Epidemiology In Africa Research Articles

RTS,S/AS01, a vaccine targeting pre-erythrocytic stages of Plasmodium falciparum.

RTS,S/AS01 is the most advanced vaccine to prevent malaria. It is safe and moderately effective. A large pivotal phase III trial in over 15 000 young children in sub-Saharan Africa completed in 2014 showed that the vaccine could protect around one-third of children (aged 5-17 months) and one-fourth of infants (aged 6-12 weeks) from uncomplicated falciparum malaria. The European Medicines Agency approved licensing and programmatic roll-out of the RTSS vaccine in malaria endemic countries in sub-Saharan Africa. WHO is planning further studies in a large Malaria Vaccine Implementation Programme, in more than 400 000 young African children. With the changing malaria epidemiology in Africa resulting in older children at risk, alternative modes of employment are under evaluation, for example the use of RTS,S/AS01 in older children as part of seasonal malaria prophylaxis. Another strategy is combining mass drug administrations with mass vaccine campaigns for all age groups in regional malaria elimination campaigns. A phase II trial is ongoing to evaluate the safety and immunogenicity of the RTSS in combination with antimalarial drugs in Thailand. Such novel approaches aim to extract the maximum benefit from the well-documented, short-lasting protective efficacy of RTS,S/AS01.

Building capacity in Clinical Epidemiology in Africa: experiences from Masters programmes

BackgroundTo describe and contrast programmatic offering of Clinical Epidemiology Masters programmes in Africa, to evaluate experiences of graduates and faculty, and assess if graduates are playing roles in research, practice and teaching of Clinical Epidemiology.MethodsWe searched and identified relevant programmes, reviewed programmatic documentation, interviewed convenors and surveyed graduates. Participants provided informed consent, interviews with faculty were recorded and transcribed for analysis purposes, and graduates participated in an online survey.ResultsFive structured Masters programmes requiring health science professionals to complete modules and research projects were assessed. Demand for programmes was high. Graduates enjoyed the variety of modules, preferred blended teaching, and regarded assessments as fair. Graduates felt that career paths were not obvious after graduating. Despite this, some have gone on to promote and teach evidence-based health care, and conduct and disseminate research. Areas of concern raised by faculty were quality assurance; research project initiation, implementation and supervisory capacity; staff availability; funding to support implementation and lack of experiential learning.ConclusionAlthough faced with challenges, these programmes build capacity of health professionals to practice in an evidence-informed way, and conduct rigorous research, which are central to advancing the practice of Clinical Epidemiology in Africa.

Infectious disease exposures and outbreaks at a South African neonatal unit with review of neonatal outbreak epidemiology in Africa

Hospitalized neonates are vulnerable to infection, with pathogen exposures occurring in utero, intrapartum, and postnatally. African neonatal units are at high risk of outbreaks owing to overcrowding, understaffing, and shared equipment. Neonatal outbreaks attended by the paediatric infectious diseases and infection prevention (IP) teams at Tygerberg Children's Hospital, Cape Town (May 1, 2008 to April 30, 2016) are described, pathogens, outbreak size, mortality, source, and outbreak control measures. Neonatal outbreaks reported from Africa (January 1, 1996 to January 1, 2016) were reviewed to contextualize the authors' experience within the published literature from the region. Thirteen outbreaks affecting 148 babies (11 deaths; 7% mortality) over an 8-year period were documented, with pathogens including rotavirus, influenza virus, measles virus, and multidrug-resistant bacteria (Serratia marcescens, Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci). Although the infection source was seldom identified, most outbreaks were associated with breaches in IP practices. Stringent transmission-based precautions, staff/parent education, and changes to clinical practices contained the outbreaks. From the African neonatal literature, 20 outbreaks affecting 524 babies (177 deaths; 34% mortality) were identified; 50% of outbreaks were caused by extended-spectrum β-lactamase-producing Klebsiella pneumoniae. Outbreaks in hospitalized African neonates are frequent but under-reported, with high mortality and a predominance of Gram-negative bacteria. Breaches in IP practice are commonly implicated, with the outbreak source confirmed in less than 50% of cases. Programmes to improve IP practice and address antimicrobial resistance in African neonatal units are urgently required.

