevenção & controle , Gastroenterite/virologia , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Filogenia , RNA Viral/genética , Rotavirus/imunologia , Infecções por Rotavirus/prevenção & controle , Vacinas Atenuadas/administração & dosagem
10.
Curr Med Chem ; 15(10): 1006-17, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18393858

RESUMO

Endometriosis, a chronic gynecologic disease frequently resulting in chronic pelvic pain, severe dysmenorrhoea, and subfertility, is defined as the presence of endometrial tissue at extrauterine locations, most commonly on the peritoneum and ovaries. Conclusive diagnosis requires laparoscopic surgery followed by histological confirmation. The treatment options -at present- are limited to hormonal therapies and/or surgical ablation of the lesions, and are characterized by high recurrence rates, significant side-effects and limited duration of administration. The pathogenesis of endometriosis is still unclear and numerous immunological and inflammatory factors have been suggested to be involved in the development of the disease, including interleukin (IL)-1, IL-2, IL-6, IL-8, IL-12, tumour necrosis factor -alpha (TNF-alpha), regulated on activation, normal T-Cell expressed and secreted (RANTES) and its receptor cognate chemokine receptor 1 (CCR1), peroxisome proliferator activated receptors (PPARs), matrix metalloproteinases (MMPs) and cyclooxygenase (COX). Another crucial mechanism in endometriosis is the vascularisation of the endometriotic lesions, with a key role for vascular endothelial growth factor (VEGF). Recently, protease activated receptors (PARs), mitogen-activated protein kinases (MAPKs) and tyrosine kinases have also been associated with the pathophysiology of endometriosis. The aim of this article is to discuss molecules that have recently been found to have connections with the pathogenesis of endometriosis, as potential targets to develop new methods for noninvasive diagnosis and for novel medical management of this disease. This review also critically addresses how these molecules can be tested in basic, preclinical and clinical research, the status of this research and the importance of potential side effects.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Endometriose/tratamento farmacológico , Feminino , Humanos
12.
East Afr Med J ; 85(9): 425-31, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19537414

RESUMO

OBJECTIVE: To demonstrate that micro-franchising system is an effective way of improving access to effective health care such as the introduction of first line antimalarias in populations living in underserved rural areas in Kenya. DESIGN: A descriptive study. SETTING: Child and family wellness (CFW) micro-franchised nurse run clinics in Kenya. RESULTS: In 2007, 39.3% of RDTs carried out were positive for malaria. All malaria positive (RDTs and microscopy) patients received artemether lumefantrine (AL) according to their weight in accordance with the Government approved treatment guidelines. During the same period a total of 3,248 community members were reached with malaria information, however, community expectations took longer to change as patients demanded AL even when the malaria diagnosis was negative. Initially, this led to the dispensing of other antimalarials to patients with malaria like symptoms even with a negative test. This demand decreased with more community education on the importance of the tests. Engaging the private sector though with challenges proved feasible and appropriate in accessing malaria treatment based on clinical diagnosis supported by RDTs to confirm the diagnosis instead of presumptive treatment based on fever. This led to a reduction of antimalarial prescriptions by more than 50%, implying better patient care, rational drug use as well as cost savings on malaria treatment. CONCLUSION: A micro-franchising system is an effective and sustainable way of improving access to effective health care by populations living in underserved rural areas of Africa. With appropriate supportive training and supervision, the system can adapt to changes in treatment guidelines and to new regimens.


Assuntos
Antimaláricos/uso terapêutico , Atenção à Saúde/organização & administração , Malária/tratamento farmacológico , Recursos Humanos de Enfermagem Hospitalar , Setor Privado , População Rural/estatística & dados numéricos , Instituições de Assistência Ambulatorial , Combinação Arteméter e Lumefantrina , Artemisininas/uso terapêutico , Combinação de Medicamentos , Etanolaminas , Fluorenos/uso terapêutico , Humanos , Quênia , Malária/epidemiologia , Malária/enfermagem , Área Carente de Assistência Médica , Adesão à Medicação/estatística & dados numéricos , Projetos Piloto
13.
Vaccine ; 36(47): 7165-7169, 2018 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-29793891

