Outbreaks In Nigeria Research Articles

Dengue virus and malaria concurrent infection among febrile subjects within Ilorin metropolis, Nigeria.

Dengue is a mosquito-borne disease of public health importance. It is caused by four serotypes of Dengue virus (i.e, DENV-1, -2, -3, and -4). As a result of practices that are conducive for mosquito breading, its vector is widespread in Nigeria and this could result to possible DENV outbreaks in Nigeria and beyond. This study aimed to assess the recency of DENV infection as well as occurrence of DENV and Malaria co-infections within Ilorin, Nigeria. Blood samples were obtained from 176 febrile subjects and analyzed using Enzyme Linked Immunosorbent Assay (ELISA) for the presence of DENV antibodies. Malaria infection was detected using a rapid diagnostic test kit for malaria parasites. Malaria and DENV (IgM positive) co-infected samples were further subjected to RT-qPCR analysis. A seroprevalence of 46.0% was recorded for anti-DENV IgM antibodies and 2.84% for concurrent Dengue and malaria infections. Out of 95 IgM negative samples, 48 were found to be positive for DENV IgG antibodies. Eleven (6.25%) samples were confirmed DENV positive following RT-qPCR. The CT values of the amplicons were between 19.0 and 20.0. DENV serotype 2 dominated the study, while serotype 3 and 4 were equally distributed. Based on the high seroprevalence of DENV obtained in this study, there is a high possibility of experiencing Dengue virus outbreak in Ilorin, Nigeria, not neglecting the fast geographical spread of the vector. Therefore, surveillance and intensive vector control program should be instituted.

Pathogenic Microbes from Unprotected Landfills Pose Health Hazards with Potentials of Disease Outbreaks in Nigeria

Pathogenic Microbes from Unprotected Landfills Pose Health Hazards with Potentials of Disease Outbreaks in Nigeria

Avian Influenza Risk Surveillance in North America with Online Media.

The use of Internet-based sources of information for health surveillance applications has increased in recent years, as a greater share of social and media activity happens through online channels. The potential surveillance value in online sources of information about emergent health events include early warning, situational awareness, risk perception and evaluation of health messaging among others. The challenge in harnessing these sources of data is the vast number of potential sources to monitor and developing the tools to translate dynamic unstructured content into actionable information. In this paper we investigated the use of one social media outlet, Twitter, for surveillance of avian influenza risk in North America. We collected AI-related messages over a five-month period and compared these to official surveillance records of AI outbreaks. A fully automated data extraction and analysis pipeline was developed to acquire, structure, and analyze social media messages in an online context. Two methods of outbreak detection; a static threshold and a cumulative-sum dynamic threshold; based on a time series model of normal activity were evaluated for their ability to discern important time periods of AI-related messaging and media activity. Our findings show that peaks in activity were related to real-world events, with outbreaks in Nigeria, France and the USA receiving the most attention while those in China were less evident in the social media data. Topic models found themes related to specific AI events for the dynamic threshold method, while many for the static method were ambiguous. Further analyses of these data might focus on quantifying the bias in coverage and relation between outbreak characteristics and detectability in social media data. Finally, while the analyses here focused on broad themes and trends, there is likely additional value in developing methods for identifying low-frequency messages, operationalizing this methodology into a comprehensive system for visualizing patterns extracted from the Internet, and integrating these data with other sources of information such as wildlife, environment, and agricultural data.

Characterization of Foot-and-Mouth Disease Viruses Collected in Nigeria Between 2007 and 2014: Evidence for Epidemiological Links Between West and East Africa.

This study describes the molecular characterization of 47 foot-and-mouth disease (FMD) viruses recovered from field outbreaks in Nigeria between 2007 and 2014. Antigen ELISA of viral isolates was used to identify FMD virus serotypes O, A and SAT 2. Phylogenetic analyses of VP1 nucleotide sequences provide evidence for the presence of multiple sublineages of serotype SAT 2, and O/EAST AFRICA 3 (EA-3) and O/WEST AFRICA topotypes in the country. In contrast, for serotype A, a single monophyletic cluster of viruses has persisted within Nigeria (2009-2013). These results demonstrate the close genetic relatedness of viruses in Nigeria to those from other African countries, including the first formal characterization of serotype O/EA-3 viruses in Nigeria. The introductions and persistence of certain viral lineages in Nigeria may reflect transmission patterns via nomadic pastoralism and animal trade. Continuous monitoring of field outbreaks is necessary to dissect the complexity of FMD epidemiology in sub-Saharan Africa.

