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1.
Emerg Infect Dis ; 29(6): 1206-1209, 2023 06.
Article in English | MEDLINE | ID: mdl-37022936

ABSTRACT

Tanapox is a rarely diagnosed zoonosis known to be endemic to equatorial Africa. All previously reported human cases were acquired within 10° north or south of the Equator, most recently 19 years ago. We describe a human case of tanapox in South Africa (24° south of the Equator). Expanded surveillance for this pathogen is warranted.


Subject(s)
Poxviridae Infections , Yatapoxvirus , Animals , Humans , South Africa/epidemiology , Zoonoses , Poxviridae Infections/diagnosis
2.
Emerg Infect Dis ; 27(12): 3159-3162, 2021 12.
Article in English | MEDLINE | ID: mdl-34808090

ABSTRACT

We detected Rift Valley fever virus (RVFV) IgM and IgG in human serum samples collected during 2018-2019 in northern KwaZulu-Natal Province, South Africa. Our results show recent RVFV circulation and likely RVFV endemicity in this tropical coastal plain region of South Africa in the absence of apparent clinical disease.


Subject(s)
Rift Valley Fever , Rift Valley fever virus , Animals , Antibodies, Viral , Humans , Rift Valley Fever/epidemiology , Seroepidemiologic Studies , South Africa/epidemiology
3.
Emerg Infect Dis ; 25(2): 338-341, 2019 02.
Article in English | MEDLINE | ID: mdl-30666946

ABSTRACT

Phylogenetic analysis of Rift Valley fever virus partial genomic sequences from a patient infected in South Africa in May 2018 suggests reemergence of an endemic lineage different from that of the epidemic in South Africa during 2010-2011. Surveillance during interepidemic periods should be intensified to better predict future epidemics.


Subject(s)
Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/virology , Disease Outbreaks , Rift Valley Fever/epidemiology , Rift Valley Fever/virology , Rift Valley fever virus , Communicable Diseases, Emerging/history , History, 21st Century , Humans , Phylogeny , Population Surveillance , Rift Valley Fever/history , Rift Valley fever virus/classification , Rift Valley fever virus/genetics , Rift Valley fever virus/immunology , Seasons , South Africa/epidemiology , Viral Proteins/genetics
4.
BMC Infect Dis ; 14: 694, 2014 Dec 16.
Article in English | MEDLINE | ID: mdl-25510622

ABSTRACT

BACKGROUND: Influenza and respiratory syncytial virus (RSV) infection are common causes of lower respiratory tract illness. Data on their burden in low and middle-income settings and from Africa are scarce. We aimed to estimate age-specific rates of hospitalization attributable to influenza and RSV among patients attending private hospitals in South Africa during 2007-2012. METHODS: We estimated annual age-specific rates of influenza- and RSV-associated hospitalization (that is respiratory hospitalizations likely due to influenza or RSV infection) by applying regression models to monthly administrative hospitalization data from a national private hospital group, using influenza and RSV surveillance data as covariates. RESULTS: Estimated mean hospitalization rates associated with seasonal influenza were 75 (95% confidence interval (CI), 41-108) and 3 (95% CI, 2-5) per 100,000 person-years for all-respiratory and all-circulatory causes, respectively. Children <1 year and adults ≥75 years were the most affected, with influenza-associated all-respiratory hospitalization rates estimated at 255 (95% CI, 143-358) and 380 (95% CI, 227-506) per 100,000 person-years, respectively. Excess all-circulatory hospitalizations associated with seasonal influenza were only observed in adults ≥65 years. Annual hospitalization rates associated with RSV averaged an estimate of 223 (95% CI, 128-317) per 100,000 person-years for all-respiratory causes. Among children <1 year, RSV-associated all-respiratory hospitalization rate of 7,601 (95% CI, 4,312-10,817) per 100,000 person-years was estimated. CONCLUSIONS: Influenza and RSV substantially contributed to hospitalizations over the study period.


