Antibiotic treatment for newborns with congenital syphilis.

BACKGROUND: Congenital syphilis continues to be a substantial public health problem in many parts of the world. Since the first use of penicillin for the treatment of syphilis in 1943, which was a notable early success, it has remained the preferred and standard treatment including for congenital syphilis. However, the treatment of congenital syphilis is largely based on clinical experience and there is extremely limited evidence on the optimal dose or duration of administration of penicillin or the use of other antibiotics. OBJECTIVES: To assess the effectiveness and safety of antibiotic treatment for newborns with confirmed, highly probable and possible congenital syphilis. SEARCH METHODS: We searched the Cochrane STI Group Specialized Register, CENTRAL, MEDLINE, Embase, LILACS, WHO ICTRP, ClinicalTrials.gov and Web of Science to 23 May 2018. We also handsearched conference proceedings, contacted trial authors and reviewed the reference lists of retrieved studies. SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing antibiotic treatment (any concentration, frequency, duration and route) with no intervention or any other antibiotic treatment for neonates with confirmed, highly probable or possible congenital syphilis. DATA COLLECTION AND ANALYSIS: All review authors independently assessed trials for inclusion, extracted data and assessed the risk of bias in the included studies. We resolved any disagreements through consensus. We assessed the quality of the evidence using the GRADE approach. MAIN RESULTS: Two RCTs (191 participants) met our inclusion criteria and none of these trials was funded by the industry. One trial (22 participants) compared benzathine penicillin with no intervention for infants with possible congenital syphilis. Low-quality evidence suggested that benzathine penicillin administration may not have decreased the rate of neonatal death due to any cause (risk ratio (RR) 0.83, 95% confidence interval (CI) 0.06 to 11.70), and showed a possible reduction into the proportion of neonates with clinical manifestations of congenital syphilis (RR 0.12, 95% CI 0.01 to 2.09). Penicillin administration increased the serological cure at the third month (RR 2.13, 95% CI 1.06 to 4.27). These results should be taken with caution, because the trial was stopped early because there were four cases with clinical congenital syphilis in the no treatment group and none in the treatment group. Interim analysis suggested this difference was significant. This study did not report neonatal death due to congenital syphilis or the frequency of serious or minor adverse events after therapy. We downgraded the quality of evidence because of imprecision and risk of bias.One trial (169 participants) compared benzathine penicillin versus procaine benzylpenicillin. High- and moderate-quality evidence suggested that there were probably no differences between benzathine penicillin and procaine benzylpenicillin for the outcomes: absence of clinical manifestations of congenital syphilis (RR 1.00, 95% CI 0.97 to 1.03) and serological cure (RR 1.00, 95% CI 0.97 to 1.03). There were no cases of neonatal death due congenital syphilis; all 152 babies who followed up survived. This study did not report on the frequency of serious or minor adverse events after therapy. We downgraded the quality of evidence because of serious risk of bias. AUTHORS' CONCLUSIONS: At present, the evidence on the effectiveness and safety of antibiotic treatment for newborns with confirmed, highly probable or possible congenital syphilis is sparse, implying that we are uncertain about the estimated effect. One trial compared benzathine penicillin with no intervention for infants with possible congenital syphilis. Low-quality evidence suggested penicillin administration possibly reduce the proportion of neonates with clinical manifestations of congenital syphilis, penicillin administration increased the serological cure at the third month. These findings support the clinical use of penicillin in neonates with confirmed, highly probable or possible congenital syphilis. High- and moderate-quality evidence suggests that there are probably no differences between benzathine penicillin and procaine benzylpenicillin administration for the outcomes of absence of clinical manifestations of syphilis or serological cure.

An atypical Bacillus anthracis infection in a bull-A potential occupational health hazard.