RESUMO

BACKGROUND: Monovalent rotavirus vaccine (RV1) was introduced in Lusaka in February 2012 and rolled out countrywide in November 2013 in the routine Expanded Programme on Immunisation and administered at 6 and 10 weeks with no catch up dose. Reported here is the monitoring of rotavirus acute gastroenteritis hospitalisations at the University Teaching Hospital, Lusaka, Zambia as part of efforts to document the impact of rotavirus vaccine. METHODS: Children <5 years hospitalised for acute gastroenteritis (AGE) from January 2009 to December 2016 were recruited into the rotavirus disease burden active surveillance and had their stools tested for rotavirus by enzyme immunoassay. We compared rotavirus-associated AGE hospitalisations of the pre-vaccine era (2009-2011) with the post-rotavirus vaccine introduction period (2013-2016). RESULTS: With the increase in RV1 coverage in Lusaka, rotavirus AGE declined significantly from 40% of diarrhoea hospitalisation in the pre-vaccine era to 29% of diarrhoea hospitalisation in the post-vaccine era (p < 0.001) in children <5 years. After a decreasing trend in rotavirus positivity from 2013 to 2015, positivity increased to 37% in 2016. However, the post-vaccine years (2012-2016) saw substantial decline in the number tested (median decline: 34% (range: 20-43%)) and the number of positive results (median decline: 52% (range: 30-65%). CONCLUSION: A sustained and significant decline in rotavirus AGE hospitalisations was observed in children <5 years since the introduction of RV1 in Lusaka, Zambia. Despite an increase in rotavirus positivity in 2016, the total number of children enrolled and the number of rotavirus positive children remained below baseline. The reason for the increase in rotavirus positivity in 2016 is unknown but could be due to an accumulation of susceptible children and the shifting of disease to children of older age groups. This finding underscores the need for continued monitoring of rotavirus vaccine impact.


Assuntos
Gastroenterite/epidemiologia , Hospitalização/estatística & dados numéricos , Programas de Imunização , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus/uso terapêutico , Doença Aguda/epidemiologia , Pré-Escolar , Diarreia/epidemiologia , Diarreia/prevenção & controle , Fezes/virologia , Gastroenterite/prevenção & controle , Humanos , Imunoensaio , Lactente , Rotavirus/imunologia , Infecções por Rotavirus/prevenção & controle , Cobertura Vacinal , Vacinas Atenuadas/uso terapêutico , Zâmbia/epidemiologia
14.
Vaccine ; 36(47): 7222-7230, 2018 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-29203181

RESUMO

BACKGROUND: The African Rotavirus Surveillance Network has been detecting and documenting rotavirus genotypes in the African sub-continent since 1998 in anticipation of the rollout of rotavirus vaccination in routine Expanded Programme on Immunisation. This paper reports distribution of the rotavirus strains circulating in 15 Eastern and Southern African (ESA) countries from 2010-2015 as part of active World Health Organization (WHO) rotavirus surveillance, and investigates possibility of emergence of non-vaccine or unusual strains in six selected countries post-vaccine introduction. MATERIAL AND METHODS: Stool samples were collected from children <5 years of age presenting with acute gastroenteritis at sentinel hospitals pre- and post-rotavirus vaccine introduction. Samples were tested for group A rotavirus using an enzyme immunoassay by the national and sentinel laboratories. At the WHO Rotavirus Regional Reference Laboratory in South Africa, molecular characterisation was determined by PAGE (n = 4186), G and P genotyping (n = 6447) and DNA sequencing for both G and P types (n = 400). RESULTS: The six-year surveillance period demonstrated that 23.8% of the strains were G1P[8], followed by G2P[4] (11.8%), G9P[8] (10.4%), G12P[8] (4.9%), G2P[6] (4.2%) and G3P[6] (3.7%) in 15 ESA countries. There was no difference in circulating strains pre- and post-rotavirus vaccine introduction with yearly fluctuation of strains observed over time. Atypical rotavirus G and P combinations (such as G1P[4], G2P[8], G9P[4] and G12P[4]) that might have arisen through inter-genogroup or inter-genotypes reassortment were detected at low frequency (2%). Close genetic relationship of African strains were reflected on the phylogenetic analysis, strains segregated together to form an African cluster in the same lineages/sub-lineage or monophyletic branch. CONCLUSION: There has been considerable concern about strain replacement post-vaccine introduction, it was not clear at this early stage whether observed cyclical changes of rotavirus strains were due to vaccine pressure or this was just part of natural annual fluctuations in the six ESA countries, long-term surveillance is required.


