Clovice Kankya

Isolation of non-tuberculous mycobacteria from pastoral ecosystems of Uganda: public health significance

BackgroundThe importance of non-tuberculous mycobacteria (NTM) infections in humans and animals in sub-Saharan Africa at the human-environment-livestock-wildlife interface has recently received increased attention. NTM are environmental opportunistic pathogens of humans and animals. Recent studies in pastoral ecosystems of Uganda detected NTM in humans with cervical lymphadenitis and cattle with lesions compatible with bovine tuberculosis. However, little is known about the source of these mycobacteria in Uganda. The aim of this study was to isolate and identify NTM in the environment of pastoral communities in Uganda, as well as assess the potential risk factors and the public health significance of NTM in these ecosystems.MethodA total of 310 samples (soil, water and faecal from cattle and pigs) were examined for mycobacteria. Isolates were identified by the INNO-Lipa test and by 16S rDNA sequencing. Additionally, a questionnaire survey involving 231 pastoralists was conducted during sample collection. Data were analysed using descriptive statistics followed by a multivariable logistic regression analysis.ResultsForty-eight isolates of NTM were detected; 25.3% of soil samples, 11.8% of water and 9.1% from animal faecal samples contained mycobacteria. Soils around water sources were the most contaminated with NTM (29.8%). Of these samples, M. fortuitum-peregrinum complex, M. avium complex, M. gordonae, and M. nonchromogenicum were the most frequently detected mycobacteria. Drinking untreated compared to treated water (OR = 33), use of valley dam versus stream water for drinking and other domestic use (OR = 20), sharing of water sources with wild primates compared to antelopes (OR = 4.6), sharing of water sources with domestic animals (OR = 5.3), and close contact with cattle or other domestic animals (OR = 13.8) were the most plausible risk factors for humans to come in contact with NTM in the environment.ConclusionsThe study detected a wide range of potentially pathogenic NTM from the environment around the pastoral communities in Uganda. Drinking untreated water and living in close contact with cattle or other domestic animals may be risk factors associated with the possibility of humans and animals acquiring NTM infections from these ecosystems.

African swine fever among slaughter pigs in Mubende district, Uganda

Owing to frequent reports of suspected outbreaks and the presence of reservoir hosts and vectors (warthogs, bushpigs and O. moubata ticks), African swine fever (ASF) is believed to be an endemic disease in Uganda. There have, however, been very few studies carried out to confirm its existence in Uganda. This study was carried out to describe the prevalence of ASF based on pathologic lesions and analysis of serum samples from slaughtered pigs during a suspected outbreak in the Mubende district of Uganda. The study was based on visits to 22 slaughterhouses where individual pigs were randomly selected for a detailed ante-mortem and post-mortem inspections. Sera were also collected for laboratory analysis. A total of 997 pigs (53.7% male and 46.3% female) were examined for lesions suggestive of ASF and sero-positivity of sera for ASF antibodies. The sera were tested using enzyme-linked immunosorbent assay (ELISA) and positive samples were further confirmed with an immunoblot assay. The results showed that 3.8% (38/997) of the pigs examined had clinical signs and post-mortem lesions suggestive of ASF. Two of 997 (0.2%) sera analysed were positive for ASF antibodies. Of the sub-counties investigated, Bagezza (12%) and Kiyuni (11%) had the highest prevalence of lesions suggestive of ASF based on ante- and post-mortem examination results, while Mubende town council (1.7%) had the lowest. This study found a low number of pigs (3.8%) with lesions suggestive of ASF at slaughter and an even lower number of pigs (0.2%) that were seropositive at slaughter, however a significantly higher number of pigs were slaughtered during the outbreak as a strategy for farmers to avoid losses associated with mortality.

Prevalence and associated risk factors of mycobacterial infections in slaughter pigs from Mubende district in Uganda