Bacillus anthracis infecting cattle is usually identified based on the typical symptom: sudden death. Bacillus anthracis causing atypical symptoms may remain undiagnosed and represent a potential occupational health hazard for, that is veterinarians and producers, butchers and tanners. In the year 2004, one case of sudden death in a dairy farm in southern Finland was diagnosed as bovine anthrax. Four years later 2008, an atypical case of anthrax was diagnosed in the same holding. The bull was taken to the Production Animal Hospital of the Faculty of Veterinary Medicine, University of Helsinki because of fever, loss of appetite and a symmetrically swollen scrotal sac. Penicillin treatment cured the fever but not the swollen scrotum. Before the intended therapeutic castration, a punctuate consisting of 10 ml fluid collected into a syringe from the scrotal sac was cultivated on blood agar at 37°C. After 24 hr, an almost pure culture of a completely non-hemolytic Bacillus cereus-like bacteria was obtained. The strain was identified as B. anthracis using Ba-specific primers by the Finnish Food Safety Authority (RUOKAVIRASTO). After the diagnosis, the bull was euthanized and destroyed, the personnel were treated with prophylactic antibiotics and the clinic was disinfected. In this particular case, treatment with water, Virkon S and lime seemed to be effective to eliminate endospores and vegetative cells since no relapses of anthrax have occurred in 10 years. This case is the last reported anthrax case in Finland.

Comparative therapeutic efficacy of Phyllanthus emblica (Amla) fruit extract and procaine penicillin in the treatment of subclinical mastitis in dairy buffaloes.

To investigate the comparative therapeutic efficacy of Phyllanthus emblica (Amla) fruit extract and procaine penicillin in the treatment of subclinical mastitis, a total of 30 subclinical mastitis positive buffaloes out of 194 lactating buffaloes were divided into 3 equal groups viz. A, B and C. Group A was treated with procaine penicillin, group B was treated with Phyllanthus emblica fruit extract and group C was served as control for 5 days respectively. The collected milk samples were subjected to the treatment trials before and after the treatment at day 0, 7th and 14th day aseptically. The evaluation parameters were bacteriological cure rate, milk pH, milk yield. The percentage cure rate of sub-clinically mastitic quarters in group A, B and C were 80.95%, 64.7% and 22.22% at day 14 respectively. The quarter based bacteriological cure rate was highest in group A (80.95%) followed by group B (64.7%) and group C (22.22%). The pH was significant (P > .05) in group A, B and C at day 0, 7 and 14. It is concluded that Phyllanthus emblica fruit extract is an inexpensive source in the treatment of subclinical mastitis in dairy buffaloes and can be used as an alternative to antibiotic therapy as for procaine penicillin.

Simplified antibiotic regimens compared with injectable procaine benzylpenicillin plus gentamicin for treatment of neonates and young infants with clinical signs of possible serious bacterial infection when referral is not possible: a randomised, open-label, equivalence trial.

