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"Moonsamy, Shelina"
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Prevalence and incidence rates of laboratory-confirmed hepatitis B infection in South Africa, 2015 to 2019
2022
Background
Hepatitis B virus (HBV), a global public health threat, is targeted for elimination by 2030. As national HBV prevalence and incidence is lacking for South Africa, our study aimed to provide such data in the public health sector.
Methods
We analysed laboratory-confirmed HBV data from 2015 to 2019 to determine annual prevalence and incidence rates of HBV infection per 100,000 population, HBsAg and anti-HBc IgM test positivity rates, and HBsAg and anti-HBc IgM testing rates per 100,000 population. Time trend and statistical analyses were performed on HBsAg and anti-HBc IgM test positivity rates.
Results
The national prevalence rate of HBV infection per 100,000 population increased from 56.14 in 2015 to 67.76 in 2019. Over the five years, the prevalence rate was higher in males than females, highest amongst individuals 25 to 49 years old and highest in Gauteng province. The HBsAg test positivity rate dropped from 9.77% in 2015 to 8.09% in 2019. Over the five years, the HBsAg test positivity rate was higher in males than females, amongst individuals 25 to 49 years old and amongst individuals of Limpopo province. Amongst HBsAg positive children under 5 years old, the majority (65.7%) were less than a year old. HBsAg testing rates per 100,000 population were higher in females under 45 years of age and in males 45 years and above. The national incidence rate of acute HBV infection per 100,000 population dropped from 3.17 in 2015 to 1.69 in 2019. Over the five-year period, incidence rates were similar between males and females, highest amongst individuals 20 to 39 years old and highest in Mpumalanga province. Amongst individuals 20 to 24 years old, there was a substantial decline in the incidence and anti-HBc IgM test positivity rates over time. Anti-HBc IgM testing rates per 100,000 population were higher in females under 40 years of age and in males 40 years and above.
Conclusion
Critical to hepatitis B elimination is strengthened infant vaccination coverage and interruption of vertical transmission. Transmission of HBV infection in adults may be reduced through heightened awareness of transmission routes and prevention measures.
Journal Article
SARS-CoV-2 genomic surveillance in wastewater as a model for monitoring evolution of endemic viruses
2023
As global SARS-CoV-2 burden and testing frequency have decreased, wastewater surveillance has emerged as a key tool to support clinical surveillance efforts. The aims of this study were to identify and characterize SARS-CoV-2 variants in wastewater samples collected from urban centers across South Africa. Here we show that wastewater sequencing analyses are temporally concordant with clinical genomic surveillance and reveal the presence of multiple lineages not detected by clinical surveillance. We show that wastewater genomics can support SARS-CoV-2 epidemiological investigations by reliably recovering the prevalence of local circulating variants, even when clinical samples are not available. Further, we find that analysis of mutations observed in wastewater can provide a signal of upcoming lineage transitions. Our study demonstrates the utility of wastewater genomics to monitor evolution and spread of endemic viruses.
SARS-CoV-2 wastewater surveillance could provide an important means of monitoring population trends as clinical testing decreases. Here, the authors demonstrate the use of wastewater to track variants of concern through a sentinel wastewater surveillance system in South Africa.
Journal Article
Effect of HIV-exposure and timing of anti-retroviral treatment on immunogenicity of trivalent live-attenuated polio vaccine in infants
by
Suchard, Melinda
,
Moonsamy, Shelina
,
Madhi, Shabir A.
in
Anti-Retroviral Agents - therapeutic use
,
Antibodies, Viral - immunology
,
Antiretroviral agents
2019
The prevalence of HIV infection in South African pregnant women has been approximately 30% over the past decade; however, there has been a steady decline in mother-to-child transmission of HIV from 8% in 2008 to <2% in 2015. We evaluated the immunogenicity of live-attenuated trivalent oral polio vaccine (OPV) following the primary vaccination series (doses at birth, 6, 10 and 14 weeks of age) in HIV-exposed uninfected (HEU), HIV-infected infants initiated on early anti-retroviral treatment (HIV+/ART+), HIV-infected infants on deferred ART (HIV+/ART-) and HIV-unexposed infants (HU) as the referent group.
Serum polio neutralization antibody titres were evaluated to serotype-1, serotype-2 and serotype-3 at 6, 10 and 18 weeks of age. Antibody titres ≥8 were considered seropositive and sero-protective.
