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.

Suitability of a rapid immunochromatographic test for detection of antibodies to human immunodeficiency virus in Ghana, West Africa.

In West African countries such as Ghana, efficient human immunodeficiency virus (HIV) testing is a priority in the fight against AIDS. A new immunochromatographic rapid test, Determine HIV-1/2 (Abbott Diagnostics, North Chicago, Ill.), that detects antibodies against HIV type 1 (HIV-1) and/or HIV-2 was evaluated using Ghanaian blood samples. Two hundred four serum and/or plasma specimens were tested. HIV screening was done by a particle agglutination test and confirmed by a Western blot (WB) test as the "gold standard." The results revealed 125 HIV-seropositive AIDS patients, 75 HIV-seronegative healthy individuals, and 4 individuals for whom the HIV-1 result was indeterminate. The results obtained by the Determine HIV-1/2 assay and Diagnostic HIV SPOT (Genelabs), which is currently widely used in many districts in Ghana, were compared with those of the WB test, excluding the four HIV-1-indeterminate samples. The sensitivity of the Determine HIV-1/2 assay was 100%, compared with 98.0% for the HIV SPOT assay. The specificity was 100% for both tests. Determine HIV-1/2 is a single-step assay and was found to be rapid and easy to perform without any special equipment. It was highly sensitive and specific. The kit can be applied without electricity and water supplies, making it suitable for the detection of HIV antibodies especially in the rural areas of Ghana, West Africa.

Genetic analysis of HIV type 2 from Ghana and Guinea-Bissau, West Africa.

The phylogenetic variability of part of the long terminal repeat (LTR) region of HIV-2 strains isolated in 1995 from five individuals residing in Bissau, the capital city of Guinea-Bissau, and collected from seven persons from Kumasi, Ghana in 1996-1997, was analyzed. All Guinean samples and all but one Ghanaian sample clustered with HIV-2 subtype A. One Ghanaian sample (14%) was classified as HIV-2 subtype B. This study adds to previous reports on HIV-2 subtype distribution in West Africa indicating local prevalence of HIV-2 subtype B in Ivory Coast and neighboring Ghana.

Haptoglobin phenotypes in HIV-1-seropositive patients in Ghana: decreased risk for Hp0 individuals.

Plasma haptoglobin phenotypes were determined by polyacrylamide gel electrophoresis, followed by benzidine staining for 58 HIV-1 seropositive Ghanaians and 79 randomly selected age-matched controls. Hp0 was present in only 14% of HIV-1 seropositive individuals compared with more than 40% of the controls. The Hp0 individuals showed a highly significant reduced risk for HIV-1 infection (OR = 0. 21, 95% CI = 0.09-0.51, p = 0.0002). Hp0 may have a protective effect in HIV-1 infection.

Relationship between immunoclinical status and prevalence of viral sexually transmitted diseases among human immunodeficiency virus-1 seropositive patients in Ghana.

In view of the strong association between the acquired immunodeficiency syndrome (AIDS) and sexually transmitted diseases (STDs), we screened 182 human immunodeficiency virus (HIV)-1 infected patients over a 15-month period for serological markers to previously encountered or current STDs, most of viral etiology. The relationship between their immunological and clinical status and the prevalence of STDs was assessed and compared with that of 88 HIV-seronegative patients. Hepatitis B virus and Treponema pallidum were the most frequently occurring pathogens in both HIV-1-infected and HIV-seronegative patients. Hepatitis C virus (HCV) infection was also observed in both groups, but no HIV-seronegative patient was infected with human T-lymphotropic virus type 1 (HTLV-1). The Centers for Disease Control clinical staging of A1 through C3, representing asymptomatic to severe AIDS conditions, was observed in HIV-1 patients with or without STDs. A mean CD4 count of 288 cells per microliter (95% CI of 237-340 cells per microliter) in HIV-1 patients was significantly lower (P < 0.05) than that in HIV-seronegative individuals with 1019 cells per microliter (95% CI of 924-1115 cells per microliter), irrespective of whether subjects in either group had previous or current STDs. The mean CD4 count of patients with a single infection from HIV-1 was not significantly different (P = 0.36) from that of HIV-1 patients with multiple infections. HIV-1 infection alone appears to be responsible for the marked immunodeficiency status of seropositive patients observed in this study.

Predominance of HIV-1 among patients with AIDS and AIDS-related complex in Ghana.