Assuntos
Variação Genética , Genótipo , Infecções por Rotavirus/epidemiologia , Vacinas contra Rotavirus/uso terapêutico , Rotavirus/genética , África Oriental/epidemiologia , Pré-Escolar , Monitoramento Epidemiológico , Fezes/virologia , Humanos , Programas de Imunização , Lactente , Filogenia , RNA Viral/genética , Rotavirus/isolamento & purificação , Infecções por Rotavirus/prevenção & controle , Análise de Sequência de DNA , África do Sul/epidemiologia , Vacinação
15.
Vaccine ; 36(47): 7198-7204, 2018 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-28958809

RESUMO

BACKGROUND: Rotavirus vaccine was introduced into the Extended Program on Immunization in Madagascar in May 2014. We analyzed trends in prevalence of all cause diarrhea and rotavirus hospitalization in children <5years of age before and after vaccine introduction and assessed trend of circulating rotavirus genotypes at Centre Hospitalier Universitaire Mère Enfant Tsaralalàna (CHU MET). METHODS: From January 2010 to December 2016, we reviewed the admission logbook to observe the rate of hospitalization caused by gastroenteritis among 19619 children <5years of age admitted at the hospital. In June 2013-December 2016, active rotavirus surveillance was also conducted at CHUMET with support from WHO. Rotavirus antigen was detected by EIA from stool specimen of children who are eligible for rotavirus gastroenteritis surveillance at sentinel site laboratory and rotavirus positive specimens were further genotyped at Regional Reference Laboratory by RT-PCR. RESULTS: Diarrhea hospitalizations decreased after rotavirus vaccine introduction. The median proportion of annual hospitalizations due to diarrhea was 26% (range: 31-22%) before vaccine introduction; the proportion was 25% the year of vaccine introduction, 17% in 2015 and 16% in 2016. Rotavirus positivity paralleled patterns observed in diarrhea. Before vaccine introduction, 56% of stool specimens tested positive for rotavirus; the percent positive was 13% in 2015, 12% in 2016. Diverse genotypes were detected in the pre-vaccine period; the most common were G3P[8] (n=53; 66%), G2P[4] (n=12; 15%), and G1P[8] (n=11; 14%). 6 distinct genotypes were found in 2015; the most common genotype was G2P[4] (n=10; 67%), the remaining, 5, G12[P8], G3[P8], G1G3[P4], G3G12[P4][P8] and G1G3[NT] had one positive specimen each. CONCLUSIONS: Following rotavirus vaccine introduction all-cause diarrhea and rotavirus-specific hospitalizations declined dramatically. The most common genotypes detected in the pre-vaccine period were G3P[8] and G2P[4] in 2015, the post vaccine period.


Assuntos
Diarreia/prevenção & controle , Gastroenterite/prevenção & controle , Hospitalização/estatística & dados numéricos , Programas de Imunização , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/uso terapêutico , Antígenos Virais/imunologia , Pré-Escolar , Diarreia/epidemiologia , Diarreia/virologia , Fezes/virologia , Gastroenterite/epidemiologia , Gastroenterite/virologia , Genótipo , Registros Hospitalares , Humanos , Lactente , Madagáscar/epidemiologia , Prevalência , Rotavirus/genética , Infecções por Rotavirus/epidemiologia , Vigilância de Evento Sentinela , Vacinação , Vacinas Atenuadas/uso terapêutico
16.
Vaccine ; 36(51): 7759-7764, 2018 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-29802002

