Spectrum of opportunistic infections in HIV infected children in North India

Introduction: Human Immunodeficiency Virus adversely affects the immune system of the body, making a person vulnerable to variety of infections. Usually benign micro organisms become virulent and cause serious illnesses. Such opportunistic infections are very common in HIV infected children. If they are not diagnosed and treated in time they may prove fatal. The pattern of opportunistic infections are changing with time and place. To study the newer pattern of opportunistic infection in HIV infected children, this study was undertaken. Methods: 140 children of both sexes between age 18 months to 15 years, diagnosed HIV positive as per NACO HIV testing guidelines, were included in this study. They were examined, investigated and classified into clinical and immunological staging as per WHO classification. They were investigated for opportunistic infections. Result: Different kinds of skin involvement including scabies, papular pruritic eruptions, seborrhoic dermatitis, pyoderma, herpes zoster, molluscum contagiosum, fungal infections were noted in 47% children. Oropharyngeal candidiasis was also common. Recurrent respiratory tract infection, recurrent diarrhea, urinary tract infection, CSOM, parotid involvement was seen in majority of children. Over all, bacterial infection was seen in 36.4% children, followed by fungal infection in 18.5%, viral infection in 14.3% and tubercular infection in 10% respectively. Several studies have reported tuberculosis as the most common opportunistic infection in HIV infected children, but contrary to this, tuberculosis was the fourth commonest opportunistic infection in our study. Recurrent bacterial infections were the commonest one. Pneumocystis Carinii Pneumonia (PCP), the hallmark of AIDS defining illness in developed world, is not so common in our set up. We found only one probable case of PCP in our study.


Introduction
HIV infection adversely affects the human immune system and making a person susceptible for micro organisms to cause disease. Usually benign microbes become virulent and cause serious illnesses. Children are easy victims of these opportunistic infections (OI), disease progression is faster and they usually die of these conditions if not diagnosed and treated in time. In our set up diagnosis is mostly based on clinical signs and symptoms and picked up when disease is quite advanced. Spectrum of these infections is changing with time and place. Pneumocystis Carinii, once upon a time said to be the hall mark of HIV infection [1], is not so common in these children [2,3]. Various studies have shown that pulmonary tuberculosis [4][5][6] and extra pulmonary tuberculosis [7] had been the most common opportunistic infection in our country but in children this trend is changing. Various types of cutaneous manifestations can occur in up to 90% of HIV infected individuals [8]. Scabies and dermatophytes are common conditions in our country [9].
Oral candidiasis is seen in 70% of cases [6]. Change in pattern of opportunistic infections may be due to various factors including individual susceptibility, prevalence of particular organism in that area, ecological factors and increasing availability and use of anti retro viral drugs. To study the emerging pattern of newer opportunistic infections, this study was planned.

Methods
This observational study was conducted at S. N. Children Hospital, department of Paediatrics, M. L. N. Medical College Allahabad and A. R. T. Centre of S. R. N. Hospital Allahabad, U.P. during the period April, 2005 -October, 2012. 140 children of both sexes between the ages 18 months to 15 years, who were newly diagnosed HIV positive as per National AIDS Control Organization HIV testing guide lines were included in this study. Previously diagnosed HIV positive children were not included in this study. Children less than 18 months were also excluded due to limitations of diagnostic facilities. These children were selected from ART Center SRN Hospital Allahabad and SN Children Hospital Allahabad, UP. Care takers were counseled by qualified counselors and written consent was taken to examine and investigate. Data was recorded on pre structured proforma.
Anthropometric measurements, general and systemic examinations, complete blood count and CD4 counts were done in all cases. Other relevant investigations to diagnose opportunistic infections were done where ever required. Clinical and Immunological staging was done as per WHO staging criteria. CD4 count was done with Partec CyFlow ® counter flow cytometer. Method-Venous blood sample was collected in a tube containing EDTA solution. 20micro L whole blood from EDTA tube was added to Partec test tube. 20microL of CD4 buffer (m Ab PE) was added to it. It was mixed gently and incubated for 15 minutes at room temperature and protected from light. Now 800microL of no lyse buffer was added and shaken gently. This 840microL prepared blood was transferred to Partec Flow Cytometer and CD4 count was carried out. CD4 count and CD4% were used to assess the immunological staging. Percentage of CD4 cells were calculated on the basis of absolute CD4 count by using following formula-Statistical analysis: To describe nominal data, simple percentages were used. Mean and Standard Deviations were used to describe normally distributed data.