Whole-Genome Characterization of Epidemic Neisseria meningitidis Serogroup C and Resurgence of Serogroup W, Niger, 2015.

In 2015, Niger reported the largest epidemic of Neisseria meningitidis serogroup C (NmC) meningitis in sub-Saharan Africa. The NmC epidemic coincided with serogroup W (NmW) cases during the epidemic season, resulting in a total of 9,367 meningococcal cases through June 2015. To clarify the phylogenetic association, genetic evolution, and antibiotic determinants of the meningococcal strains in Niger, we sequenced the genomes of 102 isolates from this epidemic, comprising 81 NmC and 21 NmW isolates. The genomes of 82 isolates were completed, and all 102 were included in the analysis. All NmC isolates had sequence type 10217, which caused the outbreaks in Nigeria during 2013–2014 and for which a clonal complex has not yet been defined. The NmC isolates from Niger were substantially different from other NmC isolates collected globally. All NmW isolates belonged to clonal complex 11 and were closely related to the isolates causing recent outbreaks in Africa.

Genetic Characterization of Circulating African Swine Fever Viruses in Nigeria (2007-2015).

Sequencing and analysis of three discrete genome regions of African swine fever viruses (ASFV) from archival samples collected in 2007-2011 and active and passive surveillance between 2012 and 2015 in Nigeria were carried out. Analysis was conducted by genotyping of three single-copy African swine fever (ASF) genes. The E183L and B646L genes that encode structural proteins p54 and p72, respectively, were utilized to delineate genotypes before intragenotypic resolution by characterization of the tetrameric amino acid repeat region within the hypervariable central variable region of the B602L gene. The results showed no variation in the p72 and p54 gene regions sequenced. Phylogeny of p72 sequences revealed that all the Nigerian isolates belonged to genotype I, while that of the p54 recovered the Ia genotype. Analysis of B602L gene revealed the differences in the number of tetrameric repeats. Four new variants (Tet-15, Tet-17a, Tet-17b and Tet-48) were recovered, while a fifth variant (Tet-20) was the most widely distributed in the country displacing Tet-36 reported previously in 2003-2006. The viruses responsible for ASF outbreaks in Nigeria are from very closely related but mutated variants of the virus that have been circulating since 1997. A practical implication of the genetic variability of the Nigerian viral isolates in this study is the need for continuous sampling and analysis of circulating viruses, which will provide epidemiological information on the evolution of ASFV in the field versus new incursion for informed strategic control of the disease in the country.

Entomological assessment of yellow fever-epidemic risk indices in Benue State, Nigeria, 2010–2011

Yellow fever (YF) is a vector-borne disease affecting humans and non-human primates in tropical areas. In the past, there have been pockets of YF outbreaks in Nigeria that resulted in preventable deaths. Surveillance efforts towards avoiding another outbreak have been put in place with the aim of early detection and control. However, risk indices relating to the density of immature YF-mosquito vectors are given little consideration even though it is the first step in curbing a possible outbreak. Immature collections from 1538 houses in Ega, Oju, Otukpoicho and Otukpo in Benue State were carried out in 2010 and 2011. Risk indices such as house index (HI), container index (CI) and Breteau index (BI) were estimated. Molecular detection of YF was carried out on randomly selected Aedes larvae and pupae. Overall, 431,381 mosquitoes were collected in and around house premises. Thirteen species were identified: Ae. aegypti (Linneaus), Ae. africanus (Theobald), Ae. albopictus (Skuse), Ae. cumminsii (Theobald), Ae. luteocephalus (Newstead), Ae. simpsoni s.l. (Theobald), Ae. vittatus (Bigot), Anopheles gambiae Giles, An. nili (Theobald), Cx. nebulosus Theobald, Culex quinquefasciatus Say, Lutzia tigripes (Grandpre and Charmoy) and Toxorhynchites brevipalpis Theobald. The HI, CI and BI for Ae. aegypti were high in all the study locations, but low for Ae. lueteocephalus except in Ega. With 50 immature Aedes mosquitoes screened across locations, only Ae. aegypti from Ega were positive for YF. This study places Ega on a high alert of an impending YF outbreak. Thus, urgent steps to clear this area of potential mosquito sites are highly recommended.