Characteristics, management, and outcomes of patients with hepatocellular carcinoma in Africa: a multicountry observational study from the Africa Liver Cancer Consortium

Hepatocellular carcinoma is a leading cause of cancer-related death in Africa, but there is still no comprehensive description of the current status of its epidemiology in Africa. We therefore initiated an African hepatocellular carcinoma consortium aiming to describe the clinical presentation, management, and outcomes of patients with hepatocellular carcinoma in Africa. We did a multicentre, multicountry, retrospective observational cohort study, inviting investigators from the African Network for Gastrointestinal and Liver Diseases to participate in the consortium to develop hepatocellular carcinoma research databases and biospecimen repositories. Participating institutions were from Cameroon, Egypt, Ethiopia, Ghana, Ivory Coast, Nigeria, Sudan, Tanzania, and Uganda. Clinical information-demographic characteristics, cause of disease, liver-related blood tests, tumour characteristics, treatments, last follow-up date, and survival status-for patients diagnosed with hepatocellular carcinoma between Aug 1, 2006, and April 1, 2016, were extracted from medical records by participating investigators. Because patients from Egypt showed differences in characteristics compared with patients from the other countries, we divided patients into two groups for analysis; Egypt versus other African countries. We undertook a multifactorial analysis using the Cox proportional hazards model to identify factors affecting survival (assessed from the time of diagnosis to last known follow-up or death). We obtained information for 2566 patients at 21 tertiary referral centres (two in Egypt, nine in Nigeria, four in Ghana, and one each in the Ivory Coast, Cameroon, Sudan, Ethiopia, Tanzania, and Uganda). 1251 patients were from Egypt and 1315 were from the other African countries (491 from Ghana, 363 from Nigeria, 277 from Ivory Coast, 59 from Cameroon, 51 from Sudan, 33 from Ethiopia, 21 from Tanzania, and 20 from Uganda). The median age at which hepatocellular carcinoma was diagnosed significantly later in Egypt than the other African countries (58 years [IQR 53-63] vs 46 years [36-58]; p<0·0001). Hepatitis C virus was the leading cause of hepatocellular carcinoma in Egypt (1054 [84%] of 1251 patients), and hepatitis B virus was the leading cause in the other African countries (597 [55%] of 1082 patients). Substantially fewer patients received treatment specifically for hepatocellular carcinoma in the other African countries than in Egypt (43 [3%] of 1315 vs 956 [76%] of 1251; p<0·0001). Among patients with survival information (605 [48%] of 1251 in Egypt and 583 [44%] of 1315 in other African countries), median survival was shorter in the other African countries than in Egypt (2·5 months [95% CI 2·0-3·1] vs 10·9 months [9·6-12·0]; p<0·0001). Factors independently associated with poor survival were: being from an African countries other than Egypt (hazard ratio [HR] 1·59 [95% CI 1·13-2·20]; p=0·01), hepatic encephalopathy (2·81 [1·72-4·42]; p=0·0004), diameter of the largest tumour (1·07 per cm increase [1·04-1·11]; p<0·0001), log α-fetoprotein (1·10 per unit increase [1·02-1·20]; p=0·0188), Eastern Cooperative Oncology Group performance status 3-4 (2·92 [2·13-3·93]; p<0·0001) and no treatment (1·79 [1·44-2·22]; p<0·0001). Characteristics of hepatocellular carcinoma differ between Egypt and other African countries. The proportion of patients receiving specific treatment in other African countries was low and their outcomes were extremely poor. Urgent efforts are needed to develop health policy strategies to decrease the burden of hepatocellular carcinoma in Africa. None.

Real-Time RT-PCR Assays for Detection and Genotyping of West Nile Virus Lineages Circulating in Africa.

