Infected Monkeys Research Articles

Wide distribution and ancient evolutionary history of simian foamy viruses in New World primates.

BackgroundAlthough simian foamy viruses (SFV) are the only exogenous retroviruses to infect New World monkeys (NWMs), little is known about their evolutionary history and epidemiology. Previous reports show distinct SFVs among NWMs but were limited to small numbers of captive or wild monkeys from five (Cebus, Saimiri, Ateles, Alouatta, and Callithrix) of the 15 NWM genera. Other studies also used only PCR testing or serological assays with limited validation and may have missed infection in some species. We developed and validated new serological and PCR assays to determine the prevalence of SFV in blood specimens from a large number of captive NWMs in the US (n = 274) and in captive and wild-caught NWMs (n = 236) in Peruvian zoos, rescue centers, and illegal trade markets. Phylogenetic and co-speciation reconciliation analyses of new SFV polymerase (pol) and host mitochondrial cytochrome B sequences, were performed to infer SFV and host co-evolutionary histories.Results124/274 (45.2 %) of NWMs captive in the US and 59/157 (37.5 %) of captive and wild-caught NWMs in Peru were SFV WB-positive representing 11 different genera (Alouatta, Aotus, Ateles, Cacajao, Callithrix, Cebus, Lagothrix, Leontopithecus, Pithecia, Saguinus and Saimiri). Seroprevalences were lower at rescue centers (10/53, 18.9 %) compared to zoos (46/97, 47.4 %) and illegal trade markets (3/7, 8/19, 42.9 %) in Peru. Analyses showed that the trees of NWM hosts and SFVs have remarkably similar topologies at the level of species and sub-populations suggestive of co-speciation. Phylogenetic reconciliation confirmed 12 co-speciation events (p < 0.002) which was further supported by obtaining highly similar divergence dates for SFV and host genera and correlated SFV-host branch times. However, four ancient cross-genus transmission events were also inferred for Pitheciinae to Atelidae, Cacajao to ancestral Callithrix or Cebus monkeys, between Callithrix and Cebus monkeys, and Lagothrix to Alouatta.ConclusionsWe demonstrate a broad distribution and stable co-speciation history of SFV in NWMs at the species level. Additional studies are necessary to further explore the epidemiology and natural history of SFV infection of NWMs and to determine the zoonotic potential for persons exposed to infected monkeys in captivity and in the wild.Electronic supplementary materialThe online version of this article (doi:10.1186/s12977-015-0214-0) contains supplementary material, which is available to authorized users.

Infectious Chikungunya Virus in the Saliva of Mice, Monkeys and Humans.

Chikungunya virus (CHIKV) is a reemerging, ordinarily mosquito-transmitted, alphavirus that occasionally produces hemorrhagic manifestations, such as nose bleed and bleeding gums, in human patients. Interferon response factor 3 and 7 deficient (IRF3/7-/-) mice, which are deficient for interferon α/β responses, reliably develop hemorrhagic manifestations after CHIKV infection. Here we show that infectious virus was present in the oral cavity of CHIKV infected IRF3/7-/- mice, likely due to hemorrhagic lesions in the olfactory epithelium that allow egress of infected blood into the nasal, and subsequently, oral cavities. In addition, IRF3/7-/- mice were more susceptible to infection with CHIKV via intranasal and oral routes, with IRF3/7-/- mice also able to transmit virus mouse-to-mouse without an arthropod vector. Cynomolgus macaques often show bleeding gums after CHIKV infection, and analysis of saliva from several infected monkeys also revealed the presence of viral RNA and infectious virus. Furthermore, saliva samples collected from several acute CHIKV patients with hemorrhagic manifestations were found to contain viral RNA and infectious virus. Oral fluids can therefore be infectious during acute CHIKV infections, likely due to hemorrhagic manifestations in the oral/nasal cavities.

