First confirmed occurrence of the yellow fever virus and dengue virus vector Aedes (Stegomyia) luteocephalus (Newstead, 1907) in Mozambique

Background: Mozambique, same as many other tropical countries, is at high risk of arthropod-borne virus (arbovirus) diseases and recently two dengue virus (DENV) outbreaks occurred in the northern part of the country. The occurrence of some important vector species, such as Aedes (Stegomyia) aegypti (Linnaeus) and Ae. (Stg.) albopictus (Skuse), besides several other sylvatic vectors, have been reported in the country, which may indicate that the transmission of some arboviruses of public health importance may involve multiple-vector systems. Therefore, knowing the occurrence and distribution of existing and the new important vectors species, is crucial for devising systematic transmission surveillance and vector control approaches. The aim of this study was to map the occurrence and distribution of mosquito species with potential for transmitting arboviruses of human and veterinary relevance in Niassa Province, Northern Mozambique. Methods: Field entomological surveys were undertaken in April 2016 in Lago District, Niassa Province, northern Mozambique. Breeding sites of mosquitoes were inspected and immature stages were collected and reared into adult. Mosquitoes in the adult stages were morphologically identified using taxonomic keys. Morphological identification of Aedes (Stegomyia) luteocephalus (Newstead) were later confirmed using dissected male genitalia and molecular based on the phylogenetic analyses of the sequenced barcode (cox1 mtDNA) gene. Results: A total of 92 mosquito larvae collected developed into adults. Of these, 16 (17.39%) were morphologically identified as Ae. luteocephalus. The remaining specimens belonged to Ae. (Stg.) aegypti (n = 4, 4.35%), Ae. (Aedimorphus) vittatus (n = 24, 26.09%), Anopheles garnhami (n = 1, 1.09%), Culex (Culiciomyia) nebulosus (n = 28, 30.43%), Eretmapodites subsimplicipes (n = 18, 19.57%) and Toxorhynchites brevipalpis (n = 1, 1.09%), taxa already known to the country. Male genitalia and phylogenetic analyses confirmed the identity of Ae. luteocephalus specimens collected in this study. Conclusions: To our knowledge, this is the first detection of Ae. luteocephalus in Mozambican territory, a vector species of yellow fever virus (YFV), Zika virus (ZIKV) and dengue virus (DENV) in Africa. Further studies are encouraged to investigate the role of Ae. luteocephalus in the transmission of arboviral diseases in Mozambique.publishersversionpublishe

A survey of RNA viruses in mosquitoes from Mozambique reveals novel genetic lineages of flaviviruses and phenuiviruses, as well as frequent flavivirus-like viral DNA forms in Mansonia

Background: Mosquito-borne diseases involving arboviruses represent expanding threats to sub-Saharan Africa imposing as considerable burden to human and veterinary public health. In Mozambique over one hundred species of potential arbovirus mosquito vectors have been identified, although their precise role in maintaining such viruses in circulation in the country remains to be elucidated. The aim of this study was to screen for the presence of flaviviruses, alphaviruses and bunyaviruses in mosquitoes from different regions of Mozambique. Results: Our survey analyzed 14,519 mosquitoes, and the results obtained revealed genetically distinct insect-specific flaviviruses, detected in multiple species of mosquitoes from different genera. In addition, smaller flavivirus-like NS5 sequences, frequently detected in Mansonia seemed to correspond to defective viral sequences, present as viral DNA forms. Furthermore, three lineages of putative members of the Phenuiviridae family were also detected, two of which apparently corresponding to novel viral genetic lineages. Conclusion: This study reports for the first-time novel insect-specific flaviviruses and novel phenuiviruses, as well as frequent flavivirus-like viral DNA forms in several widely known vector species. This unique work represents recent investigation of virus screening conducted in mosquitoes from Mozambique and an important contribution to inform the establishment of a vector control program for arbovirus in the country and in the region.publishersversionpublishe

Morphological and Molecular Characterization Using Genitalia and CoxI Barcode Sequence Analysis of Afrotropical Mosquitoes with Arbovirus Vector Potential

