Blood Samples For Serology Research Articles

First detection of Leishmania major in dogs living in an endemic area of zoonotic cutaneous leishmaniasis in Tunisia

BackgroundDogs are considered the main domestic animals that may be a reservoir for Leishmania infantum, the agent of zoonotic visceral leishmaniasis (ZVL) in several countries of the world. The dog may host other Leishmania species, but its epidemiological role in the maintenance and spreading of these parasites is not completely elucidated. Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, affects thousands of people every year and is particularly diffused in many countries of North Africa and Middle East Asia. In ZCL endemic countries, few reports of L. major-positive dogs have been reported, probably because most human cases occur in poor rural areas where the social role of the dog and its medical management is not well considered. The aim of the present study is to better understand the possible involvement of domestic dogs in the epidemiology of ZCL.MethodsOur research focused on a well-established endemic focus of ZCL, in the area of Echrarda, Kairouan Governorate, central Tunisia. A total of 51 dogs with no or mild clinical signs of vector borne diseases were selected in small villages where human cases of ZCL are yearly present. All dogs were sampled for the Leishmania spp. diagnosis, by using the following procedures: blood sample for serology and buffy coat quantitative polymerase chain reaction (qPCR), popliteal fine needle aspiration, and cutaneous biopsy punch for lymph node and skin qPCR.ResultsThe results demonstrated a high percentage (21.6%) of dogs positive at least at one or more test; the most sensitive technique was the lymph node qPCR that detected 8/11 positive dogs. Nine, out of the eleven positive dogs, resulted as infected by Leishmania infantum; ITS1-PCR-sequencing allowed Leishmania major identification in the remaining two cases, both from the popliteal lymph node samples, which can suggest a possible visceral spread of a cutaneous Leishmania species in the dog. Interestingly, one of the two L. major-positive dogs was living in the same house where 6-year-old children showed cutaneous lesions referred to as ZCL.ConclusionsTo our knowledge, this is the first report of L. major-positive dogs in Tunisia, the epidemiological role of which remains under investigation.Graphical

Household transmission investigation for Corona Virus Disease 2019 (COVID-19) in a rural and urban population of north India.

Transmissibility within closed settings, such as households, can provide a strategic way to characterize the virus transmission patterns because the denominator can be well defined. We aimed to characterize the household transmission of Severe Acute Respiratory Syndrome Coronavirus (SARS CoV-2) and its associated risk factors. This prospective case-ascertained study was conducted among the household contacts of laboratory-confirmed SARS CoV-2 cases residing in Ballabgarh, Haryana. We enrolled 148 index cases and their 645 household contacts between December 16, 2020 and June 24, 2021. We defined household contact as any person who had resided in the same household as a confirmed COVID-19 case. Baseline data collection and sample collection for real time- reverse transcriptase polymerase chain reaction (RT-PCR) and IgM/IgG against SARS CoV-2 were done on day 1 visit, and followed for a period of 28 days. RT-PCR was repeated on day 14 or whenever the contact is symptomatic and blood sample for serology was repeated on day 28. We estimated household secondary infection rate (SIR) and other epidemiological indicators-median incubation period and serial interval. We employed binomial logistic regression to quantify risk factors associated with infection. The household SIR was 30.5% (95% CI: 27.1-34.1%). The secondary clinical attack rate was 9.3% (95% CI: 7.2-11.8). The risk factors that showed higher susceptibility to infection were household contacts who were the primary care giver of the case, whose index cases were symptomatic, those with underlying medical conditions, those living in overcrowded households, who were sharing toilet with the index cases and also who were not wearing a mask when coming in contact with the case. The median (IQR) incubation period was 4 days (4, 5), mean (SD) serial interval 6.4 (±2.2) days, and median (IQR) serial interval 5 days (5, 7). Households favour secondary transmission of SARS CoV- 2, hence, index cases are recommended to self-isolate and wear masks; and household contacts to follow strict COVID infection control measures within households when a family member is infected.

Vaccination with an inactivated canine influenza H3N2 virus vaccine is safe and elicits an immune response in cats.