West Nile virus (WNV) is an emerging arbovirus, circulating worldwide between birds and mosquitoes, which impacts human and animal health. Since the mid-1990s, WNV outbreaks have emerged in Europe and America and represent currently the primary cause of encephalitis in the United States. WNV exhibits a great genetic diversity with at least eight different lineages circulating in the world, and four (1, 2, Koutango, and putative new) are present in Africa. These different WNV lineages are not readily differentiated by serology, and thus, rapid molecular tools are required for diagnostic. We developed here real-time RT-PCR assays for detection and genotyping of African WNV lineages. The specificity of the assays was tested using other flaviviruses circulating in Africa. The sensitivity was determined by testing serial 10-fold dilutions of viruses and RNA standards. The assays provided good specificity and sensitivity and the analytical detection limit was 10 copies/reaction. The RT-PCR assays allowed the detection and genotyping of all WNV isolates in culture medium, human serum, and vertebrate tissues, as well as in field and experimental mosquito samples. Comparing the ratios of genome copy number/infectious virion (plaque-forming units), our study finally revealed new insight on the replication of these different WNV lineages in mosquito cells. Our RT-PCR assays are the first ones allowing the genotyping of all WNV African variants, and this may have important applications in surveillance and epidemiology in Africa and also for monitoring of their emergence in Europe and other continents.

Sentinel surveillance for influenza among severe acute respiratory infection and acute febrile illness inpatients at three hospitals in Ghana.

BackgroundInfluenza epidemiology in Africa is generally not well understood. Using syndrome definitions to screen patients for laboratory confirmation of infection is an established means to effectively conduct influenza surveillance.MethodsTo compare influenza‐related epidemiologic data, from October 2010 through March 2013, we enrolled hospitalized severe acute respiratory infection (SARI; fever with respiratory symptoms) and acute febrile illness (AFI; fever without respiratory or other localizing symptoms) patients from three referral hospitals in Ghana. Demographic and epidemiologic data were obtained from enrolled patients after which nasopharyngeal and oropharyngeal swabs were collected, and processed by molecular methods for the presence of influenza viruses.ResultsOf 730 SARI patients, 59 (8%) were influenza positive; of 543 AFI patients, 34 (6%) were positive for influenza. Both SARI and AFI surveillance yielded influenza A(H3N2) (3% versus 1%), A(H1N1)pdm09 (2% versus 1%), and influenza B (3% versus 4%) in similar proportions. Data from both syndromes show year‐round influenza transmission but with increased caseloads associated with the rainy seasons.ConclusionsAs an appreciable percentage of influenza cases (37%) presented without defined respiratory symptoms, and thus met the AFI but not the SARI definition, it is important to consider broader screening criteria (i.e., AFI) to identify all laboratory‐confirmed influenza. The identified influenza transmission seasonality has important implications for the timing of related public health interventions.

Molecular Epidemiology of Human Rhinoviruses and Enteroviruses Highlights Their Diversity in Sub-Saharan Africa.

Human rhinoviruses (HRVs) and enteroviruses (HEVs) belong to the Enterovirus genus and are the most frequent cause of infection worldwide, but data on their molecular epidemiology in Africa are scarce. To understand HRV and HEV molecular epidemiology in this setting, we enrolled febrile pediatric patients participating in a large prospective cohort assessing the causes of fever in Tanzanian children. Naso/oropharyngeal swabs were systematically collected and tested by real-time RT-PCR for HRV and HEV. Viruses from positive samples were sequenced and phylogenetic analyses were then applied to highlight the HRV and HEV types as well as recombinant or divergent strains. Thirty-eight percent (378/1005) of the enrolled children harboured an HRV or HEV infection. Although some types were predominant, many distinct types were co-circulating, including a vaccinal poliovirus, HEV-A71 and HEV-D68. Three HRV-A recombinants were identified: HRV-A36/HRV-A67, HRV-A12/HRV-A67 and HRV-A96/HRV-A61. Four divergent HRV strains were also identified: one HRV-B strain and three HRV-C strains. This is the first prospective study focused on HRV and HEV molecular epidemiology in sub-Saharan Africa. This systematic and thorough large screening with careful clinical data management confirms the wide genomic diversity of these viruses, brings new insights about their evolution and provides data about associated symptoms.