Subject(s)
Hospitalization/statistics & numerical data , Hospitals, Private , Influenza, Human/epidemiology , Respiratory Syncytial Virus Infections/epidemiology , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Regression Analysis , South Africa/epidemiology , Young Adult
5.
Sex Transm Dis ; 40(11): 846-51, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24113405

ABSTRACT

BACKGROUND: South Africa recommends universal syphilis and HIV testing in pregnancy, with prompt antiretroviral therapy or penicillin treatment for women testing positive. METHODS: We used a multistage, purposeful sampling strategy to retrospectively identify clinical records from a sample (7.3%) of 32,518 women delivering from January 2005 to June 2006 at 6 public clinics in the Northern Cape and Gauteng. Descriptive analyses and logistic regression were used to assess coverage and factors related to testing and treatment of HIV and syphilis. RESULTS: Of 2379 women sampled, 93% accessed antenatal care (ANC) services during pregnancy and 71% before the third pregnancy trimester. Testing during pregnancy or delivery was 74% for HIV and 84% for syphilis; testing at the first ANC visit was 41% and 71%; and infection prevalence at delivery was 14% and 5%, respectively. Of 243 women with reactive HIV tests, 104 (43%) had treatment documented (single-dose nevirapine) before delivery. Of 98 women with reactive syphilis tests, 73% had documented receipt of 1 penicillin injection and 36% had all 3 recommended injections. Multivariable analysis found women tested for syphilis were almost 4 times more likely to have had no HIV test compared with those without syphilis testing (adjusted odds ratios, 3.9; 95% confidence interval, 1.7-5.5). CONCLUSIONS: Integration and provision of a package of HIV and syphilis testing at the first ANC visit and decentralizing treatments of both infections to primary care settings could increase the coverage of testing and treatment services, thus enhancing the effectiveness of current programs eliminating mother-to-child transmission of HIV and syphilis.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Anti-HIV Agents/therapeutic use , HIV Infections/transmission , Infectious Disease Transmission, Vertical , Penicillins/therapeutic use , Pregnancy Complications, Infectious/prevention & control , Prenatal Care/methods , Syphilis/transmission , Adolescent , Adult , Cost-Benefit Analysis , Female , HIV Infections/drug therapy , HIV Infections/prevention & control , Humans , Infant, Newborn , Mass Screening , Practice Guidelines as Topic , Pregnancy , Pregnancy Complications, Infectious/drug therapy , Prevalence , Retrospective Studies , Sentinel Surveillance , South Africa/epidemiology , Syphilis/drug therapy , Syphilis/prevention & control
6.
Sex Transm Dis ; 39(7): 531-6, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22706215

ABSTRACT

BACKGROUND: To determine sexually transmitted infection (STI) prevalence, and patient characteristics associated with detection of urethritis/cervicitis pathogens, among HIV-infected individuals offered voluntary STI screening at a South African HIV treatment center. METHODS: Individuals, asymptomatic for genital discharge, were screened for Neisseria gonorrhoeae (NG), Chlamydia trachomatis, Trichomonas vaginalis (TV), Mycoplasma genitalium (MG) infections (real-time polymerase chain reaction assay), for syphilis and herpes simplex type 2 (serologically), and for bacterial vaginosis and Candida (microscopy, women only). Patients' most recent CD4 and viral load results were recorded. Demographic, clinical, and behavioral data were collected by nurse-administered questionnaire. RESULTS: Compared with men (n = 551), women (n = 558) were younger (mean age, 35.0 vs. 37.9 years; P < 0.001), reported more STIs in the past year (65.5% vs. 56.5%; P = 0.002), had more urethritis/cervicitis pathogens detected (21.3% vs.16.4%, P = 0.035), and were less aware of their partner's HIV status (53.1% vs. 62.3%; P = 0.007). The overall prevalence of individual urethritis/cervicitis pathogens was TV (7.6%), MG (6.1%), NG (5.4%), and C. trachomatis (2.1%). Multivariate analysis highlighted 4 significant factors associated with the detection of specific urethritis/cervicitis pathogens, namely female gender (TV, adjusted odds ratio [aOR] 2.53, 95% confidence interval [CI]: 1.47-4.37), having a regular sexual partner in the past 3 months (NG, aOR 2.26, 95% CI: 1.01-5.08), suboptimal condom use with regular partners (TV, aOR 2.07, 95% CI: 1.25-3.42), and a history of genital warts in the past year (NG, 2.25, 95% CI: 1.26-4.03). CONCLUSIONS: Asymptomatic urethritis/cervicitis pathogens were highly prevalent in this population. Few urethritis/cervicitis pathogen-associated patient characteristics were identified, emphasizing the need for affordable STI diagnostics to screen HIV-infected patients.


