Risk factors and circulation pattern of respiratory syncytial virus in children under 2 years in Maputo, Mozambique.

BACKGROUND: Evidence on risk factors for respiratory syncytial virus (RSV) in low-resource settings is limited. In Mozambican children <2 y of age with severe acute respiratory infection (SARI), we explored risk factors for RSV, described its seasonal variation and assessed associations between RSV and a life-threatening condition. METHODS: We retrospectively included participants presenting in 2017-2018 in two hospitals in Maputo. RSV was detected and subtyped using real-time quantitative reverse transcription polymerase chain reaction on nasopharyngeal swabs. We used logistic regression and χ2 tests to assess associations and Spearman's correlation coefficient to assess the correlation between weather measurement and RSV positivity. RESULTS: RSV was detected in 23.1% (n=109) of 472 included children and in 50.0% (20/40) of those <3 months old. Being <3 months (vs >1 y) was associated with RSV (adjusted odds ratio 4.3 [95% confidence interval 2.1-8.5]). RSV status was not associated with experiencing a life-threatening condition. RSV A and B co-circulated during the study period, but one type predominated in each year. In 2017, the RSV positivity rate was correlated with monthly average temperature (r=0.793, p=0.002) and precipitation (r=0.596, p=0.041). CONCLUSIONS: In Mozambican children with SARI, RSV was prevalent, especially in neonates. However, RSV was not associated with a life-threatening condition.

H7N6 highly pathogenic avian influenza in Mozambique, 2023.

On 13 October 2023, the National Directorate for Livestock Development in Mozambique was notified of a suspected outbreak of avian influenza in commercial layers. Samples were screened by real-time and conventional RT-PCR and were positive for both H7 and N6. Full genome sequences were obtained for three representative samples. Sequence analysis of the H7 cleavage site confirmed that the viruses were highly pathogenic (i.e. 333- PEPPKGPRFRR/GLF-346). In addition, the H7 and N6 sequences were highly similar (from 99.4-99.5% and 99.6-99.7% for the HA gene and the NA gene, respectively) to the sequences of a H7N6 virus identified in the Republic of South Africa in May 2023 indicating a similar origin of the viruses. The identification of H7N6 HPAIV in Mozambique has important implications for disease management and food security in the region.

Results from the second WHO external quality assessment for the molecular detection of respiratory syncytial virus, 2019-2020.

Background: External quality assessments (EQAs) for the molecular detection of human respiratory syncytial virus (RSV) are necessary to ensure the standardisation of reliable results. The Phase II, 2019-2020 World Health Organization (WHO) RSV EQA included 28 laboratories in 26 countries. The EQA panel evaluated performance in the molecular detection and subtyping of RSV-A and RSV-B. This manuscript describes the preparation, distribution, and analysis of the 2019-2020 WHO RSV EQA. Methods: Panel isolates underwent whole genome sequencing and in silico primer matching. The final panel included nine contemporary, one historical virus and two negative controls. The EQA panel was manufactured and distributed by the UK National External Quality Assessment Service (UK NEQAS). National laboratories used WHO reference assays developed by the United States Centers for Disease Control and Prevention, an RSV subtyping assay developed by the Victorian Infectious Diseases Reference Laboratory (Australia), or other in-house or commercial assays already in use at their laboratories. Results: An in silico analysis of isolates showed a good match to assay primer/probes. The panel was distributed to 28 laboratories. Isolates were correctly identified in 98% of samples for detection and 99.6% for subtyping. Conclusions: The WHO RSV EQA 2019-2020 showed that laboratories performed at high standards. Updating the composition of RSV molecular EQAs with contemporary strains to ensure representation of circulating strains, and ensuring primer matching with EQA panel viruses, is advantageous in assessing diagnostic competencies of laboratories. Ongoing EQAs are recommended because of continued evolution of mismatches between current circulating strains and existing primer sets.

Influenza surveillance capacity improvements in Africa during 2011-2017.