Comparative Characterization of Vibrio cholerae O1 from Five Sub-Saharan African Countries Using Various Phenotypic and Genotypic Techniques.

We used standardized methodologies to characterize Vibrio cholerae O1 isolates from Guinea, Democratic Republic of the Congo (DRC), Togo, Côte d’Ivoire and Mozambique. We investigated 257 human isolates collected in 2010 to 2013. DRC isolates serotyped O1 Inaba, while isolates from other countries serotyped O1 Ogawa. All isolates were biotype El Tor and positive for cholera toxin. All isolates showed multidrug resistance but lacked ciprofloxacin resistance. Antimicrobial susceptibility profiles of isolates varied between countries. In particular, the susceptibility profile of isolates from Mozambique (East-Africa) included resistance to ceftriaxone and was distinctly different to the susceptibility profiles of isolates from countries located in West- and Central-Africa. Molecular subtyping of isolates using pulsed-field gel electrophoresis (PFGE) analysis showed a complex relationship among isolates. Some PFGE patterns were unique to particular countries and clustered by country; while other PFGE patterns were shared by isolates from multiple countries, indicating that the same genetic lineage is present in multiple countries. Our data add to a better understanding of cholera epidemiology in Africa.

HIV related pulmonary arterial hypertension: epidemiology in Africa, physiopathology, and role of antiretroviral treatment.

The development of HIV related pulmonary arterial hypertension (PAH) reduces the probability of survival by half as compared with HIV-infected individuals without HIV related PAH. HIV infected patients have a greater incidence of PAH compared to general population and have a 2500-fold increased risk of developing PAH. It is therefore important to have a recent overview of the problem in Africa, the most HIV affected part of the world (70 % of all HIV infection in the world). First, we discussed the epidemiology of HIV-related PAH in Africa. Second, the current understanding of the HIV-related PAH pathogenesis has been covered. Third, role of highly active antiretroviral therapy on HIV-related PAH has been revisited. There are few data concerning epidemiology of HIV related pulmonary hypertension in Africa leading to necessity to conduct further prospective large studies. The prevalence of PAH among HIV infected people in Africa varies from 5 to 13 %. The prevalence of HIV-related PAH in Africa is notably high compared to those in developed countries and in general population. The pathogenesis of PAH is clearly complex, and probably results from the interaction of multiple modulating genes with environmental factors. The physiopathology includes cytokines secretion increase which induces dysregulation of endothelial and vascular smooth muscle cell growth and imbalance of endogenous vasodilators and constrictors; HIV viral proteins which induces vascular oxidative stress, smooth myocyte proliferation and migration, and endothelial injury and genetic predisposition due to some major histocompatibility complex alleles, particularly HDL-DR6 and HLA-DR5. Histologically, HIV related PAH has the same characteristics with other types PAH. Antiretroviral therapy have a beneficial effect on the outcome of HIV related pulmonary hypertension, but it lacks evidence from large prospective studies.

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Pediatric HIV-HBV Coinfection in Lusaka, Zambia: Prevalence and Short-Term Treatment Outcomes.

Hepatitis B virus (HBV) is endemic in Africa, where it may occur as an HIV coinfection. Data remain limited on HIV-HBV epidemiology in Africa, particularly in children. Using programmatic data from pediatric HIV clinics in Lusaka, Zambia during 2011-2014, we analyzed the prevalence of chronic HBV coinfection (defined as a single positive hepatitis B surface antigen [HBsAg] test) and its impact on immune recovery and liver enzyme elevation (LEE) during the first year of antiretroviral therapy. Among 411 children and adolescents, 10.4% (95% confidence interval, 7.6-14.1) had HIV-HBV. Coinfected patients were more likely to have World Health Organization stage 3/4, LEE and CD4 <14% at care entry (all p < 0.05). During treatment, CD4 increases and LEE incidence were similar by HBsAg status. HBsAg positivity decreased (11.8% vs. 6.6%; p = 0.24) following HBV vaccine introduction. These findings support screening pediatric HIV patients in Africa for HBV coinfection. Dedicated cohorts are needed to assess long-term outcomes of coinfection.

