Search Results (12)

Leptospirosis is a bacterial zoonosis caused by pathogenic species from the genus Leptospira. Infection mostly occurs through indirect contact with environmental water contaminated with the urine of reservoir animals. Information on the circulation of leptospirosis in West Africa, as well as its potential reservoir hosts, is limited. Therefore, we carried out trapping surveys in the Guinean forest in November 2022, and samples were collected from 42 micromammals. The animals were both morphologically and genetically identified. The lungs and kidneys were screened for Leptospira using Lfb1-gene-targeting real-time PCR, and positive samples were genotyped based on the polymorphic Lfb1 gene. Leptospira species were detected in the kidneys of three micromammals: Mastomys natalensis, Lophuromys sikapusi, and Rattus rattus. Leptospira borgpetersenii was identified in Rattus rattus and Mastomys natalensis that were captured in two different villages. The phylogenetic analysis indicated that this subspecies had previously been detected in one patient in Mayotte, but the reservoir was not identified. A new subspecies of Leptospira kirschneri was isolated in Lophuromys sikapusi from the same village as the Mastomys natalensis positive for L. borgpetersenii. The high diversity of both the reservoirs and Leptospira species in the Guinean forest indicates that we should study other natural regions and reinforce communities’ awareness of Leptospira infection risks in Guinea. Full article

Leptospira spp. infection in small ruminants is usually asymptomatic or presents nonspecific clinical signs and has an economic impact on goat farming and public health. The aim of this study was to carry out a systematic review with meta-analysis on the global seroprevalence and distribution of leptospirosis in goats. The methodology was based on the recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and the review project was registered in the International Prospective Register of Systematic Reviews (PROSPERO—ID: CRD42023405693). Overall, 79 articles were included in the study. The global prevalence of leptospirosis in goats was 18.6% (CI 95% = 15.08–22.71%), with no publication bias and high heterogeneity. The records originated from South America (n = 32), Asia (n = 26), Europe (n = 8), North America (n = 7), and Africa (n = 6), and seropositivities were 17%, 19%, 12%, 34%, and 22%, respectively. It is concluded that Leptospira spp. infection is widespread in goat herds, including regions with semi-arid and arid climates, and it is suggested that the prospects for controlling the disease should focus on avoiding environmental contamination and improving management measures and sanitary practices. This important information provides guidance for actions to protect against human contamination and to control animal leptospirosis. Full article

Frequent animal–human interactions in sub-Saharan Africa (SSA) pose an increased risk for the transmission of zoonotic diseases. While there are sporadic reports of zoonotic diseases outbreaks in SSA, a synthetic overview is necessary to better understand how the sub-region is impacted by these pathologies. We conducted a systematic review of zoonotic diseases studies conducted in SSA between 2000 and 2022. Quantitative reports including case reports/series from countries spanning West, Central, East, and Southern SSA and that provided empirical data on the occurrence of zoonotic diseases in humans with documented evidence of animal origin were eligible for inclusion. The 55 eligible articles provided 82 reports of zoonotic diseases for a total of 28,934 human cases (pooled attack rate: 54.4 per 1000) and 1182 deaths (pooled fatality rate: 345.4 per 1000). Only 31 (37.8%) of the studies were conducted during ongoing outbreaks. We identified the zoonotic diseases in SSA with the highest attack rates (rickettsiosis, toxoplasmosis, Q-fever) and CFR (Marburg, Ebola, leptospirosis), which should be prioritized for surveillance and response preparedness. Addressing the threat of zoonotic diseases in SSA requires the strengthening of health systems and implementation of a one health approach. Importantly, research should be encouraged during ongoing epidemics to fortify immediate response strategies and work toward preventing future outbreaks. Full article