Subject(s)
AIDS-Related Opportunistic Infections/epidemiology , Chlamydia trachomatis/isolation & purification , Mycoplasma genitalium/pathogenicity , Neisseria gonorrhoeae/isolation & purification , Trichomonas vaginalis/isolation & purification , Urethritis/epidemiology , Uterine Cervicitis/epidemiology , AIDS-Related Opportunistic Infections/microbiology , AIDS-Related Opportunistic Infections/parasitology , AIDS-Related Opportunistic Infections/prevention & control , Adult , Aged , Algorithms , CD4 Lymphocyte Count , Cross-Sectional Studies , Female , HIV Seropositivity , Humans , Male , Mass Screening , Middle Aged , Polymerase Chain Reaction/methods , Prevalence , Risk Factors , Sexual Partners , South Africa/epidemiology , Urethritis/microbiology , Urethritis/prevention & control , Uterine Cervicitis/microbiology , Uterine Cervicitis/prevention & control , Viral Load
7.
Trop Med Infect Dis ; 7(2)2022 Feb 16.
Article in English | MEDLINE | ID: mdl-35202223

ABSTRACT

Abattoir workers may contract Q fever by inhalation of Coxiella burnetii bacteria in aerosols generated by slaughtering livestock, or in contaminated dust. We estimated the seroprevalence of C. burnetii and examined the associated factors in a survey of South African abattoir workers. Coxiella burnetii seropositivity was determined by detection of IgG antibodies against C. burnetii phase II antigen. Logistic regression, adjusted for clustering and sampling fraction, was employed to analyze risk factors associated with C. burnetii seropositivity. Among 382 workers from 16 facilities, the overall seroprevalence was 33% (95% confidence interval (CI): 28-38%) and ranged from 8% to 62% at the facility level. Prolonged contact with carcasses or meat products (odds ratio (OR): 4.6, 95% CI: 1.51-14.41) and prior abattoir or butchery work experience (OR: 1.9, 95% CI: 1.13-3.17) were associated with C. burnetii seropositivity. In contrast, increasing age and livestock ownership were inversely associated. Precautions to protect abattoir personnel from Q fever are discussed.

8.
Vaccine ; 40(40): 5806-5813, 2022 09 22.
Article in English | MEDLINE | ID: mdl-36058795

ABSTRACT

BACKGROUND: Crimean-Congo haemorrhagic fever (CCHF) is a priority emerging pathogen for which a licensed vaccine is not yet available. We aim to assess the feasibility of conducting phase III vaccine efficacy trials and the role of varying transmission dynamics. METHODS: We calibrate models of CCHF virus (CCHFV) transmission among livestock and spillover to humans in endemic areas in Afghanistan, Turkey and South Africa. We propose an individual randomised controlled trial targeted to high-risk population, and use the calibrated models to simulate trial cohorts to estimate the minimum necessary number of cases (trial endpoints) to analyse a vaccine with a minimum efficacy of 60%, under different conditions of sample size and follow-up time in the three selected settings. RESULTS: A mean follow-up of 160,000 person-month (75,000-550,000) would be necessary to accrue the required 150 trial endpoints for a target vaccine efficacy of 60 % and clinically defined endpoint, in a setting like Herat, Afghanistan. For Turkey, the same would be achieved with a mean follow-up of 175,000 person-month (50,000-350,000). The results suggest that for South Africa the low endemic transmission levels will not permit achieving the necessary conditions for conducting this trial within a realistic follow-up time. In the scenario of CCHFV vaccine trial designed to capture infection as opposed to clinical case as a trial endpoint, the required person-months is reduced by 70 % to 80 % in Afghanistan and Turkey, and in South Africa, a trial becomes feasible for a large number of person-months of follow-up (>600,000). Increased expected vaccine efficacy > 60 % will reduce the required number of trial endpoints and thus the sample size and follow-time in phase III trials. CONCLUSIONS: Underlying endemic transmission levels will play a central role in defining the feasibility of phase III vaccine efficacy trials. Endemic settings in Afghanistan and Turkey offer conditions under which such studies could feasibly be conducted.


Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Vaccines , Animals , Hemorrhagic Fever, Crimean/epidemiology , Hemorrhagic Fever, Crimean/prevention & control , Humans , Livestock , Vaccine Efficacy
9.
Transbound Emerg Dis ; 69(5): e1899-e1912, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35306739