Current practice of epidemiology in Africa: highlights of the 3rd conference of the African epidemiological association and 1st conference of the Cameroon society of epidemiology, Yaoundé, Cameroon, 2014.

As the study of disease occurrence and health indicators in human populations, Epidemiology is a dynamic field that evolves with time and geographical context. In order to update African health workers on current epidemiological practices and to draw awareness of early career epidemiologists on concepts and opportunities in the field, the 3rd African Epidemiology Association and the 1st Cameroon Society of Epidemiology Conference was organized in June 2-6, 2014 at the Yaoundé Mont Febe Hotel, in Cameroon. Under the theme«Practice of Epidemiology in Africa: Stakes, Challenges and Perspectives», the conference attracted close to five hundred guest and participants from all continents. The two main programs were the pre-conference course for capacity building of African Early Career epidemiologists, and the conference itself, providing a forum for scientific exchanges on recent epidemiological concepts, encouraging the use of epidemiological methods in studying large disease burden and neglected tropical diseases; and highlighting existing opportunities.

Suicidal behaviour across the African continent: a review of the literature.

BackgroundSuicide is a major cause of premature mortality worldwide, but data on its epidemiology in Africa, the world’s second most populous continent, are limited.MethodsWe systematically reviewed published literature on suicidal behaviour in African countries. We searched PubMed, Web of Knowledge, PsycINFO, African Index Medicus, Eastern Mediterranean Index Medicus and African Journals OnLine and carried out citation searches of key articles. We crudely estimated the incidence of suicide and suicide attempts in Africa based on country-specific data and compared these with published estimates. We also describe common features of suicide and suicide attempts across the studies, including information related to age, sex, methods used and risk factors.ResultsRegional or national suicide incidence data were available for less than one third (16/53) of African countries containing approximately 60% of Africa’s population; suicide attempt data were available for <20% of countries (7/53). Crude estimates suggest there are over 34,000 (inter-quartile range 13,141 to 63,757) suicides per year in Africa, with an overall incidence rate of 3.2 per 100,000 population. The recent Global Burden of Disease (GBD) estimate of 49,558 deaths is somewhat higher, but falls within the inter-quartile range of our estimate. Suicide rates in men are typically at least three times higher than in women. The most frequently used methods of suicide are hanging and pesticide poisoning. Reported risk factors are similar for suicide and suicide attempts and include interpersonal difficulties, mental and physical health problems, socioeconomic problems and drug and alcohol use/abuse. Qualitative studies are needed to identify additional culturally relevant risk factors and to understand how risk factors may be connected to suicidal behaviour in different socio-cultural contexts.ConclusionsOur estimate is somewhat lower than GBD, but still clearly indicates suicidal behaviour is an important public health problem in Africa. More regional studies, in both urban and rural areas, are needed to more accurately estimate the burden of suicidal behaviour across the continent. Qualitative studies are required in addition to quantitative studies.

A systematic review of the epidemiology of hepatitis E virus in Africa.

BackgroundHepatitis E Virus (HEV) infection is a newly recognized serious threat to global public health and Africa is suspected to be among the most severely affected regions in the world. Understanding HEV epidemiology in Africa will expedite the implementation of evidence-based control policies aimed at preventing the spread of HEV including policies for the use of available resources such as HEV vaccines.MethodsHere we present a comprehensive review of HEV epidemiology in Africa based on published data. We searched for articles on HEV epidemiology in Africa from online databases such as PubMed, Scopus, and ISI Web of Science and critically reviewed appropriate publications to extract consistent findings, identify knowledge gaps, and suggest future studies.ResultsTaking a particularly high toll in pregnant women and their fetuses, HEV has infected human populations in 28 of 56 African countries. Since 1979, 17 HEV outbreaks have been reported about once every other year from Africa causing a reported 35,300 cases with 650 deaths.ConclusionsIn Africa, HEV infection is not new, is widespread, and the number of reported outbreaks are likely a significant underestimate. The authors suggest that this is a continent-wide public health problem that deserves the attention of local, regional and international agencies to implement control policies that can save numerous lives, especially those of pregnant women and their fetuses.