To date, the public health relevance of mycobacterial infections in pigs is not well investigated despite high risk of infection. Recently, there has been a documented increase in opportunistic infections and risk of acquiring opportunistic mycobacterial infections in HIV/AIDS patients in Mubende district; unfortunately, there has been no published information on the epidemiology of mycobacterial infections in this area. This study was carried out between September 2008 and February 2009. Investigations were done to assess the prevalence and associated risk factors of mycobacterial infections in slaughtered pigs in Mubende district of Uganda. A total of 997 pigs (53.7% male and 46.3% female) from 31 different slaughterhouses were examined for the presence of lesions compatible with TB and mycobacterial infections. Pathologic tissue specimens were collected for culturing and isolation of mycobacteria. A cross-sectional technique was used based on convenient visits to slaughterhouses but random selection of individual slaughtered pigs for a detailed post-mortem inspection on a daily basis. The results reflected a 9.3% and 3.1% (95% CI) prevalence of Mycobacterium species based on necropsy examinations and culture isolation, respectively. The highest prevalence of mycobacterial infection was recorded in Buwekula County (the mixed agro-zone) whilst the lowest was in Kassanda County (pastoral zone). A multivariable logistical regression analysis identified age (P ≤ 0.001) and sex (P ≤ 0.05) as risk factors for mycobacterial infections in pigs. Post-estimation statistics of the regression model evaluation and validation fit it well into the data (HL, χ2 = 5.9; P = 0.69 for necropsy, HL χ2 = 2.9; P = 0.94 for culturing). This study documented a high prevalence of mycobacterial infections in slaughter pigs in Mubende district. The fact that pigs and human often share common housing and environment poses a high risk of zoonotic transmission. This then warrants further molecular investigation to identify the specific Mycobacterium species and their public health importance in this area.

Molecular Epidemiology, Drug Susceptibility and Economic Aspects of Tuberculosis in Mubende District, Uganda

Background Tuberculosis (TB) remains a global public health problem whose effects have major impact in developing countries like Uganda. This study aimed at investigating genotypic characteristics and drug resistance profiles of Mycobacterium tuberculosis isolated from suspected TB patients. Furthermore, risk factors and economic burdens that could affect the current control strategies were studied. Methods TB suspected patients were examined in a cross-sectional study at the Mubende regional referral hospital between February and July 2011. A questionnaire was administered to each patient to obtain information associated with TB prevalence. Isolates of M. tuberculosis recovered during sampling were examined for drug resistance to first line anti-TB drugs using the BACTEC-MGIT960TMsystem. All isolates were further characterized using deletion analysis, spoligotyping and MIRU-VNTR analysis. Data were analyzed using different software; MIRU-VNTR plus, SITVITWEB, BioNumerics and multivariable regression models. Results M. tuberculosis was isolated from 74 out of 344 patients, 48 of these were co-infected with HIV. Results from the questionnaire showed that previously treated TB, co-infection with HIV, cigarette smoking, and overcrowding were risk factors associated with TB, while high medical related transport bills were identified as an economic burden. Out of the 67 isolates that gave interpretable results, 23 different spoligopatterns were detected, nine of which were novel patterns. T2 with the sub types Uganda-I and Uganda-II was the most predominant lineage detected. Antibiotic resistance was detected in 19% and multidrug resistance was detected in 3% of the isolates. Conclusion The study detected M. tuberculosis from 21% of examined TB patients, 62% of whom were also HIV positive. There is a heterogeneous pool of genotypes that circulate in this area, with the T2 lineage being the most predominant. High medical related transport bills and drug resistance could undermine the usefulness of the current TB strategic interventions.

Molecular investigation of multiple strain infections in patients with tuberculosis in Mubende district, Uganda

Multiple strain tuberculosis (TB) infections are now an acceptable facet of tuberculosis epidemiology. Identification of patients infected with more than one strain gives an insight in disease dynamics at individual and population level. This study therefore aimed at identifying multiple strain infections among TB infected patients. Furthermore, to determine factors associated with multiple strain infections in Mubende district of Uganda. A total of 72 Mycobacterium tuberculosis isolates from patients at Mubende regional referral hospital were characterized using 15 loci MIRU-VNTR, Spoligotyping and deletion analysis. Genotypic and epidemiological data were analyzed using MIRU-VNTR plus, Bionumerics software version 6.1 and an exact logistic regression model respectively. Eight (11.1%) of the 72 patients had mixed TB infections. Five were exclusively pulmonary mixed infections while three had both pulmonary and extra-pulmonary infections (Compartmentalized TB infections). Unlike previous studies that have linked this phenomenon to Beijing strains, multiple strains in this study belonged to T2-Uganda, X2 and T1 lineages. Two of the pulmonary mixed infections were resistant to rifampicin or isoniazid. All except one were HIV positive, newly diagnosed cases and urban residents of Mubende district. The study revealed that one in nine urban dwelling, HIV/TB co-infected patient were infected with more than one M. tuberculosis strains. The molecular findings give indications of a vital component of the disease dynamics that is most likely under looked at clinical level.

