H. J. Eggers

An experimental study on the epidemiology of enteroviruses: water and soap washing of poliovirus 1 — contaminated hands, its effectiveness and kinetics

As enteroviruses are mainly transmitted by the fecal-oral route, this study was initiated to investigate the nature of the binding of enteroviruses to human skin. Using poliovirus 1, Mahoney, we investigated the overall effectiveness of soap and water hand-washing of 1 and 5 min duration. The virus-skin interaction was studied by kinetic analysis of repeated serial washings. The following results were obtained: (1) Soap and water washing for 5 min reduced the number of infective particles on hands by 2–4 logs of ten. (2) Poliovirus binding to skin was essentially reversible. (3) Removal of virus followed a triexponential decline curve, suggesting loose, intermediate, and strong binding. (4) Washing agents more effective than soap were sand, aluminum hydroxide powder, and buffer alone, suggesting that friction was more important than emulsification. The results demonstrate the tenacity of poliovirus on skin, and offer a rationale for the epidemiology of enteroviruses on experimental grounds. From a practical point of view these results stress the need for an effective chemical hand disinfectant, particularly in hospitals.

Neutralizing antibodies against Coxsackie B viruses in patients with recent onset of type I diabetes.

In a search for Coxsackie B virus-induced, insulin-dependent diabetes mellitus (IDDM) we examined sera from 166 selected patients (age 1–17 years) with recent onset of IDDM for specific neutralizing antibodies. All 166 patients investigated had a clinical history of recent infectious illness. Eighty per cent of the patients had antibodies against at least one Coxsackie B virus type. But even among the children studied with antibody titers higher than 256 only in about 44% could a recent Coxsackie B virus infection be serologically demonstrated by determining specific neutralizing IgM antibodies. This result again strengthens the notion that IDDM includes several different etiologic groups, among others possibly Coxsackie B virus infections.

Encephalomyocarditis Virus and Diabetes Mellitus: Studies on Virus Mutants in Susceptible and Non-susceptible Mice

The so-called M-variant (especially subtype D) of encephalomyocarditis virus (EMCV) induces a diabetes-like syndrome in certain mouse strains which may serve as a model of insulin-dependent diabetes mellitus (IDDM) in man. The development and course of diabetes was influenced by a number of virus and host factors, among these being virus strain, virus dose, mouse strain, age, sex, and the hosts immunological status. In a D-variant stock of EMCV, we found a virus plaque variant (PV 2) diabetogenic for DBA/2 mice, and at least one variant (PV 7) that did not affect carbohydrate metabolism. Although the diabetogenicity of PV 2 proved to be a genetically stable characteristic after further passages in vivo and in vitro, the incidence of diabetes varied somewhat (mean value 65% in 10-week-old DBA/2 mice infected with 10(5) p.f.u.). Both lower (10(1) or 10(3) p.f.u.) and higher (10(7) or 10(8) p.f.u.) virus doses led to a diminished incidence and severity of diabetes. In younger animals (5 weeks) transient hyperglycaemia often appeared, whereas in older animals (20 weeks) there was a higher rate of mortality. Histological examination of the islets of Langerhans in diabetes-susceptible (DBA/2) and resistant (C57BL/6) mice revealed that EMCV-induced hyperglycaemia appeared to develop in parallel to islet cell damage. Even in diabetic animals, some unaffected islets were regularly found. This study demonstrates that EMCV mutants may have completely different biological effects and produce diabetes only in special circumstances. Host factors play a significant role in the development of diabetes.

Problems of live virus vaccine-associated poliomyelitis a paralytic case with isolation of all three poliovirus types.

The case of a 4-month-old girl is described who developed a paralytic polio-like syndrome 3 weeks after oral polio vaccination (OPV). All three poliovirus types could be isolated (9 days after onset of disease polio type 2, and 33 days after onset of disease types 1 and 3, respectively).In order to classify these isolates as Sabin (vaccine)-like (SL) or non-Sabin-like (non-SL), several markers were tested in three laboratories [intratypic serodifferentiation, reproductive capacity at supraoptimal temperature (RTC), A1(OH)3 gel elution assay, and oligonucleotide mapping]. The results of the marker determinations were not uniform, but — summarizing all data — it seems plausible to associate the disease with the OPV. The significance of marker determinations in proving a vaccine-induced poliomyelitis is discussed in the light of this clinical case. Some comments are made on poliovirus vaccination policy in developed countries.