Funding Information: Eddyson Montalvo-Sabino was recipient of a grant from “Programa Nacional de Becas y Crédito Educativo” (PRONABEC), 2019—Beca Generacion del Bicentenario, from the “Ministerio de Educación” of Peru. A.P. Abilio was a recipient of a grant from Wellcome Trust (Grant WT087546MA) through SACIDS RVF and NPHI-Phase-II from the National Institute for Health of Mozambique through a cooperative agreement number [5NU14GH001237-03-00]. Marietjie Venter was a recipient of a sub-award from the Global Disease Detection Program, US-CDC award 5U19GH000571-02 with the NICD and University of Pretoria that funded vector surveillance in South Africa (2012–2015) and by the Cooperative Agreement Number (5 NU2GGH001874-02-00) with the University of Pretoria (2014–2017). Milehna M. Guarido received a studentship through this grant. A.P.G. Almeida has been a recipient of the Visiting Professor Programme by the University of Pretoria for the work in South Africa. This work received financial support from the Global Health and Tropical Medicine Center (GHTM|IHMT|NOVA), which is funded through FCT contract UID/Multi/04413/2013, Portugal. The findings and conclusions expressed in this manuscript are those of the author(s) and do not necessarily represent the official position of the funding agencies. Publisher Copyright: © 2022 by the authors.Potential arboviral Afrotropical mosquito vectors are underrepresented in public databases of CoxI barcode sequences. Furthermore, available CoxI sequences for many species are often not associated with voucher specimens to match the corresponding fine morphological characterization of specimens. Hence, this study focused on the characterization of Culicine mosquitoes from South Africa, Mozambique, and Angola and their classification using a complementary approach including a morphological analysis of specimens’ genitalia and phylogenetic study based on the analysis of CoxI barcode sequences using maximum likelihood and Bayesian phylogenetic inference methods, alongside Median-Joining Network and PCOORD analyses. Overall, 800 mosquitoes (652 males and 148 females) from 67 species, were analyzed. Genitalia from 663 specimens allowed the identification of 55 species of 10 genera. A total of 247 CoxI partial gene sequences corresponding to 65 species were obtained, 11 of which (Aedes capensis, Ae. mucidus, Culex andersoni, Cx. telesilla, Cx. inconspicuosus, Eretmapodites subsimplicipes, Er. quinquevittatus, Ficalbia uniformis, Mimomyia hispida, Uranotaenia alboabdominalis, and Ur. mashonaensis) are, to the best of our knowledge, provided here for the first time. The presence of Cx. pipiens ecotypes molestus and pipiens and their hybrids, as well as Cx. infula, is newly reported in the Afrotropical region. The rates of correct sequence identification using BOLD and BLASTn (≥95% identity) were 64% and 53%, respectively. Phylogenetic analysis revealed that, except for subgenus Eumelanomyia of Culex, there was support for tribes Aedini, Culicini, Ficalbiini, and Mansoniini. A divergence >2% was observed in conspecific sequences, e.g., Aedeomyia africana, Ae. cumminsii, Ae. unilineatus, Ae. metallicus, Ae. furcifer, Ae. caballus, and Mansonia uniformis. Conversely, sequences from groups and species complexes, namely, Ae. simpsoni, Ae. mcintoshi, Cx. bitaeniorhynchus, Cx. simpsoni, and Cx. pipiens were insufficiently separated. A contribution has been made to the barcode library of Afrotropical mosquitoes with associated genitalia morphological identifications.publishersversionpublishe

Prevalence and Risk Factors of Porcine Cysticercosis in Angónia District, Mozambique

Taenia solium is an important zoonosis in many developing countries. Cysticercosis poses a serious public health risk and incurs sizeable economic losses to pig production. Because data on the epidemiology of porcine cysticercosis in Mozambique are scarce, the present study was conducted to determine the prevalence and risk factors for porcine cysticercosis. A cross-sectional survey was carried out in 11 villages in Angónia district, Tete province in northwestern Mozambique. Between September and November, 2007, a total of 661 pigs were tested serologically and examined by tongue inspection. Serum samples were tested for the presence of circulating parasite antigen using a monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (Ag-ELISA). In addition, a questionnaire survey to collect information on pig production, occurrence and transmission of porcine cysticercosis, risk factors and awareness of porcine cysticercosis was conducted in the selected households from which pigs were sampled. Two hundred thirty-one samples (34.9%) were found positive by the Ag-ELISA, while by tongue inspection on the same animals cysticerci were detected in 84 pigs (12.7%). Increasing age (OR = 1.63; 95% CI = 1.13–2.37) and free-range pig husbandry system (OR = 3.81; 95% CI = 2.08–7.06) were important risk factors for porcine cysticercosis in the district. The present findings indicate that porcine cysticercosis is endemic in the region, and that increasing pig age and pig husbandry practices contribute significantly to porcine cysticercosis transmission. Further epidemiological studies on the prevalence and transmission of porcine cysticercosis in rural communities in Mozambique are needed to enable collection of more baseline data and implementation of effective control strategies within the country

Use of Oxfendazole to Control Porcine Cysticercosis in a High-Endemic Area of Mozambique