BACKGROUND: WHO recommends hospital-based treatment for young infants aged 0-59 days with clinical signs of possible serious bacterial infection, but most families in resource-poor settings cannot accept referral. We aimed to assess whether use of simplified antibiotic regimens to treat young infants with clinical signs of severe infection was as efficacious as an injectable procaine benzylpenicillin-gentamicin combination for 7 days for situations in which hospital referral was not possible. METHODS: In a multisite open-label equivalence trial in DR Congo, Kenya, and Nigeria, community health workers visited all newborn babies at home, identifying and referring unwell young infants to a study nurse. We stratified young infants with clinical signs of severe infection whose parents did not accept referral to hospital by age (0-6 days and 7-59 days), and randomly assigned each individual within these strata to receive one of the four treatment regimens. Randomisation was stratified by age group of infants. An age-stratified randomisation scheme with block size of eight was computer-generated off-site at WHO. The outcome assessor was masked. We randomly allocated infants to receive injectable procaine benzylpenicillin-gentamicin for 7 days (group A, reference group); injectable gentamicin and oral amoxicillin for 7 days (group B); injectable procaine benzylpenicillin-gentamicin for 2 days, then oral amoxicillin for 5 days (group C); or injectable gentamicin for 2 days and oral amoxicillin for 7 days (group D). Trained health professionals gave daily injections and the first dose of oral amoxicillin. Our primary outcome was treatment failure by day 8 after enrolment, defined as clinical deterioration, development of a serious adverse event (including death), no improvement by day 4, or not cured by day 8. Independent outcome assessors, who did not know the infant's treatment regimen, assessed study outcomes on days 4, 8, 11, and 15. Primary analysis was per protocol. We used a prespecified similarity margin of 5% to assess equivalence between regimens. This study is registered with the Australian New Zealand Clinical Trials Registry, number ACTRN12610000286044. FINDINGS: In Kenya and Nigeria, we started enrolment on April 4, 2011, and we enrolled the necessary number of young infants aged 7 days or older from Oct 17, 2011, to April 30, 2012. At these sites, we continued to enrol infants younger than 7 days until March 29, 2013. In DR Congo, we started enrolment on Sept 17, 2012, and continued until June 28, 2013. We randomly assigned 3564 young infants to either group A (n=894), group B (n=884), group C (n=896), or group D (n=890). We excluded 200 randomly assigned infants, who did not fulfil the predefined criteria of adherence to treatment and adequate follow-up. In the per-protocol analysis, 828 infants were included in group A, 826 in group B, 862 in group C, and 848 in group D. 67 (8%) infants failed treatment in group A compared with 51 (6%) infants in group B (risk difference -1·9%, 95% CI -4·4 to 0·1), 65 (8%) in group C (-0·6%, -3·1 to 2·0), and 46 (5%) in group D (-2·7%, -5·1 to 0·3). Treatment failure in groups B, C, and D was within the similarity margin compared with group A. During the 15 days after random allocation, 12 (1%) infants died in group A, compared with ten (1%) infants in group B, 20 (2%) infants in group C, and 11 (1%) infants in group D. An infant in group A had a serious adverse event other than death (injection abscess). INTERPRETATION: The three simplified regimens were as effective as injectable procaine benzylpenicillin-gentamicin for 7 days on an outpatient basis in young infants with clinical signs of severe infection, without signs of critical illness, and whose caregivers did not accept referral for hospital admission. FUNDING: Bill & Melinda Gates Foundation grant to WHO.

Comminuted fracture of the accessory carpal bone removed via an arthroscopic-assisted arthrotomy.

A 16-year-old American paint horse gelding was presented for evaluation of a left forelimb lameness grade III/V. Radiographs and computed tomography revealed a comminuted fracture of the accessory carpal bone involving the entire articulation with the distal radius and the proximal aspect of the articulation with the ulnar carpal bone. Multiple fragments were present in the palmar pouch of the antebrachiocarpal joint. An arthroscopic-assisted open approach was necessary to remove all fractured fragments. Subsequently the horse was re-admitted for lameness and was treated successfully with antibiotics and long-term supportive bandaging.

Fracture comminutive de l'os du carpe accessoire enlevé à l'aide d'une arthrotomie assistée par arthroscopie. Un cheval American Paint Horse âgé de 16 ans a été présenté pour l'évaluation d'une boiterie de la jambe avant gauche de grade III/V. Les radiographies et la tomodensitométrie ont révélé une fracture comminutive de l'os du carpe accessoire touchant toute l'articulation avec le radius distal et l'aspect proximal de l'articulation avec l'os du carpe cubital. Des fragments multiples étaient présents dans la poche palmaire de l'articulation antébrachio-carpienne. Une approche ouverte assistée par arthroscopie a été nécessaire pour retirer tous les fragments fracturés. Le cheval a ensuite été réadmis pour boiterie et a été traité avec succès à l'aide d'antibiotiques et de pansements de soutien à long terme.(Traduit par Isabelle Vallières).

T-CELL LYMPHOCYTIC LEUKEMIA IN A FALLOW DEER (DAMA DAMA).