ObjectivesThe aim of this study was to evaluate safety and seroconversion when an inactivated H3N2 canine influenza virus (CIV) vaccine was administered to cats.MethodsTwenty 7–8-week-old seronegative cats were randomly assigned to two groups of 10 animals each. Cats in treatment group T01 were subcutaneously administered two doses of an adjuvanted placebo 3 weeks apart to serve as non-immunized controls. Cats in treatment group T02 were subcutaneously administered with two doses of H3N2 CIV vaccine at 3 weeks apart. All animals were actively monitored for 5 days after each injection for local and systemic reactions. Tympanic temperatures were recorded the day before and 5 days after each vaccination. Blood samples for serology were collected prior to each vaccination (days –1 and 20), and 7 and 14 days post-second vaccination.ResultsMinor vocalization was observed in both control and vaccinated animals after the first and second dose administration. The only injection site reaction observed was mild swelling in one control cat, which resolved within 24 h. Transient fevers (39.5–39.7°C) that resolved within 24 h post-injection were observed in both treatment groups (T01 = 3/10 and T02 = 5/10). All vaccinated, but no control, animals successfully seroconverted within 14 days of second vaccination, with H3N2 CIV-specific hemagglutination inhibition (HAI) titers ranging from 32 to 128.Conclusions and relevanceCats vaccinated subcutaneously with an inactivated H3N2 CIV vaccine had similar rates of adverse events post-vaccination as the control group. Increased HAI titers provided evidence of post-vaccination seroconversion with the H3N2 CIV-vaccinated group.

Vaccination of dogs with Duramune DAPPi+LC protects against pathogenic canine parvovirus type 2c challenge

In this study, we determined whether vaccination with Duramune DAPPi+LC containing canine parvovirus (CPV) type 2b protects against challenge with virulent CPV antigenic type 2c. Seven healthy dogs, seronegative for...

The role of horses in the transmission of leptospirosis in an urban tropical area

The objective of this study was to demonstrate the presence of leptospires in equine urine, as evidence for a potential role of horses in transmission of this organism. Thoroughbred horses (aged 2-5 years, n = 276) from Rio de Janeiro, Brazil, were studied. After a severe storm, the premises of the animals remained flooded for 72 h. Blood samples for serology were collected on days 20 and 35 (day of storm = day 0). On day 20, 132 (47·8%) horses were seroreactive (titre ≥200) and, of these, 23 (31·0%) had increased antibody titres on day 35. Furthermore, 34 urine samples (for PCR and culture) were collected from seroreactive horses on day 35. Copenhageni was the most frequent serovar (88·8% of reactive titres). Although none of the urine samples were culture positive, 12 (35·2%) were PCR positive. This is apparently the first report of evidence of leptospires in urban horses. Furthermore, we suggest that these animals can play a role in the transmission of leptospirosis in urban areas.

Chlamydia pneumoniae in children undergoing adenoidectomy.

Chlamydia pneumoniae is a common respiratory pathogen which is often found in paediatric populations. Little is known about the true colonization rate and the localization of the bacteria in the respiratory tract. In this study, immunohistochemistry was used to examine adenoids from 69 children undergoing elective adenoidectomy. Throat swabs for polymerase chain reaction (PCR) and blood samples for serology were also obtained. Chlamydia pneumoniae was demonstrated in the adenoids by immunohistochemistry in 68 of the children. Five children (7%) had a positive C. pneumoniae PCR test from throat swabs and 14 children (20%) had detectable antibodies by the microimmunofluorescence technique. The results suggest that C. pneumoniae is a common finding in the adenoids of children undergoing adenoidectomy. Whether or not C. pneumoniae plays a pathogenic role in this patient population could not be determined from the data obtained in this investigation.

Eficacia de la determinación fecal de Helicobacter pylori mediante la técnica HpSA en enfermos con hemorragia digestiva alta

