Sequential determination of viral load, humoral responses and phylogenetic analysis in fatal and non-fatal cases of Crimean-Congo hemorrhagic fever patients from Gujarat, India, 2019

Background

Thirty-four CCHF cases (17 fatal; 17 survived) were confirmed from Gujarat state, India during the year 2019. We aimed to find out the viral load, antibody kinetics, cytokine profile and phylogenetic analysis between fatal and non- fatal cases.

Methods

Thirty four cases were included in this study. Blood and urine samples were collected from all the cases on the day of admission to hospital. Non-fatal cases were followed weekly for understanding the profile of viral kinetics, anti-CCHFV IgM and IgG antibodies. We also quantified the cytokines in both fatal and non-fatal cases. For epidemiological correlation, livestock were screened for anti-CCHF IgG antibodies and the tick pool specimens were tested by real time RT-PCR. Virus isolation was attempted on tick pools and human specimens and phylogenetic analysis performed on human and ticks complete genome sequences.

Results

CCHF cases were detected throughout year in 2019 with the peak in August. Out of 34 cases, eight secondary CCHF cases were reported. Cases were predominantly detected in males and in 19–45 years age group (55.88%). The persistence of viremia was observed till 76^th POD (post onset date) in one case whereas anti-CCHFV IgM and IgG was detected amongst these cases from the 2^nd and 20^th POD respectively. Positivity observed amongst livestock and tick pools were was 21.57% and 7.4% respectively. The cytokine analysis revealed a significant increase in the level of serum IL-6, IL-10 and IFN-γ during the acute phase of the infection, but interestingly IL-10 lowered to normal upon clearance of the virus in the clinically recovered case. Fatal cases had high viral RNA copy numbers. Bleeding from one or two mucosal sites was significantly associated with fatality (OR-16.47;p-0.0034 at 95% CI). We could do CCHF virus isolation from two cases. Phylogenetic analysis revealed circulation of re-assortment of Asian-West African genotypes in humans and ticks.

Conclusions

The persistence of CCHF viral RNA was detected till 76^th POD in one of the survivors. The circulation of a re-assortment Asian-West African genotype in a CCHF case is also reported first time from India.

Crimean Congo hemorrhagic fever is a zoonotic tick-borne viral hemorrhagic disease. This disease is reported from Europe, Mediterranean, north-western China, central Asia, Africa, and the Middle East. Several outbreaks of CCHF were reported from Gujarat and Rajasthan states, India from 2011 to 2019. In this study, we discuss the clinical, molecular, serological, and the cytokine data of 34 CCHF cases (17 fatal and 17 survived) which were detected from Gujarat state in the year 2019. A sequential weekly follow up of the CCHF survivors was performed to understand the viral kinetics and the antibody profile. Interestingly, the presence of persistence CCHF viral RNA was observed till 76^th POD in one of the survivors. To our knowledge, we are reporting this long term persistence of viremia for the first time. We also observed that the anti-CCHFV IgM detection in the serum samples starts as soon as 2^nd POD but anti-CCHFV IgG antibody could be detected in the majority of the cases only after the 28^th POD. The cytokine analysis revealed a significant increase in the level of serum IL-6, IL-10 and IFN-γ during the acute phase of the infection, but interestingly IL-10 lowered to normal upon clearance of the virus in the clinically recovered case. We did the phylogenetic analysis and concluded the circulation of the Asian-West African re-assortment genotype in humans, which has not been reported from India prior to this study.

Crimean-Congo hemorrhagic fever virus antibody prevalence in Mauritanian livestock (cattle, goats, sheep and camels) is stratified by the animal's age

Crimean-Congo hemorrhagic fever virus (CCHFV) is one of the most widespread zoonotic arthropod-borne viruses in many parts of Africa, Europe and Asia. It belongs to the family of Nairoviridae in the genus of Orthonairovirus. The main reservoir and vector are ticks of the genus Hyalomma. Livestock animals (such as cattle, small ruminants and camels) develop a viremias lasting up to two weeks with absence of clinical symptoms, followed by seroconversion. This study was carried out to assess risk factors that affect seroprevalence rates in different species. In total, 928 livestock animal samples (cattle = 201; sheep = 247; goats = 233; camels = 247) from 11 out of 13 regions in Mauritania were assayed for CCHFV-specific immunoglobulin G (IgG) antibodies using enzyme-linked immunosorbent assays (ELISA) (including a novel indirect camel-IgG-specific CCHFV ELISA). Inconclusive results were resolved by an immunofluorescence assay (IFA). A generalized linear mixed-effects model (GLMM) was used to draw conclusions about the impact of certain factors (age, species, sex and region) which might have influenced the CCHFV antibody status of surveyed animals. In goats and sheep, about 15% of the animals were seropositive, whereas in cattle (69%) and camels (81%), the prevalence rate was significantly higher. On average, cattle and camels were up to twice to four times older than small ruminants. Interestingly, the seroprevalence in all species was directly linked to the age of the animals, i.e. older animals had significantly higher seroprevalence rates than younger animals. The highest CCHFV seroprevalence in Mauritania was found in camels and cattle, followed by small ruminants. The large proportion of positive animals in cattle and camels might be explained by the high ages of the animals. Future CCHFV prevalence studies should at least consider the age of surveyed animals in order to avoid misinterpretations.