Results
Out of 140 children, 91 were male and 49 were female with male to female ratio 1.86:1. Maximum numbers of children, (61) were in between age group 5-10 years. Mean age of presentation was 7.67 (SD± 3.5) years which ranged from 18 months to 15 years. 75.71% were from rural back ground. 10 (7.14%) children lost their both parents while 37 (26.43%) children lost either father or mother. Total 47 (33.57%) children were orphan. According to IAP nutritional classification,  Table.1. Age wise distribution of opportunistic conditions in Table.2 shows that recurrent diarrhoea, recurrent respiratory infections, otitis media, tuberculosis, recurrent urinary tract infections and oropharyngeal candidiasis are common. In 31(22.14%) children more than one condition was present. Table.3 shows opportunistic organisms in relation to clinical and immunological staging. Organism wise details of UTI and Persistent diarrhoea cases are shown in Table.4 and 5 respectively. Central Nervous System involvement was seen in six (4.28%) children, bacterial meningitis in three, tubercular meningitis, cryptococcal meningitis and encephalopathy one each. By the end of this study six children lost their lives, three due to C.N.S. complications, one bacterial pneumonia, one milliary tuberculosis and one due to Non Hodgkin's Lymphoma.

Discussion
Vertical transmission is the single most important cause of paediatric HIV infection. It targets CD4 expressing cells, multiplies and establishes infection. HIV escapes neutralization and immune responses due to extensive heterogenecity, produced by rapid viral replication (10 10 particles per day) and absence of proof reading mechanism [10,11]. Two to four weeks after infection symptoms of acute viral syndrome appears in 50 -90 % infected persons [12]. Symptoms persist for few days and difficult to differentiate from other viral infections [13]. High viral load at the end of acute phase (set point) is associated with poor prognosis [14,15]. Infected person may remain asymptomatic (period of latency) for variable period of time or there may be no period of latency. Destruction of CD4 cells continues, cellular and humoral immunity is severely compromised. Child becomes susceptible to variety of infections, even non pathogenic micro organisms become virulent and cause life threatening illnesses. In 30% children disease progression is very fast and they die before one year of age [16,17].
Majority of perinatally infected children become symptomatic by five years of age [4]. In our study 97.96% children were infected through vertical transmission and mean age of presentation was7.67 (SD±3.5) years. Almost similar findings have been reported by Agarwal D et al [18], Merchant RH et al [3] and Shah I [19]. In the study of Shet et al [20] mean age of presentation was 7(±3.4) years. In our study out of 140 children, 26.43% lost their either father or mother while 7.14% lost their father and mother both and they were the worst sufferer. In the study of Foster G [21], 7 -11 % children were orphan. Failure to thrive and under nutrition is very common in these children. In our study we also noted that no child was nutritionally normal and 72.14% children had significant malnutrition.
Rakesh Lodha found 81.3% children to have failure to thrive and Ramesh R Pol [23] found significant malnutrition in 54.93% children. In our study maximum number (35.7%) of children were in immunological stage I. Similar findings were reported by Agarwal D et al [18] and Shet et al [20]. We also noted similar findings (36.4%) in our study. Diagnosis of tuberculosis in children is often difficult due to frequently negative sputum smears, less reliable Monteux test due to under lying malnutrition and atypical radiological findings. Serious form of OI was noted in immunological stage III and IV. In 31 cases (22.14%) more than one organisms were isolated in our study. Other studies [28,29] also have reported polymicrobial finding in advance stages of disease.

Conclusion
Spectrum of opportunistic infections are changing with time and place. Recurrent serious bacterial infections are most common OI in HIV infected children. Maximum children present around age of seven years with failure to thrive associated with anaemia. Different kinds of cutaneous involvement including scabies, papular pruritic eruptions, pyoderma, seborrhoic dermatitis, molluscum contagiosum, herpes, fungal nail infection etc are common in these children. Other frequent findings include oral candidiasis, recurrent diarrhoea. recurrent UTI, Parotid swelling.
If any child presents with recurrence of these symptoms with unusual severity, he or she should be investigated for HIV infection and more so if child is under nourished, father is staying away from home for longer period or there is history of unexplained untimely parental death. High suspicion index is of utmost importance to pick up early OIs to reduce morbidity and mortality.
Funding: Nil, Conflict of interest: Nil Permission from IRB: Yes