Two cases of coxsackie B2 infection in neonates: Clinical, virological, and epidemiological aspects

Two cases of neonatal coxsackie virus B2 infection are described. One infant presented with meningitis and enteritis, the other with rhinitis, meningoencephalitis, and enteritis. Both infants made good recoveries. The virus infection could also be demonstrated in all nonimmune family members, most of whom gave a history of recent mild febrile disease (pharyngitis, diarrhea). Enterovirus infections may be suspected in cases of neonatal meningitis or myocarditis associated with gastrointestinal signs, especially 1. when it is during the hot season July-October, 2. when there has been febrile illness in other family members recently. For an effective and rapid isolation of the agent, rectal swabs or stool specimens not only from the patient, but also from household contactss should be sent to the virus laboratory on several consecutive days. Meningitic infection may be proved by anearly c.s.f. sample. For serodiagnosis a first blood specimen should be drawn as soon as possible, a second one some days later. The importance of rapid virological diagnosis and of stringent hygienic measures to prevent spread of the infection is stressed.

Peripheral facial palsy and viral infections —Findings and problems

Eighty-four patients of the Cologne University ENT Clinic with a diagnosis of idiopathic peripheral facial palsy (PFP) were examined — both clinically and virologically. In addition, examinations were carried out on 33 further PFP-patients from different practising physicians (Group B) where the clinical information, however, was much less detailed. In the ENT Clinical Group (84 patients), there was a total of 12 recent virus infections (9 varicella zoster virus, 2 herpes simplex virus, 1 coxsackie B4). Proof of a recent infection depended strongly on the diagnostic prerequisites: if early and paired sera were available a virological diagnosis was possible in 32% of the cases, while in some of the other patients a recent infection could at most be suspected by the serological results. Group B with the 33 unselected patients yielded no virologically significant results. The aetiological relationship between the virological findings and PFP is discussed.

Comparison of four different methods for detection of rubella IgM antibodies

Four different tests for detection of rubella-specific IgM antibodies were compared: two Ig separation methods (centrifugation and chromatography) with subsequent haemagglutination inhibition test and two commercially available ELISA tests. The 114 sera tested had been sent to the diagnostic laboratory, mostly with insufficient clinical histories. Agreement between the centrifugation method and one of the ELISA tests was good (2 divergent results with 107 sera tested), while the other ELISA test yielded more positive (partly perhaps non-specific) results. The chromatographic method did not separate the Ig classes as reliably as the centrifugation method, but because of its simplicity it may be useful, if adequate test controls are performed. The divergent results are discussed. It is postulated that in cases with pending induced abortion, two independent tests should be performed.

Demonstration of rubella-specific IgM by serum ultracentrifugation on sucrose gradients: Comparison of a vertical and a swinging bucket rotor

The performances of a vertical and a swinging bucket rotor in the diagnosis of rubella-specific IgM were compared using two sets of predominantly low titre rubella IgM positive sera. Applying a number of subtle criteria, the vertical rotor was shown to separate IgM and IgG less well than the swinging bucket rotor. If the vertical rotor was loaded with pretreated sera with IgG content decreased severalfold, its performance was similar to that of the swinging bucket rotor with native serum. The findings are discussed from the aspect of the main indication of rubella IgM testing, and it was concluded that for the majority of cases the vertical rotor would not present an alternative to the swinging bucket rotor.

Biochemistry and pathogenicity of echovirus 9

Different clinical isolates of echovirus 9 are known to vary strikingly with regard to pathogenicity. Prototype strain Hill and strain Barty have previously been shown to differ not only in paralytogenic potency for newborn mice but also in a number of in vitro characteristics related to virus capsid structures. A series of mutants of strain Barty, thermosensitive for replication at 40 °C, was isolated after mutagenization with 5-fluorouracil. For all mutants the virus dose required to paralyse 50% of the infected animals was significantly higher than of the parent strain Barty. This reduced pathogenicity was observed at normal room temperature where the baby mice had a body temperature of 32.5 °C, which is even below the permissive temperature for growth of the mutants. The paralytogenic potencies did not further decrease when the mice where kept at elevated room temperature and had a body temperature of 35.1 °C. Thus, the reduced pathogenicity is apparently not a direct consequence of thermosensitivity of growth. Biochemical and biophysical characterization indicated that at least two of the eight mutants have an alteration in capsid protein.