BACKGROUND: Influenza surveillance helps time prevention and control interventions especially where complex seasonal patterns exist. We assessed influenza surveillance sustainability in Africa where influenza activity varies and external funds for surveillance have decreased. METHODS: We surveyed African Network for Influenza Surveillance and Epidemiology (ANISE) countries about 2011-2017 surveillance system characteristics. Data were summarized with descriptive statistics and analyzed with univariate and multivariable analyses to quantify sustained or expanded influenza surveillance capacity in Africa. RESULTS: Eighteen (75%) of 24 ANISE members participated in the survey; their cumulative population of 710 751 471 represent 56% of Africa's total population. All 18 countries scored a mean 95% on WHO laboratory quality assurance panels. The number of samples collected from severe acute respiratory infection case-patients remained consistent between 2011 and 2017 (13 823 vs 13 674 respectively) but decreased by 12% for influenza-like illness case-patients (16 210 vs 14 477). Nine (50%) gained capacity to lineage-type influenza B. The number of countries reporting each week to WHO FluNet increased from 15 (83%) in 2011 to 17 (94%) in 2017. CONCLUSIONS: Despite declines in external surveillance funding, ANISE countries gained additional laboratory testing capacity and continued influenza testing and reporting to WHO. These gains represent important achievements toward sustainable surveillance and epidemic/pandemic preparedness.

Results from the WHO external quality assessment for the respiratory syncytial virus pilot, 2016-17.

BACKGROUND: External quality assessments (EQAs) for the molecular detection of respiratory syncytial virus (RSV) are necessary to ensure the provision of reliable and accurate results. One of the objectives of the pilot of the World Health Organization (WHO) Global RSV Surveillance, 2016-2017, was to evaluate and standardize RSV molecular tests used by participating countries. This paper describes the first WHO RSV EQA for the molecular detection of RSV. METHODS: The WHO implemented the pilot of Global RSV Surveillance based on the WHO Global Influenza Surveillance and Response System (GISRS) from 2016 to 2018 in 14 countries. To ensure standardization of tests, 13 participating laboratories were required to complete a 12 panel RSV EQA prepared and distributed by the Centers for Disease Control and Prevention (CDC), USA. The 14th laboratory joined the pilot late and participated in a separate EQA. Laboratories evaluated a RSV rRT-PCR assay developed by CDC and compared where applicable, other Laboratory Developed Tests (LDTs) or commercial assays already in use at their laboratories. RESULTS: Laboratories performed well using the CDC RSV rRT-PCR in comparison with LDTs and commercial assays. Using the CDC assay, 11 of 13 laboratories reported correct results. Two laboratories each reported one false-positive finding. Of the laboratories using LDTs or commercial assays, results as assessed by Ct values were 100% correct for 1/5 (20%). With corrective actions, all laboratories achieved satisfactory outputs. CONCLUSIONS: These findings indicate that reliable results can be expected from this pilot. Continued participation in EQAs for the molecular detection of RSV is recommended.

Human respiratory syncytial virus and influenza seasonality patterns-Early findings from the WHO global respiratory syncytial virus surveillance.

BACKGROUND: Human respiratory syncytial virus (RSV) causes illnesses among all age groups and presents a burden to healthcare services. To better understand the epidemiology and seasonality of RSV in different geographical areas, the World Health Organization (WHO) coordinated a pilot initiative to access the feasibility of establishing RSV surveillance using the existing Global Influenza Surveillance and Response System (GISRS) platform. OBJECTIVES: To describe and compare RSV and influenza seasonality in countries in the northern andsouthern temperate, and tropics during the period January 2017 to April 2019. METHODS: Fourteen countries in six WHO regions participating in the GISRS were invited for the pilot. Hospitalized patients presenting with severe acute respiratory illness (SARI), SARI without fever and outpatients presenting with acute respiratory illness (ARI) were enrolled from January 2017 to April 2019. The expected minimum sample size was 20 samples per week, year-round, per country. Real-time RT-PCR was used to detect RSV and influenza viruses. Results were uploaded to the WHO FluMart platform. RESULTS: Annual seasonality of RSV was observed in all countries, which overlapped to a large extent with the influenza activity. In countries, in temperate regions RSV peaked in the autumn/winter months. In Egypt, a subtropical country, RSV activity peaked in the cooler season. In the tropical regions, RSV peaked during the rainy seasons. CONCLUSION: Early findings from the WHO RSV surveillance pilot based on the GISRS suggest annual seasonal patterns for of RSV circulation that overlap with influenza. RSV surveillance needs to be continued for several more seasons to establish seasonality patterns to inform prevention and control strategies.