A randomized controlled field trial to evaluate the effectiveness of a single oral dose of 30 mg/kg of oxfendazole (OFZ) treatment for control of porcine cysticercosis was conducted in 4 rural villages of Angónia district, north-western Mozambique. Two hundred and sixteen piglets aged 4 months were selected and assigned randomly to OFZ treatment or control groups. Fifty-four piglets were treated at 4 months of age (T1), while another 54 piglets were treated at 9 months of age (T2) and these were matched with 108 control pigs from the same litters and raised under the same conditions. Baseline data were collected on the prevalence of porcine cysticercosis using antigen ELISA (Ag-ELISA), as well as knowledge and practices related to Taenia solium transmission based on questionnaire interviews and observations. All animals were followed and re-tested for porcine cysticercosis by Ag-ELISA at 9 and 12 months of age when the study was terminated. Overall prevalence at baseline was 5.1% with no significant difference between groups. At the end of the study, 66.7% of the controls were found positive, whereas 21.4% of the T1 and 9.1% of the T2 pigs were positive, respectively. Incidence rates of porcine cysticercosis were lower in treated pigs as compared to controls. Necropsy of 30 randomly selected animals revealed that viable cysts were present in none (0/8) of T2 pigs, 12.5% (1/8) of T1 pigs and 42.8% (6/14) of control pigs. There was a significant reduction in the risk of T. solium cysticercosis if pigs were treated with OFZ either at 4 months (OR = 0.14; 95% CI: 0.05–0.36) or at 9 months of age (OR = 0.05; 95% CI: 0.02–0.16). Strategic treatment of pigs in endemic areas should be further explored as a means to control T. solium cysticercosis/taeniosis

Knowledge, attitudes, practices (KAP) and control of rabies among community households and health practitioners at the human-wildlife interface in Limpopo National Park, Massingir District, Mozambique

BACKGROUND: Rabies is a viral zoonotic disease that kills more than 26,000 people each year in Africa. In Mozambique, poverty and inadequate surveillance result in gross underreporting and ineffective control of the disease in animals and people. Little is known of the role of human attitudes and behaviour in prevention or control of rabies, thus this study was undertaken to assess the knowledge, attitudes and practices amongst selected households and health practitioners in one affected area, the Limpopo National Park (LNP), Massingir district. METHODOLOGY: A cross-sectional study was conducted among 233 households in eight villages in LNP and among 42 health practitioners from eight health facilities in Massingir district between 2016 and 2018. Consenting household representatives aged 18 years or over were purposively selected. A KAP survey was administered to obtain information on dog ownership and knowledge of rabies, host species affected, modes of transmission, symptoms, recommended treatment and preventive methods. Similar to household study participants, health practitioners were purposively selected and completed the questionnaire during the investigators’ visit. The questionnaire sought information on knowledge of rabies, management of bite wounds, vaccination sites and schedules of pre- and post-exposure prophylaxis. Descriptive and inferential data analyses were performed using SPSS software version 18.0. RESULTS: Approximately twenty per cent (18.9%; 95% CI: 14.3–24.3) and 13.3% (95% CI: 9.4–18.1) of households had good knowledge and practices of rabies, respectively. For health practitioners, only 16.7% (95% CI: 7.5–31.9) had good knowledge, whilst 33.3% (95% CI: 20.0–49.7) adopted adequate attitudes/practices towards the disease. CONCLUSIONS/SIGNIFICANCE: In conclusion, both households and health practitioners displayed poor levels of knowledge and adopted bad attitudes and practices towards rabies. The former, had more gaps in their attitudes and practices towards the disease. Village location and education level (P < .05) and similarly, sex and occupation, were found to be statistically associated with good knowledge of rabies among households as compared to HPs. Overall, a lack of community-based education and professional retraining courses contribute significantly to poor awareness of rabies in the LNP of Mozambique. Enhancing public health knowledge should consequently reduce dog-mediated human rabies deaths in this country

High seroprevalence of Rift Valley fever phlebovirus in domestic ruminants and African Buffaloes in Mozambique shows need for intensified surveillance

Introduction: Rift Valley fever (RVF) is an arthropod-borne disease that affects both animals and humans. RVF phlebovirus (RVFPV) is widespread in Africa and Arabian Peninsula. In Mozambique, outbreaks were reported in South; seroprevalence studies performed in livestock and water buffaloes were limited to central and south regions. We evaluated the seroprevalence of RVFPV among domestic ruminants and African buffaloes from 7 of 10 provinces of Mozambique, to understand the distribution of RVFPV and provide data for further RVF control programs. Materials and methods: A total of 1581 blood samples were collected in cattle, 1117 in goats, 85 in sheep and 69 in African buffaloes, between 2013 and 2014, and the obtained sera were analyzed by ELISA. Results and discussion: The overall seroprevalence of RVFPV domestic ruminants and African buffaloes was 25.6%. The highest was observed in cattle (37.3%) and African buffaloes (30.4%), which were higher than in previous studies within Mozambique. In south and central regions, the overall seroprevalences were higher (14.9%–62.4%) than in the north. Conclusion: This study showed the presence of anti-RVFPV antibodies in animals from all sampled provinces, suggesting that RVFPV is actively circulating among domestic ruminants and African buffaloes in Mozambique, therefore surveillance should be intensified