Please note: While some information will still be current in a year, other information may already be out of date in three months time. If you are in any doubt, please feel free to ask.

CF in what seems like healthy baby

The little boy in question 10 wks. old was diagnosed with CF during routine heel test. Genes have been identified as G508 Delta and G551 which I understand are Class II and III so despite being too early to run sweat test no doubt regarding diagnosis.

He has no 'salty' taste off him, gaining weight averaging 4 - 5oz per week, no oily stools, bottle fed and not greedy for additional milk, no cough etc. and high on the height scale. He immediately was seen by a 'physio at his CF centre, put on the little mask with 'physio in between once a day and on daily antibiotic twice daily as a preventative measure.

Question is it because he is at a very young age that absolutely no symptoms of CF are showing? Also he is extremely distressed taking the anti biotic by syringe and often spits this out and has to be given again. Note opinions vary on using anti biotic when only preventative. Do you think this should be discussed more fully with the CF consultant at the clinic owing to the distress to both parents and child it is causing? Apologise for two questions. Thank you.
Dear Parent
Thank you for the questions about your baby’s diagnosis and prophylactic antibiotics.

Fortunately your baby boy sounds very well and therefore it is understandably difficult to accept this diagnosis. In CF the severity of symptoms can vary at the time of diagnosis and many newly diagnosed babies have no symptoms.

There are several ways to help confirm the diagnosis of CF.
• The UK Sweat Testing Guidelines states tests can be performed after 2 weeks of age in infants greater than 3kg. As your baby is now 10 weeks old and thriving he would certainly be big enough to perform a sweat test. It would be good practise to perform a sweat test to confirm the diagnosis as recommended in the UK Newborn Screening Programme.
• The UK Screening Programme also suggests at this stage parents bloods can be taken for genetic testing and it may also be worthwhile repeating your baby’s genetic test to confirm the result from the heel prick test.
• Although your baby is gaining weight well, the genetic mutations 508del and G551D are both associated with pancreatic insufficiency. Studies show faecal elastase is an accurate, easily obtained screening test to assess pancreatic status in patients with CF. This is done by taking three separate stool samples and it takes a couple of weeks to get a result .It would be useful to check faecal elastase levels to assess pancreatic function if this has not already been done.

Staphylococcus is clearly a significant pathogen in CF patients and usually the first pathogen to colonise the CF lung.
• No clinical trial has yet answered the question whether prophylactic or intermittent anti- staphylococcal therapy is the best course of treatment. However many studies have shown that prophylactic anti-staphylococcal treatment until the age of 3 years reduces the incidence of infection with staphylococcus and would be current practice in many centres. Alternatively some centres only commence anti-staphylococcal treatment following a positive culture on a cough swab but if staphylococcus is repeatedly isolated long term prophylaxis would be recommended.
• There are many different brands of antibiotics so it may be worthwhile trying a different brand which your baby may find more palatable.
• Also changing the administration times may help. It is important to remember babies do get used to the taste of the medicines and usually administration becomes easier over time.

Hopefully this has been of some help to you.
We recommend you discuss these options further with your CF team.

Hazel Mills Specialist CF Nurse
Dr Laura Jenkins


Guidelines for the Performance of the Sweat Test for the Investigation of Cystic Fibrosis in the UK
available at :

National Standard Protocol for newborn screening for Cystic Fibrosis available at: www.newbornbloodspot

Borowitz D, Baker SS, Duffy L. Use of fecal elastase-1 to classify pancreatic status in patients with cystic fibrosis. The Journal of Pediatrics 2004; 145: 322-326.

Cystic Fibrosis Trust Antibiotic Group. Antibiotic Treatment for Cystic Fibrosis. 3rd Edition.
London. Cystic Fibrosis Trust, May 2009.

Prophylactic antibiotic therapy for Staphylococus aureus. The Leeds Method of Management.
April 2008. Available from
The answer is edited by: Laura Jenkins