ABSTRACT

Biosecurity measures have been introduced to limit economic losses and zoonotic exposures to humans by preventing and controlling animal diseases. However, they are implemented on individual farms with varying frequency. The goal of this study was to evaluate which biosecurity measures were used by farmers to prevent infectious diseases in ruminant livestock and to identify factors that influenced these decisions. We conducted a survey in 264 ruminant livestock farmers in a 40,000 km2 area in the Free State and Northern Cape provinces of South Africa. We used descriptive statistics, to characterize biosecurity measures and farm attributes, then multivariable binomial regression to assess the strength of the association between the attributes and the implementation of biosecurity measures including property fencing, separate equipment use on different species, separate rearing of species, isolation of sick animals, isolation of pregnant animals, quarantine of new animals, animal transport cleaning, vaccination, tick control and insect control. Ninety-nine percent of farmers reported using at least one of the 10 biosecurity measures investigated (median [M]: 6; range: 0-10). The most frequently used biosecurity measures were tick control (81%, 214 out of 264), vaccination (80%, 211 out of 264) and isolation of sick animals (72%, 190 out of 264). More biosecurity measures were used on farms with 65-282 animals (M: 6; odds ratio [OR]: 1.52) or farms with 283-12,030 animals (M: 7; OR: 1.87) than on farms with fewer than 65 animals (M: 4). Furthermore, farmers who kept two animal species (M: 7; OR: 1.41) or three or more species (M: 7) used more biosecurity measures than single-species operations (M: 4). Farmers with privately owned land used more biosecurity measures (M: 6; OR: 1.51) than those grazing their animals on communal land (M: 3.5). Farms that reported previous Rift Valley fever (RVF) outbreaks used more biosecurity measures (M: 7; OR: 1.25) compared with farms without RVF reports (M: 6) and those that purchased animals in the 12 months prior to the survey (M: 7; OR: 1.19) compared with those that did not (M: 6). When introducing new animals into their herds (n = 122), most farmers used fewer biosecurity measures than they did for their existing herd: 34% (41 out of 122) used multiple biosecurity measures like those of vaccination, tick control, quarantine or antibiotic use, whereas 36% (44 out of 122) used only one and 30% (37 out of 122) used none. Certain farm features, primarily those related to size and commercialization, were associated with more frequent use of biosecurity measures. Given the variation in the application of biosecurity measures, more awareness and technical assistance are needed to support the implementation of a biosecurity management plan appropriate for the type of farm operation and available resources.


Subject(s)
Communicable Diseases , Rift Valley Fever , Animal Husbandry , Animals , Anti-Bacterial Agents , Biosecurity , Communicable Diseases/veterinary , Farmers , Farms , Humans , Livestock , Ruminants , South Africa/epidemiology , Surveys and Questionnaires
10.
BMC Infect Dis ; 11: 253, 2011 Sep 26.
Article in English | MEDLINE | ID: mdl-21943076

ABSTRACT

BACKGROUND: To evaluate the knowledge, attitudes and beliefs about adult male circumcision (AMC), assess the association of AMC with HIV incidence and prevalence, and estimate AMC uptake in a Southern African community. METHODS: A cross-sectional biomedical survey (ANRS-12126) conducted in 2007-2008 among a random sample of 1198 men aged 15 to 49 from Orange Farm (South Africa). Face-to-face interviews were conducted by structured questionnaire. Recent HIV infections were evaluated using the BED incidence assay. Circumcision status was self-reported and clinically assessed. Adjusted HIV incidence rate ratios (aIRR) and prevalence ratios (aPR) were calculated using Poisson regression. RESULTS: The response rate was 73.9%. Most respondents agreed that circumcised men could become HIV infected and needed to use condoms, although 19.3% (95%CI: 17.1% to 21.6%) asserted that AMC protected fully against HIV. Among self-reported circumcised men, 44.9% (95%CI: 39.6% to 50.3%) had intact foreskins. Men without foreskins had lower HIV incidence and prevalence than men with foreskins (aIRR = 0.35; 95%CI: 0.14 to 0.88; aPR = 0.45, 95%CI: 0.26 to 0.79). No significant difference was found between self-reported circumcised men with foreskins and other uncircumcised men. Intention to undergo AMC was associated with ethnic group and partner and family support of AMC. Uptake of AMC was 58.8% (95%CI: 55.4% to 62.0%). CONCLUSIONS: AMC uptake in this community is high but communication and counseling should emphasize what clinical AMC is and its effect on HIV acquisition. These findings suggest that AMC roll-out is promising but requires careful implementation strategies to be successful against the African HIV epidemic.