Detection and assessment of infectivity of hepatitis E virus in urine

Hepatitis E virus (HEV) is known to be excreted in the stool but there has been no report of its presence in urine. This study investigated the presence of HEV RNA and antigen (HEV-Ag) in urine and its possible transmission. Serum and urine samples from patients with chronic or acute HEV infection and HEV infected monkeys were tested for viral and biochemical markers. Liver and kidney biopsies from the infected monkeys were analyzed by histopathology and immunohistochemistry. The infectivity of HEV from urine was assessed by inoculation into monkeys. HEV RNA and HEV-Ag were detected persistently in the urine of a patient with chronic HEV infection. Subsequently, HEV RNA was detected in the urine of three of the eight (37.5%) acute patients, all of whom had detectable HEV-Ag in their urine. HEV RNA and HEV-Ag were also detectable in the urine of HEV infected monkeys. The ratio of HEV-Ag to RNA in the urine of the infected monkeys was significantly higher than in their sera and feces. The parameters of routine urinalysis remained within the normal ranges in the hepatitis E patients and infected monkeys, however, pathological changes and HEV-Ag were observed in the kidneys of the infected monkeys. Furthermore, one of two monkeys became infected with HEV after inoculation with urine from another infected monkey. HEV infection may result in kidney injury and the urine may pose a risk of transmission. HEV-Ag detection in urine may be valuable for diagnosis of ongoing HEV infection.

Anti-CCR4 antibody activates virus specific immune response in STLV-1 infected Japanese monkey

Transgenic mouse model is useful to study pathogenesis of viral genes like tax and HBZ. However, it is impossible to study the host immune responses by these transgenic mice. We used simian T-cell leukemia virus type 1 (STLV-1) infected Japanese monkeys (JMs) to analyze host immune responses after treatment by anti-CCR4 monoclonal antibody (mAb). In the previous study, we reported that anti-CCR4 mAb treatment in STLV-1 infected JMs significantly reduced CCR4 positive cells and STLV-1 proviral load (PVL). In this study, we investigated the long-term effect (48 weeks) on PVL and immune responses to STLV-1 Tax (sTax) and bZIP factor (SBZ) after the anti-CCR4 mAb treatment. STLV-1 PVL in the JMs was kept at the lower level than 0 week even 48 weeks later. To further investigate the antiCCR4 mAb induced antiviral effect, we analyzed regulatory T (Treg) cells and sTax and SBZ specific T-cell responses. Treg cells, which were CCR4 positive, were rapidly reduced after the treatment. The number of activated Treg cells (most functional population) was severely suppressed. Furthermore, anti-CCR4 mAb treatment of infected CD4 T cells from the JMs enhanced engulfment by phagocytes, which likely enhances antigen-presentation. Treated JMs showed spontaneous activation of cytotoxic T-lymphocytes (CTLs) to sTax and SBZ. However, the immune response to other antigen was not enhanced. In consistent with these data, the enhanced T-cell responses (anti-Tax and HBZ) were also observed in anti-CCR4 mAb treated ATL patients. Taken together, anti-CCR4 mAb induces CTLs to sTax/Tax and HBZ/SBZ by two different mechanisms: reduced Treg cells and enhanced antigen presentation by antibodydependent cell-mediated phagocytosis. These effects of anti-CCR4 mAb induce prolonged suppression of PVL, which might enable long-term control of ATL and HTLV-1 infected cells.

Development of HTLV-1 associated myelopathy/tropical spastic paraparesis in a patient with simian T-lymphotropic virus type 1-like infection.

