Prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Antibodies in the Mozambican Population: A Cross-Sectional Serologic Study in 3 Cities, July-August 2020.

BACKGROUND: The extent of population exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was uncertain in many African countries during the onset of the pandemic. METHODS: We conducted a cross-sectional study and randomly selected and surveyed general population and occupational groups from 6 July to 24 August 2020, in 3 cities in Mozambique. Anti-SARS-CoV-2-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies were measured using a point-of-care rapid test. The prevalence was weighted for population (by age, sex, and city) and adjusted for test sensitivity and specificity. RESULTS: A total of 21 183 participants, including 11 143 from the general population and 10 040 from occupational groups, were included across all 3 cities. General population seropositivity (IgM or IgG) prevalence was 3.0% (95% confidence interval [CI], 1.0%-6.6%) in Pemba, 2.1% (95% CI, 1.2%-3.3%) in Maputo City, and 0.9% (95% CI, .1%-1.9%) in Quelimane. The prevalence in occupational groups ranged from 2.8% (95% CI, 1.3%-5.2%) to 5.9% (95% CI, 4.3%-8.0%) in Pemba, 0.3% (95% CI, .0%-2.2%) to 4.0% (95% CI, 2.6%-5.7%) in Maputo City, and 0.0% (95% CI, .0%-.7%) to 6.6% (95% CI, 3.8%-10.5%) in Quelimane, and showed variations between the groups tested. CONCLUSIONS: In the first representative COVID-19 serosurveys in Mozambique, in mid-2020, weighted and assay-adjusted seroprevalence in 3 provincial capitals of anti-SARS-CoV-2 ranged from 0.9% to 3.0%, whereas adjusted prevalence in occupational groups ranged from 0.0% to 6.6% with variation between groups. Exposure to SARS-CoV-2 was extensive during the first pandemic wave, and transmission may have been more intense among occupational groups. These data have been of utmost importance to inform public health intervention to control and respond to the pandemic in Mozambique.

Safety of incidental exposure to the novel oral poliovirus vaccine type 2 in pregnancy: A longitudinal observational study in Mozambique, 2022-2023.

BACKGROUND: To minimize the risk of vaccine-derived poliovirus emergences, the novel oral poliovirus vaccine type 2 (nOPV2), was bioengineered to have increased genetic stability compared to Sabin OPV and recommended for outbreak response Emergency Use Listing by WHO. Although pregnant women are not a target population for this vaccine, a theoretical risk of incidental exposure exists via pharyngeal or faecal shedding from vaccinated children in the household or close community. METHODS: This was an observational study of pregnant women conducted in Nampula (exposed cohort) and Maputo (non-exposed cohort) in Mozambique from August 2022 to June 2023. Two nOPV2 campaigns were conducted in Nampula and none in Maputo. Women were followed-up during routine prenatal consultation, delivery, and 28-day neonate visits for obstetric anomalies and pregnancy outcomes. Sociodemographic, medical, and obstetric history was captured. RESULTS: Three hundred twenty-six pregnant women were enrolled from Nampula and 940 from Maputo City. Stillbirth prevalence (2·3% vs 1·6%, p = 0·438), low birth weight (8·9% vs 8·2%, p = 0·989), congenital anomalies (1 % vs 0·5%, p = 0·454), neonatal death (2·3% vs 1·6%, p = 0·08), and maternal death (0 % vs 0·2%, p = 0·978) did not differ amongst exposed and non-exposed cohorts. There was an increased rate of pre-term delivery in the exposed cohort (18·4% vs 11·0%, p = 0·011). CONCLUSION: We did not observe an increased frequency of adverse pregnancy outcomes due to passive nOPV2 exposure. A higher frequency of preterm delivery needs to be further investigated. The data reported herein support the continued use of nOPV2 for poliovirus outbreak response and full licensure of the vaccine.

Trends in Prevalence of HIV-1 Drug Resistance in a Public Clinic in Maputo, Mozambique.

BACKGROUND: An observational study was conducted in Maputo, Mozambique, to investigate trends in prevalence of HIV drug resistance (HIVDR) in antiretroviral (ART) naïve subjects initiating highly active antiretroviral treatment (HAART). METHODOLOGY/PRINCIPAL FINDINGS: To evaluate the pattern of drug resistance mutations (DRMs) found in adults on ART failing first-line HAART [patients with detectable viral load (VL)]. Untreated subjects [Group 1 (G1; n=99)] and 274 treated subjects with variable length of exposure to ARV´s [6-12 months, Group 2 (G2;n=93); 12-24 months, Group 3 (G3;n=81); >24 months (G4;n=100)] were enrolled. Virological and immunological failure (VF and IF) were measured based on viral load (VL) and T lymphocyte CD4+ cells (TCD4+) count and genotypic resistance was also performed. Major subtype found was C (untreated: n=66, 97,06%; treated: n=36, 91.7%). Maximum virological suppression was observed in G3, and significant differences intragroup were observed between VF and IF in G4 (p=0.022). Intergroup differences were observed between G3 and G4 for VF (p=0.023) and IF between G2 and G4 (p=0.0018). Viral suppression (<50 copies/ml) ranged from 84.9% to 90.1%, and concordant VL and DRM ranged from 25% to 57%. WHO cut-off for determining VF as given by 2010 guidelines (>5000 copies/ml) identified 50% of subjects carrying DRM compared to 100% when lower VL cut-off was used (<50 copies/ml). Length of exposure to ARVs was directly proportional to the complexity of DRM patterns. In Mozambique, VL suppression was achieved in 76% of individuals after 24 months on HAART. This is in agreement with WHO target for HIVDR prevention target (70%). CONCLUSIONS: We demonstrated that the best way to determine therapeutic failure is VL compared to CD4 counts. The rationalized use of VL testing is needed to ensure timely detection of treatment failures preventing the occurrence of TDR and new infections.

Evolution of primary HIV drug resistance in a subtype C dominated epidemic in Mozambique.

OBJECTIVE: In Mozambique, highly active antiretroviral treatment (HAART) was introduced in 2004 followed by decentralization and expansion, resulting in a more than 20-fold increase in coverage by 2009. Implementation of HIV drug resistance threshold surveys (HIVDR-TS) is crucial in order to monitor the emergence of transmitted viral resistance, and to produce evidence-based recommendations to support antiretroviral (ARV) policy in Mozambique. METHODS: World Health Organization (WHO) methodology was used to evaluate transmitted drug resistance (TDR) in newly diagnosed HIV-1 infected pregnant women attending ante-natal clinics in Maputo and Beira to non-nucleoside reverse transcriptase inhibitors (NNRTI), nucleoside reverse transcriptase inhibitors (NRTI) and protease inhibitors (PI). Subtypes were assigned using REGA HIV-1 subtyping tool and phylogenetic trees constructed using MEGA version 5. RESULTS: Although mutations associated with resistance to all three drug were detected in these surveys, transmitted resistance was analyzed and classified as <5% in Maputo in both surveys for all three drug classes. Transmitted resistance to NNRTI in Beira in 2009 was classified between 5-15%, an increase from 2007 when no NNRTI mutations were found. All sequences clustered with subtype C. CONCLUSIONS: Our results show that the epidemic is dominated by subtype C, where the first-line option based on two NRTI and one NNRTI is still effective for treatment of HIV infection, but intermediate levels of TDR found in Beira reinforce the need for constant evaluation with continuing treatment expansion in Mozambique.