Leptospira was investigated in kidneys (n = 305) from slaughtered livestock in the Gauteng Province abattoirs, South Africa, using a culture medium to isolate Leptospira, followed by the LipL32 qPCR to detect Leptospira DNA. The SecY gene region was amplified, sequenced, and analyzed for LipL32 qPCR-positive samples or Leptospira isolates. The overall frequency of isolation of Leptospira spp. was 3.9% (12/305), comprising 4.8% (9/186), 4.1% (3/74), and 0% (0/45) from cattle, pigs, and sheep, respectively (p > 0.05). However, with LipL32 qPCR, the overall frequency of Leptospira DNA was 27.5%, consisting of 26.9%, 20.3%, and 42.2% for cattle, pigs, and sheep, respectively (p = 0.03). Based on 22 SecY sequences, the phylogenetic tree identified the L. interrogans cluster with serovar Icterohaemorrhagiae and the L. borgpetersenii cluster with serovar Hardjo bovis strain Lely 607. This study is the first molecular characterization of Leptospira spp. from livestock in South Africa. The reference laboratory uses an eight-serovar microscopic agglutination test panel for leptospirosis diagnosis, of which L. borgpetersenii serovar Hardjo bovis is not part. Our data show that pathogenic L. interrogans and L. borgpetersenii are circulating in the livestock population. Diagnostic use of molecular methods will eliminate or reduce the under-reporting of leptospirosis in livestock, particularly sheep, in South Africa. Full article

Leptospirosis is a major threat to public health worldwide; however, there is no study focused on global seropositivity in pigs. In this study, we grouped publications and performed a systematic review with meta-analysis to gather data related to swine leptospirosis seropositivity published globally. The search method initially used returned a total of 1183 results, of which 20 met all predefined criteria and were therefore included in this review. Meta-analysis with general data was performed and a combined seropositivity of 21.95% was found. Seropositivity was 36.40% in South America, 34.05% in North America, 22.18% in Africa, 17.40% in Oceania, 13.30% in Europe and 13.36% in Asia. The results suggest that there is high seropositivity for leptospirosis in pigs worldwide. Information compiled from this research is relevant to understanding the spread of leptospirosis globally. It is expected that these indicators will contribute to a better understanding of the epidemiology of the disease with a focus on its control and, consequently, on the reduction of cases in the human and animal population. Full article

Brucellosis, Q fever, and leptospirosis are priority zoonoses worldwide, yet their epidemiology is understudied, and studies investigating multiple pathogens are scarce. Therefore, we selected 316 small ruminants in irrigated, pastoral, and riverine settings in Tana River County and conducted repeated sampling for animals that were initially seronegative between September 2014 and June 2015. We carried out serological and polymerase chain reaction tests and determined risk factors for exposure. The survey-weighted serological incidence rates were 1.8 (95% confidence intervals [CI]: 1.3–2.5) and 1.3 (95% CI: 0.7–2.3) cases per 100 animal-months at risk for Leptospira spp. and C. burnetii, respectively. We observed no seroconversions for Brucella spp. Animals from the irrigated setting had 6.83 (95% CI: 2.58–18.06, p-value = 0.01) higher odds of seropositivity to C. burnetii than those from riverine settings. Considerable co-exposure of animals to more than one zoonosis was also observed, with animals exposed to one zoonosis generally having 2.5 times higher odds of exposure to a second zoonosis. The higher incidence of C. burnetii and Leptospira spp. infections, which are understudied zoonoses in Kenya compared to Brucella spp., demonstrate the need for systematic prioritization of animal diseases to enable the appropriate allocation of resources. Full article