Subject(s)
Circumcision, Male/statistics & numerical data , HIV Infections/prevention & control , Health Knowledge, Attitudes, Practice , Patient Acceptance of Health Care/statistics & numerical data , Adolescent , Adult , Cross-Sectional Studies , Humans , Male , Middle Aged , South Africa , Surveys and Questionnaires , Young Adult
11.
PLoS Negl Trop Dis ; 15(9): e0009669, 2021 09.
Article in English | MEDLINE | ID: mdl-34529659

ABSTRACT

BACKGROUND: Schistosomiasis, also known as bilharzia, is a chronic parasitic blood fluke infection acquired through contact with contaminated surface water. The illness may be mild or can cause significant morbidity with potentially serious complications. Children and those living in rural areas with limited access to piped water and services for healthcare are the most commonly infected. To address the prevalence of the disease in parts of South Africa (SA) effective national control measures are planned, but have not yet been implemented. This study aimed to estimate the prevalence and trends of public sector laboratory-confirmed schistosomiasis cases in SA over an eight-year (2011-2018) period, to inform future control measures. METHODOLOGY & PRINCIPAL FINDINGS: This is a descriptive analysis of secondary data from the National Health Laboratory Service (NHLS). The study included all records of patients for whom microscopic examination detected Schistosoma species eggs in urine or stool specimens from January 2011 to December 2018. Crude estimates of the prevalence were calculated using national census mid-year provincial population estimates as denominators, and simple linear regression was used to analyse prevalence trends. A test rate ratio was developed to describe variations in testing volumes among different groups and to adjust prevalence estimates for testing variations. A total number of 135 627 schistosomiasis cases was analysed with the highest prevalence observed among males and individuals aged 5-19 years. We describe ongoing endemicity in the Eastern Cape Province, and indicate important differences in the testing between population groups. CONCLUSION: While there was no overall change in the prevalence of schistosomiasis during the analysis period, an average of 36 people per 100 000 was infected annually. As such, this represents an opportunity to control the disease and improve quality of life of affected people. Laboratory-based surveillance is a useful method for reporting occurrence and evaluating future intervention programs where resources to implement active surveillance are limited.


Subject(s)
Schistosomiasis/epidemiology , Adolescent , Adult , Anthelmintics/therapeutic use , Child , Child, Preschool , Female , Humans , Infant , Male , Praziquantel/therapeutic use , Prevalence , Public Health , Schistosomiasis/prevention & control , South Africa/epidemiology , Time Factors , Young Adult
12.
PLoS Negl Trop Dis ; 15(5): e0009384, 2021 05.
Article in English | MEDLINE | ID: mdl-34048430

ABSTRACT

Crimean-Congo haemorrhagic fever (CCHF) is a severe tick-borne viral zoonosis endemic to parts of Africa, Europe, the Middle East and Central Asia. Human cases are reported annually in South Africa, with a 25% case fatality rate since the first case was recognized in 1981. We investigated CCHF virus (CCHFV) seroprevalence and risk factors associated with infection in cattle and humans, and the presence of CCHFV in Hyalomma spp. ticks in central South Africa in 2017-18. CCHFV IgG seroprevalence was 74.2% (95%CI: 64.2-82.1%) in 700 cattle and 3.9% (95%CI: 2.6-5.8%) in 541 farm and wildlife workers. No veterinary personnel (117) or abattoir workers (382) were seropositive. The prevalence of CCHFV RNA was significantly higher in Hyalomma truncatum (1.6%) than in H. rufipes (0.2%) (P = 0.002). Seroprevalence in cattle increased with age and was greater in animals on which ticks were found. Seroprevalence in cattle also showed significant geographic variation. Seroprevalence in humans increased with age and was greater in workers who handled livestock for injection and collection of samples. Our findings support previous evidence of widespread high CCHFV seroprevalence in cattle and show significant occupational exposure amongst farm and wildlife workers. Our seroprevalence estimate suggests that CCHFV infections are five times more frequent than the 215 confirmed CCHF cases diagnosed in South Africa in the last four decades (1981-2019). With many cases undiagnosed, the potential seriousness of CCHF in people, and the lack of an effective vaccine or treatment, there is a need to improve public health awareness, prevention and disease control.


Subject(s)
Cattle Diseases/epidemiology , Hemorrhagic Fever Virus, Crimean-Congo/isolation & purification , Hemorrhagic Fever, Crimean/epidemiology , Ixodidae/virology , Seroepidemiologic Studies , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Cattle , Cattle Diseases/parasitology , Cattle Diseases/virology , Female , Hemorrhagic Fever Virus, Crimean-Congo/immunology , Hemorrhagic Fever, Crimean/etiology , Humans , Immunoglobulin G/blood , Male , Middle Aged , Occupational Exposure , Prevalence , Risk Factors , South Africa/epidemiology , Tick Infestations/veterinary
13.
Viruses ; 13(8)2021 08 19.
Article in English | MEDLINE | ID: mdl-34452515