Crimean-Congo hemorrhagic fever virus (CCHFV) is a silent threat that repeatedly causes severe hemorrhagic disease in humans who have been in close contact with livestock of endemic countries. The detection of CCHFV IgG antibodies in livestock can be a first indication whether the virus circulates in a given region and is thus a valuable diagnostic tool for determining the endemic status. Interestingly, earlier data from Mauritania showed a noticeable difference in IgG prevalence between sheep (18%) and cattle (67%). In contrast to sheep and cattle, current monitoring data on CCHFV IgG antibody presence in camels and goats in Mauritania is very limited. This study was conducted to provide a comprehensive up-to-date overview of CCHFV seroprevalences in the four most important Mauritanian livestock species (cattle, sheep, goats and camels). It attempts to highlight the role of potential risk factors responsible for deviating prevalences. In addition, we developed a camel-specific IgG ELISA, which can be used in future CCHFV seroprevalence studies. Furthermore, findings of this study contribute to a better understanding of the current epidemiological CCHFV situation in sub-Saharan Africa and which role different livestock species play regarding the viral circulation in endemic regions.

Seroprevalence and risk factors of brucellosis among slaughtered indigenous cattle, abattoir personnel and pregnant women in Ngaoundéré, Cameroon

BACKGROUND

Brucellosis is a neglected debilitating zoonosis with a high prevalence in many developing countries. Bovine brucellosis is widespread in Cameroon but the epidemiological situation of human brucellosis is not known. A cross sectional study was carried to determine the seroprevalence and factors associated with bovine and human Brucellosis among abattoir personnel and pregnant women in Ngaoundéré, Cameroon.

METHODS

Serum sample from 590 abattoir cattle and 816 plausible occupational risk and vulnerable humans to brucellosis (107 abattoir personnel and 709 pregnant women) were collected and screened for anti-brucella antibodies using Rose Bengal Plate Test (RBPT) and ELISA tests. Structured questionnaires were used to collect data on socio-demographics and risk-factors. The differences in proportions between seropositive and seronegative reactors were tested using odds-ratio and χ2tests.

RESULTS

Bovine brucellosis seroprevalence was at 3.40% (n = 590; 3.4% for RBPT, 5.93% for i-ELISA). Human Brucella seroprevalence was at 5.6% among abattoir personnel (n = 107; 5.6% for RBPT, 12.15% for Brucella IgG ELISA) and 0.28% in pregnant women (n = 709; both tests). Breed (P < 0.00001) was associated with increased risk of brucellosis in cattle and the seroprevalence was highest among the Djafoun (OR = 16.67, 95%CI: 4.49-28.85) and Akou (OR = 16.96, 95% CI: 0.10-23.91) cattle compared to the other breeds. There was a moderate positive correlation (R2 = 0.5025) of Brucella IgG concentrations (> 200 U/ml) and clinical data for Brucella IgG ELISA seropositive humans. Several potential factors were associated (P > 0.05) with increased risk of human brucellosis seroprevalence among the abattoir personnel. The abattoir personnel were essentially males; the seropositive respondents were male and did not use protective equipment at work. Handling of foetus and uterine contents (OR = 13.00, 95%CI: 1.51-111.88) was associated with increased risk of human brucellosis.

CONCLUSIONS

Antibrucella antibodies are prevalent in cattle (3.40%), among abattoir personnel (5.60%) and in pregnant women (0.28%) in Ngaoundéré, Cameroon. The study reports the first evidence of human brucellosis in Cameroon and therefore, an indication of a real public health problem. Public awareness campaigns and health education especially among livestock professional and in agropastoral communities should be highlighted to disseminate knowledge, associated risk factors and control measures of brucellosis.

Weak Genetic Structure in Northern African Dromedary Camels Reflects Their Unique Evolutionary History

Knowledge on genetic diversity and structure of camel populations is fundamental for sustainable herd management and breeding program implementation in this species. Here we characterized a total of 331 camels from Northern Africa, representative of six populations and thirteen Algerian and Egyptian geographic regions, using 20 STR markers. The nineteen polymorphic loci displayed an average of 9.79 ± 5.31 alleles, ranging from 2 (CVRL8) to 24 (CVRL1D). Average H_e was 0.647 ± 0.173. Eleven loci deviated significantly from Hardy-Weinberg proportions (P<0.05), due to excess of homozygous genotypes in all cases except one (CMS18). Distribution of genetic diversity along a weak geographic gradient as suggested by network analysis was not supported by either unsupervised and supervised Bayesian clustering. Traditional extensive/nomadic herding practices, together with the historical use as a long-range beast of burden and its peculiar evolutionary history, with domestication likely occurring from a bottlenecked and geographically confined wild progenitor, may explain the observed genetic patterns.