Virus transmission from various wild and domestic animals contributes to increased risk of emerging infectious diseases in human populations. HTLV-1 is a human retrovirus associated with acute T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), which originated from zoonotic transmission from various African and Asian nonhuman primates (NHPs). Similar to HTLV-1, the simian counterpart, STLV-1, causes chronic infection and leukemia and lymphoma in naturally infected monkeys. However, other clinical syndromes typically seen in human such as a chronic progressive myelopathy have not been observed in NHPs. Little is also known about the development of any neurologic and inflammatory diseases in human populations infected with STLV-1-like viruses following NHP exposure. We identified and analyzed the complete genome of a primate T lymphotropic virus type 1 (PTLV-1) isolated from a patient with typical HAM/TSP who resides in the United States but was born in Liberia. Using a novel droplet digital PCR for the detection of the HTLV-1 tax gene, the proviral load in PBMC was 14.01%; however there was a distinct difference in fluorescence amplitude compared to all other H!M/TSP patient's, suggesting viral heterogeneity. A complete PTLV-1 proviral genome was amplified from DNA extracted from the PBMCs of the HAM/TSP patient using PCR to generate nine overlapping subgenomic fragments. Phylogenetic analysis of PTLV-1 env and LTR regions showed the virus was highly related with PTLV-1 from sooty mangabey monkeys and humans exposed from NHPs in West Africa. These results suggest the patient is likely infected with STLV-1, suggesting for the first time that viral transmission from monkey to human may be associated with a chronic progressive neurologic disease.

Protective effect of cytotoxic T lymphocytes targeting HTLV-1 bZIP factor

AbstractHuman T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia-lymphoma (ATL) and inflammatory diseases in a small percentage of infected individuals. Host immune responses, in particular cytotoxic T lymphocytes (CTLs), influence the proliferation and survival of ATL cells and HTLV-1–infected cells. We generated recombinant vaccinia viruses (rVVs) expressing HTLV-1 basic leucine zipper (bZIP) factor (HBZ) or Tax to study the immunogenic potential of these viral proteins. Vaccination with rVV expressing Tax or HBZ induced specific T-cell responses, although multiple boosters were needed for HBZ. HBZ-stimulated T cells killed HBZ peptide-pulsed T cells and CD4+ T cells from HBZ transgenic (HBZ-Tg) mice. The anti-lymphoma effect of the CTLs targeting HBZ was tested in mice inoculated with a lymphoma cell line derived from an HBZ-Tg mouse. Transfer of splenocytes from HBZ-immunized mice increased the survival of the lymphoma cell–inoculated mice, suggesting that the anti-HBZ CTLs have a protective effect. The rVV could also induce specific T-cell responses to HBZ and Tax in HTLV-1–infected rhesus monkeys. On the basis of the results of rVV-vaccinated mice and macaques, we identified a candidate peptide (HBZ157-176) for vaccine development. Dendritic cells pulsed with this peptide could generate HBZ-specific CTLs from human CD8+ T cells. This study demonstrates that HBZ could be a target for immunotherapy of patients with ATL.

Lung fluke (Paragonimus africanus) infects Nigerian red-capped mangabeys and causes respiratory disease

Eggs of the lung fluke genus Paragonimus were detected in red-capped mangabeys (Cercocebus torquatus) in Nigeria. We assess the role of these primates as potential sylvatic hosts and the clinical effects of the parasite on monkeys. DNA sequenced from eggs in feces were 100% identical in the ITS2 region to Paragonimus africanus sequences from humans in Cameroon. Paragonimus-positive monkeys coughed more than uninfected monkeys. Experimental de-worming led to reduction in parasite intensity and a corresponding reduction of coughing to baseline levels in infected monkeys. This report provides the first evidence of Paragonimus sp. in C. torquatus, of P. africanus in Nigerian wildlife, and the first molecular evidence of the parasite in African wildlife. Coughing, sometimes interpreted as a communication behavior in primates, can actually indicate infection with lung parasites. Observations of coughing in primates may, in turn, provide a useful mechanism for surveillance of Paragonimus spp, which are re-emerging human pathogens, in wildlife reservoirs.

Frequencies of lymphoid T-follicular helper cells obtained longitudinally by lymph node fine-needle aspiration correlate significantly with viral load in SIV-infected rhesus monkeys.