Outbreaks of highly pathogenic avian influenza H5N1 clade 2.3.2.1c in hunting falcons and kept wild birds in Dubai implicate intercontinental virus spread.

Highly pathogenic avian influenza viruses (HPAIVs) of subtype H5N1 have continued to perpetuate with divergent genetic variants in poultry within Asia since 2003. Further dissemination of Asian-derived H5 HPAIVs to Europe, Africa and, most recently, to the North American continent has occurred. We report an outbreak of HPAIV H5N1 among falcons kept for hunting and other wild bird species bred as falcon prey in Dubai, United Arab Emirates, during the autumn of 2014. The causative agent was identified as avian influenza virus subtype H5N1, clade 2.3.2.1c, by genetic and phylogenetic analyses. High mortality in infected birds was in accordance with systemic pathomorphological and histological alterations in affected falcons. Genetic analysis showed the HPAIV H5N1 of clade 2.3.2.1c is a reassortant in which the PB2 segment was derived from an Asian-origin H9N2 virus lineage. The Dubai H5N1 viruses were closely related to contemporary H5N1 HPAIVs from Nigeria, Burkina-Faso, Romania and Bulgaria. Median-joining network analysis of 2.3.2.1c viruses revealed that the Dubai outbreak was an episode of a westward spread of these viruses on a larger scale from unidentified Asian sources. The incursion into Dubai, possibly via infected captive hunting falcons returning from hunting trips to central Asian countries, preceded outbreaks in Nigeria and other West African countries. The alarmingly enhanced geographical mobility of clade 2.3.2.1.c and clade 2.3.4.4 viruses may represent another wave of transcontinental dissemination of Asian-origin HPAIV H5 viruses, such as the outbreak at Qinghai Lake caused by clade 2.2 (‘Qinghai’ lineage) in 2005.

Comparing Ebola virus disease and antimicrobial resistance outbreaks in Nigeria- a cross sectional survey of awareness level of health care workers and members of community

Ebola virus disease (EVD) outbreak in Nigeria has raised the level of awareness of both health care workers (HCWs) and members of community (MCs) on the threat posed by infectious diseases and need for improvement on infection control practices, but awareness of dangers of increasing antimicrobial resistance (AMR) remained low.

Backyard Poultry Mortality Associated with Highly Pathogenic Avian Influenza (HPAI) H5N1 outbreaks in Nigeria

Backyard poultry farms infected with highly pathogenic avian influenza (HPAI) H5N1 virus in Nigeria between 2006 and 2008 were investigated for morbidity, mortality and Pathology. Affected farms raised local chickens, duck, turkey, guinea fowl and geese and were already confirmed to be infected with HPAI virus by virus isolation and reverse transcriptase polymerase chain reaction at the National Veterinary Research Institute, Vom Nigeria. Backyard local chickens recorded the highest number of death with 89.4% of the total flock size while the duck had the highest mortality rate at 87.1%. Mortality rate was least in guinea fowls (20.55%), and above average in geese (54.64%). For Pathology, submitted carcasses comprised of sixty (60) chickens, twenty-nine (29) ducks, thirty-seven (37) turkeys, fourteen (14) guinea fowls and twelve (12) geese which were examined for gross morphological changes and histopathology. Though lesions sparingly occurred in these village poultry, main pathologic findings were associated with the nervous, circulatory, respiratory, and gastro-intestinal systems and occasionally lesions were general unspecific and multi-systemic. It was observed that mortality rate was highest in duck, then chicken and turkey compared to guinea fowl and geese

Isolation time of brooding chicks play an important role in the control of Marek's disease

This work reported the use of a combination of measures for the control of an outbreak of Marek’s disease (MD). Post- introduction vaccinations of young chickens in a farm that had an outbreak over a period of six years did not yield good result. The disease was therefore controlled by brooding new birds in isolated pens far away from the other one, use of biosecurity measures and brooding birds during the rainy season when the environment was damp with minimal dust in the air. Result showed marked reduction of infection during the first one year of trial. By the second and third years of trial, no infection was detected in the birds. This study therefore recommends isolation brooding, biosecurity measures, brooding during the rainy period and completely avoiding brooding during the harmattan period as good methods of controlling cases of MD outbreaks in Nigeria. Key words: Marek’s disease, isolation brooding, vaccination, biosecurity measures, young chickens, Nigeria.

Molecular Characterization of the Circulating Strains of Vibrio cholerae during 2010 Cholera Outbreak in Nigeria

This study aimed at characterizing the phenotypic and toxigenic status of circulating strains of cholera during outbreaks in Nigeria, employing molecular typing techniques. Two hundred and one samples of rectal swabs, stool, vomitus, water (from the well, borehole, sachet, stream, and tap) and disinfectants (sodium hypochlorite) were collected from three states in the country. The samples were inoculated on thiosulphate-citrate bile salt-sucrose (TCBS), Cary-Blair transport medium and smeared on glass slides for direct examination. The Vibrio cholerae isolates were serotyped, biotyped, and characterized using PCR of the cytotoxin gene A (ctxA), wbeO1, and wbfO139 gene primer. Of the 201 samples screened, 96 were positive for V cholerae O1 (48%), with 69 (72%) positive for ctxA gene. The results from this study showed that the circulating strains of cholera in Nigeria were of Ogawa serotype, also observed in other outbreaks in Nigeria (1991, 1992, and 1996). However, the strains were of the Classical biotype and were mainly (72%) ctxA gene-positive. This current investigation has confirmed the production of cholera toxin by the circulating strains, and this could be harnessed for possible cholera vaccine production in Nigeria.

Cholera Outbreaks in Nigeria Are Associated with Multidrug Resistant Atypical El Tor and Non-O1/Non-O139 Vibrio cholerae

BackgroundThe current millennium has seen a steep rise in the number, size and case-fatalities of cholera outbreaks in many African countries. Over 40,000 cases of cholera were reported from Nigeria in 2010. Variants of Vibrio cholerae O1 El Tor biotype have emerged but very little is known about strains causing cholera outbreaks in West Africa, which is crucial for the implementation of interventions to control epidemic cholera.Methodology/Principal Findings V. cholerae isolates from outbreaks of acute watery diarrhea in Nigeria from December, 2009 to October, 2010 were identified by standard culture methods. Fifteen O1 and five non-O1/non-O139 strains were analyzed; PCR and sequencing targeted regions associated with virulence, resistance and biotype were performed. We also studied genetic interrelatedness among the strains by multilocus sequence analysis and pulsed-field gel electrophoresis. The antibiotic susceptibility was tested by the disk diffusion method and E-test. We found that multidrug resistant atypical El Tor strains, with reduced susceptibility to ciprofloxacin and chloramphenicol, characterized by the presence of the SXT element, and gyrA Ser83Ile/parC Ser85Leu alleles as well CTX phage and TCP cluster characterized by rstR ElTor, ctxB-7 and tcpA CIRS alleles, respectively, were largely responsible for cholera outbreaks in 2009 and 2010. We also identified and characterized a V. cholerae non-O1/non-O139 lineage from cholera-like diarrhea cases in Nigeria.Conclusions/SignificanceThe recent Nigeria outbreaks have been determined by multidrug resistant atypical El Tor and non-O1/non-O139 V. cholerae strains, and it seems that the typical El Tor, from the beginning of seventh cholera pandemic, is no longer epidemic/endemic in this country. This scenario is similar to the East Africa, Asia and Caribbean countries. The detection of a highly virulent, antimicrobial resistant lineage in Nigeria is worrisome and points to a need for vaccine-based control of the disease. This study has also revealed the putative importance of non-O1/non-O139 V. cholerae in diarrheal disease in Nigeria.

Survey for Highly Pathogenic Avian Influenza from Poultry in Two Northeastern States, Nigeria

Highly pathogenic avian influenza (HPAI) is a major global zoonosis. It has a complex ecological distribution with almost unpredictable epidemiological features thus placing it topmost in the World Organization for Animal Health list A poultry diseases. Structured questionnaire survey of poultry farmer's knowledge, attitudes, and practices (KAP) in two Nigerian states revealed the presence of risk farming practices that may enable avian influenza high chance of introduction/reintroduction. There existed significant statistical association between farmer's educational levels and AI awareness and zoonotic awareness (P < 0.005). Poultry rearing of multiage and species (81%), multiple sources of stock (62%), inadequate dead-bird disposal (71%), and access to live bird markets (LBMs) (62%) constituted major biosecurity threats in these poultry farming communities. Haemagglutination inhibition (HI) test detected antibodies against H5 avian influenza (AI) in 8 of the 400 sera samples; rapid antigen detection test kit (RADTK) was negative for all the 400 cloaca and trachea swabs. These results and other poultry diseases similar to AI observed in this study could invariably affect avian influenza early detection, reporting, and control. We recommend strong policy initiatives towards poultry farmers' attitudinal change and increasing efforts on awareness of the implications of future HPAI outbreaks in Nigeria.

Awareness, Knowledge, Readiness to Report Outbreak and Biosecurity Practices Towards Highly Pathogenic Avian Influenza in Kogi State, Nigeria

Kogi state did not report Highly Pathogenic Avian Influenza (HPAI) during the 2006-2008 outbreaks in Nigeria despite the presence of favorable factors for the occurrence of the disease. A survey was conducted among stakeholders using structured questionnaires to determine the level of awareness, knowledge and readiness to report outbreak of HPAI and biosecurity practices in Kogi state, Nigeria. Awareness was 100% but knowledge of HPAI was low (9.1%). Readiness to report HPAI outbreak to relevant authorities was high (75.3%) but about 20% of respondents were not ready to report to any authority. Biosecurity practices evaluated by the presence of movement control was 38.8%; presence of footbath was rare (11.8%); handling of sick birds by isolation and treatment was 40%; improper disposal of dead birds in refuse dump was high (85.9%) and extensive management system was high (60.76%). The study revealed high level of awareness and readiness to report HPAI but poor knowledge and biosecurity practices towards it. The failures in biosecurity measures as seen in this study will greatly enhance introduction and spread of HPAI as well as other contagious poultry diseases in the state. Knowledge directly affects readiness to report hence efforts should be made to improve poultry stakeholders’ knowledge of HPAI and proper biosecurity practices.

Spatio-temporal epidemiology of highly pathogenic avian influenza (H5N1) outbreaks in Nigeria, 2006–2008

From 2006 to 2008, outbreaks of highly pathogenic avian influenza A (HPAI) virus of the H5N1 subtype occurred among poultry in Nigeria. We described the spatio-temporal patterns of the HPAI H5N1 outbreaks in Nigeria. Data of suspected and laboratory confirmed outbreaks maintained at the National Veterinary Research Institute Vom was analyzed using descriptive and exploratory analyses, GIS mapping, global and local spatial statistical analyses using the Cuzick–Edwards’ (C–E) test and SaTScan Space-Time Scan Statistic. A total of 1654 suspected outbreaks were reported from 32 of the 36 States and the Federal Capital Territory (FCT), 299 were confirmed HPAI H5N1 positive from 27 states and FCT. The outbreaks occurred as three distinct epidemic waves with peak periods of January–March mainly in the North-West, North-Central and North-East regions during 2006 and 2007 and July–September in the South-West and South-South regions in 2007. Three spatio-temporal clusters were identified extending across States and international borders, consistent with disease transmission occurring through local and long-distance spread. This calls for enhanced strategies by the states and regional authorities to improve surveillance, prevention and control measures at the states, national and international levels.

The Cholera Pandemic, Still with Us after Half a Century: Time to Rethink

The recent outbreaks of cholera in Haiti, Pakistan, and Zimbabwe suggest that our current global action plans against cholera are failing. This issue contains two important articles that will help inform our discussions on ways to respond to the global cholera situation. Cholera is a severely dehydrating illness caused by Vibrio cholerae, a Gram-negative organism. V. cholerae exists in environmental aquatic reservoirs, and, as a result, cholera is not an eradicable disease, but it is controllable. Humanity has recognized seven cholera pandemics since 1817, all originating in Asia. The most recent pandemic began in 1961 in Indonesia, making it at half a century the longest cholera pandemic on record. As opposed to burning out after 5–20 years as all previous pandemics have done, this pandemic, if anything, seems to be picking up speed. Cholera outbreaks are occurring with increasing frequency and severity, as demonstrated by the recent major outbreaks in Nigeria, Angola, Pakistan, Vietnam, Zimbabwe, and now Haiti. This is on top of all the endemic infections that largely go “unnoticed”. In fact, cholera is now endemic in approximately 50 countries worldwide, and V. cholerae infects 3–5 million individuals each year, killing approximately 100,000, only a minority of whom die in outbreaks that garner media attention.

Investigation of Different Water Sources as a Possible Cause of Cholera Outbreak in Lagos in 1997

Cholera still remains one of the major causes of high morbidity and mortality in developing countries. In Nigeria this has been attributed to poor health management response to outbreaks. So during a cholera outbreak in Lagos state in October 1997, water samples were examined to identify the epidemic strain and determine the antibiotic susceptibility patterns of any Vibrio cholerae isolated. Twenty-four water samples from various sources (wells, taps, boreholes and packaged water) from the affected areas were processed using alkaline peptone water and thiosulphate citrate bile salt agar. Various biochemical and serological tests were used for identification. Vibrio cholerae, 01 serogroup, Ogawa serotype and EI-Tor biotype was isolated from 20.8% of the water samples tested. These isolates showed multiple resistance to antibiotics particularly tetracycline but were susceptible to the cephalosporins. Eleven other water samples (45.8%) showed growth of Enterococcus faecalis while two others (8.3%) grew diptheroids. Samples from Ikeja area (control) showed no bacterial growth. This study isolated a V. cholerae that was the same as the strain reported in previous cholera outbreaks in Nigeria. Isolation of other faecal bacteria suggests faecal pollution of water sources in the areas studied. [J. of the Nig. Infection Control Assn. Vol.3(2) 2000: 6-8]

Évolution de la réglementation dans la perspective du marché unique européen de 1993

Lassa fever is an acute viral haemorrhagic illness caused by Lassa virus (LASV), which is endemic throughout much of West Africa. The virus primarily circulates in the Mastomys natalensis reservoir and is transmitted to humans through contact with infectious rodents or their secretions; human-to-human transmission is documented as well. With the exception of Dengue fever, LASV has the highest human impact of any haemorrhagic fever virus. On-going outbreaks in Nigeria have resulted in unprecedented mortality. Consequently, the World Health Organization (WHO) has listed LASV as a high priority pathogen for the development of treatments and prophylactics. Currently, there are no licensed vaccines to protect against LASV infection. Although numerous candidates have demonstrated efficacy in animal models, to date, only a single candidate has advanced to clinical trials. Lassa fever vaccine development efforts have been hindered by the high cost of biocontainment requirements, the absence of established correlates of protection, and uncertainty regarding the extent to which animal models are predictive of vaccine efficacy in humans. This review briefly discusses the epidemiology and biology of LASV infection and highlights recent progress in vaccine development.

The isolation of adenoviruses from goats affected with peste des petits ruminants in Nigeria

Mucosal scrapings from the large intestine of two goats that had died from peste des petits ruminants (PPR) in separate outbreaks in Nigeria were examined for viruses. A mixed viral infection of PPR virus (morbillivirus) and adenovirus was confirmed in both goats. The adenoviruses did not conform to any of the ovine and bovine serotypes recognised; the two isolates were considered different serotypes. It is concluded that, although the role of adenoviruses in the epizootiology of PPR in Nigeria is difficult to appraise, they are probably commensals. This is believed to be the first report of the isolation of adenoviruses from goats.