At 18 weeks of age, following the complete primary series of four OPV doses, no differences in GMTs, percentage of infants with sero-protective titres and median fold change in antibody titre (18 weeks vs 6 weeks) were observed in HEU infants (n = 114) and HIV+/ART+ infants (n = 162) compared to HU infants (n = 104) for the three polio serotypes. However, comparing HIV+/ART- infants (n = 70) to HU infants at 18 weeks of age, we observed significantly lower GMTs for serotype-1 (p = 0.022), serotype-2 (p<0.001) and serotype-3 (p<0.001), significantly lower percentages of infants with sero-protective titres for the three serotypes (p<0.001), and significantly lower median fold change in antibody titre for serotype-1 (p = 0.048), serotype-2 (p = 0.003) and serotype-3 (p = 0.008).
Delaying initiation of ART in HIV-infected infants was associated with an attenuated immune response to OPV following a four-dose primary series of vaccines, whereas immune responses to OPV in HIV-infected children initiated on ART early in infancy and HEU children were similar to HU infants.
Journal Article
Detection of Campylobacter species in stool specimens from patients with symptoms of acute flaccid paralysis in South Africa
by
Govender, Nevashan
,
Thobela, Mandile Samantha
,
Moonsamy, Shelina
in
acute flaccid paralysis
,
Campylobacter
,
Guillain-Barre syndrome
2018
Introduction: Guillain-Barré Syndrome (GBS) is an autoimmune disease characterized by acute or subacute symmetrical ascending motor weakness, areflexia, and mild-to-moderate sensory abnormalities. Campylobacter jejuni is reported to be the most common bacterium associated with GBS cases. Despite the eradication of polio, the number of reported GBS cases remains considerably high in South Africa with the causative agents not being well described. Methodology: The aim of the study was to investigate the proportion of Campylobacter spp. detected in stool specimens from patients with symptoms of acute flaccid paralysis (AFP). Stool specimens from patients presenting with AFP, that were negative for polio and non-polio enteroviruses (NPENT), were processed and screened for the presence of Campylobacter spp. using quantitative PCR (qPCR). Results: Of the 512 stool specimens screened between October 2014 to December 2015, 12% (62/512) were positive for Campylobacter spp. Of these 62 Campylobacter infections: 77.4% (48/62) was C. jejuni; 19.4% (12/62) was Campylobacter coli; 3.2% (2/62) was mixed infections of C. jejuni and C. coli. Conclusions: True association of the disease with Campylobacter spp. will enable the proportion of Campylobacter-induced GBS to be better described in South Africa; this can only be done through systematic studies that include bacterial culture and serology together with molecular methodologies.
Journal Article
Seroprevalence of polio antibodies in adult laboratory staff in South Africa, 2009 to 2013
2016
The global eradication of polio has been a World Health Organization goal since May 1988 with the current target for global eradication set at 2018. A keystone of the eradication initiative is achieving and maintaining high immunisation coverage, producing high population immunity. Assessing infant vaccination coverage does not give a reliable indication of adult immunity levels as antibody titres decline with age. A requirement of the occupational health programme at the National Institute for Communicable Diseases is to test newly appointed personnel for immunity to polio. During the period 2009 to 2013, 352 sera were collected and tested by means of antibody neutralisation assays to determine immunity to all three polio serotypes. The objective of this study was to assess immunity to polio in personnel employed at the National Institute for Communicable Diseases as a proxy for the general adult South African population. The seroprevalence to polio serotypes 1, 2 and 3 were 85.5, 90.0 and 74.0%, respectively. Of the 352 samples tested, 2.3% were sero-negative for all three serotypes and 36.0% were sero-negative to at least one of the serotypes. The seroprevalence to polio serotype 3 falls below the target of 80.0%, and could pose a potential risk following importation or development of vaccine derived poliovirus type 3.
Journal Article
Seroprevalence of polio antibodies in adult laboratory staff in South Africa, 2009 to 2013
2016
The global eradication of polio has been a World Health Organization goal since May 1988 with the current target for global eradication set at 2018. A keystone of the eradication initiative is achieving and maintaining high immunisation coverage, producing high population immunity. Assessing infant vaccination coverage does not give a reliable indication of adult immunity levels as antibody titres decline with age. A requirement of the occupational health programme at the National Institute for Communicable Diseases is to test newly appointed personnel for immunity to polio. During the period 2009 to 2013, 352 sera were collected and tested by means of antibody neutralisation assays to determine immunity to all three polio serotypes. The objective of this study was to assess immunity to polio in personnel employed at the National Institute for Communicable Diseases as a proxy for the general adult South African population. The seroprevalence to polio serotypes 1, 2 and 3 were 85.5, 90.0 and 74.0%, respectively. Of the 352 samples tested, 2.3% were sero-negative for all three serotypes and 36.0% were sero-negative to at least one of the serotypes. The seroprevalence to polio serotype 3 falls below the target of 80.0%, and could pose a potential risk following importation or development of vaccine derived poliovirus type 3.