Non-tuberculous mycobacteria isolated from slaughter pigs in Mubende district, Uganda

BackgroundThe importance of infections caused by non-tuberculous mycobacteria (NTM) in animals and humans has gained considerable recognition during the past few years. In the developed world, where pig production is extensively practiced, studies on mycobacterial infections and related control strategies have received increasing attention. The infections are reported to be caused by a wide spectrum of NTM. Unfortunately, these infections have been less recognized in sub-Saharan Africa owing to lack of awareness and systematic studies. In this study we aimed at isolating and identifying species of mycobacteria involved in causing infections in slaughter pigs in Mubende district of Uganda. Furthermore we wanted to identify factors associated with infection prevalence in the study area.MethodsA total of 363 lymph nodes were collected and cultured for the presence of mycobacteria. Isolates were identified by 16S rDNA gene sequencing. A questionnaire survey was administered to identify production related factors associated with infection prevalence. Data were assembled and analysed using descriptive statistics and mixed effects logistic regression analysis.ResultsMycobacteria were detected in 39 % (143/363) of the examined lymph nodes, 63 % (59/93) of lymph nodes with gross lesions typical of mycobacteriosis and 31% (84/270) of lymph nodes with no visible lesions. Nineteen per cent of the isolated mycobacteria were identified as Mycobacterium (M) avium, of these 78% and 22% were M. avium sub sp. Hominissuis and avium respectively. Other mycobacterial species included M. senuense (16%), M. terrae (7%) and M. asiaticum (6%). This study found free range systems (OR = 3.0; P = 0.034) and use of water from valley dams (OR = 2.0; P = 0.049) as factors associated with high prevalence of mycobacteria in slaughter pigs.ConclusionsThis study demonstrated a high prevalence of NTM infections among slaughter pigs in Mubende district of Uganda. M. avium was the most prevalent of all NTM isolated and identified. Free range system of pig management and valley dam water were the most significant factors associated with NTM prevalence in Mubende district. These findings could be of a major public health concern given that it is in a predominantly pork consuming population with 18% HIV/AIDS prevalence. Therefore, stringent post-mortem inspection at the slaughter houses is of paramount importance to reduce human exposure.

Leptospira Seroprevalence and Risk Factors in Health Centre Patients in Hoima District, Western Uganda

Background The burden of human leptospirosis in Uganda is unknown. We estimated the seroprevalence of Leptospira antibodies, probable acute/recent leptospirosis, and risk factors for seropositivity in humans in rural Western Uganda. Methodology and Principal Findings 359 non-pregnant adults visiting the Kikuube and Kigorobya Health Centers were sequentially recruited during March and April 2014. A health history survey and serum were collected from consented participants. Overall, 69% reported having fever in the past year, with 49% reporting malaria, 14% malaria relapse, 6% typhoid fever, 3% brucellosis, and 0% leptospirosis. We tested sera by microscopic agglutination test (MAT) against eight Leptospira serovars representing seven serogroups. Leptospira seroprevalence was 35% (126/359; 95%CI 30.2–40.3%) defined as MAT titer ≥ 1:100 for any serovar. The highest prevalence was against L. borgpetersenii Nigeria (serogroup Pyrogenes) at 19.8% (71/359; 95%CI 15.9–24.4%). The prevalence of probable recent leptospirosis (MAT titer ≥1:800) was 1.9% (95%CI 0.9–4.2%) and uniquely related to serovar Nigeria (serogroup Pyrogenes). Probable recent leptospirosis was associated with having self-reported malaria within the past year (p = 0.048). Higher risk activities included skinning cattle (n = 6) with 12.3 higher odds (95%CI 1.4–108.6; p = 0.024) of Leptospira seropositivity compared with those who had not. Participants living in close proximity to monkeys (n = 229) had 1.92 higher odds (95%CI 1.2–3.1; p = 0.009) of seropositivity compared with participants without monkeys nearby. Conclusions/Significance The 35% prevalence of Leptospira antibodies suggests that exposure to leptospirosis is common in rural Uganda, in particular the Nigeria serovar (Pyrogenes serogroup). Leptospirosis should be a diagnostic consideration in febrile illness and “smear-negative malaria” in rural East Africa.

Molecular characterization of Mycobacterium avium subspecies hominissuis isolated from humans, cattle and pigs in the Uganda cattle corridor using VNTR analysis