T-follicular helper (T(FH)) cells are an important population in lymph nodes (LNs) contributing to the generation of highly specific B cells. For SIV studies in rhesus macaques (RM), analysis of LN is necessary, but restricted due to invasive sampling. We applied the minimally invasive LN fine-needle aspiration (LN-FNA) and examined dynamics of T(FH) cells during SIV infection. LN-FNA and LN resection were carried out on uninfected RM. Lymphocytes were analyzed by flow cytometry. Additionally, cells obtained by LN-FNA over time from SIV-infected RM were analyzed. Percentages of lymphocyte subsets were similar in LN aspirates and whole LNs. Analysis of LN aspirates from SIV-infected RM demonstrated a decrease of CD4(+) T cells, while T(FH) cell frequencies increased over time and correlated significantly with plasma viral load. By applying LN-FNA, we showed that T(FH) cell expansion in chronic SIV infection is associated with viral load.

Hepatitis E Virus Produced from Cell Culture Has a Lipid Envelope.

The absence of a productive cell culture system hampered detailed analysis of the structure and protein composition of the hepatitis E virion. In this study, hepatitis E virus from a robust HEV cell culture system and from the feces of infected monkeys at the peak of virus excretion was purified by ultra-centrifugation. The common feature of the two samples after ultracentrifugation was that the ORF2 protein mainly remained in the top fractions. The ORF2 protein from cell culture system was glycosylated, with an apparent molecular weight of 88 kDa, and was not infectious in PLC/PRF/5 cells. The ORF2 protein in this fraction can bind to and protect HEV RNA from digestion by RNase A. The RNA-ORF2 product has a similar sedimentation coefficient to the virus from feces. The viral RNA in the cell culture supernatant was mainly in the fraction of 1.15g/cm3 but that from the feces was mainly in the fraction of 1.21 g/cm3. Both were infectious in PLC/PRF/5 cells. And the fraction in the middle of the gradient (1.06g/cm3) from the cell culture supernatant,but not that from the feces, also has ORF2 protein and HEV RNA but was not infectious in PLC/PRF/5.The infectious RNA-rich fraction from the cell culture contained ORF3 protein and lipid but the corresponding fraction from feces had no lipid and little ORF3 protein. The lipid on the surface of the virus has no effect on its binding to cells but the ORF3 protein interferes with binding. The result suggests that most of the secreted ORF2 protein is not associated with HEV RNA and that hepatitis E virus produced in cell culture differs in structure from the virus found in feces in that it has a lipid envelope.

Rapid Development of gp120-Focused Neutralizing B Cell Responses during Acute Simian Immunodeficiency Virus Infection of African Green Monkeys.

The initial phases of acute human immunodeficiency virus type 1 (HIV-1) infection may be critical for development of effective envelope (Env)-specific antibodies capable of impeding the establishment of the latent pool of HIV-1-infected CD4(+) T cells, preventing virus-induced immune hyperactivation to limit disease progression and blocking vertical virus transmission. However, the initial systemic HIV-1 Env-specific antibody response targets gp41 epitopes and fails to control acute-phase viremia. African-origin, natural simian immunodeficiency virus (SIV) hosts do not typically progress to AIDS and rarely postnatally transmit virus to their infants, despite high milk viral loads. Conversely, SIV-infected rhesus macaques (RMs), Asian-origin nonnatural SIV hosts, sustain pathogenic SIV infections and exhibit higher rates of postnatal virus transmission. In this study, of acute SIV infection, we compared the initial systemic Env-specific B cell responses of AGMs and RMs in order to probe potential factors influencing the lack of disease progression observed in AGMs. AGMs developed higher-magnitude plasma gp120-specific IgA and IgG responses than RMs, whereas RMs developed more robust gp140-directed IgG responses. These gp120-focused antibody responses were accompanied by rapid autologous neutralizing responses during acute SIV infection in AGMs compared to RMs. Moreover, acute SIV infection elicited a higher number of circulating Env-specific memory B cells in peripheral blood of AGMs than in the blood of RMs. These findings indicate that AGMs have initial systemic Env-specific B cell responses to SIV infection distinct from those of a nonnatural SIV host, resulting in more functional SIV-specific humoral responses, which may be involved in impairing pathogenic disease progression and minimizing postnatal transmission. Due to the worldwide prevalence of HIV-1 infections, development of a vaccine to prevent infection or limit the viral reservoir remains an important goal. HIV-1-infected humans, as well as SIV-infected nonnatural SIV hosts, develop pathogenic infections and readily transmit the virus to their infants. Conversely, natural SIV hosts do not develop pathogenic infections and rarely transmit the virus to their infants. The immunologic factors contributing to these favorable outcomes in natural SIV hosts could prove invaluable for directing HIV-1 vaccine and therapy design. This study identified distinctions in the specificity and function of the initial systemic SIV envelope-specific B cell response that developed during acute SIV infection in natural and nonnatural SIV host species. Identification of distinct acute B cell responses in natural SIV hosts may inform vaccine strategies seeking to elicit similar responses prior to or during the initial phases of acute HIV-1 infection.