Epidemiology of Coxiella burnetii infection in Africa: a OneHealth systematic review.

BackgroundQ fever is a common cause of febrile illness and community-acquired pneumonia in resource-limited settings. Coxiella burnetii, the causative pathogen, is transmitted among varied host species, but the epidemiology of the organism in Africa is poorly understood. We conducted a systematic review of C. burnetii epidemiology in Africa from a “One Health” perspective to synthesize the published data and identify knowledge gaps.Methods/Principal FindingsWe searched nine databases to identify articles relevant to four key aspects of C. burnetii epidemiology in human and animal populations in Africa: infection prevalence; disease incidence; transmission risk factors; and infection control efforts. We identified 929 unique articles, 100 of which remained after full-text review. Of these, 41 articles describing 51 studies qualified for data extraction. Animal seroprevalence studies revealed infection by C. burnetii (≤13%) among cattle except for studies in Western and Middle Africa (18–55%). Small ruminant seroprevalence ranged from 11–33%. Human seroprevalence was <8% with the exception of studies among children and in Egypt (10–32%). Close contact with camels and rural residence were associated with increased seropositivity among humans. C. burnetii infection has been associated with livestock abortion. In human cohort studies, Q fever accounted for 2–9% of febrile illness hospitalizations and 1–3% of infective endocarditis cases. We found no studies of disease incidence estimates or disease control efforts.Conclusions/Significance C. burnetii infection is detected in humans and in a wide range of animal species across Africa, but seroprevalence varies widely by species and location. Risk factors underlying this variability are poorly understood as is the role of C. burnetii in livestock abortion. Q fever consistently accounts for a notable proportion of undifferentiated human febrile illness and infective endocarditis in cohort studies, but incidence estimates are lacking. C. burnetii presents a real yet underappreciated threat to human and animal health throughout Africa.

Relapsing Fever Borreliae in Africa

The study of relapsing fever borreliae in Africa has long suffered from the use of non-specific laboratory tools for the direct detection of these spirochetes in clinical and vector specimens. Accordingly, Borrelia hispanica, Borrelia crocidurae, Borrelia duttonii, and Borrelia recurrentis have traditionally been distinguished on the basis of geography and vector and the unproven hypothesis that each species was exclusive to one vector. The recent sequencing of three relapsing fever Borrelia genomes in our laboratory prompted the development of more specific tools and a reappraisal of the epidemiology in Africa. Five additional potential species still need to be cultured from clinical and vector sources in East Africa to further assess their uniqueness. Here, we review the molecular evidence of relapsing fever borreliae in hosts and ectoparasites in Africa and explore the diversity, geographical distribution, and vector association of these pathogens for Africans and travelers to Africa.

MS incidence and prevalence in Africa, Asia, Australia and New Zealand: A systematic review

ObjectivesStudies of multiple sclerosis (MS) incidence and prevalence from Africa, Asia, Australia and New Zealand are relatively scarce. We systematically reviewed MS incidence and prevalence in these regions including a standardized evaluation of study quality. MethodsWe searched MEDLINE and EMBASE databases for studies of MS prevalence or incidence in Africa, Asia, Australia and New Zealand published in English or French between January 1, 1985 and January 31, 2011. Study quality was assessed using a standardized tool. All steps of the review were performed in duplicate. ResultsOf 3925 citations identified, 28 studies met inclusion criteria and 21 of these were from Asia. Quality scores ranged from 1/8 to 8/8; the lowest scores were observed in studies from Asia (median 4/8, IQR 3,6). Prevalence was lowest in South African Blacks (0.22/100,000) and highest amongst Australian-born individuals in Australia (125/100,000). Prevalence increased over time in many countries. MS prevalence increased with increasing latitude only in some regions, and prevalence varied significantly with ethnicity. Eight studies reported incidence, which ranged from 0.67/100,000/year in Taiwan to 3.67/100,00/year in Australia. ConclusionsThis comprehensive study provides an update of MS epidemiology in Africa, Asia, Australia, and New Zealand. Incidence and prevalence were lowest in Africa and Asia and highest in Australia, but many Asian studies were of poor quality. Use of consistent case ascertainment methods, standardized data collection tools, and similar outcomes would all improve study quality and comparability. The underlying basis of observed ethnic differences is an important area for future study.