Antigenic and genetic characterization of influenza viruses isolated in Mozambique during the 2015 season.

BACKGROUND: Due to the high rate of antigenic variation of influenza virus, seasonal characterization of the virus is crucial to assess and monitor the emergence of new pathogenic variants and hence formulate effective control measures. However, no study has yet been conducted in Mozambique to assess genetic, antigenic and antiviral susceptibility profile of influenza virus. METHODS: A subset of samples (n = 20) from influenza positive children detected in two hospitals in Maputo city during 2015 season as part of the implementation of influenza surveillance system, were selected. The following assays were performed on these samples: antigenic characterization by hemagglutination inhibition assay, genetic characterization by Sanger sequencing of hemagglutinin (HA) and neuraminidase (NA) and susceptibility to oseltamivir and zanamivir (NA inhibitors) by enzymatic assay. RESULTS: The A(H1N1)pdm09 subtype viruses remained closely related antigenically and genetically to the 2016 vaccine virus A/California/7/2009 and other widely distributed viruses belonging to genetic group 6B. The majority of influenza A(H3N2) viruses studied were antigenically similar to the 2016-2017 vaccine virus, A/Hong Kong/4801/2014, and their HA and NA gene sequences fell into genetic subclade 3C.2a being closely related to viruses circulating in southern Africa. The influenza B viruses were antigenically similar to the 2016 season vaccine virus and HA sequences of all three fell into the B/Yamagata-lineage, clade 3, but contained NA genes of the B/Victoria-lineage. All tested viruses were sensitive to oseltamivir and zanamivir. CONCLUSION: Overall, all Mozambican influenza A and B viruses were most closely related to Southern African viruses and all were sensitive to oseltamivir and zanamivir. These findings suggest the existence of an ecological niche of influenza viruses within the region and hence highlighting the need for joint epidemiologic and virologic surveillance to monitor the evolution of influenza viruses.

Antibodies Against Chikungunya in Northern Mozambique During Dengue Outbreak, 2014.

An outbreak of dengue and high densities of Aedes aegypti were reported in 2014 in northern Mozambique, suggesting an increased risk for other arboviruses such as chikungunya virus (CHIKV) in this region. The aim of this study was to investigate the occurrence of CHIKV during an outbreak of dengue virus (DENV) in Pemba city in northern Mozambique in 2014. Febrile patients (n = 146) seeking medical attention at the Pemba Provincial Hospital between March and April 2014 were enrolled in this study. Blood samples from each participant were tested for chikungunya and DENV RNA, IgM and IgG antibodies using PCR and ELISA, respectively. The median age of the patients was 26 years (interquartile range: 20-34 years), and 52.7% (77/146) were female. We found that 7.0% (8/114) of the patients were positive for CHIKV IgM and 31.5% (46/146) presented with CHIKV IgG antibodies. DENV IgM and IgG antibodies were detected in 38.3% (46/120) and 28.2% (33/117) of the patients, respectively. This study is the first investigation regarding the occurrence of CHIKV in the north of Mozambique over the last 60 years and our data suggest that Mozambicans had been silently exposed to the virus in this part of the country, indicating that not only DENV but also CHIKV is an arbovirus to consider in febrile patients seeking medical attention in northern Mozambique.

Clinical and epidemiological characterization of influenza virus infections in children with severe acute respiratory infection in Maputo, Mozambique: Results from the implementation of sentinel surveillance, 2014 - 2016.