Multi-host pathogens are challenging to control and are responsible for some of the most important diseases of humans, livestock, and wildlife. Leptospira spp. are some of the most common multi-host pathogens and represent an important cause of zoonotic infections and livestock productivity loss in the developing world, where contact with wildlife species is common. Although there is increasing evidence that cattle in Africa harbour a broad diversity of Leptospira genotypes and serovars, little is known about the epidemiology of these pathogens in wild bovids, such as African buffaloes (Syncerus caffer). Using microscopic agglutination testing (MAT) on serum samples collected from free-ranging buffaloes (n = 98) captured in the Hluhluwe-iMfolozi Park (HiP), South Africa, we demonstrated an overall seroprevalence of 21% with seropositivity almost exclusively limited to serovar Tarassovi (serogroup Tarassovi). Moreover, we found no evidence of seropositivity in unweaned calves and showed temporal- or herd-specific variation in exposure risk, and increased probability of seropositivity (OR = 5.44, 95% CI = 1.4–27) in female buffaloes. Together, these findings demonstrate that free-ranging African buffaloes are exposed to Leptospira spp. infections, providing insights into the epidemiology of an emerging Leptospira serovar in herds with an absence of any disease control and minimal management. Full article

Background: Leptospirosis is among the major neglected zoonoses in developing countries. The prevalence of leptospirosis remains underestimated in many African countries because of limited diagnostic facilities. We studied Leptospira seropositivity prevalence in humans, sheep, goats and rodents in a semi-arid region of central Tanzania and compared findings with reports from humid tropical areas. The aims were to establish the disease burden in different settings; understand circulating Leptospira serovars and potential major reservoirs for establishing appropriate control measures. Methods: Humans, sheep, goats, rodents and shrews (insectivores) were sampled from Bahi district, a semi-arid area in central Tanzania. Samples were tested for leptospiral antibodies using microscopic agglutination test (MAT) consisting of Leptospira serovars mainly reported in Tanzania and reference strains. Findings were compared with previous data to determine the disease epidemiological patterns. Results and conclusion: Semi-arid area showed high Leptospira seropositivity prevalence in humans and domestic animals due to intensive human–animal interactions at scarce water points and by flash flooding which occur in the area. Rodent population in the semi-arid areas was relatively low due to flooding. Leptospira seropositivity in rodents was also slightly lower, and the rodents appeared to be prolific breeders, probably as a means to compensate for the lost population during extreme drought as well as during short spells of floods. Intensive human–animal interaction in the semi-arid areas especially, in water sources in valleys where human and animals often meet, likely increased the risk of leptospirosis transmission to rice farmers in the area. Goats and sheep which are kept around homesteads had higher leptospiral antibodies prevalence (62%), nearly double of the 38% reported in same species in humid tropical regions of Tanzania. Livestock, especially goats and sheep, could be the major source of leptospirosis transmission to humans. Vaccination of livestock with vaccines against local Leptospira strains should be encouraged, and rodent control emphasized, as part of a management strategy against leptospirosis. Public awareness of leptospirosis must also be raised and supported by availability of rapid test kits in clinics for preliminary testing of leptospirosis in people with fevers of unknown origin. Full article

Leptospirosis is caused by spirochete bacteria of the genus Leptospira that affect one million and kill 60,000 persons annually in the world, who get infected through environmental mammal-excreted (notably rodent) pathogens. Using qPCR and DNA sequencing approaches, we here examine Leptospira occurrence and diversity in 971 commensal small mammals in urban and peri-urban habitats from south Benin, where socio-environmental conditions are favorable for human contamination. Prevalence reached 12.9% on average, but showed very important variations in both space and time, thus pointing toward a role of local processes in the maintenance and circulation of rodent-borne leptospires in the area. Prevalence peaks may occur during or one month after moderate (100–200 mm) monthly rainfall, suggesting that rodent-borne leptospires may be more prevalent when standing waters are present, but not at their highest levels (i.e., floods). However, this pattern will have to be confirmed through proper diachronic analysis. Finally, an incomplete but significant host-specificity was observed, with L. kirschneri retrieved only in African shrews, and the invasive Rattus norvegicus and the native Mastomys natalensis preferentially infected by L. interrogans and L. borgpeterseni, respectively. Our study highlights the urgent need for investigations on human leptospirosis in the extensively urbanized Abidjan–Lagos corridor. Full article