Journal Article
Seroprevalence of polio antibodies in adult laboratory staff in South Africa, 2009 to 2013 : survey article
2016
The global eradication of polio has been a World Health Organization goal since May 1988 with the current target for global eradication set at 2018. A keystone of the eradication initiative is achieving and maintaining high immunisation coverage, producing high population immunity. Assessing infant vaccination coverage does not give a reliable indication of adult immunity levels as antibody titres decline with age. A requirement of the occupational health programme at the National Institute for Communicable Diseases is to test newly appointed personnel for immunity to polio. During the period 2009 to 2013, 352 sera were collected and tested by means of antibody neutralisation assays to determine immunity to all three polio serotypes. The objective of this study was to assess immunity to polio in personnel employed at the National Institute for Communicable Diseases as a proxy for the general adult South African population. The seroprevalence to polio serotypes 1, 2 and 3 were 85.5, 90.0 and 74.0%, respectively. Of the 352 samples tested, 2.3% were sero-negative for all three serotypes and 36.0% were sero-negative to at least one of the serotypes. The seroprevalence to polio serotype 3 falls below the target of 80.0%, and could pose a potential risk following importation or development of vaccine derived poliovirus type 3.
Journal Article
Stem Cell Transplant in Immune-deficiency–associated Vaccine-derived Poliovirus
by
Moonsamy, Shelina
,
van Zyl, Walda
,
Phalane, Emmanuel
in
Antibiotics
,
Bone marrow
,
Cerebrospinal fluid
2024
Abstract
Patients with severe primary immunodeficiency are at risk for complications from live-attenuated vaccines. Here, we report a case of a vaccine-associated paralytic polio and Bacille Calmette-Guérin disease in a 6-month-old girl with severe combined immunodeficiency resulting from homozygous recombinant activating gene 1 deficiency. The patient was successfully treated with intravenous immunoglobulins and oral pocapavir for poliovirus, and antimycobacterial therapy for regional Bacille Calmette-Guérin disease, allowing stem cell transplant. Following transplantation, poliovirus type 3 with 13 mutations was detected from cerebrospinal fluid but not from stool, indicating ongoing viral evolution in the central nervous system despite pocapavir treatment. Clinical improvement and immune reconstitution allowed the patient to be successfully discharged with no further detection of poliovirus.
Journal Article
Investigation of Population Immunity to Poliomyelitis in HIV- Infected and Uninfected Infants in South Africa
2016
As we race towards the polio eradication endgame, it is essential to determine the population immunity to poliomyelitis. High immunity plays a vital role in reducing the risk of poliovirus transmission in an outbreak situation. One of the cornerstones of the global polio eradication initiative is to achieve and maintain high immunization coverage in children with polio vaccine given as part of the routine immunization schedule. Impaired responses to certain vaccines have been observed in HIV-infected individuals when compared to HIVuninfected individuals; as a result the need to evaluate polio immunity in HIV-infected and exposed populations is imperative to establish the influence of HIV on polio immunity. Archived serum samples collected between 2005 and 2006 were used for this purpose. During this time, oral polio vaccine (OPV) was used solely for routine immunization purposes in South Africa. The samples fell into four categories; HIV-unexposed uninfected (n = 107), HIV-exposed uninfected (n = 116), HIV-infected randomized to deferred ART (n = 74) and HIV-infected randomised to immediate ART treatment (n = 168). The HIVunexposed un infected group was considered the control group. Samples were tested for polio neutralizing antibodies at the National Institute for Communicable Diseases (NICD). The schedule for routine immunization using the OPV-only schedule in South Africa consisted of doses at birth, six weeks, ten weeks, fourteen weeks, eighteen months and a booster at six years. Samples were tested following the birth and six week doses at six weeks of age and ten weeks of age respectively. Results demonstrated a reduced response to polio vaccination following the birth and six week OPV doses in the HIV-infected groups compared with the control group, with no significant difference observed in the HIV-exposed un infected group. For poliovirus serotypes 1 and 3, infant immunity in the HIV-infected population was less than the World Health Organization (WHO) requirement of greater than 80% and as a result may pose a risk to the polio eradication initiative; the degree dependent on the prevalence of HIV in the infant population.
Dissertation