A 17-yr-old female fallow deer presented with ataxia, inappetence, decreased fecal output, and decreased mentation. A complete blood count demonstrated leukocytosis (24.1×10(3)/µl, n=1.16-7.38×10(3)/µl), characterized by lymphocytosis (22.89×10(3)/µl, n=0.18-3.65×10(3)/µl), anemia (packed cell volume 20%, n=29.0-55.8%), decreased red blood cell count (4.1×10(3)/µl, n=6.86-14.72×10(3)/µl), and decreased hemoglobin (7.5 g/dl, n=9.4-19.2 g/dl). Numerous mature, well-differentiated lymphocytes were noted on the blood film. Despite treatment and clinical improvement, the decision was made to euthanize the deer. Histopathology identified a monomorphic population of CD3 positive, CD79a negative small lymphocytes replacing most of the hematopoietic tissue in the bone marrow without evidence of tissue invasion. Results of viral screening were negative.

Randomized noninferiority clinical trial evaluating 3 commercial dry cow mastitis preparations: II. Cow health and performance in early lactation.

The objective of this randomized noninferiority clinical trial was to compare the effect of treatment with 3 different dry cow therapy formulations at dry-off on cow-level health and production parameters in the first 100 d in milk (DIM) in the subsequent lactation, including 305-d mature-equivalent (305 ME) milk production, linear score (LS), risk for the cow experiencing a clinical mastitis event, risk for culling or death, and risk for pregnancy by 100 DIM. A total of 1,091 cows from 6 commercial dairy herds in 4 states (California, Iowa, Minnesota, and Wisconsin) were randomly assigned at dry-off to receive treatment with 1 of 3 commercial products: Quartermaster (QT; Zoetis Animal Health, Madison, NJ), Spectramast DC (SP; Zoetis Animal Health) or ToMorrow Dry Cow (TM; Boehringer Ingelheim Vetmedica Inc., St Joseph, MO). All clinical mastitis, pregnancy, culling, and death events occurring in the first 100 DIM were recorded by farm staff using an on-farm electronic record-keeping system. Dairy Herd Improvement Association test-day records of milk production and milk component testing were retrieved electronically. Mixed linear regression analysis was used to describe the effect of treatment on 305ME milk production and LS recorded on the last Dairy Herd Improvement Association test day before 100 DIM. Cox proportional hazards regression analysis was used to describe the effect of treatment on risk for experiencing a case of clinical mastitis, risk for leaving the herd, and risk for pregnancy between calving and 100 DIM. Results showed no effect of treatment on adjusted mean 305 ME milk production (QT=11,759 kg, SP=11,574 kg, and TM=11,761 kg) or adjusted mean LS (QT=1.8, SP=1.9, and TM=1.6) on the last test day before 100 DIM. Similarly, no effect of treatment was observed on risk for a clinical mastitis event (QT=14.8%, SP=12.7%, and TM=15.0%), risk for leaving the herd (QT=7.5%, SP=9.2%, and TM=10.3%), or risk for pregnancy (QT=31.5%, SP=26.1%, and TM=26.9%) between calving and 100 DIM.

Successful medical management of intra-abdominal abscesses in 4 adult horses.

Four adult horses with large intra-abdominal abscesses, suspected to be complications of strangles, were treated with systemic antibiotics alone and made a full recovery. The 100% survival rate is significantly better than other reported survival rates. The median duration of treatment (35 days) was shorter than in most previous reports. This study suggests that penicillin G can be used for successful treatment of strangles associated intra-abdominal abscesses in horses.

Gestion médicale réussie d'abcès intra-abdominaux chez 4 chevaux adultes. Quatre chevaux adultes avec des abcès intra-abdominaux de grande taille, suspectés d'être des complications de la gourme, ont été traités seulement à l'aide d'antibiotiques systémiques et se sont rétablis complètement. Le taux de survie de 100 % est significativement meilleur que les autres taux de survie signalés. La durée médiane du traitement (35 jours) a été plus courte que celle indiquée dans la plupart des rapports antérieurs. Cette étude suggère que la pénicilline G peut être utilisée avec succès pour le traitement des abcès intra-abdominaux associés à la gourme chez les chevaux.(Traduit par Isabelle Vallières).