RESUMO

BACKGROUND: The high burden of rotavirus acute gastroenteritis (AGE) is well documented among children under 5 years of age, with the majority of mortality occurring in developing countries. Nigeria ranked second worldwide in the number of rotavirus deaths in 2013. As Nigeria plans to introduce rotavirus vaccine soon, a pre-vaccine documentation of rotavirus disease burden is necessary to determine vaccine impact. METHODS: Routine rotavirus surveillance was conducted during 2011-2016 in 3 sentinel sites in Nigeria using the standard WHO protocol. Children under 5 years of age hospitalized for acute gastroenteritis were enrolled and demographic, clinical and outcome data were collected. A stool sample was subsequently obtained and tested for human rotavirus antigen using the Enzyme-linked immunosorbent assay (ELISA). RESULTS: 2694 children with acute gastroenteritis were enrolled during January 2011 to December 2016; of these, 1242 (46%) tested positive for rotavirus. Among the rotavirus positive cases, 66% and 94% were younger than 12 months and 24 months respectively. Marked peaks in rotavirus positivity were seen in January of each year. Vomiting, and use of oral and intravenous fluids occurred more often in rotavirus positive cases as compared to rotavirus negative cases. CONCLUSION: The high prevalence of rotavirus disease highlights the need for urgent introduction of rotavirus vaccine in Nigeria. Additionally, this study provides pre-vaccine introduction disease-burden data that will serve as a baseline for rotavirus vaccine impact-assessment once vaccine has been introduced in the national immunization program.


Assuntos
Diarreia/epidemiologia , Gastroenterite/epidemiologia , Hospitalização/estatística & dados numéricos , Infecções por Rotavirus/epidemiologia , Doença Aguda , Pré-Escolar , Diarreia/virologia , Ensaio de Imunoadsorção Enzimática , Fezes/virologia , Feminino , Gastroenterite/virologia , Humanos , Lactente , Masculino , Nigéria/epidemiologia , Prevalência , Fatores de Risco , Vacinas contra Rotavirus , Vigilância de Evento Sentinela
17.
East Afr Med J ; 83(2): 106-12, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16708883

RESUMO

OBJECTIVE: To review recent research findings on the specific expression of endogenous retroviral sequences (ERVS) in reproductive tissues and their possible physiological roles. ERVS have been implicated in several biological events such as induction of resistance to exogenous retrovirus invasion, involvement in placental trophoblast formation, sperm maturation and differentiation; and stimulation of local immunosuppression to protect the foetus from immunological attack. DATA SOURCES: Critical review of relevant articles and abstracts cited in international and local journals, literature searches on Medline and Medchem up to 2005. DATA SYNTHESIS: Retroviruses have been implicated in the induction of tumour and immunological disorders. Over the years, endogenous retroviruses (ERVs) and retroviral elements have been detected in the genome of many vertebrate species, including primates. The evidence for the presence of retroviruses in the primate tissues such as the placenta, ovary, breast, testis and epididymis has been documented using electron microscopic studies. Retrovirus-like particles were found budding from the basal membrane of syncytiotrophoblasts, as well as in tumour cell lines in embryonic carcinoma or teratocarcinomas. Apart from their pathological effects, recent evidence suggests that these ERVs may play useful roles in normal physiological events. RESULTS: Recent studies indicate the expression of endogenous retroviruses in the testis, epididymis, placenta and breast. However, limited data exist on the detection of ERVs in the ovary. Overall, the precise functions for ERVs in these tissues are not well understood. In the testis and epididymis, speculative functions may include among others spermatogenesis and/or sperm maturation (differentiation) whereas in placenta they are possibly associated with trophoblast fusion and locally induced immunosuppression to protect the foetus from immunological attack. Experiments in our laboratory have indicated restricted expression of retroviral antigens including baboon endogenous retroviral proteins (BERV), ERV-3, HIV-1 gp41 and HERV-K env in the baboon ovary. CONCLUSION: ERVs are specifically expressed in different mammalian reproductive tissues and may have unique physiological roles.


