The threats from vector-borne pathogens transmitted by ticks place people (including deployed troops) at increased risk for infection, frequently contributing to undifferentiated febrile illness ...syndromes. Wild and domesticated animals are critical to the transmission cycle of many tick-borne diseases. Livestock can be infected by ticks, and serve as hosts to tick-borne diseases such as rickettsiosis. Thus, it is necessary to identify the tick species and determine their potential to transmit pathogens. A total of 1,493 adult ticks from three genera-Amblyomma, Hyalomma, and Rhipicephalus-were identified using available morphological keys and were pooled (n = 541) by sex and species. Rickettsia species were detected in 308 of 541 (56.9%) pools by genus-specific quantitative polymerase chain reaction assay (Rick17b). Furthermore, sequencing of the outer membrane protein A and B genes (ompA and ompB) of random samples of Rickettsia-positive samples led to the identification of Rickettsia aeschlimannii and Rickettsia africae with most R. africae DNA (80.2%) detected in pools of Amblyomma variegatum. We report the first molecular detection and identification of the rickettsial pathogens R. africae and R. aeschlimannii in ticks from Ghana. Our findings suggest there is a need to use control measures to prevent infections from occurring among human populations in endemic areas in Ghana. This study underscores the importance of determining which vector-borne pathogens are in circulation in Ghana. Further clinical and prevalence studies are needed to understand more comprehensively the clinical impact of these rickettsial pathogens contributing to human disease and morbidity in Ghana.
Ticks are important vectors of various pathogenic protozoa, bacteria and viruses that cause serious and life-threatening illnesses in humans and animals worldwide. Estimating tick-borne pathogen ...prevalence in tick populations is necessary to delineate how geographical differences, environmental variability and host factors influence pathogen prevalence and transmission. This study identified ticks and tick-borne pathogens in samples collected from June 2016 to December 2017 at seven sites within the Coastal, Sudan and Guinea savanna ecological zones of Ghana.
A total of 2016 ticks were collected from domestic animals including cattle, goats and dogs. Ticks were morphologically identified and analysed for pathogens such as Crimean-Congo haemorrhagic fever virus (CCHFV), Alkhurma haemorrhagic fever virus (AHFV), Rickettsia spp. and Coxiella burnetii using polymerase chain reaction assays (PCR) and sequence analysis.
Seven species were identified, with Amblyomma variegatum (60%) most frequently found, followed by Rhipicephalus sanguineus sensu lato (21%), Rhipicephalus spp. (9%), Hyalomma truncatum (6%), Hyalomma rufipes (3%), Rhipicephalus evertsi (1%) and Rhipicephalus (Boophilus) sp. (0.1%). Out of 912 pools of ticks tested, Rickettsia spp. and Coxiella burnetii DNA was found in 45.6% and 16.7% of pools, respectively, whereas no CCHFV or AHFV RNA were detected. Co-infection of bacterial DNA was identified in 9.6% of tick pools, with no statistical difference among the ecozones studied.
Based on these data, humans and animals in these ecological zones are likely at the highest risk of exposure to rickettsiosis, since ticks infected with Rickettsia spp. displayed the highest rates of infection and co-infection with C. burnetii, compared to other tick-borne pathogens in Ghana.
Insecticide resistance of Anopheles gambiae (s.l.) against public health insecticides is increasingly reported in Ghana and need to be closely monitored. This study investigated the intensity of ...insecticide resistance of An. gambiae (s.l.) found in a vegetable growing area in Accra, Ghana, where insecticides, herbicides and fertilizers are massively used for plant protection. The bioefficacy of long-lasting insecticidal nets (LLINs) currently distributed in the country was also assessed to delimitate the impact of the insecticide resistance intensity on the effectiveness of those nets.