Prevalence of nasal carriage and diversity of Staphylococcus aureus among inpatients and hospital staff at Korle Bu Teaching Hospital, Ghana.

There is a paucity of data on Staphylococcus aureus epidemiology in Africa. Prevalence of nasal carriage and genetic diversity of S. aureus were determined among hospital staff (HS) and inpatients (IP) at the largest hospital in Ghana. In total, 632 nasal swabs were obtained from 452 IP and 180 HS in the Child Health Department (CHD) and Surgical Department (SD). S. aureus carriage prevalences were 13.9% in IP and 23.3% in HS. The chance of being a carrier was higher in HS (P=0.005) and IP staying ≤7 days in hospital (P=0.007). Resistance to penicillin (93%), tetracycline (28%) and fusidic acid (12%) was more common than for other agents (<5%). A higher chance of multidrug-resistant S. aureus carriage was observed among IP compared with HS (P=0.01). High genetic diversity was shown by spa typing, with 55 spa types found among 105 isolates; the predominant spa types were t355 (10%) and t084 (10%). MRSA was detected in six IP with an overall carriage prevalence of ca. 1.3%, but not in HS. All three MRSA isolates from SD belonged to ST88-SCCmec IV, and two of them displayed the same spa type and antibiograms; three MRSA isolates from CHD belonged to distinct lineages (ST88-SCCmec IV, ST8-SCCmec V and ST72-SCCmec V). Altogether, these data indicate a high diversity of S. aureus, low levels of MRSA carriage, and a higher chance of nasal carriage of multidrug-resistant S. aureus among IP compared with HS in this hospital.

Using next generation sequencing to tackle non-typhoidal Salmonella infections

The publication of studies using next generation sequencing to analyse large numbers of bacterial isolates from global epidemics is transforming microbiology, epidemiology and public health. The emergence of multidrug resistant Salmonella Typhimurium ST313 is one example. While the epidemiology in Africa appears to be human-to-human spread and the association with invasive disease almost absolute, more needs to be done to exclude the possibility of animal reservoirs and to transfer the ability to track all Salmonella infections to the laboratories in the front line. In this mini-review we summarise what is currently known about non-typhoidal Salmonella in sub-Saharan Africa and discuss some of the issues which remain.

A meta-analysis of observational epidemiological studies of Newcastle disease in African agro-systems, 1980-2009.

Newcastle disease (ND) is one of the most important and widespread avian pests. In Africa, backyard poultry production systems are an important source of protein and cash for poor rural livelihoods. ND mortality in these production systems is important and seriously disrupts benefits derived from it. This study undertook an African continental approach of ND epidemiology in backyard poultry. After a systematic literature review of studies published from 1980 to 2009, a meta-analysis of spatio-temporal patterns of serological prevalence and outbreak occurrence was performed. Average ND serological prevalence was estimated at 0·67 [95% confidence interval (CI) 0·58-0·75] in regions characterized by humid ecosystems, high human and poultry densities and low altitudes; 0·36 (95% CI 0·30-0·41) in dry ecosystems at intermediate altitude where human and poultry densities are low and 0·27 (95% CI 0·19-0·38) in mountain ecosystems where human and poultry densities are intermediate. In terms of seasonality, ND outbreaks occur mostly during the dry seasons in Africa, when environmental conditions are likely to be harshest for backyard poultry. In addition, a phylogeographical analysis revealed the regionalization of ND virus strains, their potential to evolve towards a higher pathogenicity from the local viral pool and suggests a risk for vaccine strains to provide new wild strains. These results present for the first time a continent-wide approach to ND epidemiology in Africa. More emphasis is needed for ND management and control in rural African poultry production systems.