Assuntos
Antígenos/análise , Ovário/imunologia , Primatas , Infecções por Retroviridae/genética , Retroviridae/genética , Animais , Feminino , Humanos , Imuno-Histoquímica , Placenta/imunologia , Retroviridae/imunologia , Infecções por Retroviridae/imunologia , Trofoblastos/imunologia
18.
East Afr Med J ; 83(7): 360-5, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17089495

RESUMO

BACKGROUND: Rotavirus is the most common cause of severe infantile diarrhoea disease in infants and young children below five years worldwide. Rotavirus is associated with high cases of morbidity and mortality and it is estimated that up to 650,000 deaths in young children occur annually in the less developed countries and approximately 150,000-200,000 deaths occur in Africa alone. OBJECTIVE: To characterise the circulating rotavirus strains in Maua, Meru North district, Kenya. DESIGN: A prospective study to investigate and characterise rotavirus serotypes/genotypes and electropherotypes in infants and children with severe diarrhoea hospitalised and/or attending the outpatient department of Maua Methodist Hospital during the period April 2004 to September 2005. SETTING: Maua Methodist Hospital, Meru North, Kenya. SUBJECTS: Faecal samples were collected from 135 infants and children with acute diarrhoea and were screened first for the presence of human Group A rotavirus antigen using commercially available enzyme linked immunosorbent assay kit (ELISA). The positive samples were evaluated by sodium dodecyl polycrylamide gel electrophoresis (SDS-PAGE) to determine the viral RNA electropherotype profile. Rotavirus strains were also genotyped using reverse transcriptase polymerase chain reaction (RT-PCR) of the VP7 gene. RESULTS: Assay of these samples with commercial ELISA showed that 17.8% (24/135) were positive for group A rotavirus antigen. Twenty of these ELISA positive samples were also analysed by SDS-PAGE of which 75% (15/20) gave detectable electropherotype pattern with the long electropherotype being predominant 80.0% (12/15) followed by the short RNA profile 20.0% (2/ 15). Seventeen of the ELISA positive samples were genotyped for VP7 and the results showed that G9 was the most predominant genotype comprising 47.1% (8/17) followed by G8 29.4% (5/17), GI 17.4% (3/17) and the mixed genotype was G8/G9 5.9% (1/17). Most patients with rotavirus infection were of the age of 3 - 60 months, with 79% being less than 18 months old. CONCLUSION: The overall prevalence of rotavirus infection in young children with diarrhoea hospitalised and/or attending the out-patient department of Maua Methodist Hospital was 17.8% with the predominant serotype being G9. These results show that rotavirus plays an important role in severe viral diarrhoea in young children in Maua Meru North district, Kenya. Furthermore, this high G9 rotavirus prevalence in Kenya may require vaccine trials to be held in Kenya so as to determine the efficacy of new rotavirus vaccine candidates that do not include the G9 serotype.


Assuntos
Diarreia/virologia , Infecções por Rotavirus/complicações , Rotavirus/classificação , Rotavirus/genética , Pré-Escolar , Genótipo , Humanos , Lactente , Recém-Nascido , Quênia/epidemiologia , Prevalência , Infecções por Rotavirus/diagnóstico , Infecções por Rotavirus/epidemiologia , Sorotipagem
19.
East Afr Med J ; 82(7): 371-5, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16167712