In Sub-Saharan Africa, where burden, impact, and incidence of acute respiratory infections (ARI) are the highest in the world, conversely, the epidemiology of influenza-associated severe acute respiratory infections (SARI) is incompletely known. The aim of this study was to describe the clinical and epidemiological features of influenza-associated SARI in hospitalized children in Maputo city, Mozambique. Nasopharyngeal and oropharyngeal swabs were collected from children aged 0-14 years old who met the case definition for SARI in two hospitals in Maputo city after their parents or legal representative consented to participate. A structured questionnaire was used to collect clinical and demographic data. Typing and subtyping of influenza were performed by real-time PCR. From January 2014 to December 2016, a total of 2,007 eligible children were recruited, of whom 1,997 (99.5%) were screened for influenza by real-time PCR. The median age of participants was 16.9 months (IQR: 7.0-38.9 months) and 53.9% (1076/1991) were male. A total of 77 were positive for influenza, yielding a frequency of 3.9% (77/1,991), with the highest frequency being reported in the age group 1-5 years old. Cases of influenza peaked twice each year, during which, its frequency reached up to 60%-80%. Among all influenza confirmed cases, 33.7% (26/77), 35.1% (27/77) and 28.6% (22/77) were typed as influenza A/H3N2, A/H1N1pdm09, and B, respectively. This represents the first report of influenza in urban/sub urban setting in Mozambique and the first evidence of distribution of strains of influenza in the country. Our data showed that frequency of influenza was lower than reported in a rural setting in Mozambique and the frequency of seasonal (A/H1N1pdm09) and (A/H3N2) subtypes were similar in children with SARI.

Respiratory syncytial and influenza viruses in children under 2 years old with severe acute respiratory infection (SARI) in Maputo, 2015.

INTRODUCTION: Although respiratory syncytial virus (RSV) and influenza virus (influenza) infections are one of the leading causes of Severe Acute Respiratory Infections (SARI) and death in young children worldwide, little is known about the burden of these pathogens in Mozambique. MATERIAL AND METHODS: From January 2015 to January 2016, nasopharyngeal swabs from 450 children, aged ≤2 years, who had been admitted to the Pediatric Department of the Maputo Central Hospital (HCM) in Mozambique, suffering with SARI were enrolled and tested for influenza and RSV using a real-time PCR assay. RESULTS: Influenza and RSV were detected in 2.4% (11/450) and 26.7% (113/424) of the participants. Children with influenza were slightly older than those infected with RSV (10 months in influenza-infected children compared to 3 months in RSV-infected children); male children were predominant in both groups (63.6% versus 54.9% in children with influenza and RSV, respectively). There was a trend towards a higher frequency of influenza (72.7%) and RSV (93.8%) cases in the dry season. Bronchopneumonia, bronchitis and respiratory distress were the most common diagnoses at admission. Antibiotics were administered to 27,3% and 15,9% of the children with influenza and RSV, respectively. Two children, of whom, one was positive for RSV (aged 6 months) and another was positive for Influenza (aged 3 months) died; both were children of HIV seropositive mothers and had bronchopneumonia. CONCLUSIONS: Our data demonstrated that RSV, and less frequently influenza, occurs in children with SARI in urban/sub-urban settings from southern Mozambique. The occurrence of deaths in small children suspected of being HIV-infected, suggests that particular attention should be given to this vulnerable population. Our data also provide evidence of antibiotics prescription in children with respiratory viral infection, which represents an important public health problem and calls for urgent interventions.

First serological evidence of hantavirus among febrile patients in Mozambique.

OBJECTIVE: The occurrence of hantavirus in Sub-Saharan Africa is poorly studied and its clinical implications are unknown. This study aimed to determine the occurrence of hantavirus infection among febrile patients attending an outpatient clinic at a primary health care center located in a suburban area of the city of Maputo in Mozambique. METHODS: Paired acute and convalescent samples from a total of 200 febrile patients aged >5years who were recruited between February 2012 and October 2014 were screened for IgM and IgG antibodies against hantavirus using an ELISA. Acute samples were also screened for malaria and to determine hematological and clinical chemistry parameters. RESULTS: Of the 200 patients enrolled, four had IgM antibodies in their acute sample and IgG antibodies in their convalescent sample, yielding a prevalence rate of 2%. Contact with rodents was higher among IgM-positive participants than IgM-negative participants (50.0% (2/4) vs. 15.3% (30/196)). IgM-positive patients presented significantly higher levels of creatinine and alanine aminotransferase and lower platelet counts than IgM-negative patients. CONCLUSIONS: The findings of this study demonstrate human exposure to hantavirus in Mozambique for the first time; however, further studies should be conducted to investigate its clinical implications.

