Crimean-Congo hemorrhagic fever virus in livestock ticks and animal handler seroprevalence at an abattoir in Ghana.

BACKGROUND: Crimean-Congo Haemorrhagic Fever Virus (CCHFV) is a zoonotic virus transmitted by Ixodid ticks and causes Crimean-Congo hemorrhagic fever (CCHF) disease in humans with up to 50 % mortality rate. METHODS: Freshly slaughtered livestock at the Kumasi abattoir in the Ashanti Region of Ghana were examined for the presence of ticks once a month over a 6-month period from May to November 2011. The ticks were grouped into pools by species, sex, and animal source. CCHFV was detected in the ticks using reverse transcription PCR. Blood samples were collected from enrolled abattoir workers at initiation, and from those who reported fever in a preceding 30-day period during monthly visits 2-5 months after initiation. Six months after initiation, all participants who provided baseline samples were invited to provide blood samples. Serology was performed using enzyme linked immunosorbent assay (ELISA). Demographic and epidemiological data was also obtained from enrolled participants using a structured questionnaire. RESULTS: Of 428 freshly slaughtered animals comprising 130 sheep, 149 cattle, and 149 goats examined, 144 ticks belonging to the genera Ambylomma, Hyalomma and Boophilus were identified from 57 (13.3 %): 52 (34.9 %), 4 (3.1 %) and 1 (0.7 %) cattle, sheep and goat respectively. Of 97 tick pools tested, 5 pools comprising 1 pool of Hyalomma excavatum and 4 pools of Ambylomma variegatum, collected from cattle, were positive for CCHFV. Of 188 human serum samples collected from 108 abattoir workers, 7 (3.7 %) samples from 6 persons were anti-CCHF IgG positive with one of them also being CCHF IgM positive. The seroprevalence of CCHFV identified in this study was 5.7 %. CONCLUSIONS: This study detected human exposure to CCHF virus in slaughterhouse workers and also identified the CCHF virus in proven vectors (ticks) of Crimean Congo hemorrhagic fever in Ghana. The CCHFV was detected only in ticks collected from cattle, one of the livestock known to play a role in the amplification of the CCHF virus.

Laboratory diagnosis of dual HIV-1/HIV-2 infection in Ghanaian patients.

OBJECTIVE: To determine the true prevalence of HIV dual infections in a previously characterised HIV seropositive patient group due to inconsistencies between different diagnostic methods. DESIGN: A cross-sectional study of an HIV seropositive group with different diagnostic methods. SETTING: Three hospitals in the Northern, Ashanti and Greater Accra Regions of Ghana. SUBJECTS: One hundred and forty five HIV infected patients/individuals sampled from June to September 2002. MAIN OUTCOME MEASURES: Using serological and molecular methods, the seropositive status of HIV-infected patients, previously determined by a preliminary screening process, was confirmed and discrepancies noted. The data was used to propose a more accurate laboratory diagnosis of HIV dual infections involving HIV-1 and HIV-2. RESULTA: HIV-1 infections were mostly accurately detected, but difficulties were encountered in diagnosing HIV-2 infections. To achieve a positive detection on confirmatory immunoblots, antibody concentration in some samples tested was enhanced by using larger volumes. In other cases, diagnosis of HIV infections by PCR, especially HIV-2, was possible only after increasing the DNA template or MgCl2 concentrations. Such samples would otherwise have been inaccurately scored for HIV infections. CONCLUSION: Based on the results of this study, we propose that the accurate diagnosis of HIV dual infections, especially HIV-2 component, must use an algorithm that involves PCR. Our results however underscore conclusions of a previous study that most dually seroreactive samples are predominantly HIV-1 infections with crossreactivity to HIV-2 antigens.

Phenotypic characterization of HIV type 1 isolates from Ghana.

Viral isolates from 27 HIV-1-infected patients in Ghana, most of whom were symptomatic, were characterized for coreceptor usage using MT-2 and U87.CD4 cells. Irrespective of clinical status, most infections were caused by CCR5-tropic viruses although three CXCR4-tropic viruses were also found. Genotyping was performed by sequencing the gp41 region. Seven viruses clustered with subtype G reference strains, while the remaining 20 viruses clustered within the subtype A reference viruses. Most subtype A isolates clustered loosely with the CRF02_AG viruses and are described as CRF02_AG-like. The V3 loop was sequenced in selected isolates including all isolates capable of using CXCR4. The V3 region of CXCR4-using viruses contained genetic traits characteristic of CXCR4-using subtype B and C viruses, such as increased charge, the presence of positively charged residues at positions 11 and 25, and loss of a predicted glycosylation site. This study supports previous work showing that CRF02_AG is responsible for most HIV-1 infections in Ghana at this time. The predominance of CCR5-using viruses, even in symptomatic patients, suggests that CCR5-blocking strategies may be useful for prevention and treatment of HIV-1 infections in Ghana.

HIV-1 proteases from drug-naive West African patients are differentially less susceptible to protease inhibitors.

BACKGROUND: Now that highly active antiretroviral therapy (HAART) is being initiated on a large scale in West Africa, it remains controversial whether protease inhibitors (PIs), originally designed and tested against human immunodeficiency virus type 1 (HIV-1) subtype B, are equally effective against the non-B subtypes that are prevalent in West African countries. In this study, we investigated whether Ghanaian HIV-1 isolates, as representatives of West African isolates, are susceptible to PIs. METHODS: We first generated an HIV-1 protease cassette vector proviral DNA carrying a luciferase gene, which allows patient-derived HIV-1 proteases to be inserted and to be subjected to both genotypic and phenotypic assays. HIV-1 protease genes derived from 39 treatment-naive Ghanaian patients were used in this experiment as representatives of West African strains. The cloned patient-derived HIV-1 protease genes were first sequenced and then genetically compared. Phenotypic analysis was performed with Ghanaian HIV-1 protease-chimeric viruses in the presence of 6 different PIs. Structural models of HIV-1 protease homodimers were constructed by the molecular modeling software. RESULTS: Genetic analysis of cloned patient-derived HIV-1 protease genes indicated that most of the Ghanaian HIV-1 proteases are placed as subtype CRF02_AG strains, which are phylogenetically distant from subtype B strains, and that Ghanaian HIV-1 proteases do not harbor known major mutations influencing drug resistance but commonly carry 2-3 minor mutations. Phenotypic analysis performed with HIV-1 protease-recombinant viruses in the presence of 6 different PIs revealed that Ghanaian HIV-1 proteases are differentially less susceptible to the PIs. In support of this finding of differential susceptibility, structural analysis showed a significant distortion of nelfinavir, but not of amprenavir, in the Ghanaian protease pocket, suggesting nelfinavir might be less insertable into the Ghanaian protease than into the protease of subtype B. CONCLUSIONS: These findings provide implications for the combination of PIs during the introduction of HAART into West Africa.