RESUMO

BACKGROUND: Adenoviruses are known to cause several human diseases including acute febrile respiratory syndromes, epidemic conjunctivitis and gastroenteritis. These diseases associated with adenovirus infection affect adults and are usually more severe in infants and children. Forty-seven human adenoviruses serotypes have so far been identified adenovirus. The diversity of these viruses has delayed progress on vaccine development due to difficulties in identifying appropriate vaccine targets. To date, limited studies have been done to determine the prevalence of adenovirus infection in non-human primates with the goal of developing a non-human primate model that can be used to study the mechanisms of infection. OBJECTIVE: To determine the prevalence of enteric adenovirus infection in Kenyan non-human primates. DESIGN: A prospective study to investigate the prevalence of enteric andenovirus infection in captive non-human primates maintained in a colony. SETTING: Faecal samples were collected from monkeys trapped from different geographical areas of Kenya and also from the ones maintained in a colony at the Institute of Primate Research (IPR), Kenya. SUBJECTS: Ninety four faecal samples were collected from three species of non-human primates consisting of various ages and sex. Samples were collected from monkeys trapped from different geographical areas of Kenya and also from the ones maintained in a colony at the Institute of Primate Research (IPR), Kenya. All the faecal samples were screened for presence of adenoviruses using a commercial antigen-capture enzyme immunoassay (EIA) kit, this is an enzyme-linked immunosorbent assay (ELISA) kit designed for diagnosis of human enteric adenoviruses in stool samples. RESULTS: The highest prevalence of adenoviruses, detected by EIA kit, was in olive baboons (Papio anubis, 52.9%), followed by vervet monkeys (Cercopithecus aethiops, 48.9%) and the yellow baboons (Papio cynocephalus, 18.8%). Sub-grouping within each species (based on age and sex) indicated no significant differences (p > 0.05) in adenovirus infection signifying equal susceptibility. The prevalence of adenoviruses in vervet monkeys that were also Simian Immunodeficiency virus (SIV) seropositive was determined and shown to be 63.2%. CONCLUSION: The results of this study indicate that adenovirus infection is prevalent among non-human primates in Kenya. These findings suggest that cross species transmission in Kenyan non-human primates may be a common occurrence and there is a possibility of zoonotic transmission of adenoviruses. Furthermore, our results highlight the potential of using these non-human primates as models for testing safety and efficacy of candidate adenovirus vaccines prior to clinical trials in humans.


Assuntos
Infecções por Adenoviridae/veterinária , Adenoviridae/isolamento & purificação , Chlorocebus aethiops/virologia , Doenças dos Macacos/epidemiologia , Doenças dos Macacos/virologia , Papio/virologia , Infecções por Adenoviridae/virologia , Distribuição por Idade , Animais , Chlorocebus aethiops/sangue , Suscetibilidade a Doenças , Feminino , Quênia/epidemiologia , Masculino , Papio/sangue , Prevalência , Estudos Prospectivos , Estudos Soroepidemiológicos , Testes Sorológicos , Distribuição por Sexo
20.
J Reprod Immunol ; 26(2): 75-95, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7523669

RESUMO

Particles with the characteristic shape of enveloped retroviral particles and maximal specific reverse transcriptase (RTase) activity at buoyant density of 1.15-1.17 g/ml have been isolated from human first-trimester chorionic villous tissue. Murine monoclonal antibodies (mAbs) to these isolated particles were generated. One IgM mAb (RV3-27) showed granular staining of cytoplasmic structures within syncytiotrophoblast by immunohistochemistry. Immunoelectron microscopic studies have demonstrated focal localisation to small submembranous regions of syncytiotrophoblast, as well as reaction with detergent-disrupted isolated placental retroviral-like particles. The RV3-27 mAb did not stain other human tissues in this focal manner, although increased generalised cytoplasmic staining was not uncommon; also, this mAb did not react strongly with the surface or cytoplasm of a variety of human cell lines (including choriocarcinoma cells). Immunoblotting and HPLC analyses have indicated the reactive placental antigen to be a 17-25 kDa protein. It is suggested that the RV3-27 mAb may be reactive with a syncytiotrophoblast antigen encoded by an endogenous retroviral sequence.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Vilosidades Coriônicas/virologia , Retroviridae/isolamento & purificação , Trofoblastos/imunologia , Animais , Coriocarcinoma/patologia , Coriocarcinoma/virologia , Membranas Extraembrionárias/imunologia , Feminino , Humanos , Imunoglobulina M/imunologia , Técnicas Imunológicas , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , Neoplasias/patologia , Especificidade de Órgãos , DNA Polimerase Dirigida por RNA/análise , Retroviridae/enzimologia , Retroviridae/imunologia , Retroviridae/ultraestrutura , Trofoblastos/virologia , Células Tumorais Cultivadas , Neoplasias Uterinas/patologia , Neoplasias Uterinas/virologia , Proteínas Virais/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA