Ecology and epidemiology of Salmonella spp. isolated from the environment and the roles played by wild animals in their maintenance

Salmonella is a ubiquitous organism of public health importance that causes diarrhea and other systemic disease syndromes. The ecology and epidemiology of the organism in addition to the roles played by wild animals are important in understanding its disease. Relevant published peer-reviewed literature was obtained after imputing the study's keywords into the Google search engine. The publications were thereafter saved for the study. The study revealed the ecology of Salmonella is directly related to its epidemiology. These were found to be either positively or negatively influenced by the living and non-living parts of the environment. Free-ranging and captive wild animals can serve as asymptomatic carriers of Salmonella, therefore, help to maintain the cycle of the disease since wildlife serves as reservoir hosts to over 70% of emerging zoonotic diseases. Cockroaches transmit Salmonella through their feces, and body parts and when ingested by birds and animals. The statistically significant over 83% of Salmonella isolation in lizards suggests the reptile could be a source of Salmonella distribution. Snakes, foxes, badgers, rodents, and raccoons have been reported to have Salmonella as a natural component of their gut with the ability to shed the organism often. The high occurrence (>45%) of diverse Salmonella serovars coupled with the fact that some of these animals were handled, kept as pets and consumed by man portends these animals as potential sources of transmission of the organism and the disease. The etiology and epidemiology of Salmonella are overtly affected by several environmental factors which also determine their survival and maintenance. The roles played by wild animals in the relationship, transmission, growth or interaction within and between Salmonella spp., the occurrence, prevalence, and distribution of the organism help maintain the organism in the environment. An understanding of the roles played by the different parts of the environment and wild animals in the ecology and epidemiology of Salmonella can help make informed decisions on the prevention and control of the diseases it causes. This review aimed to investigate the relationship between ecology, epidemiology, and environment, including the roles played by wild animals in the maintenance of the organism and its disease.

Detection and molecular characterization of a first isolate of rabbit haemorrhagic disease virus in Nigeria

Rabbit haemorrhagic disease virus (RHDV) was recovered from necropsied rabbits that died during an outbreak characterized by epistaxis, incoordination, paralysis, and multi-organ haemorrhages in Ilorin, Nigeria. The haemagglutination test (HA) and RT-PCR assay targeted against a fragment of the RHDV VP60 gene were performed on liver, spleen, and kidney homogenates; faeces; and urine obtained from the rabbits. Amplicons were purified, sequenced, and phylogenetically analysed. The liver homogenates yielded the highest HA titres while RT-PCR of liver, spleen, and kidneys yielded the expected 1252 bp band. Sequence and phylogenetic analyses revealed that the Nigerian RHDV strain (RHDV/NGR/ILN/001) was 98.57%, 97.95%, and 96.70% homologous with RHDV2 (RHDVGI.2) strains from the Netherlands, Germany, and France, respectively. RHDV/NGR/ILN/001 induced tracheal, intestinal, and mediastinal lymph node haemorrhages, pulmonary oedema and congestion, and enlarged, necrotic liver in experimentally inoculated rabbits. The implications of this study, which is the first report of RHDV in Nigeria, are discussed.

CONTAMINATION OF COMMERCIALLY PACKAGED SACHET WATER AND THE PUBLIC HEALTH IMPLICATIONS: AN OVERVIEW

Quality water should be colourless, tasteless, odourless and free from faecal contamination. This study investigates the level of contamination of commercially vended packaged water and their public health implications. Published baseline information and data were used in the study. Using different isolation techniques, coliform bacteria of up to 100% and faecal contamination of up to 40% were reported. The consumption of contaminated commercially packaged water by the public has led to different disease conditions and death of millions of people all over the world. This calls for strict adherence to good management practices (GMP) by producers of packaged water, improved monitoring and enforcement of guidelines of production by regulatory bodies according to World Health Organization (WHO) standards, increased public awareness and sensitivity to the presence and dangers of consuming such water and creating easy, always potent reporting channels through which disease cases and suspected contaminated water manufacturers could be reported to the authority so as to prevent infection from consumption of such packaged water, diseases and deaths.

Prevalence of antibody against rabies among confined, free-roaming and stray dogs in a transit city of Nigeria

The prevalence of anti-glycoprotein antibodies against rabies virus is studied in the sera of confined, free-roaming and stray dogs in Ilorin, the capital city of Kwara State, Nigeria. A quantitative indirect enzyme-linked immuno-sorbent assay (i-ELISA) was used to detect rabies virus anti-glycoprotein antibodies in sera from 116 confined, 61 free-roaming, and 13 stray dogs. The sera were collected between June and December 2008 from apparently healthy dogs. Of these 190 dogs, 81 (42.6%), consisting of 57 confined (49.1%), 23 free-roaming (37.7%) and 1 stray (7.7%), had antibody titres that exceeded the positive threshold of 0.5 equivalent units (eu)/ml against rabies, while 109 (57.4%) presented titres that were below the threshold. Prevalence of rabies anti-glycoprotein antibody was higher in the confined dogs compared to free-roaming and stray dogs. Our results indicated low anti-rabies sero-prevalence (42.6%) in the dog population of Ilorin, a transit city that lies between northern and southern Nigeria. This is the first community-based prevalence report on the anti-rabies serological profile of dogs in Nigeria. The need for primary and booster mass vaccination of dogs and the impact of these findings on rabies control in Nigeria are discussed.