Pneumococcal disease burden high in children

Pneumococcal infections are a high disease burden among Malaysian children below 5 years, says a consultant pediatrician.

"The Health Technology Assessment report [on childhood immunization] in 2002 indicates that the burden of pneumococcal disease [in childhood] is high," said Datuk Dr. Zulkifli Ismail.

The report estimated that there were 750 cases of pneumococcal bacteremia resulting in 15 to 20 deaths, and 4,000 cases of acute respiratory infections, 200 of which resulted in death, in children below 5 years annually. [www.moh.gov.my/MohPortal/DownloadServlet?id=745&type=2 Accessed on 25 January]

In addition, pneumococcal infections could also lead to meningitis. Two studies done in Malaysia showed that the main causes of meningitis are Haemophilus influenzae and Streptococcus pneumoniae. [Ann Trop Paediatr 1990;10:89-98, Pediatr Infect Dis J 1998;17(9 Suppl):S189-90]

Hence, a vaccine against H. influenzae type b (Hib) was introduced in the national immunization program in 2002 as a combination vaccine that protects against Hib, diphtheria, tetanus and pertussis (DPT-Hib), said Zulkifli.

A study conducted by Dr. Asmiati Abdul Hamid and colleagues at the Queen Elizabeth Hospital in Kota Kinabalu, Sabah, indicated that between June 1999 and December 2001, Hib was isolated from 34 patients and S. pneumoniae from six patients. Between January 2004 and December 2006, after the Hib vaccine was introduced, Hib was isolated from seven patients and S. pneumoniae from 21 patients.

In addition, after the Hib vaccine was introduced, the annual incidence of Hib meningitis per 100,000 children aged below 5 years in a particular area in Sabah decreased from 21 to 2.9, but the annual incidence of meningitis caused by S. pneumoniae increased from 3.7 to 8.6. Complications due to meningitis included death (44.4 percent) and hydrocephalus (18.5 percent), while only 11.1 percent had no complications. [Asmiati AH. Hemofilus meningitis in children age 2-60 months at Queen Elizabeth Hospital before and after HIB vaccine introduction (M.Med thesis). Universiti Sains Malaysia; 2007]

According to an Institute for Medical Research Malaysia (IMR) study, S. pneumoniae was isolated mostly from children aged 2 years or below (64.7 percent). [Epidemiol Infect 1999;122:77-82]

Zulkifli noted that children up to age 2 years are at highest risk for meningitis because they have low levels of circulating antibodies. Those with poor immune function eg, children with thalassemia, HIV and asthmatics on regular steroids, are also at higher risk, he added.

It is also sometimes difficult to treat S. pneumoniae infections, he said, as the IMR study shows that resistance to antibiotics eg, penicillin and erythromycin, is on the rise. Hence, prevention via vaccination is the most viable strategy against childhood pneumococcal disease. This message is being disseminated by the Asian Strategic Alliance for Pneumococcal disease prevention (ASAP), which was formed by a group of pediatricians in 2007, said Zulkifli at a media briefing.

He added that evidence points to concurrent bacterial lung infections in patients who died of influenza A(H1N1) in 2009. These findings underscore the importance of pneumococcal vaccination for those at increased risk and the need for early recognition of bacterial pneumonia in persons with influenza. [MMWR Morb Mortal Wkly Rep 2009;58:1071-4]

In conclusion, Zulkifli said, "Pneumococcal disease is the most common cause of vaccine-preventable deaths worldwide [among children aged below 5 years]." [MMWR Morb Mortal Wkly Rep 2006;55:511-5] Despite its enormous impact, awareness of this disease remains low - it is estimated that only 6 percent of the Malaysian birth cohort receive pneumococcal vaccine annually. [IMS Data Q4, 2008]

Source: mims.com