Large-Scale Glycomics of Livestock: Discovery of Highly Sensitive Serum Biomarkers Indicating an Environmental Stress Affecting Immune Responses and Productivity of Holstein Dairy Cows

Because various stresses strongly influence the food productivity of livestock, biomarkers to indicate unmeasurable environmental stress in domestic animals are of increasing importance. Thermal comfort is one of the basic principles of dairy cow welfare that enhances productivity. To discover sensitive biomarkers that monitor such environmental stresses in dairy cows, we herein performed, for the first time, large-scale glycomics on 336 lactating Holstein cow serum samples over 9 months between February and October. Glycoblotting combined with MALDI-TOF/MS and DMB/HPLC allowed for comprehensive glycomics of whole serum glycoproteins. The results obtained revealed seasonal alterations in serum N-glycan levels and their structural characteristics, such as an increase in high-mannose type N-glycans in spring, the occurrence of di/triantennary complex type N-glycans terminating with two or three Neu5Gc residues in summer and autumn, and N-glycans in winter dominantly displaying Neu5Ac. A multivariate analysis revealed a correlation between the serum expression levels of these season-specific glycoforms and productivity.

Metal extent in blood of livestock from Dandora dumping site, Kenya: Source identification of Pb exposure by stable isotope analysis

Nairobi city in Kenya produces 2000 tons/day of garbage, and most of it is dumped onto the Dandora dumping site, home to a quarter-million residents. This study was conducted (1) to assess the contamination levels of nine metals and a metalloid (arsenic) in the blood of pigs, goats, sheep and cattle from Dandora, and (2) to identify a possible source of lead (Pb) pollution. Cadmium (Cd, 0.17-4.35 μg/kg, dry-wt) and Pb (90-2710 μg/kg) levels in blood were generally high, suggesting human exposure to Cd through livestock consumption and Pb poisoning among pigs (2600 μg/kg) and cattle (354 μg/kg). Results of Pb isotope ratios indicated that the major exposure route might differ among species. Our results also suggested a possibility that the residents in Dandora have been exposed to the metals through livestock consumption.

Application of a reverse dot blot DNA-DNA hydridization method to quantify host-feeding tendencies of two sibling species in the Anopheles gambiae complex

A DNA-DNA hybridization method, reverse dot blot analysis (RDBA), was used to identify Anopheles gambiae s.s. and Anopheles arabiensis (Diptera: Culicidae) hosts. Of 299 blood-fed and semi-gravid An. gambiae s.l. collected from Kisian, Kenya, 244 individuals were identifiable to species; of these, 69.5% were An. arabiensis and 29.5% were An. gambiae s.s. Host identifications with RDBA were comparable with those of conventional polymerase chain reaction (PCR) followed by direct sequencing of amplicons of the vertebrate mitochondrial cytochrome b gene. Of the 174 amplicon-producing samples used to compare these two methods, 147 were identifiable by direct sequencing and 139 of these were identifiable by RDBA. Anopheles arabiensis bloodmeals were mostly (94.6%) bovine in origin, whereas An. gambiae s.s. fed upon humans more than 91.8% of the time. Tests by RDBA detected that two of 112 An. arabiensis contained blood from more than one host species, whereas PCR and direct sequencing did not. Recent use of insecticide-treated bednets in Kisian is likely to have caused the shift in the dominant vector species from An. gambiae s.s. to An. arabiensis. Reverse dot blot analysis provides an opportunity to study changes in host-feeding by members of the An. gambiae complex in response to the broadening distribution of vector control measures targeting host-selection behaviours.

[The immune structure against q fever and tick-bite spotted fever group rickettsioses in the population and domestic animals of the Republic of Guinea]

The circulation of the rickettsiae R.africae and C.brunetii, the causative agents of African tick-bite spotted fever and Q fever, was first ascertained throughout the territory of the Republic of Guinea. The immune stratum against R.africae among the population varied 1.1 to 25.4% or 10.6+/-0.7% on average and that among the livestock did 0.6 to 18.8% or 7.6+/-0.6% on average. The proportion of sera to C,brunettii in the population was in the rage from 0.8 to 10.5% or 2.4+/-0.3% on average; that in livestock was 3.2 to 18.7% or 8.0+/-0.6% on average. However, many aspects of the circulation of rickettsiae, the pathology and importance of these fevers in the structure of morbidity in Guinea remain still unclarified and call for further investigations, by applying the current laboratory diagnostic tests for rickettsiosial diseases.