Is primary meningococcal arthritis in children more frequent than we expect? Two pediatric case reports revealed by molecular test

Background

Primary meningococcal arthritis is a rare infectious disease that occurs in less than 3% of meningococcal infections and is characterized by arthritis without meningitis, fever, rash, or hemodynamic instability Barahona [Case Rep Orthop 4696014:2017 ]. There are no validated clinical criteria that can be used for the diagnosis. We present two pediatric cases of atypical presentation of meningococcal disease revealed by molecular tests.

Case presentation

The clinical presentation of the two children (6- and 9-years-old) was characterized by signs of arthritis. By Real Time Polymerase Chain Reaction (RT-PCR), we identified N. meningitidis serogroup Y in the joint fluid in both cases. After specific antimicrobial treatment, the clinical conditions of the two patients quickly improved during hospitalization. Conclusions. We believe that the incidence of meningococcal arthritis could be underestimated in those settings where the use of RT-PCR is limited. Clearer data on the incidence of meningococcal disease would help to design specific treatments and the best possible national vaccine strategies [Fiji Sci Rep 23:39784, 2016, J Infect 67:385-90, 2013].

Bcgitis and Vaccine-Derived Poliovirus Infection in a Patient with a Novel Deletion in RAG1 Binding Site

A girl who developed severe BCGitis and vaccine-derived poliovirus infection was discovered to have a novel deletion of RAG1. A neonatal screening program for SCID would identify affected infants at birth, before live vaccines are administered.

Streptococcus pneumoniae: elusive mechanisms of the body's defense systems

Streptococcus pneumoniae is one of the most important human pathogens. It represents the most frequent cause of pneumonia, meningitis, sinusitis and otitis. After the PCV7 vaccine introduction, a serotypic switch was noticed. This phenomenon led to the replacement of the seven serotypes contained in the vaccine with other less common ones, some of which are invasive or characterised by antibiotic-resistance. This replacement is only partially due to the vaccination. Many causes have been suggested to explain this effect: apearance of new serotypes, diffusion of minority serotypes and replacement of common serotypes due to natural secular trend. Pneumococcus has a promiscuous "sex life", characterized by homologous recombinations within the same species and also between different species. This fact can unlock the secret of how these pathogens can develop antibiotic or vaccine-resistance. The serotypic switch involves big loci that are responsible for capsular polysaccharide synthesis. The most important region of the genome involved in this process is near the gene tetM. The same mechanisms are also responsible for antibiotic resistance. In recent years the growth of penicillin, macrolides and clindamycine resistance has been noticed. It is also important to underline that multidrug-resistant bacteria isolation has increased. In conclusion, to obtain more information about bacteria composition and evolution, antibiotic-resistance and vaccine response, it is fundamental to improve the epidemiological surveillance of pneumococcal infections using modern molecular diagnostic techinques.