Three- to five-day-old adult mosquitoes that emerged from collected larvae from Opeibea, Accra (Ghana), were assayed using CDC bottle and WHO tube intensity assays against different insecticides. The Vgsc-L1014F and ace-1 mutations within the population were also characterized using PCR methods. Furthermore, cone bioassays against different types of LLINs were conducted to evaluate the extent and impact of the resistance of An. gambiae (s.l.) from Opeibea.
Anopheles gambiae (s.l.) from Opeibea were resistant to all the insecticides tested with very low mortality observed against organochlorine, carbamates and pyrethroid insecticides using WHO susceptibility tests at diagnostic doses during three consecutive years of monitoring. The average frequencies of Vgsc-1014F and ace-1 in the An. gambiae (s.l.) population tested were 0.99 and 0.76, respectively. The intensity assays using both CDC bottle and WHO tubes showed high resistance intensity to pyrethroids and carbamates with survivals at 10× the diagnostic doses of the insecticides tested. Only pirimiphos methyl recorded a low resistance intensity with 100% mortality at 5× the diagnostic dose. The bioefficacy of pyrethroid LLINs ranged from 2.2 to 16.2% mortality while the PBO LLIN, PermaNet
3.0, was 73%.
WHO susceptibility tests using the diagnostic doses described the susceptibility status of the mosquito colony while CDC bottle and WHO tube intensity assays showed varying degrees of resistance intensity. Although both methods are not directly comparable, the indication of the resistance intensity showed the alarming insecticide resistance intensity in Opeibea and its surroundings, which could have an operational impact on the efficacy of vector control tools and particularly on pyrethroid LLINs.
Tick-borne pathogens harm livestock production and pose a significant risk to public health. To combat these effects, it is necessary to identify the circulating pathogens to create effective control ...measures. This study identified
Anaplasma
and
Ehrlichia
species in ticks collected from livestock in the Kassena-Nankana Districts between February 2020 and December 2020. A total of 1550 ticks were collected from cattle, sheep and goats. The ticks were morphologically identified, pooled and screened for pathogens using primers that amplify a 345 bp fragment of the 16SrRNA gene and Sanger sequencing. The predominant tick species collected was
Amblyomma variegatum
(62.98%). From the 491 tick pools screened, 34 (6.92%) were positive for
Ehrlichia
and
Anaplasma
. The pathogens identified were
Ehrlichia canis
(4.28%),
Ehrlichia minasensis
(1.63%),
Anaplasma capra
(0.81%) and
Anaplasma marginale
(0.20%). This study reports the first molecular identification of the above-mentioned
Ehrlichia
and
Anaplasma
species in ticks from Ghana. With the association of human infections with the zoonotic pathogen
A. capra
, livestock owners are at risk of infections, calling for the development of effective control measures.
Sampled ticks were screened for Crimean-Congo haemorrhagic fever virus (CCHFV) using an assay that targets the nucleoprotein gene region of the S segment, a conserved region of the CCHFV genome. ...Minimum infection rates of 0.34% and 0.10% were obtained when testing pools of
Hyalomma rufipes
and
Amblyomma variegatum
, respectively. Next-generation sequencing and phylogenetic analysis showed that the S and L segments of the CCHFV isolate clustered with those of similar isolates of genotype III. However, analysis of the M segment showed that reassortment had occurred, causing this segment to cluster with those of isolates of genotype I, providing the first evidence of such an occurrence in Ghana.
Abstract
Ticks are efficient vectors for transmitting pathogens that negatively affect livestock production and pose a risk to public health. In this study,
Babesia
and
Theileria
species were ...identified in ticks collected from cattle, sheep and goats from the Kassena‐Nankana Districts of Ghana between February and December 2020. A total of 1550 ticks were collected, morphologically identified, pooled and screened for pathogens using primers that amplify a 560 bp fragment of the ssrRNA gene and Sanger sequencing.