BACKGROUND Members of the Mycobacterium avium complex (MAC) cause disease in both human and animals. Their ubiquitous nature makes them both successful microbes and difficult to source track. The precise characterization of MAC species is a fundamental step in epidemiological studies and evaluating of possible reservoirs. This study aimed at identifying and characterizing Mycobacterium avium subsp. hominissuis isolated from human, slaughter cattle and pigs in various parts of the Uganda cattle corridor (UCC) at two temporal points using variable number of tandem repeat (VNTR) analysis. METHODS A total of 46 M. avium isolates; 31 from 997 pigs, 12 from 43 humans biopsies and three from 61 cattle lesions were identified to subspecies level using IS1245 and IS901 PCR, thereafter characterized using VNTR. Twelve loci from two previously described VNTR methods were used and molecular results were analyzed and interpreted using Bionumerics 6.1. PRINCIPAL FINDINGS 37 of the isolates were identified as M. avium subsp. hominissuis and four as M. avium subsp. avium, while five could not be differentiated, possibly due to mixed infection. There was distinct clustering that coincides with the temporal and spatial differences of the isolates. The isolates from humans and cattle in the North Eastern parts of the UCC shared identical VNTR genotypes. The panel of loci gave an overall discriminatory power of 0.88. Some loci were absent in several isolates, probably reflecting differences in isolates from Uganda/Africa compared to isolates previously analyzed by these methods in Europe and Asia. CONCLUSIONS The findings indicate a molecular difference between M. avium subsp. hominissuis isolates from pigs in Mubende and cattle and human in the rest of the UCC. Although human and cattle shared VNTR genotypes in the North Eastern parts of the UCC, it is most likely a reflection of a shared environmental source.

How severe and prevalent are Ebola and Marburg viruses? A systematic review and meta-analysis of the case fatality rates and seroprevalence

BackgroundEbola and Marburg virus diseases are said to occur at a low prevalence, but are very severe diseases with high lethalities. The fatality rates reported in different outbreaks ranged from 24–100%. In addition, sero-surveys conducted have shown different seropositivity for both Ebola and Marburg viruses. We aimed to use a meta-analysis approach to estimate the case fatality and seroprevalence rates of these filoviruses, providing vital information for epidemic response and preparedness in countries affected by these diseases.MethodsPublished literature was retrieved through a search of databases. Articles were included if they reported number of deaths, cases, and seropositivity. We further cross-referenced with ministries of health, WHO and CDC databases. The effect size was proportion represented by case fatality rate (CFR) and seroprevalence. Analysis was done using the metaprop command in STATA.ResultsThe weighted average CFR of Ebola virus disease was estimated to be 65.0% [95% CI (54.0–76.0%), I2 = 97.98%] whereas that of Marburg virus disease was 53.8% (26.5–80.0%, I2 = 88.6%). The overall seroprevalence of Ebola virus was 8.0% (5.0%–11.0%, I2 = 98.7%), whereas that for Marburg virus was 1.2% (0.5–2.0%, I2 = 94.8%). The most severe species of ebolavirus was Zaire ebolavirus while Bundibugyo Ebolavirus was the least severe.ConclusionsThe pooled CFR and seroprevalence for Ebola and Marburg viruses were found to be lower than usually reported, with species differences despite high heterogeneity between studies. Countries with an improved health surveillance and epidemic response have lower CFR, thereby indicating need for improving early detection and epidemic response in filovirus outbreaks.

Participatory evaluation of delivery of animal health care services by community animal health workers in Karamoja region of Uganda

Aim An evaluation exercise was carried out to assess the performance of Community Animal Health Workers (CAHWs) in the delivery of animal health care services in Karamoja region, identify capacity gaps and recommend remedial measures. Materials & methods Participatory methods were used to design data collection tools. Questionnaires were administered to 204 CAHWs, 215 farmers and 7 District Veterinary Officers (DVOs) to collect quantitative data. Seven DVOs and 1 Non Government Organization (NGO) representative were interviewed as key informants and one focus group discussion was conducted with a farmer group in Nakapiripirit to collect qualitative data. Questionnaire data was analyzed using SPSS version 19. Key messages from interviews and the focus group discussion were recorded in a notebook and reported verbatim. Results 70% of the farmers revealed that CAHWs are the most readily available animal health care service providers in their respective villages. CAHWs were instrumental in treatment of sick animals, disease surveillance, control of external parasites, animal production, vaccination, reporting, animal identification, and performing minor surgeries. Regarding their overall performance 88.8%(191/215) of the farmers said they were impressed. The main challenges faced by the CAHWs were inadequate facilitation, lack of tools and equipments, unwillingness of government to integrate them into the formal extension system, poor information flow, limited technical capacity to diagnose diseases, unwillingness of farmers to pay for services and sustainability issues. Conclusions and recommendations CAHWs remain the main source of animal health care services in Karamoja region and their services are largely satisfactory. The technical deficits identified require continuous capacity building programs, close supervision and technical backstopping. For sustainability of animal health care services in the region continuous training and strategic deployment of paraprofessionals that are formally recognised by the traditional civil service to gradually replace CAHWs is recommended.