We determined the prevalence of HIV among AIDS and AIDS-Related Complex (ARC) patients seen within one year in two hospitals in southern Ghana. Subjects were screened by an ELISA procedure for anti-HIV antibodies. Specific identification of the HIV type was done with a particle agglutination (PA) kit. All PA-determined dual specimens were then confirmed by Western blotting and Pepti-Lav 1/2 monoepitope kit. Virus isolation was attempted from symptomatic patients by co-culturing patient peripheral blood monocyte cells (PBMCs) and CD4+ cell lines. PBMCs and HIV isolates were characterised by PCR. By ELISA, 43.5% of the subjects (253) had anti-HIV antibodies. Of these, 61 (24%) were HIV-1 positive and 42 (18.6%) were dually reactive by PA. However, only 19% were confirmed as true dually-infected cases by western blotting and Pepti-Lav through all 42 samples were HIV-1 positive on the two tests. No subject was infected with HIV-2 alone. Three viruses were isolated. By PCR two of them had both HIV-1 and HIV-2 proviral sequences while the third virus was HIV-1 only. HIV-1 prevalence now predominates over HIV-2 implying a switch in the HIV infection pattern in Ghana. Furthermore mixed infections exist. The predominance of HIV-1 infection in Ghana may indicate a similar trend in other parts of West Africa.

PIP: Recent studies have suggested that HIV-2 infection is becoming less prevalent in Ghana, while the prevalence of HIV-1 is increasing. To confirm such a modification in the HIV infection profile in Ghana, a 1-year serologic and molecular study was conducted among 253 patients from 2 hospitals in southern Ghana (Accra and Dzodze in the Volta region) with confirmed or suspected AIDS. All 253 serum specimens were screened with enzyme-linked immunosorbent assay (ELISA) and particle agglutination (PA); the 42 dually reactive specimens were subsequently confirmed by Western blot and Pepti-Lav tests. By ELISA, 110 samples (43.5%) were positive for anti-HIV antibodies; this rate was 39.2% in Accra and 81.0% in the Volta region. Of these, 61 (24.1%) were HIV-1 positive and 42 (18.6%) were dually reactive by PA. No case of HIV-2 alone was detected. Most dually reactive cases were a cross-reaction between genetically similar regions of the 2 HIV types. Only 19% of the 42 PA-diagnosed dually reactive specimens were confirmed by Western blot and Pepti-Lav as true cases of HIV-2 only infection, and all these specimens were strongly positive for anti-HIV-1 antibodies. 3 viruses were isolated. By polymerase chain reaction, 2 had both HIV-1 and HIV-2 proviral sequences, while the third was HIV-1 only. This study's findings provide support for the hypothesis that most individuals with antibodies to both HIV-1 and HIV-2 are probably infected with HIV-1 alone. Intensified population surveillance aimed at isolating more HIV strains in West Africa could reveal the true extent of HIV genomic variation and facilitate the design of more specific diagnostic kits.

Differential reactivities of antibodies to HIV and HTLV-I in sera of suspected AIDS and ARC patients.

Sera collection from 255 clinically diagnosed AIDS and ARC patients were analyzed for antibodies to HIV and HTLV-I by Western blot and particle agglutination methods respectively. Antibodies to HIV were detected in 37.3% of the sera collected as compared to 5.5% for HTLV-I. Most (95%) of the HIV positive sera had dual reactivity to both HIV-I and HIV-2. Antibodies to HTLV-1 were more frequently detected in HIV positive sera (11.58%) than in HIV negative sera (1.88%). Conversely, antibodies to HIV were detected twice as frequently in HTLV-1 positive sera (78.6%) than in HTLV-1 negative sera (34.85%).

A study of the evolution of coxsackievirus A24 variant in Ghana by viral RNA fingerprinting analysis.

An epidemic of acute haemorrhagic conjunctivitis (AHC) caused by coxsackievirus A24 variant (CA24v) was reported in Accra, Ghana in May 1987. We studied 7 of the viral strains collected from May to November, 1987, by RNA genome fingerprinting. Pairwise comparisons of the oligonucleotide maps showed that genetic similarity among them ranged from between 60.0 to 84.7%. Using base sequence variations deduced from genetic similarity among the isolates, isolation time of the strains and the rate of nucleotide substitution (estimated in a previous paper, Miyamura et al., 1990), we calculated divergence times and constructed a phylogenetic tree. This tree indicated that all the 7 strains had diverged from each other from 11 to 26 months before the AHC epidemic in Accra. CA24v may have been introduced into the country or the neighbouring area, at least, more than two years earlier, i.e. in the early half of 1985.

Epidemic acute haemorrhagic conjunctivitis due to Coxsackie virus A24 variant in Ghana.

An outbreak of acute haemorrhagic conjunctivitis (AHC) occurred in Accra, Ghana, reaching a peak in July 1987. Individuals ranging from infants to adults over 50 years were infected, with those between 20 and 30 years being the most affected group. There was a female preponderance. Clinical features included conjunctivitis, subconjunctival haemorrhage and ocular pain. Some patients reported of blurred vision due to mild keratitis. Isolation of virus from clinical specimens of AHC patients was successful only in cells of human origin such as HeLa and FL. Coxsackie virus A24 variant (CA 24v) was identified as the aetiologic agent. This is the first report to associate CA 24v with an epidemic of AHC in Africa, south of the Sahara, which is outside the endemic area of Southeast Asia and the Caribbeans. This finding suggests that earlier outbreaks of AHC in Ghana and Africa may have been due to CA 24v but went undetected. The results of various tests performed during this study suggest that, at least, two antigenically different viruses of CA 24v circulated during the course of this epidemic.