The rapid urease test is the most commonly used test in the diagnosis of Helicobacter pylori infection in patients with upper gastrointestinal hemorrhage. However, some studies have suggested that results of this test are frequently false negative when blood is present. An effective new enzyme immunoassay for determining H. pylori antigens in stools has recently begun to be used. To determine the efficacy of the H. pylori stool antigen test (HpSAT) in patients with upper gastrointestinal hemorrhage. Thirty-two patients with upper gastrointestinal hemorrhage were prospectively studied from November 1998 to April 1999. In all patients the following tests were performed in the first 72 hours after onset of bleeding and 24 hours after hospital admission: upper gastrointestinal endoscopy, biopsy samples for the rapid urease test and histological study, blood samples for serology, stool samples for HpSAT, and the 13C urea breath test. Criteria for infection was a positive result in at least two of the four diagnostic techniques, except in the case of HpSAT. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. Of the 32 patients, 23 (71.8%) were infected. The results of four HpSAT (12.5%) were negative and 28 were positive (87.5%). HpSAT showed high sensitivity (95.6%) but low specificity (33.3%). The PPV and NPV were 78.5% and 75% respectively. Of the 32 HpSAT, 25 (78.1) were performed in melenic stools: 22 were positive and 3 were negative. Seventy-five percent of negative HpSAT and 78.5% of positive HpSAT corresponded to melenic stools. HpSAT is a rapid, non-invasive technique that does not appear to be influenced by the presence of blood. Consequently, it can be applied in patients with upper gastrointestinal hemorrhage. The rapid urease test showed high sensitivity, specificity and PPV and should remain the first-line test in patients with upper gastrointestinal hemorrhage. HpSAT is appropriate as a second-line technique and is useful when the rapid urease test is negative and infection is strongly suspected, when no samples for the rapid urease test have been taken and when endoscopy cannot be performed. The result obtained in the present study should be confirmed in future studies with larger samples.

A prospective seroepidemiologic study on dengue in children four to nine years of age in Yogyakarta, Indonesia I. studies in 1995-1996.

A prospective study on dengue (DEN) viruses was initiated in October 1995 in Gondokusuman kecamatan, Yogyakarta, Indonesia. This report presents data from the first year of the study. The studied cohort included all children 4-9 years of age living in the kecamatan. Blood samples for serology were collected from 1,837 children in October 1995 and again in October 1996. Blood samples for virus isolation and serology were collected from cohort children who were seen in municipal health clinics with febrile syndromes or admitted to hospitals with a provisional diagnosis of dengue hemorrhagic fever. Dengue serotype antibody prevalence and 1995-1996 infection rates were calculated using a single dilution (1:60) 70% plaque reduction endpoint neutralization test. Prevalence of dengue antibody at the beginning of the study was DEN 1 = 12%, DEN 2 = 16%, DEN 3 = 2%, DEN 4 = 4%, and two or more dengue infections = 22%. Total dengue antibody prevalence increased from 38% in 4-year-old children to 69% in 9-year-old children. During the observation period, primary dengue infection rates were DEN 1 = 4.8%, DEN 2 = 7.7%, DEN 3 = 4.2%, and DEN 4 = 3.4%, while two or more dengue infections occurred in 6.7% of the study population. The secondary dengue infection rate was 19.0%. From febrile cases, all four dengue viruses were isolated with DEN 3 predominating. Seven children were hospitalized, including one fatal case with a hospital diagnosis of dengue shock syndrome. Based upon presence of antibody in the initial cohort bleeding and the serologic response both weeks and several months following illness, all had secondary dengue infections. Neutralizing antibody patterns in the initial cohort bleeding and in late convalescent serum samples permitted recognition of dengue infection sequence in five patients: DEN 2-DEN 1 (3), DEN 2-DEN 4 (1), DEN 1-DEN 3 (1), and none in the sequence DEN 1-DEN 2. In the total cohort 6.5% of the observed secondary infections were of the sequence DEN 2-DEN 1, while 4.9% were DEN 1-DEN 2, a highly pathogenic sequence in previous studies. Reduced pathogenic expression of secondary DEN 2 with enhanced pathogenic expression of secondary DEN 1 infections was an unexpected finding. Further studies will be required to understand the respective contributions to pathogenicity of antibody from initial dengue infections versus the biological attributes of the second infecting dengue viruses.

Congenital Pestivirus Infection in Sheep, Ewes, Heifers and Calves with Bovine Pestivirus Strains and Detection of Anigenic Differences between Them

