1000 mg amoxicillin for chlamydia

In 2008, after two decades of increasing emphasis on the prevalence of penicillin-resistant antibiotics after tooth extraction amoxicillin pneumococci, the definitions of susceptibility were changed to reflect the site of infection and the route of therapy. For infections other than those involving the CNS that are treated with parenteral penicillin, susceptibility, intermediate resistance and resistance to penicillin are now defined as mean inhibitory concentration (MIC) less than 2?g/mL, 4?g/mL, and greater than or

equal

In CNS infection, organisms with MIC less than or equal to 0.06?g/mL are susceptible; those with MIC greater than or equal to 0.12?g/mL are regarded as resistant. Similar approaches have been developed to define susceptibility to amoxicillin, ceftriaxone, and other beta-lactam antibiotics.

For example, MICs for susceptibility, intermediate resistance, and resistance to amoxicillin are defined simply as less than or equal to 2?g/mL, 4?g/mL, and greater than or equal to 8?g/mL, respectively, reflecting the concept that no physician would use oral therapy to treat a CNS infection.

For ceftriaxone, there are separate definitions for CNS and non-CNS infections. By these definitions, at the present time in the United States: 65% of isolates appear to be susceptible to levels achieved with oral penicillin; 17% are intermediately resistant, and 17% are resistant. 93% of all pneumococci are susceptible to penicillin if given parenterally or amoxicillin if given orally; 5% are intermediate, and 2% are resistant. In cases of meningitis, 65% of organisms are susceptible to penicillin and 35% are resistant (no intermediate resistance is defined).

For ceftriaxone, in non-CNS infections, 94% of organisms are susceptible, 5% are intermediate and 1% are resistant; in CNS infections, these percentages are 88%, 7%, and 5%, respectively.

Pneumococci with low MICs for penicillin remain susceptible to most other antibiotics, whereas strains that have reduced susceptibility to penicillin tend to be multiply resistant. At present, in the United States: approximately 20% of all pneumococci are resistant to macrolides. 30% are resistant to trimethoprim/sulfamethoxazole.

In general, greater than 98% of isolates remain susceptible to fluoroquinolones, probably because these drugs are not used to treat children.

nearly all pneumococci remain susceptible to ceftaroline, vancomycin, linezolid, or tigecycline.

How do patients contract this infection, and how do I prevent spread to other patients?

pneumoniae is largely confined to humans, generally to the respiratory tract, and is spread from person to person by intimate contact or by aerosol. A single nasopharyngeal swab yields pneumococci in 5 to 10% of healthy adults and 20 to 40% of healthy children. The percentage increases to 40 to 60% or greater in toddlers and young children in daycare, and is even greater among all children in more primitive societies.

The numbers of organisms present in the nasopharynx of infants and young children is much greater than in adults, a fact that explains the high false-positive rate for the pneumococcal urine antigen test (and its lack of utility) in those populations (see later in this chapter, laboratory diagnosis).

In adults, close, crowded living conditions such as occur in military camps, prisons, shelters for the homeless,

and

The common feature for outbreaks is that, in addition to crowding and close contact, the population has some additional feature(s) that contribute(s) to susceptibility to infection, often a concurrent outbreak of a viral respiratory infection and/or physical or emotional stress. Pneumococcal colonization stimulates production of anticapsular antibody.

In infants and young children, otitis media follows acquisition of a new colonizing strain.

After a few weeks, protection reflects the presence of antibody. An important clinical corollary of this observation is that persons who are not able to mount antibody responses remain susceptible to pneumococcal disease as long as they remain colonized (see later in this chapter, predisposing factors).

Before the widespread use of conjugate pneumococcal vaccine (see later in this chapter, prevention) in infants and toddlers, the incidence of invasive pneumococcal disease was: 100 cases per 100,000 population of infants. 100 cases per 100,000 population of persons aged greater than or equal to 70 years. In

the

Spread of pneumococcal infection within a hospital environment is exceedingly rare. There are no recommendations beyond universal precautions.

Two kinds of pneumococcal vaccine are currently available. Pneumococcal capsular polysaccharide vaccine, marketed as Pneumovax®, contains 25?g of capsular polysaccharides from each of 23 common infecting serotypes of S. Protein-conjugate pneumococcal vaccine contains capsular material from 13 pneumococcal serotypes, Prevnar13® (PCV13). The capsular polysaccharides are each bound chemically to a nontoxigenic protein that closely resembles diphtheria toxin.

Many studies and meta-analyses, based largely on case control studies, have shown approximately 60 to 70% protection against invasive pneumococcal

disease

good

polysaccharide

for

General categories included within these recommendations are those persons who: (1) are over the age of 65 years; (2) have anatomic or functional asplenia, CSF leak, diabetes mellitus, alcoholism, cirrhosis, chronic renal insufficiency, chronic pulmonary disease (including asthma), or advanced

cardiovascular

such

Recommendations regarding revaccination seem to be somewhat inconsistent because the committee advocates a single revaccination in persons over the age of 65 years as well as most others. Since antibody levels decline and there is no anamnestic response, it seems

more

Revaccination every 5 years for persons who are at highest risk of recurring pneumococcal infection—those who have undergone splenectomy or have a CSF leak.

Infants and young children do not make antibody after vaccination with pure polysaccharide antigens. However, when pneumococcal capsular polysaccharides have been covalently conjugated to carrier proteins, the resulting antigens are recognized as T-cell dependent; they stimulate good antibody responses in children under the age of 2 years and induce immunologic memory.

In a field trial involving 38,000 infants and toddlers, vaccination with PCV7 produced a brilliant response, being followed by a 90% decrease in pneumococcal meningitis.

Widespread introduction of

PCV7

The decrease in incidence in unvaccinated persons is called the “herd effect;” it occurs because PCV immunizes against colonization as well as against infection, and that effect reduces the prevalence of vaccine-type pneumococci in the population at large.

An untoward result of widespread vaccination has been the appearance of new strains that are not contained in the vaccine; these are called replacement strains. The principal one, type 19A, has become the predominant cause of pneumococcal disease in all age groups in the United States. This serotype is included in PCV13 which was put into widespread use in 2010.

Hopes that protein conjugation would greatly enhance antibody responses have not been fulfilled. A comparison of antibody levels and opsonic effect after vaccination with PPV23 versus PCV showed remarkably few differences or modestly higher antibody levels after PCV. On the other hand, some congenital nonresponders to PPV23 do respond to PCV, and two large studies in African patients with acquired immune deficiency syndrome (AIDS) showed no protection from PPV23 vs. excellent protection in the year following PCV7, respectively.

A large field trial of PCV13 has shown that PPV23 protects adults against pneumococcal pneumonia and IPD. In June, 2012, the Advisory Council on Immunization Practices of the CDC recommended that: (1) adults aged 19 years or older with immunocompromising conditions, functional or anatomic asplenia, CSF leaks, or cochlear implants, and who have not previously received PCV13 or PPSV23 receive a single dose of PCV13 followed by a dose of PPSV23 at least 8 weeks later.

(2) adults aged 19 years or older with immunocompromising conditions, functional or anatomic asplenia, CSF leaks or cochlear implants, and who have previously received one or more doses of PPSV23

receive

For those that require additional doses of PPSV23, the first such dose should be given no sooner than 8 weeks after PCV13 and at least 5 years since the most recent dose of PPSV23. The lack of convincing differences in responses to the two vaccine preparations and the fact that widespread use of PCV13 in children is expected to be followed by disappearance from the population of vaccine strains suggests to some authorities that routine vaccination of adults with PCV13 in the United States will be of little benefit.