Zoonoses present a major public health threat and are estimated to account for a substantial part of the infectious disease burden in low-income countries. The severity of zoonotic diseases is compounded by factors such as poverty, living in close contact with livestock and wildlife, immunosuppression as well as coinfection with other diseases. The interconnections between humans, animals and the environment are essential to understand the spread and subsequent containment of zoonoses. We searched three scientific databases for articles relevant to the epidemiology of bacterial zoonoses/zoonotic bacterial pathogens, including disease prevalence and control measures in humans and multiple animal species, in various African countries within the period from 2008 to 2018. The review identified 1966 articles, of which 58 studies in 29 countries met the quality criteria for data extraction. The prevalence of brucellosis, leptospirosis, Q fever ranged from 0–40%, 1.1–24% and 0.9–28.2%, respectively, depending on geographical location and even higher in suspected outbreak cases. Risk factors for human zoonotic infection included exposure to livestock and animal slaughters. Dietary factors linked with seropositivity were found to include consumption of raw milk and locally fermented milk products. It was found that zoonoses such as leptospirosis, brucellosis, Q fever and rickettsiosis among others are frequently under/misdiagnosed in febrile patients seeking treatment at healthcare centres, leading to overdiagnoses of more familiar febrile conditions such as malaria and typhoid fever. The interactions at the human–animal interface contribute substantially to zoonotic infections. Seroprevalence of the various zoonoses varies by geographic location and species. There is a need to build laboratory capacity and effective surveillance processes for timely and effective detection and control of zoonoses in Africa. A multifaceted ‘One Health’ approach to tackle zoonoses is critical in the fight against zoonotic diseases. The impacts of zoonoses include: (1) Humans are always in contact with animals including livestock and zoonoses are causing serious life-threatening infections in humans. Almost 75% of the recent major global disease outbreaks have a zoonotic origin. (2) Zoonoses are a global health challenge represented either by well-known or newly emerging zoonotic diseases. (3) Zoonoses are caused by all-known cellular (bacteria, fungi and parasites) and noncellular (viruses or prions) pathogens. (4) There are limited data on zoonotic diseases from Africa. The fact that human health and animal health are inextricably linked, global coordinated and well-established interdisciplinary research efforts are essential to successfully fight and reduce the health burden due to zoonoses. This critically requires integrated data from both humans and animals on zoonotic diseases. Full article

Leptospirosis affects 1 million and kills 60,000 people annually, but it remains poorly documented in Africa. We aim to describe the large West African Conurbation Corridor where the omnipresence of slums, water and close animal/human interactions may result in high leptospiral risk. Though scarce, data from this region point towards the wide circulation of pathogenic leptospires in the urban environment as well as in humans. However, because of the absence of reliable surveillance systems together with lack of awareness, the absence of reference laboratory and/or a high number of infected people showing only mild manifestations, it is likely that the burden is much higher. We believe raising awareness of leptospirosis may have a positive impact on many vulnerable African city dwellers, as the disease is a preventable and treatable. Full article

Conditions in the Democratic Republic of the Congo provide an ideal environment for leptospirosis and plague, both of which can cause severe pulmonary manifestations. In December 2004, an outbreak of lethal pneumonia occurred in a local mining camp, affecting 130 persons and killing 57 of them. Clinical signs, fast disease spread, and initial laboratory investigations suggested pneumonic plague. While leptospirosis had not recently been described in the region, it was considered as a differential diagnosis. Anti-Leptospira antibodies were detected by microscopic agglutination test (MAT). A confirmed case of leptospirosis was defined as having consistent clinical signs and any one of the following: seroconversion or four-fold increase in MAT titre for paired serum samples, or a MAT titre ≥ 1:400 for acute-phase serum samples. Twenty-nine of the 54 patients or convalescents tested for leptospirosis were seropositive. Two cases showed a confirmed infection for both plague and leptospirosis. While evidence supports the plague nature of this outbreak, the results suggest that some of the suspected plague cases might be due to leptospirosis. In any case, this diagnosis will have to be evoked in the future if a similar outbreak occurs in this region of Africa. Full article