Naturally occurring cutaneous anthrax: antibiotic treatment and outcome.

OBJECTIVES: Cutaneous anthrax (CA) is the most common clinical presentation in human anthrax, but the duration of antibiotic therapy in naturally occurring CA is controversial. The aim of this study was to compare the clinical outcomes of patients receiving antibiotic treatment for either 3-5 days (group 1) or 7-10 days (group 2) in uncomplicated CA. METHODS: A total of 66 patients were enrolled; 29 (44%) in group 1 and 37 (56%) in group 2. Infections were classified as mild (n = 22, 33%) or severe (n = 44, 67%) CA. RESULTS: There were no significant differences between the groups in symptom resolution time, fever clearance time, healing of lesions, development and healing of eschars, requirement for surgical intervention or the development of complications. Both edema resolution time and duration of hospital stay were longer in group 2. There were no therapeutic failures, relapses or deaths in either group. Steroid therapy was used in 32% of patients with severe CA, but a beneficial effect on resolution of edema was not demonstrated. CONCLUSIONS: These results suggest that short-course antibiotic therapy is as effective as standard-duration therapy in uncomplicated CA and that steroid therapy may not be effective.

Oral amoxicillin plus gentamicin regimens may be superior to the procaine-penicillin plus gentamicin regimens for treatment of young infants with possible serious bacterial infection when referral is not feasible: Pooled analysis from three trials in Africa and Asia.

Background: Hospital referral and admission in many- low and middle-income countries are not feasible for many young infants with sepsis/possible serious bacterial infection (PSBI). The effectiveness of simplified antibiotic regimens when referral to a hospital was not feasible has been shown before. We analysed the pooled data from the previous trials to compare the risk of poor clinical outcome for young infants with PSBI with the two regimens containing injectable procaine penicillin and gentamicin with the oral amoxicillin plus gentamicin regimen currently recommended by the World Health Organization (WHO) when referral is not feasible. Methods: Infant records from three individually randomised trials conducted in Africa and Asia were collated in a standard format. All trials enrolled young infants aged 0-59 days with any sign of PSBI (fever, hypothermia, stopped feeding well, movement only when stimulated, or severe chest indrawing). Eligible young infants whose caretakers refused hospital admission and consented were enrolled and randomised to a trial reference arm (arm A: procaine benzylpenicillin and gentamicin) or two experimental arms (arm B: oral amoxicillin and gentamicin or arm C: procaine benzylpenicillin and gentamicin initially, followed by oral amoxicillin). We compared the rate of poor clinical outcomes by day 15 (deaths till day 15, treatment failure by day 8, and relapse between day 9 and 15) in reference arm A with experimental arms and present risk differences with 95% confidence interval (CI), adjusted for trial. Results: A total of 7617 young infants, randomised to arm A, arm B, or arm C in the three trials, were included in this analysis. Most were 7-59 days old (71%) and predominately males (56%). Slightly over one-fifth of young infants had more than one sign of PSBI at the time of enrolment. Severe chest indrawing (45%), fever (43%), and feeding problems (25%) were the most common signs. Overall, those who received arm B had a lower risk of poor clinical outcome compared to arm A for both per-protocol (risk difference = -2.1%, 95% CI = -3.8%, -0.4%; P = 0.016) and intention-to-treat (risk difference = -1.8%, 95% CI = -3.5%, -0.2%; P = 0.031) analyses. Those who received arm C did not have an increased risk of poor clinical outcome compared to arm A for both per-protocol (risk difference = -1.1%, 95% CI = -2.8%, 0.6%) and intention-to-treat (risk difference = -0.8%, 95% CI = -2.5%, 0.9%) analyses. Overall, those who received arm B had a lower risk of poor clinical outcome compared to the combined arms A and C for both per-protocol (risk difference = -1.6%, 95% CI = -3.5%, -0.1%; P = 0.035) and intention-to-treat (risk difference = -1.4%, 95% CI = -2.8%, -0.1%; P = 0.049) analyses. Conclusions: Analysis of pooled individual patient-level data from three large trials in Africa and Asia showed that the WHO-recommended simplified antibiotic regimen B (oral amoxicillin and injection gentamicin) was superior to regimen A (injection procaine penicillin and injection gentamicin) and combined arms A and C (injection procaine penicillin and injection gentamicin, followed by oral amoxicillin) in terms of poor clinical outcome for the outpatient treatment of young infants with PSBI when inpatient treatment was not feasible. Registration: AFRINEST study [9] is registered with the Australian New Zealand Clinical Trials Registry: ACTRN12610000286044. SATT Bangladesh study [10] is registered with ClinicalTrials.gov: NCT00844337. SATT Pakistan study [11] is registered at ClinicalTrials.gov: NCT01027429.