Amblyomma variegatum
(62.98%) was the predominant tick species. From the 491 tick pools screened, 12/15 (2.44%) positive pools were successfully sequenced. The pathogen DNA identified were
Theileria ovis
in eight (15.38%) pools of
Rhipicephalus evertsi evertsi
,
Theileria velifera
in two (0.78%) pools of
A. variegatum
and
Babesia occultans
and
Babesia
sp. Xinjiang in one (1.72%) pool each of
Hyalomma truncatum
. It was further observed that
T. ovis
occurred in ticks collected from only sheep (
p
< 0.001) which were females (
p
= 0.023) and < =1 year old (
p
= 0.040). This study reports the first identification of these pathogens in ticks within Kassena‐Nankana. With the constant trade of livestock, there is a need for effective tick control measures to prevent infection spread.
Ticks are a public health threat due to their tendency to spread pathogens that affect humans and animals. With reports of
Rhipicephalus
(
Boophilus
)
microplus
invasion in neighbouring countries, ...there is the risk of this species invading Ghana through livestock trade. Previous identification of tick species in Ghana has been based on morphological identification, which can be ineffective, especially with damaged tick specimens or engorged nymphs. This study focused on the Kassena-Nankana District, which serves as a trade route for cattle into Ghana, to determine the presence of
R. microplus
. Three genera of ticks were identified as
Amblyomma
(70.9%),
Hyalomma
(21.3%) and
Rhipicephalus
(7.8%). The engorged nymphs that could not be identified morphologically were analyzed using primers that target the mitochondrial 16S rRNA gene. This study reports the first record of
R.
(
B.
)
microplus
in Ghana. Furthermore,
R. microplus
constituted 54.8% of the
Boophilus
species collected in this study. This finding is an addition to the diverse tick species previously collected in Ghana, most of which are of veterinary and public health importance. With reports of acaricide resistance in
R. microplus
and its role in spreading infectious pathogens, the detection of this species in Ghana cannot be overlooked. Nationwide surveillance will be essential to ascertain its distribution, its effects on cattle production, and the control measures adopted.
•About 74% of the lonely lived alone but some 66% who co-resided with others felt lonely.•Loneliness and living alone were independently and interactively associated with higher mental health ...risk.•Unlike living alone, the impact of loneliness was highly differentiated and increased with age.•Physical activity and social connectedness buffered against the effects of loneliness and living alone on mental disorders.•Mental health promotion agendas in later life should include physical activity and social cohesion interventions.
Loneliness and living alone have been strongly related to mental health but limited empirical evidence of these relationships exists among older people in Ghana. We examine the pathways of independent and interactive impacts of loneliness and living alone on psychological distress (PD) risk among older people in Ghana and to investigate whether the associations are moderated by neighborhood characteristics.
Data were analyzed for 1200 community-dwelling adults aged ≥50 years from a 2016/2017 Aging, Health, Psychological Wellbeing and Health-seeking Behavior Study. Mental health and loneliness were respectively assessed using the Kessler Psychological Distress Scale (KPDS-10) and the Three-Item Loneliness Scale of the University of California, Los Angeles. OLS models estimated the associations and interactions.
Participants were mostly women (63.3% 95%CI: 60.5–66.0%) with a mean age of 66.2 ± 11.9. Mean scores for PD and loneliness were 15.9 ± 4.7 and 5.3 ± 3.9 respectively whilst the prevalence of living alone was 38.2% (95%CI: 35.4–41.0%). After full adjustment, the OLS regressions showed that loneliness (β = 1.474, SE = 0.151, p < 0.001), living alone (β = 0.381, SE = 0.162, p < 0.05) and the interaction between them (β = 0.917, SE = 0.308, p < 0.05) significantly increased the PD risk. However, engagement in regular physical activity, family contacts and social participation decreased PD outcomes among the socially isolated.
The cross-sectional nature of the data may prohibit any causal and directional inferences.
Social connectedness and neighborhood engagements strongly buffer against the risk of later life mental disorders in the context of loneliness, and living alone. Moderate-to-rigorous physical activity and social cohesion should be effectively and strategically included in interventions targeted to improve older age mental health.
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