Developing a Successful HIV Vaccine.

Human immunodeficiency virus (HIV) genome integration indicates that persistent sterilizing immunity will be needed for a successful vaccine candidate. This suggests a need for broad antibodies targeting the Env protein. Immunogens targeting gp120 have been developed that block infection in monkeys and mimic the modest success of the RV144 clinical trial in that protection is short-lived following a decline in antibody-depending cell-mediated cytotoxicity-like antibodies. Attempts to induce antibody persistence have been complicated by a loss of efficacy, presumably by increasing the number of HIV-target cells. The key seems to be achieving an immune balance.

Broadly Neutralizing Human Immunodeficiency Virus Type 1 Antibody Gene Transfer Protects Nonhuman Primates from Mucosal Simian-Human Immunodeficiency Virus Infection.

Broadly neutralizing antibodies (bnAbs) can prevent lentiviral infection in nonhuman primates and may slow the spread of human immunodeficiency virus type 1 (HIV-1). Although protection by passive transfer of human bnAbs has been demonstrated in monkeys, durable expression is essential for its broader use in humans. Gene-based expression of bnAbs provides a potential solution to this problem, although immune responses to the viral vector or to the antibody may limit its durability and efficacy. Here, we delivered an adeno-associated viral vector encoding a simianized form of a CD4bs bnAb, VRC07, and evaluated its immunogenicity and protective efficacy. The expressed antibody circulated in macaques for 16 weeks at levels up to 66 g/ml, although immune suppression with cyclosporine (CsA) was needed to sustain expression. Gene-delivered simian VRC07 protected against simian-human immunodeficiency virus (SHIV) infection in monkeys 5.5 weeks after treatment. Gene transfer of an anti-HIV antibody can therefore protect against infection by viruses that cause AIDS in primates when the host immune responses are controlled.

HIV-1 Coreceptor CXCR4 Antagonists Promote Clonal Expansion of Viral Epitope-Specific CD8+ T Cells During Acute SIV Infection in Rhesus Monkeys In Vivo.

The underlying molecular mechanisms and the kinetics of T cell receptor (TCR) repertoire selection during administration of CXCR4 or CCR5 inhibitors in infection of AIDS viruses in vivo have remained largely unexplored. Viral epitope-specific CD8(+) T lymphocytes play a dominant role in the control of HIV and simian immunodeficiency virus (SIV). We hypothesized that blockade of CXCR4 or CCR5 might influence the clonal expansion of epitope-specific CD8(+) T cells, contributing to antiviral immune responses in vivo. We measured frequencies of the dominant epitope p11C-specific CD8(+) T cells and analyzed the TCR repertoire of those cells in SIV-infected rhesus monkeys treated by CXCR4 or CCR5 inhibitors and vMIP-II, which binds multiple chemokine receptors. A significantly increase in the levels of epitope-specific CD8(+) T cells was observed after blockade of CXCR4 or CCR5 compared with untreated control groups. Those CD8(+) T cells exhibited selected usage of TCR Vβ families and complementarity-determining region 3 (CDR3) segments. The clonal expansion of distinct Vβ populations could efficiently inhibit SIV replication in vitro, and CXCR4 inhibitor induced more expansion of epitope-specific CD8(+) T cells than CCR5 antagonist (P < 0.01), whereas vMIP-II treatment showed the most marked augmentation of p11C-specific CD8(+) T cells. Antagonists of HIV coreceptors, particularly CXCR4, play an important role in the clonal expansion of SIV epitope-specific CD8(+) T cells in vivo, thus inhibitors of chemokine receptors such as CXCR4 or CCR5 may contribute to the ability of epitope-specific CD8(+) T cells to inhibit SIV or HIV infection.