Clinical spectrum of neurosyphilis in North East India.

BACKGROUND: Symptomatic neurosyphilis (NS) can have varied syndromic presentations: Meningitis, meningovascular and parenchymatous involvement. AIMS: To evaluate the different types of clinical syndrome of NS in a tertiary care hospital. MATERIAL AND METHODS: This was a study of clinical profile of 16 patients with NS, seen in between August 2008 and December 2010. RESULTS: There were 13 male and 3 female patients in the age group of 23-48 years. The clinical syndromes included: Neuropsychiatric syndromes (10), myelopathy (5), and posterior circulation stroke (1). Neuropsychiatric symptoms were dementia, behavioral abnormalities, chronic psychosis, and myelopathy syndromes included acute transverse myelitis (ATM), chronic myelopathy, and syphilitic amyotrophy. Thirteen patients had positive venereal disease research laboratory test (VDRL) and/or high Treponema pallidum hemagglutination titer in blood. Cerebrospinal fluid was positive for VDRL in 14 patients, raised protein was seen in 13 patients and lymphocytic pleocytosis was seen in 10 patients. Human immunodeficiency virus serology was negative in all the patients. Fourteen patients fulfilled the criteria of definitive NS and two of presumptive NS. All the patients except one received injection Procaine penicillin for 14 days. The patient with myelitis received a course of steroid, and one patient with associated hypothyroidism received thyroid supplement in addition to penicillin. On follow-up, dementia of short duration and ischemic stroke improved significantly and clinical status remained the same for ATM; others with mild symptoms improved with residual deficit. CONCLUSION: Syphilis can affect any part of the neuraxis. A high index of clinical suspicion is required to diagnose NS and institute the treatment early, particularly in patients with promiscuous sexual behavior.

Administration of perioperative penicillin reduces postoperative serum amyloid A response in horses being castrated standing.

OBJECTIVES: To compare postoperative inflammatory responses in horses administered perioperative procaine penicillin and those not administered penicillin using acute phase protein serum amyloid A (SAA) as a marker of inflammation. STUDY DESIGN: Randomized clinical trial. ANIMALS: Stallions (n=50) castrated under field conditions. METHODS: SAA concentrations were determined on days 0, 3, and 8. Six horses were subsequently excluded because of elevated SAA concentrations on day 0. Of the remaining 50 horses, 26 were administered nonsteroidal anti-inflammatory drug (NSAID) therapy and 24 were administered NSAID and 25,000 U/kg procaine penicillin on day 0, 1, and 2. RESULTS: SAA concentrations increased significantly from preoperative levels in both groups, and on day 8 concentrations were significantly (P<.02) higher in horses administered only NSAID than in those administered procaine penicillin and NSAID. Infectious complications occurred more frequently (P<.01) in horses with preoperatively elevated SAA concentrations (the excluded horses) than in horses with normal preoperative SAA concentrations (the included horses). CONCLUSIONS: Perioperative antimicrobial therapy reduced the postoperative SAA response, suggesting that bacteria were present in the surgical wound and contributed to inflammation after castration. Horses with elevated preoperative SAA concentrations developed infectious complications more often than horses with normal preoperative SAA concentrations. CLINICAL RELEVANCE: Administration of antimicrobials may be important in horses being castrated standing under field conditions. Increased SAA concentrations seem to be an indicator of increased surgical risk in horses and may be useful before elective surgery for planning.

