Aedes-borne diseases remain a public health challenge for many countries globally. The extent of spread of invasive species of Aedes mosquitoes and risk of transmission of the diseases especially around the point of e...Aedes-borne diseases remain a public health challenge for many countries globally. The extent of spread of invasive species of Aedes mosquitoes and risk of transmission of the diseases especially around the point of entry of goods such as ports is not well known in Ghana. This study investigated the ecology, distribution and risk of transmission of viral haemorrhagic fevers by Aedes mosquitoes around the port areas of Tema, Southern Ghana. The mosquitoes from this study were collected using human landing catches, ovitraps and larval collections for a period of six months. A total of 1092 containers were inspected in both seasons and of these, 237 (21.7%) were positive for mosquito larvae or pupae in rainy season while 181 (16.6%) were positive in dry season. A total of 6498 mosquitoes were collected and identified morphologically using taxonomic keys. 6038 (92.9%) were Aedes aegypti, 337 (5.2%) were Culex spp. and 123 (1.9%) were Anopheles gambiae. The Ae. aegypti larvae were found breeding in a series of water-holding containers which included disposed plastic containers, earthenware pots, car tyres, plastic barrels, plastic basins, buckets, metal drums, jerrycans and poly tank. A high proportion of Aedes aegypti eggs were found in the ovitraps during the rainy season than in the dry season in the study sites. Ae. aegypti was the most common mosquitoes biting mostly outdoors (65.6%) with more bites occurring in the rainy season (63.6%) in the two residential sites (Tema Community One and Tema New Town). The risk of transmission of viral haemorrhagic fever in the study sites was assessed using House Index, Container Index, Breteau Index and was found to be higher in Tema New town area with seasonal variations within the sites. The man-vector contact rates for the two residential sites were also found to be higher in rainy season than the dry season. These observations indicate that the risk of transmission of viral haemorrhagic fevers in the study areas is high especially in the rainy season. The implications of the findings in the formulation of future vector control programmes around the port areas in the country are discussed in the paper.展开更多
Background:In recent years there have been reports of viral haemorrhagic fever(VHF)epidemics in sub-Saharan Africa where malaria is endemic.VHF and malaria have overlapping clinical presentations making diferential di...Background:In recent years there have been reports of viral haemorrhagic fever(VHF)epidemics in sub-Saharan Africa where malaria is endemic.VHF and malaria have overlapping clinical presentations making diferential diagno‑sis a challenge.The objective of this study was to determine the prevalence of selected zoonotic VHFs and malaria co-infections among febrile patients seeking health care in Tanzania.Methods:This facility-based cross-sectional study was carried out between June and November 2018 in Buhigwe,Kalambo,Kyela,Kilindi,Kinondoni,Kondoa,Mvomero,and Ukerewe districts in Tanzania.The study involved febrile patients seeking health care from primary healthcare facilities.Blood samples were collected and tested for infections due to malaria,Crimean-Congo haemorrhagic fever(CCHF),Ebola virus disease(EVD),Marburg virus disease(MVD),Rift Valley fever(RVF)and yellow fever(YF).Malaria infections were tested using rapid diagnostics tests while exposure to VHFs was determined by screening for immunoglobulin M antibodies using commercial enzyme-linked immuno‑sorbent assays.The Chi-square test was used to compare the proportions.Results:A total of 308 participants(mean age=35±19 years)were involved in the study.Of these,54(17.5%)had malaria infection and 15(4.8%)were positive for IgM antibodies against VHFs(RVF=8;CCHF=2;EBV=3;MBV=1;YF=1).Six(1.9%)individuals had both VHF(RVF=2;CCHF=1;EVD=2;MVD=1)and malaria infections.The highest co-infection prevalence(0.6%)was observed among individuals aged 46‒60 years(P<0.05).District was signifcantly associated with co-infection(P<0.05)with the highest prevalence recorded in Buhigwe(1.2%)followed by Kinondoni(0.9%)districts.Headache(100%)and muscle,bone,back and joint pains(83.3%)were the most signifcant complaints among those infected with both VHFs and malaria(P=0.001).Conclusions:Co-infections of VHF and malaria are prevalent in Tanzania and afect more the older than the younger population.Since the overlapping symptoms in co-infected individuals may challenge accurate diagnosis,adequate laboratory diagnosis should be emphasized in the management of febrile illnesses.展开更多