Using immunoglobulin Y as an alternative antibody for the detection of hepatitis A virus in frozen liver sections.

An increasing amount of research has been conducted on immunoglobulin Y (IgY) because the use of IgY offers several advantages with respect to diagnostic testing, including its easy accessibility, low cost and translatability to large-scale production, in addition to the fact that it can be ethically produced. In a previous work, immunoglobulin was produced and purified from egg yolks (IgY) reactive to hepatitis A virus (HAV) antigens. In the present work, this anti-HAV-specific IgY was used in an indirect immunofluorescence assay to detect viral antigens in liver biopsies that were obtained from experimentally infected cynomolgus monkeys. Fields that were positive for HAV antigen were detected in liver sections using confocal microscopy. In conclusion, egg yolks from immunised hens may be a reliable source for antibody production, which can be employed for immunological studies.

Simian immunodeficiency virus infection evades vaccine-elicited antibody responses to V2 region.

An effective AIDS vaccine should elicit protective antibody responses against HIV/simian immunodeficiency virus (SIV) infection. We recently reported that mucosal priming with a replicating modified vaccinia Tiantan virus (MVTTgpe)-based vaccine regimen induces durable protection against pathogenic SIVmac239 infection in rhesus monkeys. Here, we aim to conduct a comprehensive analysis on antigenic determinants recognized by specific antibody responses generated by vaccination and SIVmac239 infection. A novel yeast surface displayed antigen library of entire SIVmac239 envelope (Env) glycoprotein was established and validated to map the major antigenic determinants (MAD) in monkey sera elicited by vaccination and infection. MAD-directed antibody responses were further analyzed for correlation of protection. The yeast surface displayed library allows the mapping of SIV-specific linear and conformational MAD. The MVTTgpe-based regimen induces antibodies targeting mainly to 6 antigenic domains covering the entire gp160. Critically, this regimen induced a uniquely predominant antibody response against a distinct MAD in variable region 2 (V2) as compared with the Ad5gpe-based vaccine and SIVmac239 infection. This MAD was associated with a higher titer of anti-V2 antibody responses, which was inversely correlated with peak and set-point viral loads. Unexpectedly, the pathogenic SIVmac239 challenge evaded the vaccine-elicited anti-V2 antibody response. Instead of recalling B-cell memory responses to the V2 MAD, viral infection directed anti-V1V2 antibodies primarily to V1 region. Moreover, the anti-V1V2 antibody responses diminished significantly in infected macaques after they enter the stage of simian AIDS. Our findings have critical implications to AIDS vaccine efforts with focus on V2 region.

Gastrointestinal parasites of vervet monkeys around Lake Hawassa recreational sites, southern Ethiopia

Vervet monkeys (Chlorocebus pygerythrus) are non-human primates belonging to the family Cercopithecidae, which are native to Africa. The objective of the present study was to assess the occurrence of gastrointestinal parasites in free-ranging vervet monkeys. A total of 140 free-ranging vervet monkeys found in the recreational areas of Hawassa city, Ethiopia, were examined for gastrointestinal parasitic infection from November 2013 to April 2014. For the identification of eggs and larvae of nematodes and cysts, oocysts and trophozoites of protozoa, faecal samples were subjected to direct smear and floatation techniques. Overall, out of 140 faecal samples examined, 75 % were found to harbour one or more gastrointestinal nematode parasites. The most frequently detected nematode parasite was hookworms (45.7 %). Parasite eggs suggestive of cestode parasites were found in 7.9 % of the samples. Coccidia were the most commonly detected protozoa parasites (27.1 %). Mixed infections with two or more parasites were detected in 74.3 % of the examined faecal samples. The present study can give baseline information on the occurrence of parasitic infection in wild vervet monkeys in the area. Future studies in the area should focus not only on the animals but also on the determination of the possible transmission of the parasites to humans which do have close interaction with the vervet monkeys.