ABSTRACT

Diagnostic performance of an indirect enzyme-linked immunosorbent assay (I-ELISA) based on a recombinant nucleocapsid protein (rNP) of the Rift Valley fever virus (RVFV) was validated for the detection of the IgG antibody in sheep (n = 3367), goat (n = 2632), and cattle (n = 3819) sera. Validation data sets were dichotomized according to the results of a virus neutralization test in sera obtained from RVF-endemic (Burkina Faso, Democratic Republic of Congo, Mozambique, Senegal, Uganda, and Yemen) and RVF-free countries (France, Poland, and the USA). Cut-off values were defined using the two-graph receiver operating characteristic analysis. Estimates of the diagnostic specificity of the RVFV rNP I-ELISA in animals from RVF-endemic countries ranged from 98.6% (cattle) to 99.5% (sheep) while in those originating from RVF-free countries, they ranged from 97.7% (sheep) to 98.1% (goats). Estimates of the diagnostic sensitivity in ruminants from RVF-endemic countries ranged from 90.7% (cattle) to 100% (goats). The results of this large-scale international validation study demonstrate the high diagnostic accuracy of the RVFV rNP I-ELISA. Standard incubation and inactivation procedures evaluated did not have an adverse effect on the detectable levels of the anti-RVFV IgG in ruminant sera and thus, together with recombinant antigen-based I-ELISA, provide a simple, safe, and robust diagnostic platform that can be automated and carried out outside expensive bio-containment facilities. These advantages are particularly important for less-resourced countries where there is a need to accelerate and improve RVF surveillance and research on epidemiology as well as to advance disease control measures.


Subject(s)
Antibodies, Viral/blood , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin G/blood , Rift Valley Fever/blood , Rift Valley fever virus/immunology , Animals , Cattle/blood , Goats/blood , Nucleocapsid Proteins/genetics , Nucleocapsid Proteins/immunology , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Rift Valley Fever/diagnosis , Rift Valley Fever/immunology , Rift Valley Fever/virology , Rift Valley fever virus/genetics , Rift Valley fever virus/isolation & purification , Sheep/blood
14.
Sci Rep ; 10(1): 5489, 2020 03 26.
Article in English | MEDLINE | ID: mdl-32218486

ABSTRACT

Rift Valley fever (RVF) is a mosquito-borne viral zoonosis showing complex epidemiological patterns that are poorly understood in South Africa. Large outbreaks occur in the central interior at long, irregular intervals, most recently in 2010-2011; however, the level of herd immunity of ruminant livestock, a key determinant of outbreaks, is unknown. During 2015-2016 a cross-sectional study on 234 randomly-selected farms investigated the prevalence, patterns of, and factors associated with, antibodies to RVF virus (RVFV) in livestock in an area heavily affected by that outbreak. A RVFV inhibition ELISA was used to screen 977 cattle, 1,549 sheep and 523 goats and information on potential risk factors was collected using a comprehensive questionnaire. The estimated RVFV seroprevalence, adjusted for survey design, was 42.9% in cattle, 28.0% in sheep and 9.3% in goats, showing a high degree of farm-level clustering. Seroprevalence increased with age and was higher on private vs. communal land, on farms with seasonal pans (temporary, shallow wetlands) and perennial rivers and in recently vaccinated animals. Seropositivity amongst unvaccinated animals born after the last outbreak indicates likely viral circulation during the post-epidemic period. The current level of herd immunity in livestock may be insufficient to prevent another large outbreak, should suitable conditions recur.


Subject(s)
Rift Valley Fever/epidemiology , Animals , Antibodies, Viral/blood , Cattle , Cattle Diseases/epidemiology , Cross-Sectional Studies , Disease Outbreaks/veterinary , Female , Goat Diseases/epidemiology , Goats , Immunity, Herd , Male , Rift Valley Fever/immunology , Rift Valley Fever/prevention & control , Rift Valley fever virus/immunology , Risk Factors , Seroepidemiologic Studies , Sheep , Sheep Diseases/epidemiology , Sheep, Domestic , South Africa/epidemiology , Vaccination/veterinary , Zoonoses/epidemiology , Zoonoses/immunology , Zoonoses/prevention & control
15.
Travel Med Infect Dis ; 36: 101766, 2020.
Article in English | MEDLINE | ID: mdl-32525075