Periparturient use of parenteral micronised procaine penicillin to reduce the risk of clinical mastitis in heifers after calving.

Mastitis in primiparous heifers immediately postpartum can be both a significant welfare concern and a heavy economic loss. Interventions successfully researched include intramammary therapies. This study considered the clinical and practical effects of a parenteral approach to controlling clinical mastitis in heifers immediately postpartum. The objective of this field trial was to determine whether preventative treatment of heifers with a single parenteral treatment of 15 million iu micronised procaine penicillin within 12h after calving would reduce the incidence of clinical mastitis in early lactation as detected by farmers. All heifers (n=609) calving on three commercial dairy farms in New Zealand during the spring of 2006 were randomly allocated to either treatment or no treatment. Treatment (15 million iu micronised procaine penicillin) was given at the first milking following calving. All clinical mastitis was recorded. Treatment reduced the odds of having clinical mastitis within the first 7 days in milk by over half (Mantel-Haenszel adjusted OR=0.456; p=0.044); and reduced the odds of having mastitis within the first 100 days in milk by just under half (Mantel-Haenszel adjusted OR=0.518; p=0.027). Treatment had a significant effect on increasing the median days to clinical mastitis (p=0.019; beta=1.961, LCI 1.117, UCI 3.445). Preventative treatment of heifers immediately following calving with 15 million iu micronised procaine penicillin parenterally could be of benefit as part of a control programme aimed at reducing the incidence of clinical mastitis in heifers in their first lactation.

Chemotherapy of experimental streptococcal endocarditis. IV. Further observations on prophylaxis.

The ability of antibiotics to prevent Streptococcus sanguis endocarditis was tested in rabbits. Only vancomycin or a combination of penicillin G plus streptomycin always prevented infection when administered as a single dose. A loading dose of 30 mg/kg of phenoxymethyl penicillin (penicillin V) followed by additional 7.5 mg/kg doses for 48 h proved to be the only successful prophylactic program that could be given orally to man. Cefazolin alone or with streptomycin in multiple doses was also an effective alternative to penicillin or penicillin derivatives. Erythromycin uniformly failed to protect animals from bacterial endocarditis but showed greater prophylactic efficacy when a low inoculum of streptococci was used.

Protective study with a group A streptococcal M protein vaccine. Infectivity challenge of human volunteers.

Healthy adult male volunteers were immunized with purified M protein from Group A streptococci. Type 1. The vaccine was administered subcutaneously as an aluminum hydroxide-precipitated antigen in three montly doses. Control subjects received a placebo of the aluminum hydroxide adjuvant. To test the efficacy of the immunization, vaccinees and controls were challenged with a virulent strain of Type 1 streptococci applied to the pharynx. The immunization and challenge of the vaccinated and control subjects (19 men in each group) were carried out as a double blind experiment. All subjects were carefully screened by physical and laboratory examinations before and after the immunization and infectivity schedules. 30-50 days after the last injection, the vaccinees and control subjects were infected with the streptococci. Careful surveillance was maintained to evaluate the extent of acquired streptococcal infection. Throat cultures, leukocytes counts, temperatures, and physical signs and symptoms were monitored daily. All subjects received 1.2 million U of penicillin intramuscularly no later than 6 days after inoculation with the culture. Illness was judged by the appearance of exudative pharyngitis and cervical adenopathy accompanied by a positive throat culture. By these criteria, 9 of the 19 placebo controls, and 1 of 19 vaccinees were ill. No residual illness or clinical complications was observed after the penicillin treatment. It is concluded that the alum-precipitated M protein vaccine afforded protection against an upper respiratory Type 1 streptococcal infection.