Larva migrans in squirrel monkeys experimentally infected with Baylisascaris potosis

Roundworms of the genus Baylisascaris are natural parasites primarily of wild carnivores, and they can occasionally cause infection in humans and animals. Infection results in visceral larva migrans and/or neural larva migrans, which can be severe or fatal in some animals. Recently, Baylisascaris nematodes isolated from kinkajous (Potos flavus) and previously referred to as Baylisascaris procyonis were renamed as Baylisascaris potosis; however, data regarding the pathogenicity of B. potosis towards animals and humans are lacking. In the present study, we experimentally infected squirrel monkeys (Saimiri sciureus) with B. potosis to determine the suitability of the monkey as a primate model. We used embryonated eggs of B. potosis at two different doses (10,000 eggs and 100,000 eggs) and examined the animals at 30days post-infection. Histopathological examination showed the presence of B. potosis larvae and infiltration of inflammatory cells around a central B. potosis larvae in the brain, intestines, and liver. Nevertheless, the monkeys showed no clinical signs associated with infection. Parasitological examination revealed the presence of B. potosis larvae in the intestines, liver, lung, muscles, brain, kidney, and diaphragm. Our findings extend the range of species that are susceptible to B. potosis and provide evidence for the zoonotic potential of larva migrans in high dose infections.

Simian malaria in the Brazilian Atlantic forest: first description of natural infection of capuchin monkeys (Cebinae subfamily) by Plasmodium simium.

BackgroundIn Brazil, two species of Plasmodium have been described infecting non-human primates, Plasmodium brasilianum and Plasmodium simium. These species are morphologically, genetically and immunologically indistinguishable from the human Plasmodium malariae and Plasmodium vivax parasites, respectively. Plasmodium simium has been observed naturally infecting monkeys of the genera Alouatta and Brachyteles in a restricted area of the Atlantic Forest in the south and southeast regions of Brazil. However, its reported geographical distribution and the diversity of its vertebrate hosts may be underestimated, since available data were largely based on analyses by microscopic examination of peripheral blood, a method with limited sensitivity, considering the potential sub-patent feature of these infections. The present study describes, for the first time, the natural infection of P. simium in capuchin monkeys from the Brazilian Atlantic Forest.MethodsBlood samples from 30 non-human primates belonging to nine species kept in the Primate Centre of Rio de Janeiro were collected. Fragments of spleen and liver from one dead monkey found in the neighborhoods of the Primate Centre were also analysed. Molecular diagnosis was performed by nested PCR (18SSU rRNA) and the amplified fragment was sequenced.ResultsThirty per cent of the captive animals were infected with P. simium and/or P. brasilianum. The dead monkey tested positive for DNA of P. simium. For the first time, Cebinae primates (two specimens of genus Cebus and two of genus Sapajos) were found naturally infected by P. simium. The infection was confirmed by sequencing a small fragment of 18SSU rRNA.ConclusionThe results highlight the possibility of infection by P. simium in other species of non-human primates whose impact could be significant for the malaria epidemiology among non-human primates and, if it becomes clear that this P. simium is able to infect monkeys and, eventually, man, also for the maintenance of transmission of human malaria in the context of a zoonosis in areas under influence of the Atlantic Forest.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0606-6) contains supplementary material, which is available to authorized users.

Risk factors associated with Toxoplasma gondii infection in captive Sapajus spp.