ABSTRACT

BACKGROUND: Sixty cases of rabies in international travellers from 1990 to 2012 were previously reviewed. We present here an update of rabies cases in international travellers from 2013 to 2019. METHODS: We systematically reviewed the existing literature and collected 23 cases of rabies in individuals who crossed an international border between the time of infection and diagnosis, or who were infected following expatriation or migration. RESULTS: Most cases were in male adult travellers and diagnosed in Europe and the Middle East, with most exposures in Asia or in Africa. Migrants originating from rabies-endemic low-and-middle income countries and their descendants accounted for two thirds of cases. Other cases were in tourists, business travellers and expatriates. Median travel duration (excluding migration trip) was 60 days (range 7-240 days). Most cases were due to dog bites and most common clinical presentation was furious rabies. In most patients (74%), no rabies post-exposure prophylaxis (RPEP) was administered before rabies symptoms appeared. Other patients received incomplete RPEP series. CONCLUSION: Rabies should be suspected in any patient with encephalitis or paralysis who travelled to, or migrated from a rabies-endemic country. Comprehensive information about a rabies risk should be given to travellers to rabies endemic countries, notably migrants visiting friends and relatives.


Subject(s)
Rabies , Travel-Related Illness , Adult , Africa , Animals , Asia , Dogs , Europe , Humans , Male , Middle East , Rabies/epidemiology , Retrospective Studies , Travel
17.
Viruses ; 11(8)2019 07 24.
Article in English | MEDLINE | ID: mdl-31344850

ABSTRACT

Filovirus serological diagnosis and epidemiological investigations are hampered due to the unavailability of validated immunoassays. Diagnostic performance of three indirect enzyme-linked immunosorbent assays (I-ELISA) was evaluated for the detection of IgG antibody to Ebola virus (EBOV) in human sera. One I-ELISA was based on a whole EBOV antigen (WAg) and two utilized recombinant nucleocapsid (NP) and glycoproteins (GP), respectively. Validation data sets derived from individual sera collected in South Africa (SA), representing an EBOV non-endemic country, and from sera collected during an Ebola disease (EBOD) outbreak in Sierra Leone (SL), were categorized according to the compounded results of the three I-ELISAs and real time reverse-transcription polymerase chain reaction (RT-PCR). At the cut-off values selected at 95% accuracy level by the two-graph receiver operating characteristic analysis, specificity in the SA EBOV negative serum panel (n = 273) ranged from 98.17% (GP ELISA) to 99.27% (WAg ELISA). Diagnostic specificity in the SL EBOV negative panel (n = 676) was 100% by the three ELISAs. The diagnostic sensitivity in 423 RT-PCR confirmed EBOD patients was dependent on the time when the serum was collected after onset of disease. It significantly increased 2 weeks post-onset, reaching 100% sensitivity by WAg and NP and 98.1% by GP I-ELISA.


Subject(s)
Antibodies, Viral/blood , Enzyme-Linked Immunosorbent Assay , Hemorrhagic Fever, Ebola/blood , Hemorrhagic Fever, Ebola/diagnosis , Immunoglobulin G/blood , Antigens, Viral/immunology , Disease Outbreaks , Ebolavirus , Glycoproteins/immunology , Humans , Nucleocapsid Proteins/immunology , Sensitivity and Specificity , Sierra Leone , South Africa
18.
Viruses ; 11(2)2019 02 07.
Article in English | MEDLINE | ID: mdl-30736488

ABSTRACT

Rift Valley fever (RVF) is a re-emerging arboviral disease of public health and veterinary importance in Africa and the Arabian Peninsula. Major RVF epidemics were documented in South Africa in 1950⁻1951, 1974⁻1975, and 2010⁻2011. The number of individuals infected during these outbreaks has, however, not been accurately estimated. A total of 823 people in close occupational contact with livestock were interviewed and sampled over a six-month period in 2015⁻2016 within a 40,000 km² study area encompassing parts of the Free State and Northern Cape provinces that were affected during the 2010⁻2011 outbreak. Seroprevalence of RVF virus (RVFV) was 9.1% (95% Confidence Interval (CI95%): 7.2⁻11.5%) in people working or residing on livestock or game farms and 8.0% in veterinary professionals. The highest seroprevalence (SP = 15.4%; CI95%: 11.4⁻20.3%) was detected in older age groups (≥40 years old) that had experienced more than one known large epidemic compared to the younger participants (SP = 4.3%; CI95%: 2.6⁻7.3%). The highest seroprevalence was in addition found in people who injected animals, collected blood samples (Odds ratio (OR) = 2.3; CI95%: 1.0⁻5.3), slaughtered animals (OR = 3.9; CI95%: 1.2⁻12.9) and consumed meat from an animal found dead (OR = 3.1; CI95%: 1.5⁻6.6), or worked on farms with dams for water storage (OR = 2.7; CI95%: 1.0⁻6.9). We estimated the number of historical RVFV infections of farm staff in the study area to be most likely 3849 and 95% credible interval between 2635 and 5374 based on seroprevalence of 9.1% and national census data. We conclude that human RVF cases were highly underdiagnosed and heterogeneously distributed. Improving precautions during injection, sample collection, slaughtering, and meat processing for consumption, and using personal protective equipment during outbreaks, could lower the risk of RVFV infection.