ABSTRACTSheep, ewes, cows and heifers were used in experiments for inoculation with different pestivirus strains inducing congenital infection. Intranasally and intramuscularly inoculated five groups (A-E) of seronegative sheep, ewes, goats, cattle, heifers and caws at days 49th and 126th of gestation with either of four antigenically different BVDV reference strains (OREGON C 24, NADL, OSLOSS, ALFORT-187) and one BVDV Bulgarian strain (KABLESHKOVO-76). A sixth group (F) was housed for 7 days with persistently infected calf and a seventh group (G) served as controls. From each of the experimentally groups half of the sheep and the calves were killed 2 weeks and a half of them 4 weeks after infection. All ruminants of groups were seronegative in the ELISA and in the virusneutralization test (β-procedure). At 2 and 4 weeks after infection the virus was isolated from almost all foetal organs in the all groups inoculated with different pestivirus strains. In the control group no virus was isolated from foetal organs. In experiments the sheep, ewes, goats and saws were inoculated with antigenically heterologous strains at 49th day of pregnancy. The caws and heifers were challenged at 126th day of pregnancy with homologous and one heterologous pestivirus strains (ALFORT-187). Blood samples for serology were collected on the day of inoculation, every week thereafter and on the day of killing of different groups sheep, goats, pigs and calves. Nasal swabs for isolation were taken on day 6th and day 10th after inoculation. Rectal temperatures of sheep, goats, pigs and calves were recorded daily during 14 days, starting 2 days before inoculation and clinical observation of all ewes, saws and heifers were performed daily during the experiments. From the sheep, ewes, caws, cattle, heifers and different foetuses the following organs were collected—placenta, tonsils, ovaris, pylorus, kidneys, small intestine for reisolation of using different pestivirus strains. A control group was left uninfected. The data obtained were mathematically calculated by dispersion analysis.

Immunogenicity and safety of Haemophilus influenzae type b polysaccharide- Neisseria meningitidis conjugate vaccine in 7.5 μg liquid formulation: a comparison of three lots with the 15.0 μg lyophilized formulation

We conducted a multicenter, single-blind, randomized comparison of the immunogenicity and safety of three manufacturing-scale lots of 7.5 μg liquid Haemophilus influenzae type b polysaccharide- Neisseria meningitidis conjugate vaccine (PRP-OMPC) and a single lot of 15.0 μg lyophilized PRP-OMPC. A total of 908 infants were entered into the study. Each infant received two primary injections intramuscularly 2 months apart beginning at age 2–6 months and a booster injection at 12–15 months. Blood samples for serology were obtained before each injection and 1 month after the second and the booster dose. Immune responses were measured by radioimmunoassay. Approximately 80% of the infants achieved a titer >1.0 μg ml −1 after the second primary dose of all four lots tested; the geometric mean titer (GMT) was ca 3 μg ml −1 for each vaccine group. After the booster dose, more than 90% of infants from each vaccine group had a titer >1.0 μg ml −1; GMTs ranged from 8 to 10 μg ml −1. No serious vaccine-associated adverse reactions were reported. Thus the 7.5 μg liquid PRP-OMPC vaccine was at least as immunogenic and well tolerated as the 15.0 μg lyophilized vaccine.

Long-term study of Lyme borreliosis in a highly endemic area in Sweden.

From May 1991 to May 1994, Lyme borreliosis was studied prospectively in 301 residents living on Aspö, a highly endemic area for the disease. The study included annual questionnaires and blood samples for serology. Immunoglobulin G (IgG) antibodies to Borrelia burgdorferi sensu lato were detected by enzyme-linked immunosorbent assay in 63/301 (21%) of the residents at the start of the study. Seropositivity rates increased with time, and 3 years later 101/301 (34%) were positive. A total of 34 individuals developed physician-verified manifestations of Lyme borreliosis during the study period. Nine individuals developed an erythema migrans, despite a previously treated Lyme borreliosis or pre-existing high levels of IgG antibodies to B. burgdorferi s.l.

Helicobacter pylori in 205 Consecutive Endoscopy Patients

The presence of Helicobacter pylori in the gastric, antral mucosa of 205 consecutive, unselected gastroscopy patients was investigated by 1-3 biopsies for urea broth test and culture, 1 biopsy for histological examination and 1 blood sample for serology by ELISA. Overall, 41% were positive for H. pylori by culture, 32% by urea broth test, 24% by histological staining and 67%, 56% and 49% for the 3 cut-off limits applied to serology. Culture and serology indicated the presence of H. pylori in 79-92% of the 14 cases with duodenal ulcer, in 59-82% of the 28 cases with gastric ulcers, in 45-71% of the 51 cases with endoscopic gastritis and in 33-69% of 13 cases with oesophagitis. In patients with histological antritis, H. pylori was identified by culture in 71% (60/84), by serology in 95%, 88% and 81% with the different cut-off limits. The sensitivity of serology ranged from 99-78% depending on the cut-off limits and the specificity from 78-100% against all parameters combined. These results suggest that serology is a useful screening method for the presence of H. pylori. Future antibiotic treatment studies are required to evaluate the clinical relevance of H. pylori in gastrointestinal disease and to investigate the possibility to monitor eradication by serology.