文摘Aedes-borne diseases remain a public health challenge for many countries globally. The extent of spread of invasive species of Aedes mosquitoes and risk of transmission of the diseases especially around the point of entry of goods such as ports is not well known in Ghana. This study investigated the ecology, distribution and risk of transmission of viral haemorrhagic fevers by Aedes mosquitoes around the port areas of Tema, Southern Ghana. The mosquitoes from this study were collected using human landing catches, ovitraps and larval collections for a period of six months. A total of 1092 containers were inspected in both seasons and of these, 237 (21.7%) were positive for mosquito larvae or pupae in rainy season while 181 (16.6%) were positive in dry season. A total of 6498 mosquitoes were collected and identified morphologically using taxonomic keys. 6038 (92.9%) were Aedes aegypti, 337 (5.2%) were Culex spp. and 123 (1.9%) were Anopheles gambiae. The Ae. aegypti larvae were found breeding in a series of water-holding containers which included disposed plastic containers, earthenware pots, car tyres, plastic barrels, plastic basins, buckets, metal drums, jerrycans and poly tank. A high proportion of Aedes aegypti eggs were found in the ovitraps during the rainy season than in the dry season in the study sites. Ae. aegypti was the most common mosquitoes biting mostly outdoors (65.6%) with more bites occurring in the rainy season (63.6%) in the two residential sites (Tema Community One and Tema New Town). The risk of transmission of viral haemorrhagic fever in the study sites was assessed using House Index, Container Index, Breteau Index and was found to be higher in Tema New town area with seasonal variations within the sites. The man-vector contact rates for the two residential sites were also found to be higher in rainy season than the dry season. These observations indicate that the risk of transmission of viral haemorrhagic fevers in the study areas is high especially in the rainy season. The implications of the findings in the formulation of future vector control programmes around the port areas in the country are discussed in the paper.
文摘Background:In recent years there have been reports of viral haemorrhagic fever(VHF)epidemics in sub-Saharan Africa where malaria is endemic.VHF and malaria have overlapping clinical presentations making diferential diagno‑sis a challenge.The objective of this study was to determine the prevalence of selected zoonotic VHFs and malaria co-infections among febrile patients seeking health care in Tanzania.Methods:This facility-based cross-sectional study was carried out between June and November 2018 in Buhigwe,Kalambo,Kyela,Kilindi,Kinondoni,Kondoa,Mvomero,and Ukerewe districts in Tanzania.The study involved febrile patients seeking health care from primary healthcare facilities.Blood samples were collected and tested for infections due to malaria,Crimean-Congo haemorrhagic fever(CCHF),Ebola virus disease(EVD),Marburg virus disease(MVD),Rift Valley fever(RVF)and yellow fever(YF).Malaria infections were tested using rapid diagnostics tests while exposure to VHFs was determined by screening for immunoglobulin M antibodies using commercial enzyme-linked immuno‑sorbent assays.The Chi-square test was used to compare the proportions.Results:A total of 308 participants(mean age=35±19 years)were involved in the study.Of these,54(17.5%)had malaria infection and 15(4.8%)were positive for IgM antibodies against VHFs(RVF=8;CCHF=2;EBV=3;MBV=1;YF=1).Six(1.9%)individuals had both VHF(RVF=2;CCHF=1;EVD=2;MVD=1)and malaria infections.The highest co-infection prevalence(0.6%)was observed among individuals aged 46‒60 years(P<0.05).District was signifcantly associated with co-infection(P<0.05)with the highest prevalence recorded in Buhigwe(1.2%)followed by Kinondoni(0.9%)districts.Headache(100%)and muscle,bone,back and joint pains(83.3%)were the most signifcant complaints among those infected with both VHFs and malaria(P=0.001).Conclusions:Co-infections of VHF and malaria are prevalent in Tanzania and afect more the older than the younger population.Since the overlapping symptoms in co-infected individuals may challenge accurate diagnosis,adequate laboratory diagnosis should be emphasized in the management of febrile illnesses.