Caracterização genética do vírus influenza A(H1N1)pdm09 circulante em Moçambique durante o período pandêmico - 2009/2010 / Genetic characterization of the influenza A (H1N1) pdm09 virus circulating in Mozambique during the pandemic period - 2009/2010

A emergência do vírus influenza A(H1N1) pdm09 no México e EUA no princípio de 2009 e que se disseminou pelo mundo, causando considerável morbidade, com cerca de 18000 mortes, oferecendo uma oportunidade de se estudar a evolução do vírus influenza pandêmico em humano sem diversas partes do mundo. Observou-se que o vírus evoluiu com taxas elevadas e diversas variações genéticas foram reportadas em diferentes países desde a sua introdução em humanos. Em Moçambique, 60 casos foram a influenza A (H1N1) pdm09 foi detectado a partir de agosto de 2009, oferecendo a primeira oportunidade para a sua caracterização molecular no país durante a pandemia (junho de 2009 a agosto de 2010),através do sequenciamento completo e parcial (piros sequenciamento) dos genes da hemaglutinina e Neuraminidase, respectivamente. Análises de 23 sequências do gene HA revelaram a co-circulação de diversas variantes do influenza A (H1N1)pdm09 em dois principais grupos filogenéticos, caracterizados pelas variações P100S e I338V acompanhadas de S202N, S220T e D239E no grupo Iede Q310H, I421V e K2E no grupo II. O piros sequenciamento do gene da NA revelou a ocorrência da variante N248D em todas amostras analisadas (49/60), mas não detectou as mutações I223V,H275Ye N295S associadas à resistência viral ao oseltamivir. A co-circulação de outros patógenos respiratórias com influenza A(H1N1)pdm09 durante a pandemia foi pesquisada em 119 amostras clínicas de secreções orofaríngease nas ofarígeas das quais 81.5% apresentaram pelo menos um patógeno, entre bactérias e vírus, incluindo o influenzaA(H1N1)pdm09.Os outros agentes virais não-influenza A(H1N1)pdm09 foram detectados em 19.59%dos casos.53.3%dos casos de influenza A(H1N1)pdm09apresentaram entre um a quatro co-patógenos, dos quais 25% envolviam vírus…

The emergence of influenza A(H1N1)pdm09 in Mexico and the U.S. in early 2009 and spread around the world, causing considerable morbidity, with about 18,000 deaths, provided an opportunity to study the evolution of pandemic influenza in humans in various parts the world. The virus evolved at a high rate and several genetic variations have been reported in different countries since its introduction in humans. In Mozambique, the influenza A(H1N1)pdm09 was detected from August 2009, providing the first opportunity for the molecular characterization in the country during the pandemic, through the full and partial sequencing (pyrossequencing) of hemagglutinin and neuraminidase genes, respectively. Analysis of 23 sequences of the HA gene revealed the co-circulation of several variants of influenza A(H1N1)pdm09 in two major phylogenetic groups, characterized by variations P100S and I338Vaccompanied by S202N, S220T and D239E in group I or Q310H, I421V and K2E in group II. The piros sequencing of the NA gene revealed the occurrence of variant N248D in all analyzed samples (49/60), but did not detect mutations I223V, N295S and H275Y associated with viral resistance to oseltamivir. The co-circulation of other respiratory pathogens with influenza A(H1N1)pdm09 during the pan demy was investigated in 119 oropharyngeal and nasopharyngeal clinical samples. At least one pathogen, including influenza A(H1N1)pdm09,was found in 81.5% of the samples. Viral pathogens other than pandemic influenza were detected in 19.59% of all cases. One to four of other respiratory pathogens were co detected in53.3% of the influenza A(H1N1)pdm09cases, of which25% had viral co-pathogens involvement…