The aim of this study was to identify risk factors associated with prevalence of Toxoplasma gondii infection in captive capuchin monkeys at a facility in the northeastern Brazil. Serum samples from 116 bearded capuchin (Sapajus libidinosus), nine blonde capuchin (Sapajus flavius), five black-capped capuchin (Sapajus apella), and four capuchin monkeys (Sapajus spp.) were tested for T. gondii antibodies using the modified agglutination test (MAT, cut-off ≥25); antibodies were found in 85.3% (99/116) of S. libidinosus, 55.6% (5/9) of S. flavius, 80.0% (4/5) of S. apella, and 75.0% (3/4) of S. spp. The risk factors associated with T. gondii seropositivity were ingestion of raw meat [OR = 4.13 (1.26; 13.50)] and old age [OR = 4.90 (1.70; 14.13)]. Results indicate a very high T. gondii seropositivity in these primate populations. To minimize exposure to T. gondii raw meat should not be fed to these animals.

Ebola virus - an Indian perspective.

The current ongoing outbreak of Ebola Virus Disease (EVD) in West Africa is unprecedented in many ways. It is certainly one of the largest and deadliest outbreaks in recent times. It began in Guinea in late 2013 and spread to neighboring countries of Liberia and Sierre Leone. A total of 18,464 suspected, probable and confirmed (11,699) cases with 6841 deaths have been reported till 13th December 2014. Limited transmission is reported from United States of America (4 cases, 1 death) and Mali (8 cases, 6 deaths) whereas, Nigeria (20 cases, 8 deaths), Senegal (1 case, 0 deaths) and Spain (1 case, 0 deaths) have been declared free of EVD [1]. The outbreak has mounted exceptional concern, preparedness and response worldwide as it is dreaded as one of the most virulent disease causing high fatality in humans. It has no specific treatment or vaccine despite it being known since 1976 when it first appeared in Democratic Republic of the Congo (DRC) in two simultaneous outbreaks in Nzara, Sudan, and Yambuku, DRC. Until December 2013, a total of 23 outbreaks recorded 2388 human cases and 1590 deaths [2]. Formerly known as Ebola hemorrhagic fever, in the current outbreak EVD involved the health care workers and further weakened the already compromised health care system in the affected countries. Notably, experimental drugs were used in the treatment of humans. UN and other agencies and experts have accelerated the research, clinical trials and resolution of ethical concerns so that drugs and vaccines can be made available for prevention and control of EVD. Ebolavirus is one of three members of the Filoviridae family (filovirus), along with genus Marburgvirus and Cuevavirus. There are five distinct species of Ebolavirus viz. Bundibugyo ebolavirus (BDBV), Zaire ebolavirus (EBOV), Reston ebolavirus (RESTV), Sudan ebolavirus (SUDV) and Tai Forest ebolavirus (TAFV). While BDBV, EBOV, and SUDV have been associated with large EVD outbreaks in Africa, RESTV and TAFV have not yet been implicated in a human outbreak. The RESTV species, found in Philippines and the People’s Republic of China, can infect humans, but no illness or death in humans has been reported [3, 4]. The natural reservoir of Ebola viruses has not yet been proven conclusively. However, fruit batsHypsignathus monstrosus, Epomops franqueti and Myonycteris torquata, may be the natural hosts in Africa. Human beings can get infected and initiate human to human transmission on contact with infected animals or their carcasses. In Africa, infection has been documented through the handling of infected chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines found ill or dead or in the rainforest [3]. The most common mode of human-to-human transmission is direct contact through broken skin or unprotected mucous membranes e.g., the eyes, nose, or mouth, with the blood or body fluids (urine, feces, saliva, semen, and other secretions) of a person who is sick or has died of EVD. However, infection cannot be transmitted before the appearance of symptoms. Transmissionmay also occur with contaminated needles or infected animals. Ebola does not spread through the air or by water. In Africa, it can spread by handling infected bush meat. There is no evidence that mosquitoes and other insects can transmit the virus [3]. V. Mittal (*) :M. Chhabra Zoonosis Division, National Centre for Disease Control, Dte.GHS, 22-Sham Nath Marg, Delhi 110054, India e-mail: veena_m12@yahoo.com