Subject(s)
Antibodies, Viral/blood , Farmers/statistics & numerical data , Occupational Exposure , Rift Valley Fever/epidemiology , Veterinarians/statistics & numerical data , Adolescent , Adult , Age Factors , Aged , Animals , Cross-Sectional Studies , Epidemics/prevention & control , Female , Health Knowledge, Attitudes, Practice , Humans , Livestock/virology , Logistic Models , Male , Middle Aged , Red Meat/virology , Rift Valley fever virus , Seroepidemiologic Studies , South Africa/epidemiology , Surveys and Questionnaires , Young Adult
19.
Vector Borne Zoonotic Dis ; 18(12): 713-715, 2018 12.
Article in English | MEDLINE | ID: mdl-30183525

ABSTRACT

Major Rift Valley fever (RVF) epidemics in South Africa occur at irregular intervals, usually spanning several decades, with human cases rarely reported in the absence of widespread outbreaks in livestock. This report describes four cases of RVF in farm workers associated with an isolated outbreak on a sheep farm in the Free State Province of South Africa, in 2018. In contrast to the last major RVF epidemic in South Africa in 2010-2011, where detection of human cases served as an alert for an ongoing outbreak in livestock, the current isolated outbreak was first detected in livestock, and human cases recognized following subsequent epidemiological investigation. This highlights the importance of early recognition of livestock cases in reducing risk and impact of a subsequent RVF epidemic in humans. People working with animals should be aware of transmission routes and take precautions to minimize risk of infection.


Subject(s)
Rift Valley Fever/epidemiology , Adult , Animals , Female , Humans , Male , Middle Aged , Sheep , Sheep Diseases/epidemiology , Sheep Diseases/virology , South Africa/epidemiology , Young Adult , Zoonoses
20.
Pediatr Infect Dis J ; 32(12): 1359-64, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24569308

ABSTRACT

BACKGROUND: Oral rotavirus vaccine was introduced into the South African routine immunization program in August 2009 administered at 6 and 14 weeks with no catch-up. We described the change in rotavirus-associated diarrheal hospitalizations among children <5 years at 3 sentinel sites from 2009 through 2011. METHODS: During 2009 through 2011, we compared the proportion of enrolled children aged <5 years hospitalized with acute gastroenteritis and testing rotavirus positive. We used hospital data to determine the change in diarrhea hospitalizations and estimated total numbers of rotavirus hospitalizations by adjusting for nonenrolled patients. Stool samples were tested for rotavirus using enzyme immunoassay. RESULTS: In 2009 (May-December), 46% (404/883) of samples among children <5 years tested rotavirus positive, decreasing to 33% (192/580) (P < 0.001) in 2010 and 29% (113/396) (P < 0.001) in 2011. Compared with May-December 2009, total diarrhea hospitalizations among children aged <5 years was one-third lower in May-December of 2010 and 2011. Among infants, adjusted rotavirus hospitalizations were 61% (n = 267) and 69% (n = 214) lower, respectively, in 2010 and 2011 when compared with 2009 (n = 689), and 45 and 50 percentage points greater than the reduction in rotavirus-negative cases. Among children <5 years, rotavirus hospitalizations were 54% and 58% lower in 2010 and 2011, compared with 2009 (40 and 44 percentage points greater than reduction in rotavirus-negative cases). Rotavirus reductions occurred in rural and urban settings. CONCLUSION: Using published estimates of rotavirus hospitalization burden, we estimate that at least 13,000 to 20,000 hospitalizations in children <2 years were prevented in the 2 years after rotavirus vaccine introduction.


Subject(s)
Diarrhea/epidemiology , Immunization Programs/statistics & numerical data , Rotavirus Infections/epidemiology , Rotavirus Vaccines/administration & dosage , Child, Preschool , Diarrhea/prevention & control , Diarrhea/virology , Hospitalization , Humans , Infant , Infant, Newborn , Prospective Studies , Rotavirus Infections/prevention & control , South Africa/epidemiology
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